Would it surprise you to know that the price you pay for fossil fuels could be as little as 20% of their real cost? That's because they're often subsidised by the government. Cynics would say that this is to keep prices low and ensure that business keeps booming for the people who control the resources and, in many ways, history shows they're right.

Many people who consider installing renewable energy systems in their homes are put off by the relatively high investment. Why would you choose a solar thermal system that could cost thousands of dollars when you can buy an electric water heater for a couple hundred?

One of the most compelling arguments for widespread adoption of renewable energy systems is the frightening idea that the world is going to run out of fossil fuels. While this is not an immediate concern, there is a strong movement to switch entirely to renewable sources by the middle of the century.

The industry standard for solar fluid is a mix of propylene glycol and water. It's non-toxic, biodegradable and relatively stable. However, you should always mix as much water as possible with your choice of glycol product, as simple water is the ideal solar fluid.