The atmosphere, oceans and land mass of the Earth absorbs enough energy from the sun in one hour to power the entire planet for one year. Surely we are clever enough to capture some of this magnificent force and use it to fuel our environment.
Solar energy and its use can be divided into two areas. Those are static or passive solar energy collection and dynamic, or perhaps better termed, kinetic solar energy collection and use.
An example of passive solar energy collection would be building a house so that the windows face the morning sun in colder climates. An even more rudimentary example would be that of an alligator sunning himself on the edge of the water. In both cases the sun’s energy is simply absorbed for warmth. And the simplest use of solar energy is as the very daylight we walk about in. Our Earth automatically uses the power of the sun in millions of ways. Not the least of which is photosynthesis by plants for production of oxygen for our atmosphere. Ours is an inherently rechargeable renewable world, provided we use our resources such as solar energy wisely.
To that end, we must examine dynamic solar energy collection for the production of warmth and light.
When you walk though almost any shopping mall built in the last twenty years you will probably notice a flood of bright natural light all around you. Most large malls and department stores are built with double paned insulated windows that allow light to enter yet keep heating or cooling locked inside. But what happens when the sun follows its arc away from those windows? Active solar lighting can use mirrors that track with the sun’s movement and then reflect light into fiber optic cable that can carry that light into any part of our same department store.
We can create transfer warmth through various forms of solar thermal energy. Since the 1950s it has not been uncommon to see simple glass paned boxes filled with copper pipes used to help heat water for swimming pools and boilers. These low temperature collectors are fine for space heating but there are far more effective ways to heat water with the sun’s rays and put that water to work.
High temperature parabolic shaped mirrors can heat water to far greater temperatures than made possible by our simple rooftop hot boxes. In fact bowl and trough type mirrors can boil water to steam which in turn uses a turbine to generate electricity for heating, air conditioning and general power supply. When properly applied, this concentrated solar power can supply 50% of the power needs for a modern factory. Concentrated Solar Power is one half of our method for creating electricity from the sun’s radiant energy.
The most commonly thought of use and form of solar energy conversion is that of relying upon solar voltaic cells. These solar cells are also called photovoltaic. First developed in the 1880s, photovoltaic cells rely upon the electronic reaction of certain key elements to the Sun’s rays so as to produce a tapable flow of electrons that are in turned used to create current flow. In short photovoltaic cells turn sunlight into energy. And lest we think we are so clever for figuring out how to do this, consider that plants have been turning sunlight into energy for millions of years.
Advances in the development of photovoltaic cells have increased drastically since the oil shortages of the 1970s. This is primarily due to development of silicon technologies. Crystalline silicon cells when working in conjunction with CSP (concentrated solar power) as supplied by parabolic mirrors have improved output from Photovoltaic cells by a factor of 50 since their more basic development in 1954. Increases in demand and subsequent increases in production have lowered the price of solar cells to the point that they are now almost competitive with wind power technology and like their low emissions wind counterparts are far less costly than nuclear power.