The UK government could trigger a ‘hyperdegression’ in the rooftop solar feed-in tariff by pursuing  its ambitious targets of installing 500MW of solar capacity on the roofs of government-owned estate, Savills Energy director Giles Hanglin has warned.

Speaking on a panel discussing the rooftop market at today’s Large-Scale Solar UK event, Hanglin said that if the government was to install that capacity by the end of the year as expected, the UK’s rooftop market could be hit by a similar feed-in tariff (FiT) degression to that recently recorded by the ground-mount sector.

Higher than expected activity in ground-mounted developments built under the FiTs in the first three months of 2015 has triggered a degression rate of 28%, meaning that as of 1 July the FiT for such projects will fall from 6.16p/kWh to 4.43p/kWh.

The industry has warned that such a drop in the feed-in tariff would create an era of ‘hyperdegression’ and speaking on today’s panel, Hanglin warned that it could result in rooftop installers cutting corners and risking health and safety in the rush to meet deadlines.

Hanglin added that the industry would need to make the government aware of the pressures such a degression would cause, with one possible option to be for the government to stagger its roll-out program.

SunEdison’s Alex Goodall condemned the government’s “use of taxpayer money” to fill-out capacity and receive subsidies for rooftop installations on government estate, adding that he hoped there would be a push for the government to employ UK-based companies somewhere in the supply chain.