Solar panel electricity systems, also known as solar photovoltaics (PV), capture the sun's energy using photovoltaic cells. These cells don't need direct sunlight to work – they can still generate some electricity on a cloudy day. The cells convert the sunlight into electricity, which can be used to run household appliances and lighting.
The benefits of solar electricity
• Cut your electricity bills. Sunlight is free, so once you've paid for the initial installation, your electricity costs will be reduced.
• Get paid for the electricity you generate. The Karnataka government’s Feed-in Tariffs pay you for the electricity you generate, even if you use it.
• Sell electricity back to the grid. If your system is producing more electricity than you need, you can sell the surplus back to the grid.
• Cut your carbon footprint. Solar electricity is green renewable energy and doesn't release any harmful carbon dioxide or other pollutants. A typical home solar PV system could save over a tonne of carbon dioxide per year – that's more than 30 tonnes over its lifetime.
How do solar panels (PV) cells work ?
PV cells are made from layers of semi-conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers. The stronger the sunshine, the more electricity is produced. Groups of cells are mounted together in panels or modules that can either be mounted on your roof or on the ground.
The power of a PV cell is measured in kilowatts peak (kWp). That's the rate at which it generates energy at peak performance in full direct sunlight during the summer. PV cells come in a variety of shapes and sizes. Most PV systems are made up of panels that fit on top of an existing roof, but you can also fit solar tiles.
Solar tiles and slates
Solar tiles are designed to be used in place of ordinary roof tiles. A system made up of solar tiles will typically cost about twice as much as an equivalent panel system. Solar tile systems are not normally as cost-effective as panel systems, and are usually only considered where panels are not considered appropriate for aesthetic or planning reasons.
Other factors that affect PV installation costs are :
• The more electricity the system can generate, the more it costs but the more it could save.
• Larger systems are usually more cost-effective than smaller systems (up to 4kWp).
• PV panels are all about the same price per kWp, but PV tiles cost much more than a typical system made up of panels.
• Panels built into a roof are more expensive than those that sit on top.