The Future of Renewable Energy

The Future of Renewable Energy

energy sources
Energy Generation by Fuel
Energy Information Administration

With regulatory and market forces chipping away at the profit margins for coal-fired and oil-fired power plants, will the next few decades usher in a surge in more cost competitive renewable energy projects throughout the United States?  Not likely.  The reason is that most renewable energy sources are also facing similar challenges in addition to technological barriers.

Currently, renewable energy sources make up only 13% of the power generation in the U.S., with hydroelectric power being the largest renewable energy source at 63%.  By 2040, renewable energy as a percentage of total power production is only expected to reach 16%, while coal is expected to drop from 42% to 35%.  Natural gas will replace the lost coal capacity and is expected rise from 25% to 30%.  Why is there not a larger growth in renewable energy as a percentage of total energy production?

renewable energy
photo by andjohan on Flickr

Wind Power

Take wind power for instance.  Many of the best locations for wind generated electricity are off-shore where the wind gusts are frequent and strong enough to keep the blades turning profitably.  The problem is that offshore turbines need maintenance to keep them running, which requires specialized equipment and procedures.   Also, salt water increases corrosion and can wreak havoc on the electronics. That makes off shore maintenance a costly endeavor.  The U.S. Energy Information Agency states that less than 2% of global wind capacity is located offshore, likely because of the high capital cost to build in the ocean.

One potential solution is to build the wind turbines on shore and construct them in places like the Great Plains where the wind is plentiful and maintenance costs are low.  In fact, one-fifth of the United States possible wind resource is located in North and South Dakota (Bret Harper, 2005).   Here the issue is that there are not enough transmission lines to carry the power to the places where it is needed.  No company is willing to build wind turbines in a location where there are no transmission lines or build transmission lines where there is no power being generated.   There are a few locations that are both near transmission lines and where there is sufficient wind, but the best locations are being snapped up quickly, leaving new projects to compete for less desirable locations.

Lastly, the love affair with wind power is rapidly becoming limited to those who don’t have to live anywhere near them.  The public is more aware of the complaints from wind farm neighbors concerning turbine noise, its impact on birds and bats, and the amount of land it takes to collect enough wind to make a project worth doing.  The result is that it is becoming increasingly more difficult to get projects approved in a reasonable time period.

solar energy
Solar panels
Photo by Aaronazz

Solar Power

Solar power is hardly worth even talking about in terms of a viable solution to the energy needs in the United States, at least with the current technology.  Who by now has not heard about the number of solar power companies that have gone under due to high production costs and low wage competition from China.  Even if we can get cheaper solar panels from overseas, solar power is very expensive to produce, whether being generated by giant light collecting mirrors harnessing sunlight to boil water to make electricity or using solar panels to make electricity directly.   The places where sunlight is plentiful tend to be places that are dusty and hot.  A thin layer of dust that is barely perceptible to the human eye can reduce the light power 20% or more.  Also, high temperatures tend to cause problems with solar panels that are made with semiconductor devices that are sensitive and unreliable when temperatures get too hot.  And, as with wind, there  is the chicken and egg problem, because some of the best locations for generating solar power are not on the grid.

Biomass Power

Biomass is a catchall that can refer to burning plant or animal derived materials to make power and includes municipal garbage.   When biomass is burned it has the benefit of lowering the amount that needs to be landfilled and is considered a renewable resource.  While biomass power plants are more easily located near transmission lines and fuel sources, they typically have other challenges that make them less competitive with fossil fuel-fire power plants.   Most biomass plants are operated on a much smaller scale than traditional power plants, which means that they don’t produce enough power to keep the lights on without the aid of fossil fuel burning plants. Among the reasons is that biomass fuels do not have the same energy density (i.e. the amount of energy that can be generated per unit mass) as fossil fuels.  In addition, air emissions such as acid gases can be comparable to a similar sized coal plant.  Wood burning power plants, in fact, tend to have higher nitrous oxide and methane emissions when compared to a similar sized coal plant.  Nitrous oxide and methane are  31 to 300 times more potent in absorbing heat than carbon dioxide. The fact that wood-fired biomass plants emit more potent greenhouse gases (GHG) makes Environmental Protection Agency’s statement of the benefits of renewable energy posted on their website somewhat awkward:

“Environmental and economic benefits of using renewable energy include: generating energy that produces no anthropogenic GHG emissions and reduces some types of air pollution”

For more information on renewable energy resources see the following links:

About Mark Shepherd

I work in the environmental movement helping to protect the air we breathe, the water we drink, the land that sustains us and the natural and biological resources we depend on.

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