Heat from the Ground
"Not to step on anybody's toes, [but] it's the only green energy that makes sense in Michigan--that actually produces more energy than it takes to make," he said. "Solar panels wear out, and you have to replace them about the time they've produced as much energy as went into them."
Since then, overproduction in Asia has slashed the cost of solar-electric systems--but Vlasic remains unimpressed. Though prices have come down, he explains in a recent email, "the laws of physics have not changed. Photo voltaic cells convert, at best, 10% of captured solar energy into electricity, and this efficiency declines over time. Right now 25 years seems to be the outside lifespan ... If you include the energy created to their manufacture, transportation, installation and removal they do not produce net energy.
"Geothermal on the other hand, has shown no tendency to decline in efficiency over time.