The value of the Queen's so-called "sea-bed rights" surged to £5bn on the back of record prices for offshore wind farms.
The crown estate, which generates money for the UK Treasury and the royal family, is now valued at £15.6bn, an increase of 8.3%, swelled by the first auction of its seabed licences in 10-years.
As a result, profits at the estate, which includes everything from thousands of miles of UK coastline to the country's most desirable properties, jumped £43.4m to £312.7m in the year to the end of March, according to the Guardian.
Queen Elizabeth II is known as one of the largest landowners in the world. But her holdings also include most of the seabed encircling the UK, out to 12 nautical miles from shore, National Geographic said.
The estate awarded licences for six offshore windfarms off the coast of England and Wales, which could generate up to £9bn over the next 10 years.
The successful bidders included Germany’s RWE (ETR:RWE) Renewables, which won two licences at Dogger Bank, off the Yorkshire coast, and two from a consortium which includes the oil company BP, which is also investing in renewable energy.
Though all of the projects have yet to be approved by the government, based on independent appraisals of their potential earnings, the crown estate's marine business was valued at £5bn, up 22% on last year.
The windfarms could be able to supply electricity to 7mln homes.
As part of the Crown's drive to generate income, it plans to license renewable energy projects such as windfarms in shallow waters, carbon capture storage, and leasing floating wind farms.
A floating windfarm planned for the Celtic Sea is expected to generate up to 4GW of energy.
Crown estate profits are handed to the Treasury before 25% of them are returned to the royal household as the sovereign grant - a funding formula that is under review by the government.
The sovereign grant was raised from 15% in 2017 to cover extensive renovations at Buckingham Palace.