With all of the interest in renewable energy in the United States, there seems to be a serious misalignment of priority.
Everyone seems to be buzzing about photovoltaic (PV) panels (which convert sunlight directly into electricity). Meanwhile, we have millions of electric water heaters all around the country which are guzzling up valuable kilowatt-hours in the name of heating water to coffeepot temperatures, and millions of homes with electrical resistance heating which convert the most versatile form of energy known to man into incredibly useless 72°F space heat. Energy may not be created or destroyed, but it surely loses quality. Try running your new ultra-fast quad-core PC on 72 degree space heat. Oh, yeah, the exhaust coming out the back of the PC is hotter than 72 degrees - if only we could violate the second law of thermodynamics...
My point is that we are concentrating far too much on creating electricity from the sun's dilute light and heat while at the same time we are turning electricity into dilute light and heat. Photovolatics are expensive. Solar thermal collectors (which skip the electricity step and directly utilize solar heat) are cheap. Why the focus on PV? If you have to power a plasma TV or computer, then PV is necessary. If you only need to heat water, cheaper and more efficient options are available.
A few steps to boost renewables and reduce coal:
- Stop burning natural gas solely for heat.
- Stop using electricity for low-grade space/water heating.
- Burn natural gas in cogeneration units. Get the electricity from it, then take off the waste heat.
- Use Solar energy to meet heating and lighting needs before venturing into producing electricity.
When you install a new fancy-schmancy $30,000 photovolatic array on your roof with feed-in back to the grid it is somewhat discouraging to know that all of the electricity created by your system will be guzzled by your neighbors' electric water heaters so that they can stand in the shower for two hours.
There is also much desire to reduce the use of natural gas for electricity generation. Instead, what should be reduced is the use of natural gas solely for heating. Unlike sunlight, natural gas burns at a high temperature and allows for the efficient production of electricity (combined gas-steam cycle generators approach 60% heat-to-electricity efficiency). The waste heat of natural gas power plants can also be utilized for heating, and the low emissions and small footprint of gas-fired generation equipment makes possible placement in urban areas where this waste heat can be actually utilized. By using solar for heating, gas can be directed into power plants (and possibly vehicles) where its high level of exergy can be utilized. The smaller capital cost of gas-fired generation coupled with greater thermal and electrical efficiency and utilization of the waste heat would mean that even economically coal units could be shut down.