The price of solar panels is falling and the price of electricity is rising. This is good news for solar electricity in homes, businesses, caravans, canal boats. Here are a few things you should think about before you invest in solar electricity in your home or business.
- How much electricity do you use? An average household uses 3,600 kWh a year, or 36 kWh per square metre a year. If you are using less than this then solar electricity is less likely to be a viable investment (at the time of writing – August 2021).
- What time of the day or night does your building use electricity? If there is daytime electricity use then solar might work for you. If your electricity use is mostly at night, then it might not be worth it. You can store solar electricity in a battery for use at night, but only if you use electricity at night.
- Remember that common household appliances such as fridges, washing machines, TVs, computers, kettles are becoming more and more efficient and need less electricity. The appliances in use in a typical household might not use enough electricity to make solar electricity worthwhile. There is no public subsidy for solar electricity and so correct design of your solar system is key to making it financially viable. The days when people put solar panels on roofs willy-nilly are over.
- There are certain appliances that you might have in your home or business that will take your electricity consumption well above the average household use of 3,600 kWh a year. An immersion heater can use several thousand kWh a year; a heat pump will use at least 5,000; air conditioning will use several thousand; an electric vehicle will use at least 2,000 kWh a year. If you have any of these appliances, then solar electricity becomes more viable. You can make the most of the sunniest times of the day to store water in an immersion heater or heat pump; in an electric vehicle battery, plus of course air conditioning uses most electricity when the sun is shining.
- If you use a gas or oil boiler, or immersion heater, for hot water, then solar thermal is an alternative to solar electricity. If you use a lot of hot water, for catering, washing, showers, or manufacturing processes, then solar thermal could work for you.
- You will need a south-facing pitched roof ideally; solar can also work on flat roofs or south-facing walls. With solar electricity you will usually need a modern electricity meter and consumer unit; and space for a battery if necessary. If you are having solar thermal you will need an airing cupboard sized space for a hot water cylinder.
Solar energy in the right building gives you cost-effective reductions in greenhouse gas emissions. In some circumstances it will also be cheaper than fossil fuels. You should consider solar energy as part of a whole-building approach to energy saving. Even if solar doesn’t work in your building, there is always something you can do.
If you need expert advice on energy saving in your home or business, check out my energy advice packages. If you are within 50 miles of Birmingham, you will get a site visit, a thermal imaging survey and a comprehensive written report that includes a costed assessment of the suitability of solar electricity for your building. I will also show you what to look for when you are choosing solar products and installers, and help you to interpret quotes you receive from installers.