Solar cells are capable of producing a reasonable amount of electric energy from solar light. This has stimulated the imagination of many creative people around the world.
One of the most attractive uses for the photo electricity –electricity produced by light– are the vehicles powered by solar energy. So far, tests on airplanes, boats and cars have been performed with different results. A light airplane, which had all the roof covered by solar cells capable of producing enough energy to move an electric engine, was able to fly over the English Channel.
Each year on Australia an original race is celebrated where only solar powered cars run. The participants have to travel from side to side the Australian continent and most of them don’t finish. The average speed accomplished by these cars is between 50 and 80 Km per hour.
The disadvantage of vehicles directly powered by photovoltaic cells is that they only work well on places with a exceptionally clear and sunny weather.
As usually happens on the high technology business, Japan is one of the pioneers on solar energy applications to transportation. The main inconvenient of using solar energy on vehicles is the necessity of using heavy accumulators or batteries that occupy too much space. This is because of the need of store energy for the vehicle when there is no solar light available. The batteries store the energy when solar light is abundant.
A possible dream
In the 60’s, experts around the world worked in a project that could look as science fiction. It involves launching an enormous space station to convert solar energy into electricity and send it to the earth in form of microwaves.
The space station would have 3 main parts: a solar collector of 6 Km long by 2.5 Km width, build of mirrors and photovoltaic cells; a energy central and a microwave transmitter. Despite its cost, an installation of this magnitude could be rentable on the long run thanks to the fact that the energy efficiency of solar cells is higher outside the earth’s atmosphere. This microwaves could be transformed into electricity again on earth.
The microwave transmitter space station project has never go further than in paper, many hoped that this could have been the end of the fossil fuels. Nevertheless, some day we could have to give a chance to these exotic and crazy methods to obtain efficient energy for men.