Biofuels

There is great interest in getting agriculture involved in fuel production. Several different methods exist to convert biomass into fuels. The National Renewable Energy Laboratory (NREL) has a large biomass program. Biofuels can give farmers new streams of revenues. Biofuels have the potential to produce energy with lower greenhouse gas emissions than fossil fuels. However, if they are produced from crops that are used as foodstuff or feedstock, they can drive up the cost of food. If they are produced by using fertilizer or energy intensive steps such as distillation, then they consume as much energy in their production as we get back from burning them. Therefore, there are lots of scientific projects to create more efficient pathways to biofuels.

Biodiesel is formed by adding methanol to fats and oils using sodium hydroxide (NaOH) as a catalyst. New methods of production are being developed. In particular, it would be interesting to find methods that do not produce glycerin as a byproduct or that use caustic NaOH as a catalyst.

Biodiesel clearly has an energy advantage (more energy out than required to produce it). It can also be produced from waste products such as used deep fryer fat; hence, its production can facilitate turning a waste product into something valuable.

A great deal discussion surrounds bioethanol. When produced from sugar cane (as done in Brazil, where the waste biomass is burned to provide the energy for distillation and the resulting charcoal is used as fertilizer rather than using fertilizer that requires natural gas for its production) more energy is derived from burning the ethanol than is used to produce it. When produced from corn (as done in the USA, where ammonia produced from nitrogen and natural gas or coal is used as fertilizer, conventional electricity is used to heat the distillation aparatus and the biomass is thrown away), the energy balance is negative or only slightly positive.

Other alcohols are also being considered for bioproduction. One of these is butanol.Other plants and parts of plants are also being considered for production of alcohols. If we could get alcohols from agricultural and timber wastes - in particular, from cellulose - there could be great potential for biomass to produce inexpensive fuels. Cellulose is a material that is contained in the stringy bits of plants - the parts that humans and animals don't eat - such as corn stalks and cobs.

The Bioenergy Feedstock Information Network (BFIN) is a gateway to a wealth of biomass feedstock information resources from the U.S. Department of Energy, Oak Ridge National Laboratory, Idaho National Laboratory, National Renewable Energy Laboratory, and other research organizations.

Fossil Fuels

As can be seen here, the price of crude oil has dropped from an all-time high but is still expensive compared to historical values. While this causes problems as far as the cost of filling your gas tank, as far as providing an incentive for finding alternative and for the reduction of the impact of burning fossil fuels, this is highly advantageous.

The cost of a gallon of gasoline or a kilowatt-hour of electricity, however, does not fully reflect the cost of that energy source. A recent report from the National Academies of Science concludes that "hidden" costs of energy production and use - such as the damage air pollution imposes on human health - that are not reflected in market prices of coal, oil, other energy sources, or the electricity and gasoline produced from them. The report estimates dollar values for several major components of these costs. The damages the committee was able to quantify were an estimated $120 billion in the U.S. in 2005, a number that reflects primarily health damages from air pollution associated with electricity generation and motor vehicle transportation. The figure does not include damages from climate change, harm to ecosystems, effects of some air pollutants such as mercury, and risks to national security, which the report examines but does not monetize.
Requested by Congress, the report assesses what economists call external effects caused by various energy sources over their entire life cycle - for example, not only the pollution generated when gasoline is used to run a car but also the pollution created by extracting and refining oil and transporting fuel to gas stations. Because these effects are not reflected in energy prices, government, businesses and consumers may not realize the full impact of their choices. When such market failures occur, a case can be made for government interventions - such as regulations, taxes or tradable permits -- to address these external costs, the report says.

You can learn more about fossil fuels at the DOE site and the Office of Fossil Energy.

Fusion

Fusion is what powers the sun. If we could harness nuclear fusion on Earth, we would be assured of having enough energy for all future needs of mankind. However, the technical challenges are enormous leading some to suggest that fusion was, is and always will be the power source of the future.

Fusion is the process of creating a new nucleus out of two light ones. During the process, a small portion of matter is converted into energy according to Einstein's famous equation E = mc². Very little mass is the equivalent of an enormous amount of energy.

In the sun, the primary fusion path is the reaction of two hydrogen nuclei (protons) to form a deuterium nucleus (a heavier isotope of hydrogen). The deuteron and another proton then fuse to form helium. The sun achieves this reaction because its gigantic mass gave it enough gravitational force to jam the protons together in the first place. Now that fusion has started, it also keeps the sun at ridiculously high temperatures. The high temperature ensure that when the protons collide they have enough energy to undergo fusion reactions.

Here on Earth it is difficult to recreate the conditions found in the Sun. Therefore, scientists such as those at the Princeton Plasma Physics Lab or the ITER, use a deuterium + tritium plasma (tritium is yet another heavy isotope of hydrogen). The energy required to fuse deuterium (D) and tritium (T) is much less than that required for proton + proton fusion. A machine known as a tokamak is used to create huge magnetic fields to confine the plasma of D and T ions and to heat them to millions of degrees.

Getting a D+T plasma to "burn" so that it releases more energy than is required to ignite it, to extract the released energy, and to turn this energy into electricity is no mean feat. To learn more about proposals to do this, go to the ITER introduction to fusion energy.

Hydrogen & Fuel Cells

The DOE Hydrogen Program looks at all aspects of using hydrogen as a fuel. In principle, molecular hydrogen (composed of two hyrogen atoms H₂) seems to be an ideal fuel. When it is burned in oxygen (a molecule of two oxygen atoms O₂) it forms water (H₂O). No carbon dioxide (CO₂) is formed.

The problem is that H₂ only exists in very small quantities. Hydrogen does exist in very large quantities in nature. However, it tends to be bound up in chemical compounds such as water or in hydrocarbons such as oil, natural gas and coal. Coal gasification is one possible route to H₂ production. The problem is that this generates a huge quantity of CO₂, just as much as burning the coal in a conventional power plant.

An alternative is to liberate H₂ from water. There are two was to do this. The first is electrolysis: by passing electricity of the proper voltage through water, the water is dissociated to form H₂ and O₂ molecules. The question, of course, is how do we produce the electricity in the first place without generating as much CO₂ as we are trying to replace with the H₂. If the electricity can be generated by solar panels or wind turbines, then the H₂ is produced without significant production of greenhouse gases.

An alternative is to produce the H₂ thermochemically from water, perhaps in the presence of a catalyst. The idea here is to put heat up water to the point at which is breaks down to produce H₂ and O₂. The thermal energy can be provided by concentrated sunlight (solar thermal H₂ generation) or by the heat given off by a nuclear reaction (that is, a nuclear power plant used just to generate heat not electricity).

  Fuel Cells

What is the best way to get the energy back out of H₂? We could just burn it, as gasoline and diesel are burned in a conventional internal combustion engine. This is a simple solution that does not require much alteration of current vehicle designs. However, combustion has a limited efficiency and it will always also produce byproduct pollutions such as nitrogen oxides (a component of smog)

A better way to extract energy from H₂ is to put it in a fuel cell. A fuel cell is an electrochemical device. It produces H₂O from H₂ and O2 not by burning it; rather, it uses electron transfer to facilitate the reaction. This is a much more efficient method to extract the energy.

If we had copious inexpensive quantities of H₂, the H₂ + O₂ fuel cell would be our best option. There are many techical hurdles that need to be overcome for incorporation into automobiles, but it would clearly be a good choice. But we do not yet have copious quantities of inexpensive H₂. Therefore, scientists are also looking at alternative sources of hydrogen. In effect, other molecules that also contain hydrogen atoms can be used as a carrier of the hydrogen. Some candidates include methanol, ethanol, formic acid, and acetic acid.

NREL has lots more information on hydrogen and fuel cells.

Nuclear (Fission)

Nuclear energy is released when atoms break up into smaller atoms and subatomic particles. This process is known as nuclear fission. When certain isotopes of uranium and other elements are involved, energy is released and the subatomic particles that are generated can be used to create a chain reaction. Thereby a source of power is created. In a conventional nuclear power plant, the neutrons released in fission are used to heat and boil water. The steam produced is then passed through turbines to generate electricity in a similar fashion to how steam generated in a coal fired power plant generates electricity.

Nucelar power is controversial and often a divisive issue. One the one hand there are the worries than its use may contribute to large scale acidents and nucelar weapons proliferation. The disposal of nuclear waste also presents a long-term challenge. On the other hand, it is a mature technolgy than is constantly evolving toward greater efficiency and safety. It does not produce significant quantities of greenhouse gases. Its role in the future of US power production continues to be a hotly debabted political issue.

The International Atomic Energy Agency (IAEA) is the world's center of cooperation in the nuclear field. It was set up as the world's "Atoms for Peace" organization in 1957 within the United Nations family. The Agency works with its Member States and multiple partners worldwide to promote safe, secure and peaceful nuclear technologies.

The DOE spends most of its research budget on nuclear power. You can learn more about what they are doing here.

Solar

The Solar America Initiative is a U.S. Department of Energy (DOE) effort to accelerate the development of advanced solar energy technologies. The goal is to make solar electricity from photovoltaics (PV) cost-competitive with conventional forms of electricity from the utility grid by 2015.

Light from the sun can be harnessed either to generate heat or electricity. Direct conversion of solar energy into electricity is performed by photovoltaic cells. This online tutorial describes all aspects of the production of solar photovoltaic cells as well as describing relevant aspects of solar radiation.

Solar radiation can also be used in a photothermal system in which the light heats a fluid. Heat exchangers extract the thermal energy from the fluid and are used to generate steam that drives a turbine, just as in a conventional combustion or nuclear electrical generator.

There are numerous issues involving chemistry as it relates to solar power applications. Recently the NSF opened a center for chemical innovation called Powering the Planet. This Center is located at Caltech and focuses on the efficient and economical conversion of solar energy into stored chemical fuels. Their Education Page contains further information.

Here are a couple of links to some cool frontier ideas about integrating solar power production into building designs

• Paint on solar power
• Transparent solar power windows

NREL has lots more information on solar power.

If you are thinking about installing solar power or water heating, you can look to Philly Solar.org for more information.

Solar has great potential for both on-grid (hooked up to the wires that deliver electricity to homes and businesses) and off-grid applications. Off-grid applications are important to isolated communities: islands, remote villages, low population density areas, nomadic populations and the developing world. Small-scale off-grid solar energy capture, storage and use has the promise of allowing such areas to develop without having to build up an extensive (and expensive) infrastructure that may be inpracticable and difficult to maintain. The Lighting a Billion Lives project seeks to reach out to such populations and deliver basic solar lighting to them.

Founded by TERI, this campaign aims to bring light into the lives of one billion rural people by replacing the kerosene and paraffin lanterns with solar lighting devices. This will facilitate education of children; provide better illumination and kerosene-smoke-free indoor environment for women to do household chores; and provide opportunities for livelihoods both at the individual level and at village level. Each solar lantern in its useful life of 10 years displaces the use of about 500-600 litres of kerosene, thereby mitigating about 1.5 tonnes of CO₂.

Wind

According to the Department of Energy (DOE), the United States has enough wind resources to generate electricity for every home and business in the nation. However, this potential is not equally distributed across the country. Wind generation is one of the fast growing sources of electricity but even with over 11.6 gigawatts (GW) of installed capacity in 2006, this represented less than 1% of the US electrical generation capacity. The promise of wind is great because it can generate electricity without production of greenhouse gases or waste heat.
Wind can be used to generate electricity directly when a turbine driven by wind is hooked up to appropriate power electronics. It can also be used for mechanical work (traditional uses such as puming water and grinding grain) or emerging applications such as production of hydrogen from water..
Small wind turbines can be connected to homes, barns, factories and commercial buildings. Could you hook one up to your home or business? Here is a listing of essentially all small wind turbines from allsmallwindturbines.com/. The DOE provides a FAQ page for consumers considering the installation of small wind turbines on their property.
Generally, you need to place a wind turbine at least 15 feet above your roof, while some suggest that it should be at least 30 feet above the highest object in the vicinity for the best air flow characteristics.
Wind farms are large commercial scale installations. These involve placing a large number of wind turbines (a few hundred to a few thousand) in one area and connecting them to the conventional electrical grid.
You can learn more about wind power at Ingreenious. or the American Wind Energy Association.
The DOE provides information on the DOE wind programs. This includes a hisotry of wind energy and a tutorial on how wind turbines work. Some have worried about the environmental impact of wind farms. The National Academies of Science recently released a report on this. The full report and free executive summary are available here. Newer large, slow moving turbines are less likely to kill or injure birds and the siting of wind farms can be arranged so as to mitigate the impact on birds and bats.

NREL has lots more information on wind power.

Exotic Sources

Other potential energy sources include geothermal energy, and waves or ocean currents.

Negawatt

The term negawatt was first coined by Amory Lovins of the Rocky Mountain Institute. One of the primary ways of not consuming more energy is to avoid waste. A number of ways to avoid waste are outlined in our Reduce, Reuse, Recycle pages.

Passive House

The passive house is a paradigm changing idea.In a passive house, insulation and advanced doors and windows are used to encase the house in an airtight shell. The passive house is warmed not only by the sun, but also by "waste" heat from appliances and even from occupants' bodies. Just as importantly, the house is not sealed, which leads to stagnant air and mold growth. Instead passive houses harness central ventilation system that effeciently exchanges heat between the warm interior air on its way out and cold air coming in.

This may sound exotic and expensive but in Germany, where the concept was pioneered, passive houses cost only about 5 to 7% more to build than conventional houses

Find out more at the Passive House Institute US.

Energy Audits

The Energy Coordinating Agency (ECA) is a non-profit corporation, founded in 1984, whose mission is to help people conserve energy and to promote a sustainable and socially equitable energy future for all in the Philadelphia region.