It says the 133 MWp involved developing and connecting 34 projects to the grid, and entailed an investment of over £180 million.
Based on data published by Bloomberg New Energy Finance, this represents over one third of the 350 MWp of commissioned solar capacity which came on stream in the first quarter.
Nick Boyle, ceo of Lightsource, said: “The tremendous success of the first quarter of 2013 reinforces Lightsource’s position as the leading developer of utility scale solar in the UK.
“It is my firm belief that the UK has one of the most robust solar markets in the world. These results show we are well on track to achieving the government’s target of 22GW installed solar PV by 2020.”
Lightsource works in partnership with Octopus Investments, one of the UK’s largest investors in commercial solar.
Matt Setchell, who heads up the solar team at Octopus, said: “The solar and broader renewables market in the UK is growing rapidly and there continues to be a great opportunity to deliver attractive and stable returns to our investors.
“We look forward to developing our partnership with Lightsource as we continue to grow our portfolio of solar assets and build on the success of our investments to date.”