Detached property, hosted by David

The panels were part of a larger project to do our bit to reduce our use of fossil fuels. We already have an electric car and a hybrid car, but we wanted to get off the gas grid completely. This project would involve a heat pump, PV array and batteries. 

Installation was quite disruptive! However, we were expecting that, and had prepared for it. We had to upgrade about 5 m cold water supply pipe from 15 mm to 22 mm fitted between an existing 22 mm supply on the landing to the airing cupboard. However, the disruption was minimised by having previously used my endoscope through a few exploratory holes drilled in the floorboards from above, and up through spot-light fittings from below, to search out the gauge and route of the existing pipework, so that the installers knew exactly where to cut.

90% of the plumbing in the airing cupboard needed replacing to accommodate the modern, stainless steel, pressurised hot tank with all its associated buffer, pressure vessels, etc. There was a problem locating the return from radiators which required additional and unexpected routing of pipes from the tank, up into the loft, across to the master bedroom, then down through the back of a cupboard where they also ran parallel with the solar array string cables descending to the garage beneath. We also needed 11 radiators upgraded to bring all our rooms up to 3* rating in order to qualify for the £7,500 government grant. The fitting of the pump itself was not at all disruptive, nor the panels, since that was all outside.

 

There were often 4 men working on all these and we had several outside doors permanently open, so we were glad of the wood-burner in the lounge which was kept going every day for about a week while we had no heating. It was November! But the installers ensured that we were never without hot water, even on the day the tank was changed. Step-off, disposable flooring was used throughout to minimise dirt from feet.

 

The electrical side was mostly on the roof and in the garage, so it affected us very little, except for the day the batteries were unpacked when we couldn’t move in the garage because of the amount of discarded packing materials!

 

One significant challenge here was the scaffolding on East and West sides of the house and the amount of moss that was dislodged from the roof. A big clear-up operation was needed gathering several buckets of moss from gutters before, and extensive window cleaning after, the scaffolding was removed. 

 

All the renewables were installed over a 2-week period which extended into a third, and the scaffolding was not off-site until the end of that week. So, it was significant disruption for about 3 weeks. But then you have to take into account we have a big pump (14 kW), tank (290l), and a big array (34 panels), 54 kWh battery bank and 3-input string inverter.

It's a different mindset to heating, using only a small difference between day and night-time room temperatures. However, the system has worked very well and we are well pleased. In combination with the solar and storage, the heating and hot water have supplied us very well, even in the sub-zero external conditions in winter. 
A full year April '24-March '25, fully settled down with Octopus, we were net exporting from 1/4/24-23/9/24, and again from 18/3/25. But with the £450 export credit accrued over the summer we didn't actually pay anything until January. Our final annual bill was £350.