The vast majority of these systems were solar PV panels, which tallies with the government data published so far and backs up reports that the tariffs have proved a much greater success than originally predicted.

The figures were released today as part of Ofgem’s annual round-up of its sustainable development work, Sustainable Development Focus, which was published alongside a set of five green indicators that will be updated throughout the year with new data.

The report also rounds up the energy market regulator’s progress in accelerating the development of supporting infrastructure for green energy over the past 12 months.

In particular, it details how the watchdog’s Revenue= Incentives+ Innovation+ Outputs (RIIO) framework will aim to stimulate the £32bn investment it estimates is needed to update the UK’s networks.

The report said that from 2013 the RIIO will extend price controls to cover eight-year periods, introduce result-based incentives for network operators, and expand the £500m Low Carbon Network Fund to encourage smart grid and energy efficiency programmes.

“This is the biggest change to the regulatory framework for 20 years and sets the network companies on a path to playing their full role in the transition to a low-carbon economy while delivering value for money for all consumers,” chief executive Alistair Buchanan wrote in a foreword to the report.

Ofgem has already authorised more than £300m of funding for transmission network upgrade programmes and also this year concluded the first round of competitive tenders for connecting offshore wind farms under the Offshore Transmission Owners regime.

Three preferred bidders were selected to run the transmission assets for nine wind farm projects, resulting in £1.1bn of investment in transmission links and savings of £350m for offshore wind farm operators and consumers, Ofgem said.

The watchdog also confirmed that a second tender process will be conducted before the end of the year.