Solar energy is fast becoming a popular choice for households looking to invest some cash and cushion themselves from the regular price hikes we all see in our energy bills. With the introduction of the Feed in Tariff (FIT) for those generating electricity and the Renewable Heat Incentive (RHI) for solar thermal on the horizon, the economic viability of solar technology is in a good place.
But before you rush out and sign up with the first installer who comes along, it is worth doing a bit of a personal check to see if your home is suitable for solar. Although most installers will only recommend solar if they think you are going to get a substantial benefit from it, there is no harm doing your homework first and making sure you understand what to expect.
Sarah / CC BY-NC-ND 2.0
Where do you live?
You might have heard that living north of the Midlands means you cannot benefit from solar, but this is fundamentally untrue. Because solar (both photovoltaics and solar thermal) require ambient light to work, you can still gain significant benefits from the technology whether you live in Lands’ End or John O’Groats. There is a difference in daylight hours north to south. Reduced daylight hours and lower levels of solar radiation mean solar may be less efficient in the far north or Scotland. Achieving a return on your investment can take slightly longer but it is very much still an option.
Which way does your home face?
The orientation of your roof is very important in determining the amount of sunshine you receive during the day. The closer your roof is to a southerly orientation, the more efficiently your system will work. Again, that doesn’t mean that if you are in a house which has a west to east facing roof you can’t have solar; just that you need to account for this in your calculations.
How pitched is your roof?
The angle of your pitch is another confounding factor in the efficiency of your panels, but unlike orientation can be rather difficult to measure yourself. The ideal pitch will be between 30 – 45 degrees, but you can still expect good performance from pitches as shallow as 15 degrees or as steep as 50. If you plan to mount your panels on a flat roof, your installer will often be able to use a mounting frame to angle your panel at the perfect pitch.
How strong is your roof?
Solar panels in themselves are not particularly heavy, but if you are considering photovoltaics, then a whole solar array and the mounting frames used can weigh around 275kg. The majority of modern homes will have no issue in supporting this weight, but make sure your installer conducts an integrity survey to make absolutely sure.
How much external space do you have?
For solar thermal, you’ll only need around 4 square metres of unobstructed space to mount the panel. If you are considering PV, it is closer to 10 square metres, about the size of a car parking space. For most homes this won’t be an issue, but check for vents and skylights you might have forgotten about to make sure you have enough space.
How much internal space do you have?
For solar thermal, you’ll need space for a larger than average hot water tank. If you already have a tank, often a solar thermal tank can be installed in that space without too much effort, but if you don’t then you’ll need to allocate a space in the loft, kitchen or garage to accommodate this. For photovoltaics the space requirement is less, as the only bulky piece of internal equipment is the inverter, which requires around a metre squared of room and can normally be accommodated in the loft.
Do you live in the woods?
It might sound like a silly question, but shading of any type can adversely affect the performance of your solar system. For solar thermal it is not such a major problem, as it will only be the shaded section of the panel that is reduced in efficiency. However, with a PV array, if any portion of the array is shaded then the efficiency of the entire system is drastically reduced. Don’t forget that the angle of the sunlight changes over the year, so ask your installer to do a seasonal variation model to see if your roof becomes shaded in the winter.
If, after asking yourself these questions, you think your home will be suitable for solar, it’s time to call in the installers to conduct more detailed investigations. Always choose an installer who is a member of a professional body such as the Solar Trade Association, and get at least three quotes before deciding which company to go with.