The new online calculator provides an estimate on the schools maximum potential based on our database of 24,000 schools in the UK and then calculates costs, savings and funding required to achieve them for 3 different system sizes based on expected subsidy levels.
Having used the tool to review a number of schools it becomes quite clear that:
1) The fixed costs of developing and then maintaining a solar panel system means that small system below 10kW are less attractive than larger ones where these costs are spread across more panels. Obviously if the school raises all the capital required from donations, savings will be significant, but less so than if those donations were put towards buying a larger system partly funded by others.
2) Although the next tariff banding is at 50kW and thus the next size to aim for, it usually makes more sense to install a 30kW system as there is no obligation to pay for an export meter so the amount of electricity exported is then ’deemed’ under the subsidy rules to be 50% of the total. As most schools will consume 70-95% of the energy generated by the panels and therefore only export 30% at most, this results in a small uplift in returns. i.e. a rare case of having your cake and eating it!
3) For much larger schools, with roofs capable of more than about 80kWp it only makes sense if either:
The school has a very low cost of capital
Or it can raise significant amounts from donations
Or it has a very large energy consumption
Note that, the drop in subsidy after 50kW needs at least a further 30kW in scale to make up for it.
Our review indicates that schools with good roofs in sunny locations capable of taking a 30kW system and being able to consume at least 95% of the electricity generated from the solar panels can, in most cases, still benefit from an entirely ‘free’ system. The system is funded directly by SolarforSchools in exchange for the school buying the green electricity at the same price as they are currently paying for normal electricity.
In all other cases the school will need to raise some funds from donations or the school can provide some of the investment required itself, in order to contribute to making a better world and educating future generations on living sustainably. If they only raise the minimal amount to fund the system they will not save on electricity costs in the first few years, but as general electricity prices continue to rise faster than the retail price index, which is used to adjust the price paid for the electricity from the panels, the schools will save money over time too. If the schools raise more than the minimum amount to make the project viable, the additional contribution will translate into additional savings from the first year.
Whilst long term savings to the schools will be a fraction of what they would have been for solar pv systems pre-subsidy cuts, if electricity prices rise faster than inflation as expected, schools will still save money in the long term. Of course the educational and environmental benefits remain unchanged and this has always been the main driver for schools to want to go solar in the UK.
The new calculator allows you to see first hand the figures for your school - we know that's a useful tool for every school, as well as ourselves!