One of the most well-known renewable energy technologies, solar energy is being installed across the world to great effect. So what are the facts to know about this clean and green energy source?

Firstly, it is entirely free and found in abundance, even though the sun is 90 million miles away. The energy is made up of light and radiant heat, which can be harnessed using a range of technologies, including solar PV, solar heating, solar thermal and solar architecture. The earth receives a whopping 174 Petawatts of solar radiation, and around a third is reflected back towards space.

There are two different types: passive and active. Solar thermal and solar PV systems are active because they harness solar power, but passive approaches include designing space to use sunlight in an efficient way and building rooms to better air circulation.

Solar energy also works to create biomass by using photosynthesis to create chemical energy from plants. It can also be used to make saline water or brackish water. Consider too some of the easiest ways of using solar, which include drying clothes in the sun and drying, cooking and even pasteurising food.

Solar hot water systems can also use the sun's rays to heat water. In some areas, up to two-thirds of the water that a typical house needs can be made from solar heating, with temperatures reaching 60 degrees.

Solar panels are one of the most widely used type of renewable technology in the UK. The cost of the technology has plummeted in recent years as manufacturing processes have refined and made unit costs far cheaper than they used to be. This has helped to hasten their adoption in the UK even in the face of widespread government subsidy cuts.