After deliberating since January 13, the Court of Appeal has today ruled that the Department of Energy and Climate Change (DECC) did indeed act unlawfully. As a result, DECC has lost its appeal, meaning the feed-in tariff will now go back to 43.3p for <4kW systems installed until March 3, 2012.

The three Lords Justices of Appeal announced their reserved judgment this morning following a hearing on January 13.

The court judgement means customers who have installed solar since December 12, and those who intend to install systems before the March 3 cut-off point, will receive the higher feed-in tariff rates for the full 25 years. However, customers who register on or after March 3 will qualify for the current higher rate until April 1, when the FiT will drop to the lower rates, as set out in the October 31 announcement.

Commenting on the decision, Daniel Green, CEO of HomeSun, said: “Four judges, including three in the Court of Appeal, have now called the Government’s actions illegal. That’s a four-nil victory and a decisive ruling that Government may not make retrospective changes to the FiT because, as Lord Justice Moses concludes, to do so ‘would be to take away an existing entitlement without statutory authority.’”

“Both this appeal and the Judicial Review in The High Court would not have been required had DECC simply followed its own process and allowed the industry, that it claims to support, time to prepare for a lower feed-in tariff,” continued Green.

Tweeting post judgement, Greg Barker, Minister of State for Energy and Climate Change, said, “Win, lose or draw today, important we move forward together, drive down costs + step up deployment.”

Clare King, a renewable energy lawyer at Osborne Clarke, said: “This decision will be a surprise to many observers. We, like many others, will be studying the judgment closely so as to fully understand the implications for the UK solar industry.”

It is currently unclear whether Government will appeal to the Supreme Court.