Biomass to Fuels: Grasses like the field of Miscanthus above can create as much as 15 dry tons of biomass per acre. This can be converted into 870 kilowatt-hours of electricity to power a plug-in hybrid or electric vehicle; or into 80 gallons of ethanol to power a flex-fuel vehicle. This article compares the two choices.

Most electric vehicles were removed from the U.S. market when California withdrew the legal requirement to sell zero-emission vehicles in April 2003. It is hard to find former owners of electric vehicles who did not become attached to their cars’ noiselessness, lower fuel costs and ability to refuel at home instead of the local gas station.

Ethanol could displace most of our gasoline usage if we solve the technical challenge of making it from plant "biomass" such as agricultural waste, grasses and forest residue (known as cellulosic ethanol), rather than corn. (See Biomass Basics for background.) In our February 2006 newsletter , we described how liquid fuels derived from plant material, like ethanol, can compete with gasoline.

Alternatively, biomass can also be used to produce renewable electricity to power electric vehicles - if more powerful batteries can be developed. If cellulosic ethanol or electric vehicles - or both - become mainstream, the opportunity exists to replace significant amounts of gasoline with fuel derived from biomass.

As President Bush identified in his most recent State of the Union speech, America is addicted to oil. Alternative fuels that use less oil and produce less pollution reduce our dependency on oil, put price pressure on gasoline and diesel, and can reduce global warming pollution.


Batteries have not been successful as automotive power sources primarily because the amount of energy in a battery is a small fraction of the amount of energy in gasoline. This problem is known as "energy density." To hold the same amount of energy as gasoline, today’s vehicular batteries would require over 100 times more space. Current nickel metal hydride (NiMH) batteries hold only about one percent of the "energy density" of gasoline.

Hybrid cars, cell phones, and a myriad of other consumer products have been driving demand for light-weight, high-capacity, rechargeable batteries. There has been a steady advance in batteries based on NiMH, such as those in the Toyota Prius, and lithium-ion in research vehicles. Lithium-ion batteries, while not yet in passenger cars, have also dramatically improved, are prevalent in cell phones and consumer electronics and have twice the energy density of NiMH batteries.

The typical lithium-ion cells used in laptops and camcorders weigh about 40-45 grams, have an output of 8.6 watt-hours, cost about $2 per cell, and have been improving in storage density at about eight percent per year. To travel 250 miles (using a projected 200 watt-hours per mile), an electric car would require a battery weighing over 500 pounds and costing about $12,000. If lithium-ion batteries continue to improve at eight percent per year, this would bring the cost down to $6,000 and the weight to 250 pounds in 10 years.

The fuel efficiency of all cars decreases as weight increases. Mile per watt-hour is the electric car’s measure of fuel efficiency, just as miles per gallon is the measure of fuel efficiency for gasoline cars. Increasing the size of the battery in the electric car decreases its fuel efficiency in proportion to the weight it adds to the car.

An electric vehicle will have much more weight in its batteries than a gasoline-powered vehicle with a full tank of gas. However, an all-electric vehicle avoids the weight of the gasoline motor (an electric motor is much lighter), the transmission and other items.

The issues of weight and efficiency have lead to three design choices:

1. The all-electric vehicle: An all-electric vehicle is simple, reliable and produces no "tailpipe" emissions (see below for discussion of the pollution from electric generation). It is limited in range due to battery capacity, and the time to "refill the tank" (recharge the battery) is measured in hours. It is possible to augment the range of an all-electric vehicle by adding a small diesel/gasoline generator. This configuration is commonly referred to as a "serial hybrid."
2. The hybrid vehicle: The hybrid vehicle, like the Honda Civic, Ford Escape or Toyota Prius, uses just enough battery electricity to make the gasoline engine more efficient and to absorb excess energy from braking and de-accelerating back into the battery. The hybrid’s only source of fuel is gasoline, as all electricity is generated in the vehicle. The efficiency of the hybrid’s gasoline engine is quite good compared to a standard gasoline vehicle. A gasoline engine is about 37 percent efficient only when it is on the highway. Efficiency in the city is much lower because the engine is idling at a stop or operating far from its optimum efficiency during acceleration and deceleration. The great virtue of a hybrid is that its engine does not idle. It is either off or it is operating near its optimum efficiency, so a hybrid engine actually operates at 37 percent efficiency a majority of the time.
3. The plug-in hybrid: The plug-in hybrid provides a way to charge the battery separately and is both a complete battery-electric vehicle and a gasoline vehicle. More battery is added so the electric driving range of the vehicle is between 20 and 40 miles. (All-electric vehicles usually are designed for a 100 mile range.) For more information about current plug-in hybrids, see CalCars.

The all-electric vehicle and plug-in hybrid vehicles allow us to displace gasoline with electricity. As batteries decrease in price and increase in energy density, electricity could power more - or most - of our vehicles.

Is There a Hybrid Premium? We looked at 2007 Camry literature to see if we could discern a "hybrid premium" - that is, the extra cost of a hybrid vehicle compared to a gasoline engine model of comparable performance and features. The Camry is the latest hybrid offering from the highest-volume hybrid manufacturer, so it should be state-of-the-art. The following table summarizes the performance (horse power and torque) of three models of the Camry which otherwise have comparable features. The final column is the list price of these models. Model Camry Horsepower Torque (ft-lb) Mile per Gallon (city/highway) Price XLE 4 cyl 158 161 24/33 $24,425 Hybrid 4 cyl 187 199 40/38 $25,900 XLE 6 cyl 268 248 22/31 $27,520 The hybrid Camry is intermediate in performance and price between the four-cylinder and six-cylinder gasoline engine models. If we scale by horsepower, we could argue that the Camry hybrid with no premium should cost $25,230, and if we scale by torque it should cost $25,787. That implies a hybrid premium of either $670 or $113. To the power-seeking consumer, the hybrid’s performance - let alone its fuel efficiency.- is justification enough for choosing it over the gas-only models.

Using the Toyota Prius as our test case, we can compare its gasoline engine performance to its electric engine performance. The author’s car actually gets 44 miles per gallon as measured over the last five years. A modified Prius developed by CalCars running only on battery power requires about 11,400 watt-hours of electricity (this is the equivalent power of 114 one-hundred-watt incandescent light bulbs turned on for one hour - or about 500 compact florescent bulbs) vs. one gallon of gas to travel the same 44 miles. CalCar’s plug-in Prius uses 260 watt-hours of electricity to go one mile. In general, recently built electric vehicles require 200-400 watt-hours per mile depending primarily on the weight of the vehicle and the battery technology.


Both Ethanol and electricity can be produced from biomass. This is done either by using agricultural waste or specific plants such as switch grass, and either converting the energy stored in the cellulose plant cells to ethanol or combusting the dried plant material and converting it to electricity. The question becomes: Which is better?

Biomass -> ethanol -> ethanol/gasoline vehicle,

or

Biomass -> electricity -> electric vehicle?

According to the NRDC report Growing Energy , one can reasonably expect future conversions of biomass to ethanol to produce up to 80 gallons of fuel per dry ton of biomass.

According to the California Biomass Collaborative , one dry ton of biomass can produce about 870 kilowatt-hours of electricity.

Both ethanol and electricity have to be delivered to the vehicle and that requires some energy. In the case of ethanol, we estimate it requires about one gallon of fuel to deliver 100 gallons (assuming about 500 mile delivery). In contrast, transmission of electricity results in roughly a 10% reduction in energy. Charging the battery requires an additional 10% of the energy.

To summarize, one dry ton of biomass can deliver 79 gallons of ethanol to the vehicle or 705 kilowatt-hours into the battery of a vehicle (870 x .9 transmission efficiency x .9 charging efficiency).

A plug-in hybrid Prius goes one mile using 260 watt-hours. A "flexible fuel" Prius, one modified to run on either gasoline or ethanol, would achieve about 33% fewer miles per gallon running on 100-percent ethanol than 100-percent gasoline due to the lower energy in pure ethanol. This would drop the miles per gallon from 44 to 29. Thus, one dry ton of biomass will produce:

Prius running on electricity	Prius running on ethanol
2,700 miles/ton	2,300 miles/ton

In other words, biomass-to-electricity and biomass-to-ethanol produce similar number of miles achievable per ton of biomass. However, there are major differences in feasibility today which will change over time:

• Biomass-to-electricity and plug-in hybrid technology exists today while the potential of biomass-to-cellulosic ethanol is still unproven in volume.
• Electricity can be transmitted to every home that an electric vehicle can be plugged in to, compared with the current limited infrastructure for delivering ethanol.
• The auto companies have sold more than 5 million flex-fuel (ethanol-based) vehicles, but few have announced plans for electric vehicles. GM is rumored to be working on a plug-in hybrid (see GM Eyes Plug-in Hybrid . Toyota is starting to talk about their plug-in hybrid plans (see Toyota to Explore Plug-In Hybrids ).
• According to the U.S. Department of Energy, advanced technologies for biomass-to-electricity such as gasification could double the electricity produces per ton which would provide 5,400 miles/ton.
• Market pricing for electricity is relatively independent of oil, while ethanol directly displaces gasoline and, even though its production cost is currently significantly less than that of gasoline, tends to be priced just below gasoline.

There is considerable savings in buying electricity to charge a battery vs. gasoline in today’s market. Using the night time electricity rate of 8.8 cents per kilo-watt hour, the cost to drive is about 2.3 cents/mile. At 44 miles/gallon, this is the equivalent of buying gas at $1.02 per gallon. If a driver recharges during the day, the price is likely to be 50 percent higher or more.


According to Joe Romm, former head of the U.S. Office of Energy Efficiency and Renewable Energy, the "lifecycle" greenhouse gas emissions from a gallon of gasoline are about 25 pounds of carbon per gallon (20 from burning the fuel and five from making the fuel). In a Prius getting 44 miles/gallon, this equates to 0.57 pounds of carbon per mile.

The national grid averages 1.3 pounds of carbon per kilo-watt hour . Using the plug-in hybrid efficiency of 260 watt-hours/mile (plus 10 percent for battery charging), the vehicle emits 0.37 pounds of carbon per mile, or about 35 percent less than gasoline when using electricity only.

All this applies to vehicles using today’s infrastructure. We are now witnessing the deployment of E85 motor fuel (85 percent ethanol, 15 percent gasoline). (E85 is common in Brazil, but is only starting here). The decrease in the net carbon released into the atmosphere by combustion of ethanol depends on what type of ethanol is blended - 20 percent with corn-derived ethanol, 80 percent with sugar cane ethanol in Brazil, and 90 percent with cellulosic ethanol. The higher the percentage blend, the greater the greenhouse gas benefits.

There is also much discussion of carbon sequestration. Carbon dioxide generated from power plants of the future may, for example, be pumped into geological structures that formerly contained oil and/or natural gas to be sequestered from the atmosphere indefinitely.

If motor fuels go green before power generation goes green the lifecycle GHG emissions of hybrids will be lower than electric vehicles. If power generation goes green first, hybrids will compare unfavorably. In the distant future, when both power generation and motor fuels are green, it won’t make a significant difference.


As the U.S. looks to biomass as a renewable source of energy for transportation, two paths hold promise. In one case, the U.S. fleet would comprise increasing numbers of flexible fuel vehicles that can run on gasoline or ethanol. Ethanol production would transition from corn-based to cellulose-based. Alternatively, the U.S. fleet could be increasingly based on electricity, either through plug-in hybrids or all-electric vehicles.

In the first case, the major risk is the ability to produce cellulosic ethanol on a large scale. In the second case, it is the ability to develop higher-energy density batteries. Consumers are likely to find electricity significantly cheaper than ethanol. This is because electricity prices are regulated while ethanol prices are likely to be priced just below gasoline until there is a significant oversupply. E2 believes both paths should be aggressively pursued as they both offer alternatives to oil that will save consumers money and help reduce emissions of greenhouse gases.

Many thanks to E2 member Tony Bernhardt for co-authoring this article. Thanks also go to E2 members Felix Kramer and Ron Lloyd, and to Joe Romm and Brian Jenkins for providing key details.

On June 19, the U.S. Senate approved re-authorization of the Magnuson-Stevens Fishery Conservation and Management Act (MSA), a bill that maintains key protections for the nation’s fisheries and takes new steps to rebuild fish populations, which would boost the economies of coastal communities throughout the country. Under the direction of Senator Stevens (R-AK) and Daniel Inouye (D-HI), the Senate has passed a bill that not only maintains key provisions of current law, but also takes important steps forward by providing accountability in fisheries management, increasing the role of science and an ecosystem-based approach, and strengthening protections for valuable marine resources in international waters.

In our meeting with Senator Stevens’ staff, we were told E2’s involvement was important to the MSA’s Senate success in several key respects: demonstrating the economic importance of maintaining the law’s current rebuilding requirements through E2’s Fish Economics report; and signing petitions and personally meeting with legislators to advocate for strong provisions requiring annual harvests be set with a penalty imposed if limits are exceeded, and maintaining protections for depleted Pacific groundfish species.

The House, which is poised to roll back key provisions of the MSA in its re-authorization bill, is expected to take up the measure next month. Read NRDC’s press statement.

The Massachusetts state senate is considering a global warming bill that would enable Massachusetts to join the Regional Greenhouse Gas Initiative (RGGI) to limit greenhouse gas emissions from power plants. On June 14th, E2 members Dan Goldman, Tedd Saunders, Berl Hartman and Jeff Lissack, along with Ashok Gupta, Senior Energy Economist and Director of NRDC’s Air and Energy program, met with Alex Grimes, legislative aide to Senate Majority Leader Frederick Berry, to discuss the issue.

The E2 members made the case that joining RGGI now was critical in order for Massachusetts to have a voice in shaping the pact, which eight other Northeastern states have already signed, and to stimulate clean energy investment in the state. As a follow-up to the meeting, E2 responded to questions that were raised with in-depth information showing the advantages of RGGI over a competing proposal made by Governor Mitt Romney.

On June 14, E2 members Greg Hale, Wendy Neu and John Sullivan joined advocates from NRDC and other environmental groups in Albany to urge New York State Senators to pass the New York Oceans and Bay Protection Act (S-7244A) this legislative session. The bill, which passed the State Assembly in May, takes an important step towards improving the health of New York’s coastal areas by creating a New York Ocean and Bays Protection Council, which will coordinate state marine resources and decisions, encourage ecosystem-based management approaches, and ensure that accurate information about the state of coastal fisheries is widely available. It also calls for the establishment of a comprehensive ocean management plan by the fall of 2008.

E2 members met with eleven Senate offices - including those of Senate Majority Leader Joseph Bruno, Senate Deputy Majority Leader Dean Skelos and Senate Environmental Conservation Committee Chair Carol Marcellino - to impress upon them the critical role healthy ocean and bay ecosystem play in the economic well-being of New York. S-7244A would promote improved coordination and management of NY’s waterways and would direct state agencies to conduct their activities in ways that protect, conserve and restore ocean and coastal resources.

Learn more about the New York Ocean and Bays Protect Act.

NRDC’s Day of Discovery family event provided attendees the opportunity to engage in an array of hands-on learning activities.

On May 21, NRDC hosted Day of Discovery, our first ever family event and fundraiser at the Wadsworth Theater Grounds in Brentwood. Over 1,100 NRDC supporters from the business, entertainment, and philanthropic community attended, helping us raise over $1.1 million. Chaired by Colleen Bell and NRDC trustee Elizabeth Wiatt, this unique event brought together a variety of hands-on environmental exhibits, interactive demonstrations, educational games, and art projects for families to engage in while learning about the environment and NRDC’s work.

Guests had the opportunity to explore six different activity ’zones’ - including Global Warming, Green Building, Oceans, E-Activism, Paper/Recycling, and Biogems/Endangered Species-each staffed by NRDC experts. Each featured an entertainment and environmental activity - from touching tide pool species; painting a mural of the Cumberland Plateau BioGem; and observing principles of solar energy and energy conservation. Catered buffet stations served delicious organic picnic food and desserts and fair trade and organic coffee. Closing the event was a special musical performance by Grammy Award winning singer-songwriter John Mayer.

Our special thanks to the many E2 members whose generous support helped make this fantastic event possible. To download a brief slideshow, please click here (save file and then view for best slideshow results).

Accompanied by fellow NRDC staff, Devra Wang (L) and Ann Notthoff (R), David Hawkins addresses the audience at a May 25 event on global warming.

On May 25, E2 members Kathy and Gary Swart hosted an event to increase awareness of global warming among fellow Californians and introduce friends to E2. Over 50 guests gathered at the Menlo Park Circus Club to hear NRDC climate and energy experts discuss the reality of global warming and the solutions we can achieve if we act now. David Hawkins, director of NRDC’s Climate Center and the recent recipient of the Environmental Protection Agency’s Lifetime Achievement Award, made a compelling case for why we’re at the tipping point for addressing global warming’s impacts. Devra Wang, director of NRDC’s California energy program, discussed California’s leadership on implementing solutions, from legislation to increased energy efficiency to consumer purchasing decisions. She also emphasized that, in the absence of federal leadership on global warming, California is poised to take action in a way that would reduce our greenhouse gas emissions while positioning California as a leader in the global clean technology market. Currently, E2 is actively involved in promoting California global warming solutions. Check out our campaign.

On June 14 at the Harvard Faculty Club, NPR’s Steve Curwood and NRDC’s Ashok Gupta led a lively discussion on how to harness the power of the market to reduce our country’s dependence on oil and put us on a more sustainable path. Both agreed that the private sector is critical to getting alternative energies to market.

Steve hosts NPR’s weekly environmental news program Living on Earth and has devoted many segments of his show to the feasibility - technical, economic and otherwise - of alternative energy sources. Ashok directs NRDC’s Air and Energy program with a focus on electric utility restructuring, energy efficiency, green building design, climate change, clean tech and alternative energy.

On June 26, the U.S. Supreme Court announced it will hear a case on whether global warming pollution from the nation’s vehicles can be regulated under the Clean Air Act by the Environmental Protection Agency (EPA). The case will review the Bush administration’s decision in 2003 that EPA has no authority to limit emissions of carbon dioxide and other pollutants that cause global warming. NRDC is a party in the case, which was brought by the State of Massachusetts and joined by 13 other states and cities and more than a dozen environmental organizations. The case comes from the U.S. Court of Appeals for the District of Columbia Circuit, which in July 2005 delivered a splintered decision with three separate, inconsistent opinions from the three-judge panel. The case is expected to be argued before the Supreme Court this fall. A Supreme Court ruling that the Clean Air Act covers global warming pollution would open the door to federal action to curb emissions from vehicles, power plants, and other industries. A favorable ruling also would knock the legs out from under the auto industry’s lawsuit challenging California’s landmark standards for heat-trapping emissions from motor vehicles.

On June 23, state officials passed the New York Ocean and Great Lakes Ecosystem Conservation Act (S-8380, A-10584B), making New York the second state in the country (after California) to establish a state council to coordinate marine resource efforts through the implementation of an ecosystem-based management approach. The act establishes a strong state policy of conserving and restoring our ocean and coastal resources and embraces the concept of ecosystem-based management, which considers the interplay between different species and their habitats and is an important alternative to managing only on a specific species or problem. The act also creates an interagency New York Ocean and Great Lakes Ecosystem Conservation Council to improve coordination and ensure accountability among those responsible for marine resources. The Council will complete a report defining government actions needed to integrate ecosystem-based management with existing programs and create an atlas of ocean and coastal resources.

More than 40 percent of New York’s coastal estuary and bay waters are impaired or threatened, and more than 35 percent of the state’s most important commercial and recreational saltwater fish and shellfish are depleted or being harvested at unsustainable rates.

Starting June 1, U.S. oil companies will be required to clean up the diesel fuel used by millions of trucks and buses, kicking off a program that will ultimately reduce tailpipe emissions from new vehicles by as much as 95 percent. Although the standards apply only to fuel used in road vehicles (construction, farm and other non-road equipment are covered under separate regulations), according to NRDC, they constitute the greatest single step in reducing vehicle emissions since lead was removed from gasoline a generation ago. Diesel engines emit huge quantities of particulate matter, nitrogen oxides and more than 40 chemicals that are known or suspected to cause cancer. Particulates are associated with increased asthma emergencies; bronchitis and other cardiopulmonary ailments; cancer; and heart disease.

Also starting June 1, refineries and importers will have to cut the amount of sulfur in diesel fuel by 97 percent, which in turn will allow engine makers to use new pollution controls to cut particulate soot emissions by 90 percent, starting with the 2007 model year. By 2010, all on-road diesel fuel will meet the new "ultra low" sulfur standard, and manufacturers will have to cut nitrogen oxide emissions (which create smog) from new diesel engines by 95 percent. In addition to smog, nitrogen oxides contribute to acid rain, and nutrient pollution in waterways.

On May 30, the U.S. Government Accountability Office (GAO) issued a report which found the Bush administration’s voluntary approach to reducing global warming pollutants to be inadequate. (Download the report.) The report uncovered significant shortcomings in two partnership programs - one at the Department of Energy and the other at the Environmental Protection Agency - that are supposed to encourage the private sector to reduce heat-trapping pollution. For example, of the 74 companies participating in the EPA program, only one quarter have committed to reduce their total global warming emissions. Another quarter merely are limiting their emissions growth, not reducing actual emissions. And the other half have set no targets at all. Both programs were also found to have no means to enforce any pollution-cutting goals.

Thanks for your support. Comments, questions and introductions to possible new members are always welcome! Learn how to join E2 at how to join. To learn more about the leaders of E2 please read about the E2 co-founders. 

Bob Epstein and Nicole Lederer, Editors
bob@e2.org nicole@nicolelederer.com