Having been through the process and making several mistakes along the way, these are some of the questions I think you should ask a solar panel installer before agreeing to any work.
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Is the solar panel installer certified?
Needs to be accredited with MCS (Microgeneration Certification Scheme) or a similar scheme. This protects you against faulty work.
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Is a Structural Report included in the quotation?
You need to know that your roof will be able to hold the extra weight and factors have to be taken into account such as rafter size, spacing and wind zones. Some roofs may need strengthening and will add an extra cost to the installation.
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Is a shading analysis included in the quotation?
Neighbouring buildings, large trees and roof orientation can affect the efficiency of the panels. You need to know how much electricity the panels will generate.
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What guarantees are given?
The panels are designed to last 20 years but some installers only offer 10years. The inverter is usually guaranteed for 10 years, this is an important part of the system. Sometimes you can extend the guarantee for this at extra cost.
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What monitoring system is offered?
Most solar systems come with some form of monitoring panel. This may be a static LCD screen attached to your system or an app. The monitoring panel details the amount of energy generated by the solar panels, as well as how much electricity you use and send to the grid. If you have a battery as part of your system it will show the state of charge and battery health. This information will be useful and can be used to compare with the quotation of energy saving given by your installation company.
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Do I have the correct time of electricity meter?
This is potentially the most important question to ask. Get the answer in writing!
You need to have a second generation smart meter (SMETS 2) for any of this to work correctly. If you do not have one you must insist that the meter is changed to a SMETS2 meter immediately.
A SMETS2 meter can accurately measure both incoming and outgoing electrical charge and updates its reading every ½ hour. If you already have solar panels installed at your property and ask your energy provider to upgrade your meter they are not going to rush as they are making free money from your generation going into the grid.
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Do you install solar batteries?
To get the most out of your solar system you will need a battery, especially if you are out at work during the day. If you have a battery the energy produced during the day will be saved to the battery and can be used when the sun goes down. It is surprising how much electricity you will use when cooking the evening meal. The size of the battery is important.
We were persuaded to go for a 5.8kWh battery, even though we said we wanted a 10kWh battery. We think that this was much more to do with the installers stock rather than what was best for us. A 10kWh battery should be able to see you through the evening and night until the next morning sunrise.
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If I get a solar battery, will I be able to force charge my battery from the grid?
To get the most from your solar battery in the winter you will need to be on a variable rate tariff and be able to force charge your battery. During the winter months solar panels rarely fill up your battery or provide enough electricity for your household use (especially if you have electric cars).
Being able to force charge your battery during the night time at a lower price per kw could save you quite a bit of money. The current Octopus Go rates are 30.23p/kWh at standard rate and 7.5p/kwh at off peak. Force charging could potentially save you £2.25 per day on your electricity bills during the winter (based on a 10kWh battery).
Postscripts
This may not be an exhaustive list of all the questions you should ask. But they are the ones we asked, and some we wished we had asked!
If you get a representative to come and visit make sure you have a sheet of paper with your questions on. Write down their answers, ask them to ready over your notes at the end of the meeting and get them to sign that it was an accurate record. What reps say can be substantially different to what the companies put in their small print.
Get three quotes and don’t be pressurised.
And finally, check out their reviews on Google and Trustpilot. If we had it would have saved us a considerable amount of money and hassle!
