Friday, May 22, 2009
CO2 emissions of electric cars
Often, when speaking of electric drive vehicles, one wonders whether the transfer of petroleum fuel emissions to emissions from power plants will actually make things better on greenhouse gases.
To answer this question, we must first consider the CO2 emissions of the various grids, expressed in grams of CO2 per kilowatt-hour of electricity produced. These values can be obtained from the statistics of ministries or departments of energy or environment in different countries or states, or through the electricity companies.
However, emissions of greenhouse gases by these organizations or corporations are often those resulting from the combustion of fossil fuels in power plants themselves. It lacks the emissions from mining coal or uranium and drilling for oil and gas. These data do not include either the transformation of raw materials and their transport, or the construction of power plants. Also missing are the emissions resulting from the decomposition of trees submerged in the reservoirs of hydroelectric dams. To account for these aspects, we must conduct a study of the life cycle of a kilowatt-hour of electricity, from the earth at the socket. Various studies have taught us, basically, to add 15% of emissions for oil and coal and 25% for natural gas. Regarding nuclear power, the emissions are usually 15 gCO2/kWh, and we must add 18 gCO2/kWh for hydroelectric dams. In doing so, we get for California, the United States, France, Canada and Québec the emission intensities in the table below.
Now, an intermediate electric car (1,500 kg), built in 2009 with the best commercially available technology, consumes approximately 17 kWh/100 km of electricity stored in its battery. In addition, with wheel-motors, a reduction in the car weight and improved aerodynamics, consumption should be reduced in the future to about 12 kWh/100 km, say around 2020. So, to assess the CO2 emissions we assume an electricity consumption of 15 kWh/100 km from the battery. We add 6% for the losses from the outlet to the battery while recharging, bringing the actual consumption to 16 kWh/100 km, from the power plant to the wheels. For CO2 emissions of the electric car, simply multiply the actual electric consumption by emissions from the various grids, as given in the previous table.
The results are presented on the chart at the beginning of this post. On this chart, there is also the CO2 emissions of various gasoline cars of different sizes for comparison purposes. The intermediate 1500 kg gasoline car (thick blue line) is equivalent to the intermediate electric car for which we've done the emissions calculations.
For CO2 emissions from conventional cars, we assume that gasoline is burned completely, which releases 2.36 kg of CO2 per liter. To take into account the CO2 released from oil well to the tank of the car, we add 15%, which corresponds to the assessments of various studies on the subject.
It is particularly interesting to note that in the United States with power stations that burn fossil fuels to produce 70% of electricity (50% from coal and 20% from natural gas), CO2 emissions of an electric car is still better than a gasoline car that consumes 5 liters per 100 km, as a Prius. In France and Québec, electric cars emit significantly less CO2 than a Prius, as can be seen.
Québec appears, in fact, a fourfold privileged place to implement the electrical mobility, due to
- the substantial reduction in greenhouse gases that will result,
- the abundance of electricity thereon,
- to its low cost (0.07 $ / kWh)
- and to the important savings in oil imports (100% of import)
To better see the difference between various types of power plants, the following graph presents CO2 emissions by an intermediate electric car whose battery is recharged with electricity from different power plants.
The method of calculation is identical to the previous graph, except the intensity of emissions that are not those of the grids as a whole, in different places, but the GHG intensity of various types of power plants, from the earth to the outlet. The following table summarizes the results obtained using the computer lifecycle analysis software GHGenius developed for Natural Resources Canada (www.ghgenius.ca.
So, as you can see, CO2 emissions from electric drive vehicles are still considerably lower than those of traditional vehicles using petroleum fuels. The last graph also shows the importance of using renewable energy to reduce our emissions drastically.
Tuesday, April 07, 2009
Underground pumped hydro storage to increase renewables and the efficiency of thermal power plants
Illustration - Principle of the underground pumped hydro storage proposed by Pierre Couture. It can store power and regulate variations in renewable energy, among others, and is an essential component of intelligent electricity networks of tomorrow. (Illustration: Paul Berryman, from my book Driving Without Oil)
On 5 March 2009, Steven Chu, the United States Secretary of State for Energy, stated before a Senate committee his government's priorities in research and development. Five areas were identified and the storage of energy on a large scale is one of them. Storage units of appropriate size would compensate for daily variations of solar and wind, and increase the efficiency of thermal power plants. Energy storage is a key element to reduce greenhouse gas emissions as well of toxic emissions associated with electricity production.
Currently, the most used technology for large-scale storage of energy is pumped hydro. In its traditional version, there are two water tanks located one above the other, connected by an underground tunnel which houses a turbine that can operate in both directions. During periods of low electricity demand (eg at night) the electric motor-generator coupled to the turbine pump water from the lower reservoir to upper reservoir. In periods of high demand, we let the water flow from upper to the lower reservoir, which causes the turbine to generate electricity. In a well designed power plant, the movements of water between the two reservoirs cause a loss of about 20% of stored energy.
But to regulate the daily fluctuations of wind and solar power or to control the variations in demand throughout the day, we do not need to store more than 25% of the energy produced. Hence, regulation leads to a loss of only 5% of the total energy produced.
Illustration - Principle of a traditional pumped hydro storage facility. (source: Wikimedia Commons)
There are currently about 200 pumped storage facilities on the planet, totaling 90 GW of power, or about 3% of the installed capacity at the global level, according to the ESA (Electricity Storage Association).
The obligation to have a significant height difference between the two water tanks has brought many people to say that pumped hydro storage is a technology that could not operate on a large scale. As proof, the following statement
"Expanded use of this technology depends on the availability of suitable geography"
found in the "National Energy Policy Recommendations" of the IEEE-USA (Institute of Electrical and Electronics Engineers), dated 15 January 2009 (download HERE under the heading Energy and Environment).
But it seems that such an assertion is a lack of imagination, because one can very well build pumped hydro storage in the midst of vast plains or in the heart of a city. Just dig a deep well in the rock and build galleries at the bottom to get the second tank.
This is the concept which was proposed by Pierre Couture, a researcher for Hydro-Quebec and inventor of the modern wheel motor (previous post). Louis-Gilles Francoeur, journalist at Le Devoir has unveiled the project in an article dated 22 January 2004.
To avoid too large excavation for the galleries, it is expedient to settle at a greater depth. Pierre Couture recommended digging a well about 2 meters in diameter and three kilometers deep. Turbines that can be reversed and also act as pumps are placed at every kilometer going down, with a buffer cave behind each group of turbine-generators assembly (see illustration at the top of the post).
Calculations show that for a 1 GW of power lasting 10 hours, one must have 3 kilometers (1.9 miles) of galleries with a 20 meters x 20 meters (65 feet x 65 feet) opening, that is 1.2 million cubic meters, to store water at the bottom. The cost of such a plant would be in the range of $ 700 million to $1,000 million, and could regulate power plants with nameplate power of 3 to 4 GW.
If the facility lasts 50 years, we arrive ultimately at a cost below 0.2 cents / kWh of energy produced and regulated, which is only a few percent of the production cost.
Such pumped hydro storage facilities can be used in multiple ways. One can, of course, increase the percentage of renewable energies on a grid by regulating their inherent fluctuations. To reduce the need for too large storage facilities, we need to set up power lines to connect wind farms over thousands of kilometers, because there is always wind somewhere. The high voltage DC power lines are particularly interesting in this regard since they generate only 3% loss per 1000 km (600 miles). As for the solar power plants, they follow quite well the daily demand for electricity (more sun at noon). By placing them in desert areas, one ensures a minimum of cloud cover, which requires less storage of energy for the fluctuations. Most of the storage would be used to postpone to the night a part of the energy produced in the day.
Furthermore, pumped hydro is also interesting to increase the efficiency of thermal power plants. We know, for example, that gas-fired combined cycle plants can achieve an efficiency of 60%. Unfortunately we can not vary significantly the power of such plants to follow daily demand. We must use for that gas power plants whose efficiency is less than 40%. Thus we see all the benefits of coupling a pumped hydro storage to one or more gas-fired power plants. We could then use the most efficient combined cycle gas-fired power plants operating at constant optimal conditions. The daily fluctuations would be managed by the pumped hydro facility. In doing so, we would obtain 50% more electricity with the same natural gas!
With the additional electricity recovered one could close much dirtier coal power plants, waiting to close also, over time, the gas power plants and replace them with renewable energy.
Pumped hydro storage is an essential element of any smart energy policy! And with the underground concept proposed by Pierre Couture, it will become more and more interesting.
Monday, April 06, 2009
How much water to produce biofuels?
Illustration - Fresh water, a resource to preserve. (photo: Wikimedia Commons)
One of the main arguments put forward against biofuels is the high consumption of fresh water to produce them, at least with current technologies. But, as you will see, advanced plug-in hybrid of tomorrow will consume less than one liter of water per day.
To begin, let us look at a midsize car that normally consumes 8 liters of gasoline per 100 kilometers (60 miles) (fuel efficiency of 29 mpg). If we run it with 85% ethanol (E85), the largest commercial concentration, then we will need 11.2 liters of E85 (including 9.6 liters of ethanol) to travel 100 km. The highest amount is required due to the fact that ethanol contains only 2/3 of the chemical energy of gasoline, for a given volume.
Now, if to produce this E85 biofuel we use corn grains from Nebraska, we know that this corn requires 780 liters of irrigation water per liter of ethanol produced (see my book Driving Without Oil for more details). In addition, about 4 to 5 liters of water per liter of ethanol is needed for the manufacturing plant. In total, 785 liters of water are required for each liter of ethanol produced.
Thus, our traditional midsize car running on E85 ethanol in Nebraska consumes 7500 liters (1980 gallons) per 100 km (60 miles). This represents about 4,100 liters (1,082 US gallons) of water a day for someone who will travel 20,000 km (12,420 miles) per year. It is therefore understandable why many environmentalists are not warm to the idea!
But before you throw out the baby with the bathwater, let's see how we can achieve a consumption of less than one liter of water per day!
This requires, of course, the use of energy crops that do not involve watering, which is the case for wild prairie grasses, such as switchgrass. We have seen in a previous post that these perennial plants have roots 3 meters deep that are very effective in capturing soil moisture.
Furthermore, we have also seen in another post that advanced plug-in hybrid cars will consume 4 times less fuel than conventional cars when running on fuel, after their battery is discharged. But as these cars of tomorrow will run 80% of their mileage on electricity, they will actually consume 20 times less fuel.
But we have mentioned earlier that a traditionnal midsize car running with E85 ethanol mixt requires about 10 liters of ethanol per 100 km. The plug-in hybrid cars of tomorrow will therefore need only 0.5 litres/100 km on average (20 times less), which corresponds to 0.28 liters (0.6 pint) of ethanol per day for an annual mileage of 20,000 km (12,420 miles).
Finally, new ethanol plants will reduce their water consumption to about 3 liters of water per liter of ethanol produced, thanks to new technologies such as the one developed by the company Vaperma. This innovative company has developed molecular filters used to separate very efficiently water from ethanol without using distillation. They can save up to 45% of the energy normally used in an ethanol plant, while consuming less water. The decrease in CO2 emissions is also considerable.
Illustration – Vaperma molecular filter used to separate water from ethanol without distillation. The filters are made of polymeric membranes in the form of hollow fibers that are gathered to form the filter cartridge.
Furthermore, for thermochemical biofuel fabrication technologies (pyrolysis, gasification) manufacturing plants consume less than 2 liters of water per liter of biofuel produced.
There is also a new thermo-biological hybrid technology put forward by the company Coskata, which uses microorganisms to convert the syngas (mixture of CO, H2 and CO2) from a thermal process (gasification) into ethanol. According to Coskata, the process consumes less than one liter of water per liter of ethanol produced! This is less than for gasoline. To achieve such performance, Coskata does not use distillation but a molecular filtration process to separate water from ethanol, probably similar to Vaperma filters. In addition, the Coskata process does not include drying of tailings, as is found in the traditional corn ethanol plants, to make the solid protein supplement sold to the livestock industry. The distillation of the beer (fermentation mixture) and drying of tailings are the two processes that consume most water, by evaporation.
Illustration - Coskata thermobiologic process of making ethanol (Source: Coskata).
Ultimately, our advanced plug-in hybrid car traveling 20,000 km (12,420 miles) per year from which 16,000 km (10,000 miles) on electricity, will consume less than one liter (2 pints) of water per day, using biofuels based on tall wild grasses that do not require watering, and manufactured with the best technologies!
To put this water consumption of our future cars into perspective, it is interesting to know the consumption of water per kilogram for different food products. The table below summarizes the results found in the book by David Pimentel and MH Pimentel, Food Energy and Society, CRC Press, 2008. It shows that we need 43,000 liters (11,360 gallons) of water to produce 1 kg (2,2 lbs) of beef, which means more than 6,000 liters (6,000 quarts) of water for a steak of 150 grams (5,3 ounces)! So it is not the 1 liter (1 quart) of water per day consumed by our car that will endanger our freshwater resources. Too large portion of meat in our diet, particularly red meat, is much more worrying in this respect ...
Illustration - Number of liters (1 US gallon = 3.785 liters) of water required to produce one kilogram (2.2 lbs) of different foods, according to the work of David Pimentel, professor of ecology and agriculture at Cornell University.
Sunday, April 05, 2009
Is There Enough Lithium for the Batteries of 1 Billion Plug-in Hybrid Electric Vehicles?
Illustration – Salt « mining » in the Salar of Uyuni in Bolivia, the largest lithium reserves in the world (source: Wikimedia Commons)
The introduction of Li-ion high-performance batteries was, without doubt, the trigger for the imminent revolution in road transport. But is there enough lithium to power a billion cars on the planet, ultimately?
To respond, we must know first that according to the U.S. Geological Survey (USGS), the reserve base for lithium on the planet is estimated at 11 million metric tons. But these estimates do not include reserves of Argentina reported recently by the company Orocobre (3 million tons). A very informative report on the global lithium reserves and markets is available from this company. This report by Martin Place Securities can be downloaded by clicking on the news dated March 31, 2008 about Project Olaroz. In United States, the company Western Lithium is currently conducting geological expertise of a large clay deposit of lithium in Nevada, at King Valley. The estimated reserves are 2.08 million tonnes of lithium (11 million tons of lithium carbonate, Li2CO3) and they are not included neither in the USGS evaluation. Updating the USGS assessment, there is therefore a global reserve base of 16 million metric tons of lithium.
In addition, the USGS reports a global annual production of 25,000 metric tons of lithium in 2007. At this rate of exploitation, there would be enough lithium for several hundred years. This abundance and the low price of lithium (8$/kg) obviously did not stimulate the exploration of new deposits. We can therefore expect that global reserves are more than 16 million tons.
Now, in the Martin Place Securities report mentioned above, we learn that the percentage of lithium recovery from the reserves is about 50% on average. Thus, counting 16 million tons of reserve base it means that 8 million metric tons of lithium are available for the industry.
75% of the Lithium reserves are in the form of salt, mainly lithium carbonate from the deserts of salt. The key deserts are found in South America (top of photo) and also in Tibet. Lithium carbonate is the raw material used by the battery industry (5.3 kg carbonate give 1 kg of lithium).
Now, for a midsize plug-in hybrid car a battery giving it a range of 100 km in electric mode currently requires storing 20 kWh of electric energy. In addition, the company LG Chem, which provides the Li-ion batteries for the GM Chevy Volt, through its subsidiary Compact Power, says on its website (in the Technology section at the FAQ page http://www.compactpower.com/faq.shtml) that they need 140 g of lithium per kWh of battery, giving 2.8 kg of lithium for 20 kWh, which we round up to 3 kg (6.6 lbs). Let us recall that with this 3 kg (6.6 lbs) of lithium, a midsize car can run 100 km (60 miles) in electric mode with today commercial technologies.
Now, hybrid cars of the 2020s will be lighter, more aerodynamic and will be equipped with wheel motor powertrains that consume considerably less energy. These midsize cars of tomorrow will consume about 12 kWh/100 km instead of 20 kWh/100 km as mentioned above (see my book Driving without oil). So one will need only 2 kg (4,4 lbs) of lithium per car [for 100 km (60 miles) all electric range] in 2025. Thus, for a billion vehicles (there are currently 800 million on the planet), we would need about 2 million tonnes of lithium, a quarter of global reserves base available after extraction.
There is therefore enough lithium on the planet for plug-in hybrid cars. But if we wanted to use all electric cars with batteries providing a 400 km range (240 miles), then we would have problems. It is always preferable to use the smallest battery possible to travel 80% of our mileage.
Now, we must realize that the Li-ion batteries can be recycled at 95%. Finite lithium reserves can not therefore be compared with finite oil reserves, since oil is totally lost in an internal combustion engine.
Some critics of electric mobility also point out that about 60% of lithium world reserves are located in South America and that it is a similar situation than the Middle East for oil. But, as lithium price goes up steadily, more and more companies will search for new deposits. Only in the King Valley deposit in Nevada, there is sufficient lithium for 500 million advanced midsize cars with an all electric range of 100 km (60 miles).
Illustration - A mining project of the company Lithium Canada Corporation, near Val d'Or in Quebec, could produce enough lithium to equip all Canadian vehicles with a battery giving a range of 100km (60 miles) in electric mode. (source: Lithium Canada Corporation)
The company Lithium Canada Corp. also uses an old mine near Val d'Or Quebec. It expects to produce the equivalent of 55 million kg (120 million lbs) of lithium, enough for 25 million advanced midsize cars with a range of 100 km (60 miles) in electric mode, which would fulfill the needs of all Canadians.
Where to find land for biofuels?
Illustration - The livestock industry emits more greenhouse gases than all vehicles on the planet. (photo: Wikimedia Commons)
When we talk about biofuels, people are afraid of losing land to feed people and say that it makes no sense. But let us try to be objective and to look at our land management on the planet from a broader perspective and see if we could not do better.
First, according to a report of the United Nations published in 2006, 70% of farmland in the world are dedicated to the livestock industry [H. Steinfeld et al., Livestock's long shadow, Food and Agriculture Organization (FAO), Rome 2006]! These lands are divided into pastures and cultivated areas to feed livestock (33% of cultivated land on the planet).
Moreover, according to the same report, the livestock industry is responsible for 15% to 18% of anthropogenic emissions of greenhouse gases (GHG) expressed in CO2 equivalents. But what we need to know is that all road vehicles in the world are responsible of approximately 12% to 13% of greenhouse gas emissions (including GHGs to produce fuel). So, the livestock industry emits 50% more GHG than road vehicles!
Another factor to consider also is that one hectare of land (1 hectare = 2.47 acres) produces about 25 kg (55 pounds) of beef protein, whereas the same hectare can produce 400 kg (880 pounds) of vegetable protein with soy, 300 kg (660 pounds) of protein with rice and 150 kg (330 pounds) with wheat. Not to mention that to produce 1 kg (2.2 lbs) of beef, it takes more than 40,000 liters (10,566 US gallons) of water, which means more than 6000 liters (1,585 US gallons) of water for a steak of 150 grams (5.3 ounces) (see the website of the organization Compassion In World Farming www.ciwf.org.UK, in particular The report Global Benefits of Eating Less Meat, 2004)! Too much meat in our diet is therefore a blatant waste of our planet's resources in agricultural land and fresh water, not to mention other resources such as fossil fuels (natural gas for fertilizers and oil for machinery).
We must know these facts if we are to make informed decisions about the use of our farmland.
In my last book Driving without oil, I recommend to reduce our meat consumption by 15% (one day a week without meat). In doing so, it releases more agricultural land than necessary to produce biofuels equivalent to 5% of petroleum fuels currently used. Now, 5% that's all we need from energy crops to remove oil from the road transport (see previous post).
In closing, we must not forget that by reducing our consumption of meat to produce second generation biofuels, we DOUBLY reduce greenhouse gas emissions, since the livestock industry emits more than all vehicles on the road.
Labels:
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Saturday, April 04, 2009
Carbon negative Biofuels: 2 - Polyculture of wild grasses
Illustration - The wild prairie grasses have abundant and deep roots reaching 3 to 4 meters under the surface. (source: United States Department of Agriculture, the depth in meters was added by the author of this blog)
With petroleum fuels, one takes carbon that was underground, burns it and constantly increases the CO2 content of the atmosphere. The idea behind biofuels is not to emit CO2 from carbon sequestered in geological formations (géocarbone) and use in place of biocarbon found in plants. Biocarbon enters in what is called the carbon cycle, where the carbon we send into the atmosphere by burning biofuels is reabsorbed by plants that grow to produce biofuels. It does not constantly adds to the atmosphere if we do not use fossil fuels to produce biofuels. In this ideal case we say that biofuels are carbon neutral.
This ideal case is not achieved in practice and net CO2 emissions are also associated with biofuels, but at lower levels than CO2 emissions from petroleum fuels. This reduction is only 20% for ethanol produced from corn, and some even say it is zero if one takes into account the greenhouse gas involved in the fabrication of the machinery. Add to this the problems of land degradation and water pollution caused by fertilizers and pesticides, and we understand why many environmentalists do not like biofuels.
However, second-generation biofuels have the potential to reduce greenhouse gas emissions by 80% to 90%, using the whole plants instead of only grains and fruit, as it is currently the case. But the problems of degradation and soil erosion by intensive monocultures must also be taken into account.
To solve these issues, in the last few decades researchers have studied the advantage of wild tall prairie grasses, as switchgrass. First, these plants are perennials, they do not need to be sowed each year, such as corn or soybeans. In addition, these grasses have well-developed and deep root systems (illustration at top of post). With these two features, the wild prairie grasses protect soil from erosion, rather than increasing it as do the intensive in row monoculture of annuals.
Furthermore, wild grasses need not be watered because their roots are very efficient to retrieve soil moisture, 3 to 4 meters deep. By comparison, corn requires often watering with several hundreds of liters of water per liter of ethanol produced.
But the cultivation of wild grasses becomes particularly interesting when it is grown in a mixture, including plants that fix nitrogen. This was studied by researchers at the University of Minnesota for 10 years on degraded land. They cultivated 152 different parcels of land containing different mixtures of up to 16 different plants in the same plot. The astonishing results of their study were published in 2006 (Tilman, Hill and Lehman, Science, Vol. 314, December 8, 2006, pages 1598 to 1600).
First, the quantities of fertilizers and pesticides required are significantly reduced compared to corn and soybeans, as shown in the chart below, taken from their publication. The word "Biomass" in this graph represents the high diversity mixture of 16 different plants.
Now the surprise is that second generation biofuels from such high diversity prairie grasses mixture are strongly carbon negative! This means that in addition to avoid net emissions of CO2 in the atmosphere (carbon neutral), these cultivations are literally removing CO2 from the atmosphere to reduce its concentration. The reason is simple, the carbon is stored underground in large quantities in the roots. It's a bit like charcoal in the Terra preta, buried by the Amazon natives (see previous post).
However, to get stong carbon negative biofuels (-150% to -250%), we must cultivate several plants together. For example, plots with a mixture of 16 plants store 31 times more carbon in the soil than in monoculture plots!
No, definitely, biofuels of tomorrow will have nothing to do with those of today, hence the importance of not throwing the baby out with the bathwater. Sustainable development of biofuels is entirely feasible, if done intelligently and if we produce only small quantities.
In my last book ”Driving without oil”, I demonstrate that cultivating energy crops to produce biofuels equivalent to 5% of current petroleum fuels would be sufficient to stop oil consumption in road transport. The electricity networks would, of course, provide the main ”fuel”. One would also use municipal waste, forest residues and recycled oils and fats from the food industry to produce biofuels, which can easily supply the equivalent of 2.5% of current petroleum fuels, for a total of 7.5% in biofuels (including dedicated energy crops).
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Carbon negative biofuels: 1-The lesson of ancient Amazon natives
Illustration - Micrograph of a piece of charcoal (biochar) showing its extreme porosity, small holes are about 1 / 100 of a millimeter in diameter. It is an ideal environment to retain water, nutrients and microorganisms, increasing soil fertility. (Source: Best Energies)
Over the past ten years, agronomists and environmentalists are increasingly interested in Amazon Terra preta, an extremely fertile black soil resulting from amazing agricultural practices of ancient natives.
Their secret was charcoal buried deep in the soil, hence the name Terra preta, in Portuguese. The appearance of porous charcoal, also called biochar, helps retain nutrients, water and microorganisms. These features facilitate the growth of plants and reduce the need for fertilizer while reducing more than 50% the emission of nitrous oxide, a gas 300 times more potent for global warming than CO2.
To produce biochar, one uses a process of thermal decomposition of biomass called pyrolysis, which involves heating wood or crop residues in an enclosure with scarce oxygen environment. Combustible gases are then released containing, among other things, hydrogen and methane, which are partly used to produce the heat required by the process. A bio-oil is also formed after processing and cooling, that can used in heating furnaces. You can also turn this bio-oil into biofuels more suitable for transport, such as diesel and synthetic gasoline or ethanol with proper thermo-catalytic processes. One obtains then second-generation biofuels.
Now, when we bury biochar, in addition to fertilize the land we also sequester in the ground some CO2 from the atmosphere which had been absorbed by plants. It helps to remove greenhouse gases, a bonus specifically sought these days! The combination of buried biochar and biofuel production, therefore makes these biofuels carbon negative, which is still better than carbon neutral biofuels. Professor Lehmann of Cornell University estimates that implementing these practices on a large scale, could both produce biofuels and withdraw annually 9.5 billion tonnes of carbon from the atmosphere by 2100. That is more than what we send in the atmosphere today in the world by burning fossil fuels!
For more information, please visit Terra preta site and the site of The International Biochar Initiative (IBI), where we find the illustration of the pyrolysis process shown above. In addition, the following video is an excellent documentary on the subject.
Terre preta - biochar
Labels:
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Saturday, March 07, 2009
Transport of goods in sustainable mobility
Illustration - Transit Connect EV Van presented by Ford at the Chicago Auto Show in February 2009. It will be marketed in 2010 (photo: Ford)
Recently, Ford announced that its first electric vehicle will be the Transit Connect EV van, promised for 2010. (photo above). They team up for this new product with the English company Smith Electric Vehicles already well established and which offers a range of electric trucks, as can be seen on their web site.
In fact, the urban transport of goods is probably the area where vehicles will be electrified first. Indeed, these vehicles do not need to run faster than 90 km/h (56 mph) or travel distances over 160 km (100 miles) per day. In addition, the vehicles return to the company every evening, where you can easily recharge their battery. The TNT company, the largest express delivery company in England, has understood this issue since it bought in 2007 and 2008, 150 Newton electric trucks with a payload of 7.5 metric tonnes (8,3 short tons), from the company Smith Electric Vehicles (illustration below).
Illustration - One of 150 Newton electric trucks from Smith bought in 2007 and 2008 by the express delivery company TNT in England. (Photo: TNT)
The transportation of goods by 18 wheelers is more difficult to electrify due to their high daily mileage, often up to 800 km (500 miles) per day, while these semi trailers consume much more energy than a light vehicle. In my book «Rouler sans pétrole» (Driving Without Oil), I show that advanced tractor-trailers of the future could consume 3 times less fuel than today when running on fuel. To achieve this, we should rely on a good and strong hybridization, a heat engine 25% more efficient, better aerodynamics (see figure below), electric wheel motors and the reduction of speed on motorways to 95 km/h (60 mph).
Illustration - Trucks designed by Luigi Colani (Source: Wikimedia Commons, author: Wikipedia is, August 2005)
Afterwards, having reduced energy consumption by a factor of 3, semi trailers could be fitted with 2 to 3 metric tonnes (4,400 lbs to 3,600 lbs) of high performance Li-ion battery, which would allow them to travel about 300 km (187 miles) on electricity. With lithium titanate batteries, it would be possible to fill them up in less than 20 minutes with a one megawatt (1 MW) charger. For reference, the electricity is transferred to a high-speed train like the TGV in France with a power of 9 MW.
Moreover, in a context of scarce energy, it is desirable that people consume more locally, thereby reducing the number of trucks on the roads. Also, the high cost of oil in 2008 led to cooperation between transport companies, which are now increasingly sharing trucks when they are not full, which, again, reduces the number of lorries on the roads. Finally, we can also divert a portion of semi-trailers through the trains. That is the principle of piggybacking, more and more popular in Europe, where trains run largely on electricity.
Illustration - Intermodal rail station for freigh transit between Luxembourg and Perpignan, managed by the French company Lorry-Rail (Source: Lorry-Rail)
In closing, we should not forget that we can also transport goods through the high-speed monorail that I presented in my post of March 3, 2009.
Labels:
electric truck,
electric van,
hybrid semi,
smith
Friday, March 06, 2009
How much additional electricity for electric drive vehicles?
In addressing the topic of electric and plug-in hybrid electric vehicles (electric drive vehicles), the layman often points out the fear of running out of electricity. But we must not forget that this transition to electric drive vehicles will be gradual over 20 to 25 years and will provide us with a rare opportunity to stimulate local economies.
With regard to additional amounts of electricity required the calculations are explained in my book «Rouler sans pétrole» (Driving without oil), assuming that 70% of the mileage of vehicles is traveled with electricity. The results are shown on the graph above. The higher values correspond to the technologies to be commercialized within the next few years, while the lower values refer to the mature technologies, consuming less energy, which will be widely available after 2020.
With this graph we realize that the province of Quebec is very privileged, as the additional electricity required is only about 7% by 2030 say. One could easily obtain this amount by relying on greater energy efficiency. Another option would be to install geothermal heat pumps to heat half of the homes and buildings. This would save the 7% of the electricity we need (70% of space heating is electric in Quebec). If the percentage of additional electricity is so low in Quebec, this is because Quebecers have at their disposal 3 times more electricity per capita than the French and the Californians, and two times more than the U.S. citizens, on average. In addition, the electricity in Quebec is cheap (CDN $ 0.07/kwh) and clean (95% hydroelectric).
Illustration - The wind can provide a significant portion of the additional electricity required. (photo: Wikimedia Commons, author: Kapipelmo, April 2008)
For the United-States, it is about 22% extra electricity that is needed to power vehicles. But as 70% of U.S. electricity comes from gas and coal power plants, these plants are under-utilized at night, and could be used partly to recharge the vehicles, without building new power plants.
Furthermore, installing solar panels on the roofs of buildings in the southern U.S. to recharge plug-in vehicles is cheaper than buying gasoline for a traditional vehicle. It is very conceivable also to add 15% to 20% of wind power in the coming 20 years. And with new technologies for the storage of heat in molten salt, we can now build solar thermal power plants that operate 24 hours a day, and sunny arid locations are not lacking in the United-States. The engineers of the Ausra company have calculated that it would suffice to cover a 150 km x 150 km (94 miles x 94 miles) square area into the desert to supply all the electricity consumed in the United-States. Finally, the Raser company has just opened a geothermal power plant of a new type, operating 24 hours a day, and using water at a lower temperature than traditional geothermal plants. They estimate that over 10% of U.S. electricity could be generated by geothermal energy. If moreover we add energy efficiency for buildings, smaller vehicles, and more public transit, we realize that the only problem is political will, not the additional electricity required. Fortunately, with president Obama it seems to be a thing of the past.
In closing, we should not forget that implementing renewables to increase the electric power capacity of a country will stimulate its economy. As for the financing of these projects, they will be paid with the money saved by lowering oil imports, which account for tens and hundreds of billions of dollars annually, depending on countries.
4 times less fuel without using electricity from the grid
Illustration - Graphic showing decreases in fuel consumption of an advanced hybrid car, compared to a conventional car today that consumes 100 units of fuel for a given distance.
For those who have read my previous notes, you know that for me the Car of Tomorrow (2030) is a plug-in hybrid. In what follows, you will see that when this car will run in fuel mode, after having exhausted its available electrical energy from the battery, the car of tomorrow will consume 4 times less fuel, on average, than conventional cars today. For the coming paragraphs, please refer to the chart above.
First, experts agree that a robust good hybridation with a central electric motor can reduce fuel consumption by one third. To do this, we have to use high power Li-ion batteries whose efficiency reached over 98%, and high efficiency electric motors as well (some reach 96% today). For comparison, Ni-MH batteries, such as the ones in the Prius, have an efficiency of approximately 75%.
In a second step, we can further decrease by one third the fuel consumption of hybrid cars by improving their fuel engine through the use of various technologies. The table below lists several. The first three (in orange) are quite independent of each other and together can provide a reduction in consumption approaching 25%. The other technologies listed, all contribute to a better combustion and cannot simply be added as they are in competition one with another. I will give more information on some of these technologies in future posts, but for impatient readers you can always consult my last book «Rouler sans pétrole» (Driving without oil), where you will find details and references. Also, remember that the mere fact of moving from a gasoline engine to a diesel engine reduces the consumption by around 20%.
In addition to the many improvements that can be brought to piston engines, the plug-in hybrid car of Tomorrow is an extraordinary opportunity to try new types of rotary engines more energy efficient, as potentially the Quasiturbine invented by Gilles Saint-Hilaire, or the Radmax engine from Reg / Regi Technologies. The idea is that these engines will be used at most 80 000 km (50,000 miles) on the life of the car, since the majority of the mileage will be driven with electricity. The constraint of durability is much less severe. Moreover, these rotary engines are about 4 times lighter and more compact than piston engines, with far fewer moving parts. They should thus be cheaper. Such engines would operate as a generator to recharge the battery without being connected mechanically to the wheels.
Illustration - 3D representation of the different components of a Quasiturbine with carriage, invented by Canadian physicist Gilles Saint-Hilaire.
Now, continuing our quest for the reduction of fuel consumption, if we refer again to the graph at the beginning, we see that we can reduce consumption by 25% more if we play on the car's weight, aerodynamics and tires. A realistic weigh reduction of 30% is accompanied by a decrease in consumption of around 18%. To achieve the 25% reduction in consumption of our car, we can also use low-rolling resistance tires that bring the fuel consumption down by 2% to 5%. The remaining of the 25% is obtained by implementing a better aerodynamic profile for the car.
At this point, we have an advanced plug-in hybrid car with a central electric motor, that consumes 3 times less fuel than a traditional car today, when operating in fuel mode.
The last step in our scenario to reduce consumption is to equip our plug-in hybrid car with 4 wheel-motors. These motors give an additional 25% of fuel consumption reduction in mixed driving, as we have seen in the previous note on wheel-motors. The result is, ultimately, a reduction of fuel consumption by a factor of 4 mentioned in the title of this post. The consumption of an intermediate advanced hybrid car would thus be 2 to 2.5 litres/100 km (fuel economy of 95-115 mpg).
Furthermore, if plug-in hybrid cars make 80% of their mileage with electricity, these cars will consume 20% ÷ 4 = 5% of the fuel used by cars today, that is 20 times less in a year! With small amounts like that we can envision without any trouble a sustainable development of second generation biofuels, made from waste, residues and non-food plants. We will learn more on this topic in later notes.
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Thursday, March 05, 2009
The great importance of wheel-motors
Illustration - Representation of a wheel-motor similar to those developed by the team of Pierre Couture at Hydro-Québec and presented to the public in 1994. The author of this blog has drawn it from public information contained in the promotional materials and patents.
Quebecers over 30 years old remember seeing on television in 1994 and 1995 a revolutionary experimental car equipped with high performance electric wheel-motors. It was a Chrysler Intrepid transformed by researchers from Hydro-Quebec, under the direction of Dr. Pierre Couture, a brilliant physicist ahead of its time, the main inventor of this power train, unmatched so far. The press conference to announce this brilliant technology took place on December 1st, 1994. To see the flyer distributed on that occasion click HERE, and to read the transcription in english of Pierre Couture’s speech explainaing the technology ckick HERE.
The basic idea was to convert the Intrepid in a plug-in hybrid car. By recharging the battery during the night at home, the owner of the car could travel 65 km (40 miles) in electric mode for each day without consuming fuel. For journeys longer than 65 km (40 miles), a small fuel engine activates a generator to recharge the battery while driving, giving the car a range similar to that of a traditional car. This is what we call today a series hybrid vehicle, whose fuel engine is not mechanically connected to the wheels. Furthermore, since 80% of people drive less than 65 km (miles) per day with their car, on average, the vast majority of their mileage would be done with electricity.
It is this concept that is used by GM in its Chevy Volt, which should be commercialized in 2011. However, the Chevy Volt is not equipped with wheel-motors, but with a central electric motor under the hood. This makes the car heavier and more expensive, while consuming more electricity and leaving less space available for the passengers and the trunk.
Unfortunately, in 1995 Hydro-Quebec has taken a completely incomprehensible decision to significantly reduce its proposed development of Couture’s power train, which led to the resignation of its inventor in 1995. Pierre Couture has never worked on this project since. The TM4 company, a subsidiary of Hydro-Québec, which was set up to commercialize the Couture power train with 4 wheel-motors, hence its name (Technology Motor 4 “wheels”), has stopped working on the high power wheel-motor for all practical purposes and works now mainly on central electric motors, like everyone else.
The author of this blog is absolutely convinced that the wheel-motor power trains, similar to the one developed by Pierre Couture, are the best and will be the power trains of the future. Here's why.
First, looking at the illustration above, we find that the permanent magnets (green and orange) are fixed near the rim of the wheel, giving the motor a large diameter, which increases its torque and power. There are of course other innovations designed by Pierre Couture that contribute to its high efficiency (above 96%), with a power greater than 100 kW (134 hp) and a torque of 1200 N.m (885 lbs-ft) for each motor, which was 2.5 times more than a Corvette engine of the time! The total power with 4 wheel-motors would have exceed 400 kW and the total torque 4800 N.m, which would have propel the Chrysler Intrepid from 0 to 100 km / h (0-60 mph) in 3 seconds, according to calculations by Pierre Couture!
The performance of these wheel-motors have been tested in the laboratory, but at the time of the resignation of Dr. Couture, only 2 wheel-motors were installed on the Intrepid and the power electronics was not yet complete, hence the impossibility to have full testing on the road. However, the illustration below shows a field test where the two motorized wheels were spinning while remaining on the spot and burning rubber. This performance was simply not possible with the V8 engine of the original Chrysler Intrepid.
Illustration - Images from the TV program Découverte broadcasted by Radio-Canada in 1997. (Photo: Archives of Radio-Canada)
The goal of having such powerful motors was not to race but to recover more of the car kinetic energy when braking, even suddenly. With four wheel-motors and good batteries we can recover nearly 90% of the kinetic energy since the four motors act as four powerful electromagnetic brakes that produce electricity to recharge the battery. This is called regenerative braking. In traditional cars, the kinetic energy is lost in heat in the mechanical brakes. Now, in an electric car with a central motor, we can only recover 20% to 25% of the kinetic energy when braking. This is because the electric motor is connected to two wheels only, while we must have four brakes, and because the motor being located behind a differential we must have mechanical brakes even on the two motorized wheels. Otherwise if one wheel is on ice, the driver could lose control of the car.
Moreover, with four wheel-motors, there is no differential neither transmission. It is a direct drive, and there is no energy loss between the motor and wheels, as in a car with central engine. This is a second reason why wheel-motors consume less energy, particularly during cold winters.
Moreover, since energy consumption is lower, we can reduce the size of the battery, engine-generator and fuel tank. Besides the wheel-motors themselves are lighter than a central electric motor of equivalent power, since their external structures fulfill a dual function, serving also to support structure to the wheels. The reduction of the car weight is therefore a third cause of reduction in energy consumption.
Now, the fact that with wheel-motors there is no motor under the hood allows us to taper the front of the car and close the underside. These changes improve aerodynamics and provide a fourth contribution to reducing its energy consumption.
These four factors combine to give an energy consumption in urban driving about 35% less than a car having a central electric motor, and about 15% lower when driving on the highway. In mixed driving, we obtain a reduction in consumption of around 25% with four wheel-motors. THIS IS A BIG DIFFERENCE, ESPECIALLY FOR URBAN CARS, TRUCKS AND BUSES! This reduced energy consumption affects not only the operating cost of vehicles but also the purchase cost, since the battery (very expensive) and the engine (for plug-in hybrids) can be scaled down considerably. Moreover the wheel-motor vehicles have significantly less parts (no differential, no transmission, no cardans, no ABS braking hardware).
BESIDES, NOT ONLY THE WHEEL-MOTOR CARS ARE THE MOST ENERGY-EFFICIENT BUT THEY ARE ALSO THE MORE POWERFUL, WHICH IS REALLY A PARADIGM SHIFT. James Bond and Al Gore could carpool together in a wheel-motor car and the two would be very happy!
In closing, it would be good to mention four other advantages of wheel-motors that are not related to energy consumption or power. The fact that there is no engine under the hood increases the crush zone of the metal during a frontal impact, improving the safety of passengers. Furthermore, the lack of engine under the hood gives more flexibility to the car designers. Also, with four wheel-motors, we can incorporate an anti-skidding system and an ABS braking system only by software. Finally, the driver has a four-wheel drive vehicle, which is quite popular in winter in the nordic countries, and well appreciated by those who drive off-road.
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Hydro-Québec,
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Wednesday, March 04, 2009
Fast opportunity charging electric buses
ILLUSTRATION - The ancestor of fast opportunity charging electric buses, the Gyrobus from Oerlikon corporation, was used in Switzerland in the early 1950s. The electrical energy gained during the 70 seconds recharges every 2 km accumulated in a flywheel. This illustration is the cover page of the former Science and Mechanics magazine of April 1954.
As we have seen in my note on the depletion of global resources (March 3, 2009), the sustainable development of people transportation goes through public transit systems much more developed than today.
The all-electric vehicles are ideal for the quality of life (no pollution and little noise). Already metros, trams and trolley buses are operating in several cities. But the bus remains a very important component of urban public transport. We see more and more battery electric buses make their appearance, such as the small fleet of electric minibuses set up in old Quebec City in 2008, but their range is limited to approximately 100 km (60 miles) due to the cost and weight of batteries.
With the advent of fast charging fast lithium titanate batteries, since 2007, it is now possible to have fast opportunity charging electric buses. These buses will fill up with electricity at regular intervals along their way by means of a retractable pantograph making momentary contact with the overhead conductor of a fast charging station, for about one minute every 5 km (3.1 miles), or 25 seconds every 2 kilometers (1.25 miles).
The advantage is that opportunity charging does not need overhead cables all over the streets, as in the trolley buses, or rails like tramways. The cost of infrastructure is thus reduced, as well as the cost of batteries, since a range of about 20 km is sufficient. A system of opportunity charging electric buses also offers more flexibility since you can easily change the itinerary. This is not the case for trams or trolley buses, which must follow their predetermined itinerary all the way to be supplied with electricity.
If we want to increase the transit capacity of buses and approach the capacity of tramways, we need only to drive the buses in dedicated lanes, not available to other vehicles. This is the busway concept, becoming increasingly popular as cheaper than the tram. The city of Nantes in France, among others, installed a very popular line in November 2006. Most busways today use articulated buses (120 passengers) running on diesel or natural gas. The next logical step would be fast opportunity charging electric Busways.
The principle of fast opportunity charging is not new. It was tried in Switzerland in the early 1950s with the Gyrobus, built by the company Oerlikon (illustration at the beginning of this post). At that time, there was obviously no long lasting and fast charging batteries. The energy storage system used was a flywheel set in rotation at a speed of 3,000 rpm.
Furthermore, the Swiss company Numexia is currently developing autonomous small electric vehicles with fast opportunity charging for public transit without drivers (recharges in 5 seconds to regularly spaced stations). The system will be installed in Switzerland, at the site of École Polytechnique Fédérale de Lausanne in 2010 and will serve a distance of 4.6 km (2.9 miles). It will use 30 small vehicles and 15 non contact fast charging stations. This innovative transportation system was introduced in the program Nouvo at the television channel TSR in Switzerland.
In California, Proterra company just introduced in February 2009 its all electric bus EcoRide BE35 (shown below) that can travel 50 km to 60 km on a recharge of its lithium titanate battery from Altairnano. The battery can be recharged in less than 10 minutes through a high power charger also sold by Proterra. The bus is also available in plug-in hybrid version, giving it the same range as a traditional diesel bus. It is a very interesting intermediate step before the actual fast on the way opportunity charging electric buses.
For further reading on this topic, you can explore the website www.nanobus.org developped by Roger Bedell.
Labels:
electric bus,
fast charging,
opportunity charging,
transit
Tuesday, March 03, 2009
High speed monorails instead of high speed trains
ILLUSTRATION - Artistic View of a high speed monorail equipped with wheel-motors, as designed by Pierre Couture at the beginning of the years 1990s. Illustration taken from my latest book «Rouler sans pétrole»(Driving without oil). (Drawing: Paul Berryman)
The author of this blog who has lived in France for two years knows how much the TGV (from the French expression «Train à Grande Vitesse», High Speed Train) are comfortable and faster than the plane for travels of less than 1000 km, taking into account the loss of time at airports and between airports and city centers.
But the establishment of a high speed railroad line costs around 15 million euros/km (15 M€/km) in France, or 23 M CDN $/km (29 M US $/mile). In the Nordic countries such as Canada, it is necessary to have deeper foundations for the railroads in the event of freezing and thawing, and the bill could climb to more than 30 M CDN $/km (37 M US $/mile). The cost of a high-speed train between two cities 250 km (156 miles) apart could very well exceed 7.5 billion CDN $ (5.8 billion US $). To make such infrastructures worth it requires a high population density, while in countries like Canada there are few populous cities far apart.
This problem of fast interurban transportation was the subject of much thoughts from Pierre Couture, the inventor of modern wheel-motor (with the Institut de Recherche d'Hydro-Quebec in 1994). It led him to a concept quite revolutionary. Judge for yourself.
To minimize the foundation works for the tracks which must be resistant to frost, the solution proposed by Pierre Couture is to build a lightweight monorail with two lanes suspended to the same structure, itself supported by poles every 60 meters (180 feet) or so. The self-propelling cars, suspended and powered by 16 wheel-motors, are capable of carrying sixty passengers and travel apart from each other at a speed of 250 km/hour (155 miles/hour).
To avoid having to expropriate land for the lines, the monorails are constructed between the two lines of a highway. The surfaces used on the ground are just a few square meters every sixty meters. For tight turns, it would suffice to overflow slightly plots and tilt the rails. Since the wheels are equipped with rubber tires, they offer a better grip than the iron wheels of trains, allowing the monorail to climb the slopes of highways and step over crossing bridges. The I beam on which the motorized wheels roll is embodyed from the top by a light enclosure, that protects the rail-beam from snow falls.
When you think of it, this light and fast monorail would greatly benefit all over the world, not only in cold countries. Especially as the cost of infrastructure is at least 3 times lower than that of a TGV (High Speed Train), given the little work done with the ground, the absence of expropriation, and construction of structures in automated factories, 12 months a year ! We could develop these monorails only with the money saved by introducing a line of 250 km, since this line would cost about $ 5 billion less than a TGV! Thereafter, the commercialization of this technology would quickly recover the investment.
These light and fast monorails would also be ideal for connecting downtowns to airports, or for people transit across a river to reduce the traffic congestions on bridges at rush hour. We only have to hang the monorail guiding lines on the side structures of bridges. Such a service of public transportation is much less expensive than a subway under the river.
Who will do it?
The depletion of global ressources commands more public transit
ILLUSTRATION - Number of years remaining before the exhaustion of resources at the global level, assuming a geological exploitation equal to that of 2006. The data come from the U.S. Geological Survey, the report BP Statistical Review of World Energy, June 2008 and an article by Paul Mobbs on reserves of uranium.
Even if cars with electric motorization are much more efficient than traditional cars, the fact remains that it is not very wise to constantly move a vehicle of 1500 kg (3,300 lbs) to carry a person of 75 kg (165 lbs). We must not only consider fuel consumption of vehicles. We will have to be very cautious also about the consumption of many metals that will disappear in a few decades, if we continue to exploit them at current rates (see chart above).
Given this finding on resources, the author of these notes is convinced that true sustainable development of road transport requires a very large investment in public transit, our governments have a duty to improve it, to attract more customers. Carpooling and urban community-electric cars are also very important to help us eliminate our dependence on oil while reducing consumption of raw materials. Cycling and walking complement well these ecological transport means. But we will also have to rethink suburban sprawl, promote 4-day working weeks, when possible, and telecommuting.
To minimize the consumption of raw materials in vehicle construction as such, the wheel-motor powertrain is the one that allows the greatest economy, as we shall see in another note. Besides the wheel-motors are ideal for urban transit, as they allow the bus to recover the maximum amount of energy during their many stops, which minimizes power consumption. In fact, buses are probably the vehicles that would benefit most from the wheel-motors technology.
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Fuel cells and hydrogen for cars, a dead end
ILLUSTRATION - Comparison between the chain of energy processing and distribution for vehicles with hydrogen-FC, right, and the chain for battery electric vehicles to the left. FC-hydrogen vehicles use 3 times more electricity than battery electric vehicles or plug-in hybrid vehicles in electric mode. (Drawing from my latest book «Rouler sans pétrole»)
Hydrogen and fuel cells (FC) have been presented since the mid-1990s as a panacea to the problems of pollution caused by motor vehicles, as only water vapor comes out the exhaust pipe. Furthermore, knowing that 96% of hydrogen is currently produced from fossil fuels, oil and gas industries see the arrival of a hydrogen economy as a good thing for their businesses.
The main advantages of hydrogen put forward are the ability to tank in less than 10 minutes and offer a range of 500 km, unlike batteries, which took several hours to recharge and limited the range of an electric car at about 200 km. However, since 2007 the new lithium titanate batteries, such as those of Altairnano or Toshiba, can also be recharged in less than 10 minutes. In addition, with a plug-in hybrid car we can also fill up with gazoline in less than 10 minutes for a range of 700 km, while driving the vast majority of our mileage with electricity from the grid.
Let us not forget that hydrogen does not occur naturally on Earth. It is associated, among others, with oxygen to form water and carbon to form hydrocarbons (oil and natural gas) or coal. To obtain the hydrogen, we must first separate it from the molecules where it is found. This separation process consumes energy, and produces CO2 when using fossil fuels as a source of hydrogen.
Although some automobile manufacturers have built great FC-hydrogen cars without emissions when we drive them, hydrogen is not as good as they say. Several experts, including Ulf Bossel, demonstrated that the hydrogen economy was not really viable, and that we go away from sustainable development by taking this path. The main reasons are (details and demonstrations in my book «Rouler sans pétrole»):
* When the hydrogen is produced by reforming natural gas and electricity is produced with a natural gas power plant, a FC-hydrogen car emits 50% more CO2 than a battery electric car or a plug-in hybrid in electric mode.
* When the hydrogen is produced by electrolysis of water using renewables (no CO2) FC-hydrogen vehicles use three times more electricity than battery electric vehicles or plug-in hybrid vehicles in electric mode.
* We would have to invest hundreds of billions of dollars to set up a distribution infrastructure for hydrogen.
* Filling up with hydrogen would be at least five times more expensive than with electricity. It is about 15 times more expensive today.
* The explosive aspect of hydrogen brings security problems with its distribution on a large scale to the common people. In addition, to supply a service station, we need 15 trucks of compressed hydrogen to replace one gasoline truck, adding to the dangers on the roads.
* The development of FC-hydrogen vehicles is ten years late with respect to plug-in hybrids. Thus, FC-hydrogen vehicles offering no particular advantage, on the contrary, makes a penetration of the market very unlikely.
It is time to turn the page of the "hydrogen expenditure" to quickly develop a real "electron economy".
Monday, March 02, 2009
Natural Gas or Electricity for Vehicles?
Illustration - Natural gas power plant at Currant Creek, Utah, photo by David Jolley, 2007, Wikipedia, Creative Commons
Since 2008, T. Boone Pickens, a multibillionaire of the oil and natural gas industry, made a name for himself with his plan, Pickens Plan, to reduce oil imports from the United-States using natural gas in motor vehicles specially adapted, such as Honda Civic GX. These cars emit about 20% less CO2 than equivalent petrol car. However, the range of cars using compressed natural gas is only 300 km on a single tank.
The Pickens Plan is simple, it is to close the majority of natural gas power plants in the United-States within 10 years and use the gas to run internal combustion engines of road vehicles instead. In his plan, the natural gas power plants are replaced by wind turbines, which can provide up to 20% of the electricity the United-States, according to experts, while the natural gas power plants currently provide 22%. The Pickens Plan would save up to 38% of oil imports from the United States, according to its author.
At first glance it seems interesting, because it does not consume more natural gas, reduces oil consumption and increase renewables, while powering the United-States' economy, and strengthening energy security!
I have nothing against the building of wind turbines. But, it is much better to consume natural gas in power plants and produce electricity with up to 60% efficiency. Indeed, a vehicle with a good electric motorization is 85% efficient in converting electricity into motive power. Thus, about 50% of the natural gas energy would propel such vehicles, instead of less than 25% for internal combustion engines using directly natural gas.
So, vehicles with electric motorization could reduce U.S. oil imports about twice as much as natural gas vehicles of the Pickens Plan! Moreover, to distribute natural gas to vehicles we would have to implement a new infrastructure, while electric grid and service stations for petrol fuels are already in place, today, for plug-in hybrid electric vehicles.
Consequently, it is much better for vehicles to use electricity as an energy carrier rather than natural gas. This last gaseous fuel is better used in power plants.
All-electric or plug-in hybrid electric vehicles?
Illustration - Powertrain of a plug-in hybrid electric vehicle with 4 wheel-motors, as conceived by Pierre Couture at the Hydro-Quebec Research Institute and announced in 1994. (drawing: Pierre Langlois)
We are currently at a turning point in the history of the automobile, where we will have to invest considerable sums to reduce our dependence on oil. The rapid depletion of oil, the geopolitical conditions that are attached, the problems of air pollution and global warming are strong incentives to drive more and more with electricity. In this regard, it is important to identify the best technologies to implement by 2030 to avoid investments that lead nowhere, like hydrogen cars. Should we invest in all-electric vehicles or plug-in hybrid electric vehicles (PHEV)?
The company Project Better Place is campaigning for all-electric cars, by offering to install expensive infrastructure of recharging points and battery exchange stations to «fill up» with electricity in less than 5 minutes. With PHEV, no need to install new infrastructure since you can go to fuel stations across the existing infrastucture, while passing through 80% of our mileage in electric mode, and recharging a smaller battery each day, at home or at work. In addition, PHEV enjoy full range (electric and fuel) of more than 700 km, in contrast to 150 km to 200 km for all-electric cars.
Some defenders of Project Better Place concept say that it is cheaper to install recharging and exchange of batteries infrastructure than installing two engines (one electric and thermal) in PHEV, on a large scale. But to reach such a conclusion, they must certainly exclude the cost of batteries. Because the cost of performing and long life lithium batteries is about $ 20,000 to give a range of 100 km (60 miles) to a midsize car. Assuming that the price decreases by half with a mass production, we will still have to pay for the battery about $ 20,000 for a fully electric car with a range of 200 km (120 miles).
But you must know that 2 in 3 drivers drive less than 50 km (30 miles) per day United-States, and less daily mileage in Europe, on average. However, a battery capable of a range of 50 km (30 miles) would cost $ 5000 to equip a PHEV instead of $ 20,000 for a fully electric car that can travel 200 km (120 miles). For the PHEV, just add about $ 3,000 to include a gas motor-generator to recharge the battery while driving during long journeys. Therefore, the high cost of batteries means that PHEV cost $ 12,000 less than fully electric cars of same size and performances.
Also, why one would install a battery offering 200 km (120 miles) of range when a battery allowing 50 km (30 miles) of range would be sufficient for daily needs? This is a real waste of resources. Let us not forget that the global lithium reserves are estimated at 11 million tonnes, according to the U.S. Geological Survey, and that one expects that over 1 billion vehicles will be on the roads in 2030.
Now it must be said, a range of 200 km (120 miles) for a fully electric car is not sufficient to meet all the needs of a driver, especially that this 200 km (120 miles) falls rapidly to less than 150 km when using the heating or air conditioning. Increasing the battery range is too expensive and makes the car too heavy, since it takes about 200 kg per 100 km of range for high performance lithium-ion batteries. Thus, for a range of 400 km one would require a battery of 800 kg, which increases the energy consumption of the car and decreases its performances inevitably.
Finally, fully electric cars are facing the another problem of an increased vulnerability to a major power outage. Quebecers who have experienced the ice storm of 1998 and were without power for 3 weeks in winter know something about it. All electric cars could not move in such a situation, whereas PHEV could have powered houses from their on board gas generator. The energy redundancy offered with liquid fuels is thus very important. How to escape from a big hurricane with an all-electric car when power is down?
It is possible that in 25 or 30 years all-electric cars take over. But before this could happen, it would be necessary to have batteries that are capable of storing 5 times more electricity for the same weight as the Li-ion batteries today, that their price be ten times less, and that our electricity networks are decentralized to reduce their vulnerability. Until then, all-electric cars could may be reach 20% of the market, as a second family car for comuting. But for that we do not need an infrastructure to exchange batteries or removable batteries. It is sufficient to add gradually recharge points at strategic locations, accessible to all electric cars, not only those of Project Better Place. In fact, most people will simply recharge their urban electric car home at night, when rates are lower.
Our analysis shows that the vast majority of cars of the next quarter century should be PHEV able to travel up to 100 km in electric mode. By 2010, PHEV could consume 10 times less fuel than conventional cars, since 80% of their mileage could be done in electric mode and that these cars use about half the fuel used by conventional cars, when operating mode fuel. In 15 years from now, advanced PHEV will be able to consume 20 times less fuel than petrol cars of today. It will then be possible to drive without oil and use only second-generation biofuels (made from waste and non-food plants).
Labels:
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cars,
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plug-in,
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