s – Solarizing the Electrified
|Solar electric modules cover the rooftops of this apartment complex in Bremen, Germany|
When governments of developing countries began to fund solar energy programs in the mid-1970s and early 1980s, they favored large-scale, centralized solar-cell plants. Since engineers can tailor solar electric modules to any particular electrical need at the site of use, many came to realize that solar cells could allow each building to become its own electrical power plant by placing them on the roof. This would eliminate much of the capital costs inherent in constructing a centralized power plant such as buying land, putting up transmission lines, laying foundations and support structures and so on. Swiss engineer Marcus Real proved the economic advantages of the micro approach by selling 333 rooftop solar systems to homeowners in Zurich, Switzerland. After the success at Zurich, no one talks about centralized solar-cell plants anymore. Instead, governments are developing financial incentives to encourage homeowners to place modules on their rooftops. Architects and builders can use solar-cell material to build with, becoming facades, roofing, walls and windows. This eliminates a lot of duplication and extra work. For such reasons, Architectural Record lauds this approach as “a cost-effective energy option that architects should routinely consider.
1990s – Better Cells, Cheaper Cells
|Tubular octagons of crystalline silicon shaped in a die eliminate much of the expense of producing solar cells.|
As the price of solar cells has dropped over the years, they have become the least expensive power source for small-scale electrical demands located away from utility lines. Solar cells have also proven a cheaper source of electricity whenever people have to excavate to lay utility lines underground. Solar cells have therefore saved taxpayers millions in powering emergency call boxes along highways. When a new bus shelter goes up, cities have discovered that it costs less to install solar cells to keep it lit at night than to dig up pavement for the placement of power lines. For the same reason, many municipalities or the highway departments choose solar cells to run street lamps or warning lights. However, solar electricity still costs more to generate than power from existing overhead utility lines. Many believe that current production methods – growing silicon into cylinders or casting them as ingots and then cutting them into very small pieces – cost too much to ever bring down the price to compete with centrally-generated electricity. To dramatically bring down their price, solar cell companies have invested a lot of money to somehow either grow the silicon into a shape that eliminates most of the slicing or merely deposit solar cell material onto an inexpensive but rigid support structure such as ceramic, glass, plastic, or steel.
The Silent Revolution Continues…
|With its wing covered entirely by solar cells, the Pathfinder has flown higher than any other aircraft except for the famous spy plane, the Blackbird.|
The solar-cell industry has grown dramatically over the last twenty years, increasing output 200 fold in this time period. Today, those needing power in remote areas no longer regard solar cells as an alternative source of energy but consider them the most effective solution. Institutions like the World Bank now believe that solar cells “have an important and growing part to play in providing electrical services to the developing world.” In less developed countries, where over half of the population must travel over two hours just to make a phone call, the United Nations today sees solar cells offering these people “for the first time a real practical possibility of reliable telecommunications for general use. Opportunities for solar cells in the developed world continue to grow as well. Solar cells produce electricity than highly polluting diesel generators. The National Parks Service and Defense Department have begun to replace their generators with solar cells. No longer on the highways or ro