Energy from the sun is abundantly available all over the earth and will not run out for millions of years. The solar energy striking the earth in one year is almost 1,500 times all of man’s annual energy needs! Solar energy does not have to be mined, drilled for, refined, or transported around the world. Solar power is a form of distributed generation – making energy where it is needed, rather than transmitting power from large central power plants.
Many people wonder if the manufacturing processes for photovoltaic modules and other PV equipment are harmful to the environment or especially carbon intensive. According to NREL (the National Renewable Energy Laboratory), the truth is a PV module will produce enough clean energy in about four years to offset the energy required to manufacture it. After a module is manufactured and installed, it will be a zero emissions energy source for the rest of its life (usually 30 years or more).
The major manufacturing input of PV modules is silicon, one of the most abundant elements on earth. It is easily gathered from the top of the earth’s crust and is available all over the world, eliminating the need to transport heavy raw materials.
From the very first day it is installed and commissioned, a PV system will produce clean, green electricity. Whatever a system produces reduces its owner’s need to purchase “dirty” electricity produced by burning fossil fuels or harnessing the power of a nuclear reactor. Translating an array’s power production to common measures of energy or energy-related items helps to understand PV’s value. For example, a hypothetical 5kW PV array in New England should produce the equivalent energy of 10-12 barrels of oil each year. This is like saving 10,000 pounds of carbon or greenhouse gas emissions. Another way to express this system’s beneficial attributes is to say the greenhouse gas emissions it offsets are equivalent to planting about 20 mature trees each year, or driving your car about 7,000 miles less than you typically would in a year.