The great green energy debate

If all the heat generated by community debates over biomass, biofuels and green energy could be channeled into the grid, the Twin Cities could go petroleum-free any day now. Unfortunately, we have no way to harness that energy to light the streets or run the trains. Instead, vehement and sometimes vitriolic discussion sometimes narrows the focus of the debate to what's wrong with one source of energy, rather than a broad analysis of costs of various kinds of energy and conservation.

Any evaluation of fuels and energy production needs to include a multi-factor analysis. While there may be more, I believe every analysis must include at least four green factors:

• 1 – Source/production: Where does the fuel come from? How is it grown, mined, harvested, produced?

• 2 – Transportation/distribution: How, and how far, does the fuel travel from where it is produced to the place it is used to generate energy? How, and how far, does the energy travel to the consumer?

• 3 – Energy generation: What happens at the point of energy generation? What costs, financial and environmental, are associated with energy generation?

• 4 – Emissions/wastes/residues: What byproducts are left after energy generation? Where do these by-products go?

Source/production

Ethanol offers a local example of the need to consider source and production costs. Ethanol was touted as a green fuel, especially here in the Midwest where major grain companies (think Cargill, ADM) convinced many farmers that raising corn for ethanol would increase corn prices, neglecting to mention that most profits would still accrue to the grain traders.

Arguments in favor of ethanol generally focus on the end product, a less-polluting fuel. Looking at the source and production of ethanol raises different environmental questions. Intensive corn production depletes the soil and requires the use of petroleum-based and environmentally-destructive fertilizers and pesticides. Any environmental accounting for ethanol has to include the pollution of rivers, lakes and groundwater by fertilizer run-off and pesticide residues. Irrigation sucks groundwater reservoirs, and, in some areas, contributes to the emergence of sinkholes. Replacing smaller farms with miles-long cornfields cultivated and harvested by diesel-powered giants results in human costs to community and to local businesses.

Sounds grim – but then look at the production costs of coal, including strip-mined landscapes and dead miners. No fuel comes without cost. My point is not that ethanol is evil, but that accounting of environmental costs and benefits must not stop at the filling station nozzle or the refinery, but instead must reach back to the cornfield and community. In order to compare fuels, we need to look at all the costs and all the benefits.

Transportation/distribution

Transportation and distribution of petroleum, even domestically-produced petroleum, has clear costs. The Alyeska Pipeline Service Company boasts, that the 800-mile-long Trans-Alaska Pipeline "has successfully transported over 15 billion barrels of oil."

And then there were the unsuccessful transports, notably the 1989 Exxon Valdez disaster, which spilled 11 million gallons of oil in Prince William Sound, and the 2006 pipeline leak, which spilled at least 250,000 gallons of oil on the Alaskan tundra. In between, according to the Christian Science Monitor, "about 500 oil spills have occurred in the Prudhoe Bay oil fields and along the 800-mile pipeline each year."

The environmental costs of transport have to include the destruction of wildlife habitat by the pipeline's construction and maintenance, the oil spills, and the diesel emissions from truck transport to gas stations and other consumers.

Few fuels come without some kind of transportation impact on the environment. The current system of electricity generation relies on massive production at centralized places and then delivery of electricity through transmission lines. Even discussion of wind energy focuses on large "wind farms" that would produce electricity to be shipped elsewhere. In contrast, decentralized production of electricity by home solar panel arrays, smaller-scale windmills or backyard bio-diesel operations offer alternatives that have different costs and benefits.

Energy generation

What does it take to turn fuel into energy? Burning comes immediately to mind, but nuclear power plants, wind farms and solar panels all produce energy without burning. Any ranking of fuels needs to include an analysis of the place and method of energy production. Environmental factors at the point of production may include the machinery used, the use of water for cooling or for co-generation of steam heat, and other factors that don't come immediately to my mind.

Garbage, aka refuse-derived fuel (RDF), raises particularly difficult questions. Before becoming fuel, garbage is processed into the "fluffy" RDF. That processing should be part of the cost analysis. Then RDF is burned, and its burning typically raises two other issue: it needs to be co-fired with some other fuel (such as coal) and it gunks up (technical term) the incinerator, raising maintenance costs. Granted, most environmental arguments against RDF focus on the emissions factor, but these production/generation factors are also part of the equation.

Emissions/wastes/residues

Carbon emissions, contributing to global warming, are part of everyone's consciousness in the green energy debate.

Toxic chemical emissions, such as mercury, also figure in the equation for some fuels. Micro-particulates emitted from smokestacks as a consequence of burning anything clearly contribute to health problems in the community. Scrubbers and filters can eliminate many harmful emissions, and need to be considered as part of any debate.

The residues of energy productions, from ash that gets landfilled to nuclear wastes that continue to pile up, present their own environmental issues.

And, in conclusion … Much more could be said, but this post is already too long. My point is—green energy issues are complicated. All of these factors need to be part of the discussion and part of the calculus for decision-making.