For people planning to install solar photovoltaic (PV) panels, there are a number of factors which will influence the cost of installation and the size of any savings they are likely to generate. There are a number of online solar PV calculators which can be used by prospective purchasers to gauge the overall cost effectiveness of such a system and these are offered by suppliers of solar panels, as well as on independent websites.
Some calculators are more sophisticated than others and are able to analyse the information from a greater number of variables. For instance, some calculators will be able to factor in issues such as the pitch of your roof and where in the country your installation is based. Some calculators include an environmental impact calculation which allows you to show the reduction in your carbon footprint over the life of the installation. When calculating the rate of return of installing solar panels on the roof, all calculators make the assumption that you will use a company which is certified under the Microgeneration Certification Scheme as this is a requirement for anyone wanting to claim Feed-In Tariffs.
What Information Will I Need?
If you want to use a solar PV calculator, you will need to gather some information in advance to be able to generate an accurate result. For the most basic sites, the information you will need will include your postcode, the direction in which your roof faces and how much space is available for panels. For some calculators, you will also need to know the pitch of your roof. The more accurate the information you supply, the more accurate the results will be. Sites will then usually calculate how long it will take for the cost of the panels to be recouped, the profit over twenty five years and the rate of return. Some sites will also give you a number of scenarios based on the cost and efficiency of a number of different panels. However, calculators will base their results on a number of assumptions which will affect their overall accuracy as bill reductions will depend on your current electricity usage and tariff.
Which Solar Calculator to Use?
Providers of solar PV calculators include the Centre for Alternative Technology which offers an environmental impact calculation, as well as the financial calculator. Solar Guide’s website gives a number of calculations including the earliest payback, the greatest payback and the greatest annual income. This site also allows adjustment for the assumption about the inverter or cable loss, the annual energy price inflation and panel degradation. If your installation site has significant shade coverage, you can choose a calculator such as that provided by Solar Insiders as this includes the ability to factor in how the shade will affect the savings and income generated by the installation. If you opt to invest in solar trackers, which allow the panels to move and follow the sun during the day, then the calculator may underestimate the efficiency of the system.