Photovoltaic solar panels and roof tiles are becoming increasingly popular for a variety of reasons, both economic and environmental. Not only do they help reduce your carbon footprint, photovoltaics can cut your bills and even generate money, thanks to payments you can receive from your energy supplier. If you are ready to join the domestic green energy revolution, you may be wondering exactly how many panels or roof tiles you need.

There are a number of factors which affect how big an installation you should go for and any competent installer should help you calculate this. Here are some of the things you need to consider when making your decision.

What you want to achieve

Deciding exactly what you want to get out of your photovoltaic installation is a vital first step. Do you simply want to reduce your bills and carbon footprint, or are you aiming to go completely off grid? Are you hoping to produce enough electricity to make a healthy profit? If you know exactly what you want to achieve, you can discuss this with potential installers and they can advise you on exactly how many solar panels or tiles you will need to meet your goals.

Calculating your consumption

According to government data from 2012, the average UK homes used 4,100 kilowatt hours (kWh) of electricity a year. Your own consumption will, of course, depend on the types and size of your property, how many people live there, the kinds of appliances and devices you use and number of other factors. If you are adding photovoltaics to your current home, you should be able to get a pretty accurate idea of your current usage, but if you are building a new home or carrying out other improvements to your existing home you will have to rely on an estimate.

Installers should be able to help you make a reasonable estimate of your properties energy needs, but in order to do this as accurately as possible you need to have as much information as you can for them. This includes details such as the square footage of your house, type of heating system and the sorts of insulation and windows you are using. This will all help them to make a realistic calculation of your likely energy usage and allow you to adjust your photovoltaic requirements accordingly.

Feed-in Tariffs

One of the most attractive things about installing domestic solar energy generating technology at the moment is that your electricity supplier will actually pay you for the power you generate. This is part of a government scheme called Feed-in Tariffs (FITs) where your supplier will pay you for ever kilowatt hour of electricity you generate. Therefore, the more solar panels or tiles you have, the more kilowatt hours of electricity you can produce and the more money you will earn.

Other factors which affect how much you can earn through the FIT scheme include the angle of your roof (around 20° is optimal while most UK roofs are about 40°), how much shade your photovoltaics will be exposed to and which direction they face (panels should generally face south, south east or south west). Your FIT payments also depend on how energy efficient your home is, as defined by an Energy Performance Certificate (EPC). This will place you in a certain EPC band, with properties in band E or below earning lower FIT payments.

The Energy Saving Trust’s Solar Energy Calculator will allow you to work out how much income you are likely to generate from your solar panels or tiles.

Please note: in order to qualify you have to use a FITs-licensed supplier and both the products you use and your installer must be certified by the Microgeneration Certification Scheme.

Metrotile supply a wide range of photovoltaic roof tiles and panels worldwide. Our team are always on hand to offer advice about individual projects, so if you would like to know more or to find out about our prices, call 01249 658 514 today or fill out our contact form for a swift response.