Solar panels#

Photovoltaic (PV) solar panels generate electricity for you to use in your building, either immediately or by storing it in a battery, or for you to sell to the grid. Solar panels can also be used to produce hot water, but most community buildings don’t use enough hot water to make that worthwhile.

Larger installations tend to be cheaper to install per panel, but if you have a high roof, you need to consider the added cost of working at height. You also need to think about the state of your roof. You will need a structural engineer to make sure your roof can hold their weight and to consider whether your current roof covering is secure enough for the solar panels not to cause it problems. Slates are fragile and require maintenance that is more difficult with solar panels in place.Also, solar panels can change the flow of rainfall and might require some changes to water clearance arrangements. Dormers, steeples, chimneys, skylights, and ventilation stacks can all get in the way and make an installation more complicated.

The ideal roofs for solar panels face south and have a 30 degree slope - the steeper the roof, the more important it is that it faces the right direction. Shading will reduce the output of solar panels, so it’s important to keep in mind that trees grow and new buildings might go up during their 25 year lifespan.

If you have a suitable roof for solar panels but would struggle to raise the cost of installation, there are solar cooperatives that might be willing to take the project on.

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Generation technology is starting to be integrated straight into slates that can be made integral to your roof. They’re shinier than normal slates, but Historic Environment Scotland has commented that they are perfectly acceptable on some listed buildings, as long as there’s nothing particularly special about the roof. It’s hard to know whether to recommend them. Like most new technologies, they have a reputation for teething problems. In this case, it’s water ingress. Some countries have better technology than others, and we don’t know the situation in the UK. If you think you may need to replace your roof at some point anyway, this is a technology to watch.

Sometimes community groups are very keen on solar panels, but have difficult roofs. Ground-mounting the panels is more expensive than on a normal roof, but bypasses that problem. Some churches in North America are starting to put them in their grounds instead, for instance, in graveyards. Sometimes the panels look a lot like the roof ones, and sometimes they are on mounted on poles. Occasionally they are built into garden features. It’s important to think about flooding and vandalism if you are considering this option.

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