We often see housebuilders encounter the same pitfalls when installing solar PV across their sites.
The biggest of these happens when developers choose to install solar PV through mechanical and electrical contractors, who will then subcontract out the installation process to solar specialists. This seems like the simplest solution because developers can put everything through one order with one contractor; but this can cause countless problems.
Secondly, there’s cost; contractors will often add on a much higher margin to existing quoted solar installation, and if they are aligned to a particular solar supplier or technology, they will specify these materials without necessarily taking into consideration whether there’s a better, more cost-effective solution available.
Thirdly, non-solar specialists may not be up to date on the latest technologies and innovations, so if the energy targets presented by a local authority or consultant are inaccurate or out of date or based on old-fashioned panels, the contractor may not realise there’s a better or cheaper solution.
One developer we worked with had given 60 plots with solar PV to a roofing contractor, who installed a clumsy on-roof system that cost more £60,000 more than a more attractive in-roof alternative.
Additionally, there’s the solar supply chain and the numerous issues we see when the chain breaks down. For example, on one site we assisted on where PV was carried out by a roofing contractor, the roofer assumed the developer had completed the application for connection with the National Grid, while the developer assumed it had been done by the electrician, resulting in the Grid refusing connection at the handover stage.
Another point of note is that we have previously seen energy consultants propose systems to be installed in small arrays with very high ballast levels, meaning higher costs and increased loads exceeding structural capacity.
Therefore, it’s essential to use a technology-neutral solar PV specialist who can recommend the best systems for your development and create CAD drawings for your architects, with expertise in meeting energy targets and liaising with the relevant authorities and DNOs, SAP Assessors to remove any pitfalls along the way.