FAQs

Q?

Do I need planning permission for solar panels?

A.

No planning permission is required for solar panels systems below 12m2 in surface area – the typical system would come in under 6m2. If you have any questions about planning contact your local county council and they will let you know if there are any requirements

Q?

What is the warranty on Solar Panels?

A.

What warranty is there on solar panels? This is the most common question we get on our Solar Panel FAQ after cost! We mainly supply the premium Kingspan solar panels and to go with their quality build they have a quality warranty - at 20 years! This warranty is on their solar tubes if installed by a registered solar panel installer. All Flat Plate solar panels have a 10 year warranty All other components are guaranteed for the manufacturer guarantee period.

Q?

What size solar cylinder should I fit with my solar panels?

A.

The size of the cylinder is very important as it is really the heart of your solar panel system. Sizing it according to your needs is important but standard sizes typically get you what you need. The sizings below are for standard south facing roof mounted systems. If you go east-west an extra panel is usually required. Let us know and we can tell you exactly what your options are.

Evacuated Tube Solar Panels:
20 tube solar panel will heat a 200L cylinder
30 tube solar panel will heat a 300L cylinder
40 tube solar panel will heat a 400L cylinder

Flat Plate Solar Panels:
4m2 of Flat Plate solar panels will heat 200L
6m2 of Flat Plate solar panels will heat 300L
8m2 of Flat Plate solar panels will heat 400L

Larger cylinders can be heated with 2 or more panels, and it is possible to add an extra panel to benefit from higher temperatures in the winter. In fact, if you fit a smaller cylinder, you will have hotter water, but of course less of it.

An interesting and popular option is to put a smaller cylinder in and set the controller to allow this cylinder rise to 75 degrees – but we recommend you fit a solar Heat Dump to dissipate excess heat in the summer and a thermostatic mixing valve on the outlet to bring the temperature back down and prevent scalding. This increases the effective heat storage and at the same time, on partially cloudy days you are more likely to have water at an acceptably high temperature

Q?

What is the output of solar panels in terms of kWh?

A.

This varies according to the time of year – in summer we get almost 10times the amount of solar energy that we do in the winter. On standard systems in the summer, you can expect to get about 6kWh of heat per day from 20 tube solar panels for example, whereas in December you can expect only 0.6kWh per day on average. But even in the winter, it is possible to preheat the water to 40C or more if the sun comes out.  In fact, if you fit multiple solar panels, it is possible to heat your hot water to 100C in January.

Q?

How hot will the water get from solar panels?

A.

This depends on the size of the solar cylinder you chose, and the amount of hot water you use a day. A smaller solar cylinder will be heated to higher temperatures by solar panels, whereas a larger cylinder will heat more water, but not to the same extent. Systems are generally designed to heat water to 65C or so, although during the winter, it will be necessary to ‘top-up’ the heat on less sunny days.

Q?

Where do solar panels need placing and at what angle?

A.

Solar Panels should be sited on a south facing wall or roof. In fact, anywhere between South-West and South East will give good results. If you have an East-West facing solar system you will typically need to increase the size of your solar panels array by 30% at least to provide the same amount of hot water as a south-facing roof slope.

Solar panels  will operate anywhere between 15 and 90 degrees angle of inclination.  The pitch of an average house roof is somewhere between 30 and 50 degrees so most people simply settle for whatever angle their roof slope is. The extra cost of trying to stand panels off the roof to achieve better efficiency would probably be better spent on purchasing a second panel!

Q?

Are spare tubes for my solar panels available?

A.

Yes, spares for solar panels are always available fro Glenergy, should you need them. With no moving parts, it is very unlikely that you will need to replace anything, but occasionally tubes break.. You can purchase a modestly-priced replacement. However, it is not possible to post a replacement solar tube, so you will need to collect it. The tubes are very tough when in situ on a roof but need to be transported with care.

Q?

How much maintenance do solar panels require?

A.

We recommend servicing your solar panels every 3 - 5 years.  This is to ensure you get the most out of your system.  Other wise very little maintenance is required for solar panels on water heating systems. You should occasionally check the system pressure, to make sure there has been no water loss, and to check for any air in the system. The only other requirement is to ensure that there is an electricity supply connected at all times, otherwise without pump circulation, in strong sunshine, the panel could overheat, and start to boil off water.