(Bloomberg) -- The Crown Estate, the property company that generates income for Queen Elizabeth II, returned a record 343.5 million pounds ($437 million) to the U.K. Treasury after a surge in its offshore wind business.

The full opening of the world’s largest offshore wind farm, the Walney Extension in the Irish Sea, helped boost the Crown’s wind capacity to 7.7 gigawatts, up 4% from a year earlier and enough to supply the electricity needs of 6.6 million homes. That helped boost the value of the company’s overall portfolio to 14.3 billion pounds in the year through March.

“Offshore wind has enjoyed an incredibly milestone year,” Crown Estate Chief Executive Officer Alison Nimmo told reporters. “It played a really key role in this year’s financial performance.”

The Crown Estate manages the seabed off England, Wales and Northern Ireland, where thousands of wind turbines are being built as the U.K. seeks to meet some of the toughest climate-change targets in the world. That’s helping the company deliver record returns even as its core property portfolios are buffeted by political and economic uncertainty.

Rent cuts and a handful of store closures by retailers undertaking so-called company voluntary arrangements, a form of bankruptcy protection, cost the Crown Estate about 1 million pounds in rent. That contributed to a 7% fall in the value of its regional portfolio of predominantly retail property, according to a company statement on Tuesday.

“It has been a tough year for retail, particularly outside London,” Nimmo said. “We all know retail is changing and changing fast.”

The Crown Estate’s central London portfolio, which includes the majority of Regent Street and the St. James’s district, also increased office rents and values in the year due to a supply shortage, Chief Investment Officer Paul Clark told reporters.

The company oversees real estate surrendered by the monarchy in 1760 in exchange for annual payments. The U.K. Treasury collects its earnings and provides Queen Elizabeth with a percentage.

To contact the reporter on this story: Jack Sidders in London at jsidders@bloomberg.net

To contact the editors responsible for this story: Shelley Robinson at ssmith118@bloomberg.net, Patrick Henry, James Hertling

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