Solar-powered Homes are Becoming a Reality
Solar power has made great advances since it was developed as a power source for NASA’s space program. I remember seeing one of the first video simulations of these large arrays of photovoltaic panels unfolding from the earth orbiting satellites. These huge photo arrays converted the sun’s light energy into electricity while the satellite was in direct sunlight. The electrical power was stored in the satellite’s rechargeable capacitors for 24/7 operations. We were told that owning a device powered by a photo cell would be commonplace in 20 to 30 years. That was more than 40 years ago.
We “recycled” our battery-powered calculators several years ago when we got our first solar-powered calculator. A couple of days ago my wife was balancing her checkbook, and I had to laugh when I observed her holding a flashlight just inches from her photo cell-powered calculator. The indirect sunlight in our living room was not sufficient to power the calculator, so she was using a battery-powered light to make her calculator work. I guess that means we still have a “battery-powered” calculator.
One of the shortcomings of using solar power as an alternative energy source has been we only get cost-effective electric power from direct sunlight. Power on a 24/7 basis is not available from this renewable energy source unless there is a method for storing the energy.
Scientists world wide have been working on cost-effective technologies to store electrical energy produced by solar cells. Lead acid and metal halide batteries work but are not considered cost effective. A recent discovery by researchers at Harvard University is to convert the electrical energy produced by photovoltaic panels into chemical energy by using photosynthesis—without using a living plant. Indications are that this process is considerably more efficient than the biological process.
Development of a super-efficient energy storage technology by a former subsidiary of Coors Brewing Company has just been announced. This $2,000 battery uses an ultra-thin ceramic membrane to separate metallic sodium from a strong mineral acid. This new generation of battery was developed by Ceramatec, a subsidiary of CoorsTek (formerly part of Coors, now private). The battery can store 40 kWh of power with eight hours of sunlight in a package the size of a refrigerator. The average American household uses 33 kWh per day. In short, it’s a battery big enough to power your home operating at a peak temperature of 90 degrees. Unfortunately, power converters cost $10,000 and up based on the technology used.
Additionally, the Ceramtec battery can be recharged through 3,650 cycles — or once a day — for 10 years. Deep-cycling lead acid batteries often last less than two to three years with daily use. The implications of such a battery may not be readily apparent to many, but the larger reality is these batteries make “the great disconnect” a real possibility as more and more homes go off grid using wind and/or solar power.