Someday solar energy will fuel America's bright future

“The amount of energy that the sun shines onto the earth’s desert regions in six hours is roughly the global demand for energy for an entire year.” – Prof. Michael Dueren of the University of Giessen, quoted in Welt Online.

Solar thermal energy could make a major contribution to American energy independence and quality of life. It might be essential, given the apparent permanent uncertainty of supply and price in the international petroleum market.

Instead of converting sunlight directly into electricity, solar thermal energy concentrates the heat of sunshine, typically to generate steam for turbines that drive electrical generators. The heat can be stored for use when the sun is not shining.

A few utilities have used solar thermal power generators in the past, and more are being built. MarketWatch on June 18 reported that BrightSource Energy closed a $115 million round of financing from Chevron Corp., Google, BP PLC, and others after making a deal with Pacific Gas & Electric for 900 megawatts of solar thermal power. Yes, Chevron and BP are financing solar thermal energy. MarketWatch reported further that BrightSource earlier this month had dedicated a pilot project in the Israeli desert consisting of 1,600 mirrors and a boiler atop a 60-foot tower, a model for plants to be built in the Mojave. Edison International agreed to buy 245 megawatts of solar thermal electricity from a Mojave Desert plant utilizing 500,000 parabolic mirrors, to be completed in 2011.  New Solar Ventures plans to build a 300-megawatt solar thermal plant in Deming, N.M.

They are expensive to construct, but the fuel is free and does not have to be purchased or transported to the power plant. Hence the initial cost can be quickly recovered over time, not only from selling power but also from avoiding the need to purchase fuel and the flexibility to locate a plant on cheap land without considering proximity to ports, roads or rail lines for fuel handling.

Electricity could eventually supplant internal combustion as the predominant motive power. Electric motors have a number of inherent advantages over reciprocating piston engines. An electric motor is far simpler; it has about one tenth the number of moving parts of a reciprocating engine. Because it’s rotary, an electric motor is smoother.  It is highly durable. It gives maximum torque immediately from zero RPM, allowing snappy acceleration when the light changes. The Tesla electric runabout, with chassis by Lotus and lithium ion batteries, has scintillating acceleration and handling; it beats Ferraris and Porsches in races.

The problem with electrics has been the batteries. Significant progress has been made in this regard, not only in the batteries themselves but also in regeneration, using the motor as a generator when coasting or braking. In a modern society, there are many potential access points for the recharging of batteries. Eventually, it should be possible to make vehicles with photovoltaic glass and body surface materials, so that they are always being charged when in the sun, whether rolling or parked.

All of these prospects will keep scientists and engineers busy for years, and their discoveries and designs will generate work for vast arrays of workers of all skill levels.

Internal combustion engines are likely to be with us for a long time, as cheaper fuels for them are found, domestic drilling is encouraged, and the use of electric vehicles reduces the demand for petroleum, thus lowering its price.  But someday the typical motorist might start the day by unplugging a fully charged electric vehicle from an outlet, setting out with smooth, silent, strong acceleration from the electric motor with confidence that he can go two hundred miles or more without the need to plug into an outlet and that he can readily find an outlet if he needs one, and at his destination looking for a sunny place to park, to give the battery a boost.  At the end of his day, if he’s thoughtful, he might wonder how he ever got along without driving exclusively on electricity, before he was forced into it.

Albert W.L. Moore Sr. lives in Independence.