Using Solar and Nuclear Energy Won't Cut Our Oil Bill

A few days ago I heard a radio talk-show host say we should cut our dependence on foreign oil by using more wind, solar and nuclear power. While this is a popular notion, increasing our use of these sources will do extremely little to reduce our oil consumption.

Reason: Oil-fueled power plants generate less than 1% of U.S. electricity. Most of our power is produced from domestic fossil fuels like coal and natural gas.

According to the U.S. Energy Information Administration, in the 12 months ending March 2010, about 45% of our electricity came from coal, 23% from natural gas, 20% from nuclear plants, and 7% from hydroelectric sources.

Renewable sources like wind, solar, biomass and others contributed nearly 4% of our power.

So where does the oil we drill or import go?

Once again, the EIA to the rescue. In March 2010, finished gasoline accounted for 46% of our oil usage. The rest is used in the manufacture of diesel oil, jet fuel, heating fuel, asphalt, plastics, etc., etc.

Which means if we want to reduce our dependence on oil, we need to severely curtail our use of gasoline-powered cars.

Fuel cells, anyone?

Wood Burning Power Plants in Massachusetts -- Doubts Creep In

Massachusetts had embraced wood-burning power plants in a big way, investing $1 million this year in power plants in the western part of the state.

The Boston Herald now reports that the state is rethinking its emphasis on wood-burning plants. Critics of the wood-burning plants say supplying the plants with sufficient wood would cause deforestation in the surrounding areas. And the plants would emit more carbon dioxide than coal-fired plants.

Massachusetts's Patrick Administration is seeking more information into the adverse effects of generating electricity from wood-burning plants. The state Environmental Affairs Secretary is ordering a 6-month study of the issue. Meanwhile, the Department of Energy Resources is developing new regulations for biomass power plants.

This is the kind of news one has mixed feelings about. On the one hand, it's gratifying to note the government is taking environmentalists' concerns seriously and ordering a review of the greenhouse-gas and deforestation effects of the wood-burning plants.

On the other hand, shouldn't they have done this before spending $1 million on the plants?

On balance: better to reconsider late than never. And it's not like the $1 million was a total waste. I'm sure it did a lot of good for many state residents.

World's 10 Largest Renewable Energy Projects

From Scientific American, a slideshow of the world's 10 largest renewable energy projects.

The world is going to need 2 TW (terawatts, or million megawatts) of electricity in the next 40 years. The projects shown in this slideshow are producing electricity right now. They are:

1. Horse Hollow Wind Energy Center, Taylor and Nolan Counties, Texas (currently overtaken by the Roscoe Wind Complex 220 miles west of Dallas)
2. Lynn and Inner Dowsing Wind Farm near Skegness, Lincolnshire, England (now in second place behind the Horns Rev 2 project off Denmark)
3. Rance Tidal Barrage in Bretagne, France
4. SeaGen Turbine in Strangford Lough, Ireland
5. Solar Energy Generating Systems in Southern California
6. Olmedilla Photovoltaic Park in Olmedilla de Alarcón, Spain
7. The Geysers in Sonoma and Lake Counties, Calif.
8. Oy Alholmens Kraft in Pietarsaari, Finland (dry biomass-fired power plant)
9. Aguçadoura Wave Farm near Póvoa de Varzim, Portugal
10. China's Three Gorges Dam
11. (Bonus) Puente Hills in Whittier, Calif. (landfill gas recuperation plant)

Rubber Trees to Provide Electricity in Liberia

Biomass produces a minuscule fraction (0.9% in 2007) of all the electricity in the United States. Liberia, however, is planning to make all -- or most -- of its electricity from trees.

Old, non-performing rubber trees, to be specific.

The country hosts the world's largest single natural rubber operation, a Firestone plantation with 8 million trees. Those trees will be used in a new $150-million power plant to produce 35 MW of electricity, and double that when the nation's power grid gets upgraded. The Liberian Electric Company will sell that power to citizens for half what they are paying now.

A bonus result of felling trees for energy: More room to plant new rubber trees, leading to continuous rubber production. You can tap your tree and burn it too.

Other benefits from the biomass energy operation include 400 new jobs in electricity generation and distribution. And as businesses save money through lower rates for energy, they're likely to hire more workers.

Wood-Burning Plants Generate Energy in Massachusetts

Massachusetts has 3 million acres of underutilized forestland. They aim to utilize it to produce energy.

The state's Sustainable Forest Bioenergy Initiative seeks to burn wood to make electricity. Even if half the state's annual supply of woody biomass of 4 million tons was used for electricity, it would generate as much as 150 MW. That's enough to power about 75,000 homes.

The state has already invested $1 million in 4 wood-burning plants in the western Massachusetts towns of Russell, Greenfield, Springfield and Pittsfield.

At first, igniting wood seems a bad idea. Burning wood produces carbon dioxide, carbon monoxide, particulate matter, nitrogen oxides, heavy metals, volatile organic compounds and other disagreeable discharges.

But modern wood-burning plants are different from your ancient residential wood stove, according to this report from the Bioenergy Initiative (pdf):

...with proper design, operation, maintenance and emission control devices, modern biomass energy systems can produce little or no visible smoke and low emissions.

Besides, wood combustion releases almost the same amount of CO₂ as that absorbed by the tree during its growth. Thus, the net addition of carbon to the environment is close to zero.

By contrast, the carbon in fossil fuels has been isolated from the atmosphere for millions of years. When fossil fuels are burned, they emit "new" CO₂ into the air, increasing the total amount of carbon in the environment.

Fuel Cells Create Electricity From Onion Waste

What do you do with 150 tons of onion waste per day?

If you're Gills Onions, the U.S.'s largest producer of fresh onions, you buy two fuel cell power plants and make electricity, that's what.

Last Friday, the Oxnard, Calif., company unveiled a waste-to-power fuel cell generation plant that will annually cut $700,000 from its electricity bill and $400,000 in onion peel and shavings disposal costs.

Here's how the system works: The onion waste is pressed into juice and animal feed. The juice is then digested by bacteria, or fermented, a process that releases methane gas. The methane, instead of being burned, goes into two fuel cell power plants that produce a combined 600 kW of electricity -- enough to meet half the company's power needs.

Gills had bought the fuel cells in August 2006 from FuelCell Energy, a company that manufactures stationary fuel cell power plants and is based in my home state of Connecticut.

The entire system cost $9.5 million. Southern California Gas and the state government provided credits of more than $3 million. Gills expects the plant will pay for itself in under 6 years. After that, the savings drop straight to the bottom line.

By converting farm waste to energy, Gills Onions will eliminate about 30,000 lbs. of carbon dioxide-equivalent gases from the air. It will also conserve land and water that would otherwise have been used in disposing and composting the waste.

(Photo of the two fuel cell power plants © Deaton & Associates LLC.)

Bioelectricity Beats Biofuel in Efficiency

Burning plants to produce electricity is a more efficient way to power cars than turning those plants into biofuels.

That's the conclusion reached by a study conducted by a team from the University of California at Merced and reported in the journal Science.

In fact, the bioelectricity from an acre of crop would propel a car 81% farther than the ethanol produced from the same acre. The bioelectricity would power an electric car, of course, while the ethanol would turn an internal combustion engine.

Electric powertrains are more efficient than internal combustion engines, giving biolectricity an inherent edge over ethanol.

Another advantage of using bioelectricity: Unlike the ethanol conversion process, bioelectricity generation produces no greenhouse gases. The carbon released during combustion is the same carbon that the plant absorbed during its growth, which means there's no net gain of CO2 in the atmosphere.

To make bioelectricity, crop is burned and the steam is used to turn the turbines of a generator. Ethanol is produced through fermentation and distillation.

The study's authors hope it will be used to expand the discussion from how we can best produce and market ethanol to how we can use our land most efficiently.

(Photo: University of California at Merced.)

Biomass - the old and new renewable fuel

Biomass sounds like one of those new renewable fuels produced by some exotic modern technology. In reality, it's one of the most ancient forms of clean fuel.

Long, long before people were extracting energy from water wheels and whale oil, they were igniting wood -- or biomass -- for warmth.

Today, wood continues to be the largest biomass source of energy. Whether straight from the tree or from the residue of lumber mills, wood is used all over the world. Other sources of biomass include crops, grasses, and the organic components of animal, industrial and municipal waste.

Biomass can be burned to generate heat or to make steam for driving turbines that produce electricity. Some kinds of biomass, like corn, sugar cane and certain grasses, can be fermented and transformed into liquid fuel. Methane released by decomposing organic waste can be used either directly as fuel, or converted to methanol, added to animal and vegetable fat, and turned into biodiesel.

The range of applications for this clean, renewable source seems limitless.

If you're wondering why biomass is called a clean source when burning it deposits ash on the ground and releases carbon dioxide into the air, here's the answer.

The carbon in biomass is "new" carbon, absorbed from the air during photosynthesis. This carbon is returned to the air when the biomass is burned, for no net gain of CO2 in the atmosphere. (Some carbon is consumed and emitted while harvesting, processing and transporting the biomass, but ignore that for now.)

The carbon in fossil fuels, on the other hand, is "old" carbon, captured millions of years ago. When a fossil fuel is burned, it increases the amount of carbon dioxide in the air today.

And the ash from biomass combustion isn't left to smother the soil, but used in agriculture, industry, mining and wastewater treatment.

Biomass currently supplies about 3% of the US's energy. Raising that percentage is not easy, mainly because of the limitations of biomass.

Growing biomass for energy takes up a lot of land and requires a well-developed transportation infrastructure. If food crops are diverted to energy production, foodstocks get depleted and prices rise. The spurt in food prices during 2008 was blamed partly on the dispatch of huge amounts of corn to ethanol-processing plants and not to our dinner tables.

Further, unsustainably grown biomass causes deforestation and barren cropland. And third, biomass combustion technology is different from that of fossil fuels. Improper or inefficient combustion methods can lead to polluted air, ground or water.

Biomass will probably remain a niche, distributed source of clean energy. It's hard to see biomass ever approaching the mass availability and acceptance of solar, wind or geothermal.