A Part of the Solution : Solar Panels
Written with the collaboration of Sam Myles P.E.

Greenhouse gases and the exhaustion of petroleum and natural gas reserves are constantly in the news. The Kyoto Accord is still not universally accepted and drilling for oil is now proposed in an ecologically fragile place. As with most public policy issues, many solutions are required. Certainly, political will to act seriously is primordial. This will is lacking at present in the United States, India and China. Of these three major polluting nations, the United States is by far the most able to make the financial sacrifices required to clean up its environmental policies. Canada, with an economy one tenth the size of that of the U.S.A., is also a vigorous polluter, but at least it is talking the good talk, and the minority Federal government has advanced some definite proposals. An interesting North American exception is California, where Governor Arnold Schwarzenegger is serious about environmental issues and is working specifically to strengthen relatively strict vehicular emission standards further.

Individuals and organisations that are committed to a cleaner environment must not delay taking action merely because countries — large and small, rich and poor — are not yet on board. On the contrary, individuals should try to make solutions work so that others can adopt them as soon as possible. There are also numerous private enterprises in this area and they need to be encouraged in any way practical. For example, governments can finance research and encourage environmental preservation strategies by offering tax breaks or through legislation. Individuals can buy fuel-efficient or hybrid cars or at least abandon the behemoth gas-guzzlers they are now driving. They can lobby to make public transport better and affordable, maximize recycling and reduce the waste of energy and resources in many ways. They can join NGO’s which share their views and which energetically (no pun intended) advocate measures leading to a cleaner environment. The inevitable upcoming shortage of petroleum and natural gas, and the fact that these energy sources are harmful to the environment, should logically cause tremendous efforts to be made in the direction of renewable energy, particularly since coal, the only abundant hydrocarbon remaining, creates the most pollution.

However, these efforts are significant but not impressive. Renewable energy has become a buzzword but is nothing new. Water power has been used for at least a hundred years to generate electricity either by using natural waterfalls to drive turbines or by damming rivers to create artificial waterfalls (usually hidden in very large pipes). Unfortunately, most of the sites suitable for this method of generating electricity are already in use. The construction of additional dams in many instances would cause enormous environmental damage to the areas that would have to be flooded, and is therefore not practical. Wind power has also been used for hundreds of years to grind grain and to power water pumps. In this area substantial progress has been made since the new wind turbines are much more efficient than the picturesque windmills which used to dot the Dutch countryside. The new turbines are several storeys high and usually installed in “farms” in the windiest places which, ironically, are often scenically beautiful. This gives rise to the NIMBY (Not In My Backyard) syndrome, but there will have to be some tradeoffs.

Solar energy is the renewable energy source with great potential which is just now being seriously utilized. Raw solar power affecting the earth is enormous. The world’s entire annual energy needs could theoretically be met by the energy beamed onto a relatively small patch of earth. Solar energy can provide hot water through the use of elliptical metal collectors found on the roofs of some houses on the Greek islands. But for more flexible use and the storage of solar energy, solar cells arranged in many multiples as solar panels are the most practical.

Becquerel discovered the photovoltaic effect in 1839. In today’s solar cells, sunlight (in the form of tiny particles/photons,) hits a silicon wafer and separates into positive and negative charges. The surface of the wafer has been treated with phosphorous and attracts the negative charges, while the rest of the wafer has been treated with boron and attracts the positive charges. The charges accumulate at the two poles and create an electric potential. When the two poles are bridged, electric current results. While this process seemed abstruse to me initially, it is similar to one that is familiar to all of us. Chemical reactions are the basis for the electrical energy in our flashlights and car batteries. Most flashlight batteries have a relatively short life, and car batteries would not last long if the car engines did not charge them continuously. But sunlight is inexhaustible, and while not continuous, the energy it produces can be stored in batteries during very cloudy periods and at night. Until quite recently, solar panels were used only where other sources of energy were unavailable or impractical such as for remote radio repeaters, navigational aids, railroad signals, etc. Since use was not very common, the individual panels were expensive. Now their price has made them practical for the roofs of houses, and possibilities are limitless. The appearance of the panels has also drastically changed. One can install whole walls of them and they look as attractive as dark glass — no more unsightly toaster wires!

Production of solar panels soared to 746 megawatts in 2003 (one Mw = 1 million watts) representing a growth of 34% over 2002. Of the installations of the panels, Japan had 39%, Germany 25%, the rest of Europe 9%, the United States 11% and the rest of the world 16%. Global production in 2004 rose to approximately 1200 megawatts, a 60% increase over 2003. For further information, readers may wish to consult PHOTON International a general publication on solar energy, or Solarbuzz Inc., a consultancy which publishes details of commercial developments.

April 2005