The next time you're out enjoying the sunshine, consider this: everyday the sun offers us an abundance of clean, renewable energy that can create electricity and heat water, homes and buildings. Incredible, isn't it? We can use the sun's energy to create "photovoltaic" (PV) energy. This technology uses PV cells (like the one shown in the picture at the right) to capture the sun's energy. These PV cells use semi-conductor material that, when exposed to sunlight, energizes electrons, separating them from their atoms to create an electrical current.
There are essentially three types of PV systems.
- Autonomous systems rely exclusively on the sun's energy for power using batteries to store energy for use at night or periods of low sunlight.
- Hybrid systems combine solar power with a supplementary energy source. This might be a wind turbine or a fuel operated generator. The benefit of a hybrid system is that you get a reliable source of sun energy as well as the ability to switch to a different power source when there is no sunlight.
- Grid-Connected PV systems are those arrangements that create enough electricity to power all your operations and feed surplus energy to the province's electrical grid.
In addition to generating electricity, solar power can be used for a variety of heating applications. For example, a solar water heating system can provide enough energy to meet half of the water needs for a family of four. Whether it's hot water needed for showers, washing clothes, dishes or heating the swimming pool, solar energy is a cost-effective alternative to traditional heating systems.
Solar water heating systems can be broken down into three main parts. These include the solar collector, heat exchange/pump module and storage tank. As the sun light hits the solar collector, it transforms the solar energy into heat. This heat is then used to warm the home's water supply. Once heated to the proper temperature, the water is sent to the storage tank for later use.
For solar air heating, the sun's energy pre-heats cool air entering a home or building reducing the demand placed on conventional heating systems. This system works by drawing cool air through a solar collector mounted on the external wall of a home or building. As cool air passes through the collector it is gradually heated and then brought into the building's air ventilation system. There's a hidden benefit with this too. Because the solar collector is mounted on the exterior wall, it draws on interior heat that would normally escape through the wall. By capturing this heat, the panels become remarkably efficient and provide an extra layer of insulation to capture and use any escaping heat.
To learn more about solar energy, visit Solar Energy Society of Canada.