Okay, call me a spoilsport, but as much as we all might wish otherwise, there really is no free energy lunch. Not so long as much or more needs to be put in to get it than it yields, that removes more valuable land and other resources from more beneficial uses than it is worth, that isn't reliably available in sufficient quantities when and where needed, that promises highly debatable environmental advantages, that costs consumers lots more than "nonrenewable" alternatives, and whose sustainability depends upon endless government mandates and subsidies.
Might evolutionary technology developments change this picture? Yes, maybe in certain cases. But don't count on any fossil and nuclear alternatives making much of a difference anytime soon, regardless how much taxpayer green we throw at them.
On the automotive fuel side of the sustainability picture, corn ethanol is a huge loser for many reasons. It competes for land needed for food crops, requires large amounts of precious water for production and processing, releases as much or more CO2 emissions as petroleum (if you actually care), and yields lousy energy efficiency. It certainly isn't renewable at all when you consider that nearly as much fossil fuel-generated energy is required to produce it as it actually yields.
And forget about any notion that it can offer salvation from dependence upon foreign oil. If all current U.S. corn were to be dedicated to ethanol (180-proof grain alcohol) it would displace, at most, about 14% of the gasoline we presently consume. An attempt to produce enough ethanol to replace gasoline altogether would require that about 71% of all U.S. farmland be dedicated to energy crops. Each additional acre of corn used to produce ethanol is one less that is available for other crops such as soybeans and wheat, which have seen price increases of more than 240% over the past five years. This, in turn, produces a ripple effect that raises costs of meat, milk, eggs, and other foods.
About 35% of the estimated 4.6 billion bushels of all U.S. corn grown this year was consumed by the ethanol industry, producing nearly 14 billion gallons of alcohol. Congress has mandated that ethanol blended into U.S. gasoline will increase to 35 billion gallons per year by 2022. This will require that crop land dedicated to this purpose be expanded from 88 million acres now to about 233 million acres (slightly more than half of our 461 million acres total crop land to meet about 7% of our total automotive fuel needs). Cellulosic ethanol produced from switch grass and other low maintenance plant materials wouldn't compete nearly as much for land needed for food crops, but despite generous government subsidies, remains far from realizing commercial viability.
Regarding "renewable" electricity sources, the two most heralded and hyped power prospects are wind and solar. Let's forget about hydropower which produces more than three times as much U.S. electricity as both of them combined since most environmental groups don't want to claim or credit it. And for sure forget about nuclear which produces ten times more, also with no CO2 or particulate emissions.
First consider that even gargantuan wind installations covering thousands of acres generate only small amounts of expensive and unreliable power. Even those relatively anemic outputs can't be sustained without fossil-fueled turbines (typically natural gas) that provide "spinning reserves" to balance out power grids as wind levels fluctuate. Starting and stopping those turbines is a very inefficient use of fuel, also producing more greenhouse gas emissions than under normal operation.
Advocates often grossly exaggerate the capacity of wind power to make a significant impact on our electrical needs through a failure to differentiate between maximum total capacities, rated in megawatts (MW)—vs. actual predicted kilowatt hours (kWh) determined by annual average wind conditions at a particular site. Seasonal and daily velocities are often out of synch with power needs, such as during hot summer days when demands for air-conditioning are highest.
Output volatility due to wind's intermittency varies greatly according to site location and month of year, typically ranging from 0% to about 50%. Texas, one of the most promising wind energy states, averages about 16.8% of installed capacity, yet the Electric Reliability Council of Texas assigns a value of 10% due to unpredictability. Only about 20% of that capacity is generally available during peak demand periods (about 5:00pm), while average generation during off-peak time averages about 40% of capacity.
Another major limitation of individual wind farms is that they don't produce power on massive scales needed in large cities and industrial areas where necessary space is at a premium and land is expensive. The most ideal locations are typically remote from areas where demands are highest, requiring large investments for power transmission lines and land right-of-way use.
And although wind turbines kill endangered species of bats, raptors and other birds, their operators receive exemptions from environmental review, biodiversity and endangered species laws that conventional energy companies must follow. Also, while turbines and associated transmission lines that dominate scenic vistas are unpopular, unsightly hill-top mining is coming to be outlawed altogether.
Solar power, like wind, is a natural, free source of energy— provided that public subsidies and customers of high-priced electricity cover the costs. In the U.S. the main federal subsidy currently pays for 30% of the cost for a residential system. Then when other subsidies are added, as much as 75% of the cost can be covered. The U.S. Energy Information Administration estimates that electricity produced by solar is presently three times more expensive than power produced by natural gas.
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