Homeowners who installed and registered solar panels before 3 March finally have certainty over the cash they'll earn for generating their own electricity after the Government lost a court battle over the payouts.

The Supreme Court today refused it permission to appeal against a ruling that its solar subsidy cuts were unlawful.

The Department for Energy and Climate Change (DECC) had planned late last year to halve the feed-in tariff for anyone who installed and registered the panels after 12 December 2011, even though a consultation on the plans ran until 23 December 2011.

In December, the High Court ruled these "retrospective" cuts were unlawful. That judgment was upheld by the Court of Appeal in January, so the Government proposed a new 3 March cut-off date.

DECC had applied for permission to take its case to the highest court in the land so it could put the date back to 12 December, but that attempt has now failed.

Energy Minister Ed Davey says: “We are disappointed by the decision of the Supreme Court not to grant permission to hear this case. But the court's decision draws a line under the case.

"We will now focus all our efforts on ensuring the future stability and cost effectiveness of solar and other microgeneration technologies for the many, not the few.”

What will I get paid?

This depends on when the process was completed, with the figures below now final.

  • Before 3 March. Feed-in payments will be 43.3p per kWh.
  • 3 March or later. 21p per kWh, slashing typical earnings and savings from £1,190 to £640 a year.

Andy Atkins, executive director of charity Friends of the Earth, which was jointly responsible for launching the legal challenge, says: "This is the third court that's ruled that botched Government solar plans are illegal – a landmark decision which will prevent Ministers causing industry chaos with similar subsidy cuts in future.

"The coalition must now get on with the urgent task of restoring confidence in UK solar power."