How Does Solar Power Work

With the rising costs of energy the thought of finding a more affordable alternative is definitely appealing. The sun provides the most abundant energy source on earth. There are number of ways to make use of it. One of the most common is to use it to power your home. There are a few ways to do this. The first is using solar thermal application, which means you use the sun to directly heat up air and/or liquids to power your home. The other way is through photovoltaic methods.

Humans use 15 TW (terra watts) of energy per year. The amount of solar energy available from the wind is 370 TW. The amount of solar energy supplied by the sun is 89,000 TW that is usable. The sun actually supplies 174,000 TW but much of it either bounces off the atmosphere or is diffused before it gets to the earth. So in one year the sun produces enough solar energy to supply the people of earth with over 5,900 years of power. The sun drives a large part of the weather on the planet because of the 89,000 TW that the oceans and land absorb per year. The water cycle that allows us to have rain and wind is driven by the solar energy being supplied.

So how to best use this over abundance of solar energy? As I said earlier one of the ways is to use it to heat up air and/or liquid to power your home. This is the cheapest way to take advantage of the sun's energy. So you heat water using the sun. These types of systems have been around since 1890. Up to the 1920's this way of heating water was growing in popularity but after this time relatively cheap and reliable ways to heat water (oil, electricity) came into favor. In the US 14 percent of the power consumed is used to heat water. In a house this is one of the largest expenditures of energy. A solar heating system can supply up to 75% of hot water for a home.

China is the current leader of solar heating with 80% of the market. Israel is the leader when measured by per capita. 90% of home in Israel use it. In the US solar heating is primarily used to heat swimming pools.

One of the downsides of solar technologies is that they are not overly efficient. Of these technologies solar heating is the most efficient. These efficiencies can be expected to be above 60%. Solar heating systems come in batch systems, flat plate collectors and evacuated tube collectors. Of these flat plate collectors are the most common.

In the next article in this series the other ways that solar energy can be used will be explored. This will include heating, cooling and ventilation.