Living with Solar: part 2
The Installation
Getting the system installed by a professional installer was straightforward. These are the steps involved.
Outline design
You should contact several installers — I recommend at least three. Ensure they are registered with the relevant trade bodies, such as the Renewable Energy Consumer Code.
Tell them your outline requirements and get them to provide an indicative quote for the system cost.
Installers can quickly look at your property’s roof elevation on Google Earth and make a good estimate of how many panels can fit. If you already have an idea how many you think will fit, perhaps because a neighbour in a similar house already has a system, let them know. Also say if you want batteries, or any other specific features like an EV charger. (In part 4 I’ll discuss the available options and how they affect the price).
Talk to them on the phone, take the opportunity to ask any questions you have, and ask about installation lead times.
One of the installers I talked to — the one who eventually got my business — used a computer package to create a detailed PDF design document, which included things like the sun’s path across the sky at my location, predicted system yields, and system payback time.
Another installer took several weeks to get back to me with just a basic cost figure for panels only. Another one quoted me for a Tesla Powerwall-based system, with a price tag almost double what I ended up paying.
It definitely pays to shop around to find the system that suits you best, and an installer who is responsive.
Survey
Once you have chosen your installer, they will visit your property to inspect and measure your roof, look for obstructions, check how your existing electrics are laid out, and discuss with you details such as the best place to install the inverter. This is another opportunity to discuss any questions you have with the surveyor.
After this, the design and the quotation can be finalised, and you will likely have to sign contracts and pay a deposit before proceeding.
DNO application
In the UK, microgeneration systems with a capacity of more than 3.68kW (e.g. 4kW of panels with a 92% efficient inverter) are required to get approval from the Distribution Network Operator before connection, to ensure that the local power network is not overloaded.
The application will be made on your behalf by your installer, but you will have to sign and submit the documents. This can take 4 to 6 weeks.
I was told that in the unlikely event that the DNO did not approve the application, a clamp dummy load would be fitted to limit the amount of power which could be exported to the grid (at no cost to myself).
Installation
Installation can be completed in a day, although in my case it wasn’t.
I was visited by two teams of two people. The first team fitted the panels to the roof. They installed the mounting system, which consisted of brackets that screwed into the roof rafters, and replaced some tiles with rubber ones for the brackets to rest on.
Here they are part way through mounting 6 panels to one roof surface: the brackets and supporting rubber tiles are clearly visible.
They also fitted another 8 panels to a roof surface further back along the house, the optimizers (which clip into place behind the panels), and the bird netting. The whole job was completed in a morning.
The second team were the electricians, who were delayed by an earlier job over-running, and didn’t arrive until 3pm. They got the inverter and batteries in place that afternoon, but had to come back the next day to wire everything up and sort out some problems.
By about 2.30pm on the second day, I was generating electricity!
In part 3, I’ll show what these graphs mean — and how they showed me that the system had a problem.
