Installing solar photovoltaic cells produces clean, renewable energy, and can result in financial benefits by saving money that would otherwise have been spent on electricity from the power grid. Solar systems that produce a surplus amount of electricity also afford owners the opportunity to sell extra electricity back to the power grid. In addition, the UK’s Feed-In Tariff scheme offsets the costs of installation by rewarding renewable energy system owners with payments from their energy provider.
The only costs associated with solar power are those required for the purchase and installation of the photovoltaic cells. Installing a larger system will cost more, but also has the potential for greater savings in the future. Larger systems are also usually more cost effective than systems smaller than 4kWp (kilowatts peak). Photovoltaic panels are less expensive than photovoltaic tiles, which are usually installed for aesthetic reasons, but for both systems costs will be higher when the cells are built into a roof, rather than sitting atop it.
After installation, a solar system operates with little to no upkeep costs, as the panels simply need to be kept free of debris to produce electricity. By keeping solar panels off the ground, debris can be kept off the panels. Mounting panels at an angle greater than 15 degrees will have the added benefit of cleaning the panels via rainfall, which will keep them more efficient at producing electricity.
Solar energy systems are measured in kilowatts peak (kWp). The kWp of a solar cell is the amount of energy it produces when exposed to a maximum amount of direct sunlight during the summer. Most domestic photovoltaic systems are 4kWp systems, yet the production of a system will vary depending on the amount of sunlight the system actually receives. 4kWp systems in England and Wales will produce roughly 3,800 kilowatt hours of electricity annually. The same size system in Scotland or Northern Ireland will produce roughly 3,100 or 3,400 kilowatt hours of electricity respectively. A typical household in England or Wales will use roughly 3,800 kilowatt hours of electricity every year, while a typical household in Northern Ireland will use roughly 3,400 kilowatt hours of electricity every year. In Scotland, a typical household will use more electricity, roughly 4,000 kilowatt hours, meaning that a 4kWp solar system there will produce slightly over 75% of a household’s electricity needs (3,100 kilowatt hours).
Based on the figures above, households in England and Wales, Scotland, and Northern Ireland will receive varying annual benefits. Unless registered before 31st March 2014, households in England and Wales will experience a benefit of roughly £770 per year. Households in Scotland and Northern Ireland will benefit £640 and £750 per year respectively. For systems in England and Wales registered on or before 31st March 2014, the benefit per year will be roughly £785. For systems in Scotland registered on or before 31st March 2014, the benefit per year will be roughly £655. To find a more specific financial benefit of a solar power system for one’s household, homeowners should use the Solar Energy Calculator provided by the Energy Saving Trust.