The most precise Solar Energy definition is simply: Energy from the sun. But what is solar energy really? There are two types of solar energy: Thermal Energy & Electric Energy Thermal Energy Thermal Energy is everywhere. Its lights up our days. It heats the earth, our bodies and our homes. It dries our clothes and gives us produce like sun-dried tomatoes. All for free! Its also used to heat water for domestic use or even pools. There are two ways in which water can be heated: 1. Actively, when a conventional heating element within the solar hot water system heats water on hot days. 2. Passively, when water is preheated before it is delivered to the cold inlet of a conventional gas/ electric water heater. Electric Energy Electric Energy uses the power of the sun to produce electricity through solar cells, otherwise known as photovoltaics (PV). It can be applied in three ways: 1. Stand-alone 2. Grid-connected 3. Back-up Stand-alone: also called Solar Home System (SHS): A system not connected to the grid. More often than not, these systems are installed in remote areas where there is no utility-supplied power, like remote holiday cottages. It is often cheaper to install a solar energy system than lay electricity cables to the site. Excess energy can be stored in a battery for use during times where there is no sunshine. Grid-connected: A system where utility supplied electricity is connected to the property, but the owners wish to harvest clean, free energy from the sun. Usually in a quest to live a more sustainable, environmentally friendly existence. Electricity is supplied firstly from the solar energy system, then the connected battery if one has been installed and finally from the grid if there is still a need. Back-up: A system connected to an unreliable grid or one of poor quality. These types are usually installed in areas where a lot of power blackouts occur. A small system will service the most important electrical appliances and lights, but a bigger system will be required to keep the fridge running during a blackout. So, what is solar energy used for then? 1. To provide heating 2. To provide electricity |
