Wednesday, 27 March 2013

Are renewable resources practical?

Are renewable resources practical?


While few people disagree that renewable energy is a good idea, most also recognize there are two practical barriers to implementation on a wide scale.
First, all renewable energy sources, except for hydro-electric power, cost from two to five times what fossil fuel and nuclear energy costs, even when their “free” fuel costs are factored into the analysis. Many, first-world countries could afford the higher cost, thus decreasing their emissions and fossil fuel use at some slight reduction in spending on other items. But lowcost power is essential to the industrial processes that provide the basis for the world economy, not just that of rich nations.
And among the first “other items” for which spending would be reduced would no doubt be charity and aid given to developing nations. In addition, those third-world countries cannot improve their standards of living unless plentiful, cheap power is available in growing amounts.
As a result, while renewable energy costs will likely continue to decrease at a slow pace as technology improves, only cost competitiveness will bring about big changes and thus widespread usage.

Site requirements

Second, all renewable energy sources have some type of special site requirements that make them suitable for only some parts of the world and some locations. Many renewable methods, such as hydro, geothermal, and wind, can be used only at a relatively small number of locations, where the water, geological, or wind energy can be found.
The power must be generated there, regardless of where it will ultimately be used. Considerable land must then be cleared and devoted to high-voltage transmission lines to get the power to where it is consumed – creating another type of significant environmental impact.
Solar powered house
Solar powered house

Even solar power has only regional applicability. While theoretically, solar thermal and photovoltaic power will work anywhere, both are practical only in locations where the sun shines a good portion of the day. Near the equator, solar thermal power plants receive nearly 12 useful hours of sunlight daily. But beyond 50 degrees latitude north or south, there are many days of the year when there is simply not enough daylight, leaving energy consumers in need of spending more on some other “backup” supply for those times.
Similarly, biomass plants work only in areas where there is a long growing season. Year-round growing seasons are best, of course, although biomass can also work where the added cost of considerable fuel storage for cut grass and timber is feasible.

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