During 2011-12 Suffolk county council ran a project called SABRE (Suport and Advice to Businesses around Renewale Energy). Claydon Court was subject to a free feasibility review offered by this scheme but none of the proposed options were fit enough to be invested in at the time. Four years have since passed, so we thought we’d update the solar panel feasibility in current circumstances.
First, a quick summary of SABRE’s 2011 recommendations. They reckoned there was space for a 4kW solar system – a more or less standard domestic sized system. The up-front cost of this would have been £7,000 in total including labour, the panels, cabling and an inverter with a pay back period of 9.1 years given the feed-in tariff at that time.
We called some suppliers for up-to-date prices on fully installed systems. Prices varied not only due to different suppliers and panel manufacturer but also the type of ‘inverter’ you use. If you elect to use a micro-inverter, you allegedly spend more on up-front investment but improve the efficiency of your panels.
Generally the costs ranged between £5500 – 6500, which if you went with the lower of the suppliers would be a considerable saving on the 2011 estimated cost.
Interestingly, a quotation from supposedly the same source – the government’s installation advice service called SAP – quote different rates of productivity from the panels. The 2011 estimate was 3,305kWh/ year whilst the latest is 3,433, a negligible difference but an interesting one none the less.
Another factor to consider when costing solar panels is the feed-in-tariff – money paid to the panel owner for every kilowatt hour they generate. In 2011, the feed-in tariff was paid at 16p/ kWh whilst it’s now only 13.39p/ kWh increase the length of the payback period on a set of installed panels.
The final thing to consider on a solar panel investment is the amount of energy that you no longer need to buy from your current supplier. By our calculations, at the current rate this would be £348 per year whilst it would have been £208/ annum in 2011.
Based on these factors, the 2011 quote of a 9.1 year pay back is now down to only 7.4 years before it begins becomes profitable. It’s also worth noting that we calculate a system such as this would prevent 1.8 tonnes of CO2 per year entering the atmosphere as a result of our buildings’ consumption.
All can do now is factor it into our finances and get them installed!