Queen's ‘focus’ on Philip despite Harry’s interview says expert
Despite the eye-watering costs, the Queen’s residences have already begun looking for greener alternatives including energy-efficient LED lighting and using hydroelectric power from the River Thames. The research has been released by price comparison website Uswitch.com, with its calculations based on the assumption that the properties in question are running on domestic tariffs. Buckingham Palace, with its 775 rooms, 77,000 square metres of floor space and swimming pool is estimated to be the most expensive royal residence in the UK, costing £1.1million a year to power.
Uswitch.com have cited energy experts as estimating 200kWh per m2 for an old house, while the average price of gas according to the Energy Saving Trust is 4.17p/kWh.
The average cost of running a swimming pool is estimated at £5,000 a year. The average UK electricity bill is currently £563 each year.
Windsor Castle is estimated to have the next highest energy bill of £393,523, with Kensington Palace third with £260,448.
But despite the eye-watering costs, the Queen is saving 40 percent on her annual electricity bill at her residence of Windsor Castle thanks to a hydroelectric power scheme on the River Thames.
Queen news: The Royal Family have been urged to cut energy costs - but the Queen has saved 40%
Queen news: Her Majesty's residences have already begun looking for greener alternatives
This saves Her Majesty around £262,349 a year, reducing them from a potential bill of £655,872, according to Royal Household and Environment
The Royal Family website says that energy-efficient LED lighting is being trialled across the estate. These lamps use up to 86 percent less electricity and "have a longer life than traditional fittings, reducing energy and maintenance costs".
They are also said to produce less heat than tungsten halogen fittings, "helping to maintain a comfortable environment for The Queen and The Royal Family, guests, residents, staff and the works of art in the Royal Collection".
The Royal Family website says: "Combined Heat and Power has been in use at Buckingham Palace and Windsor Castle since 1994-95.
READ MORE: Furious Queen finally loses patience with Prince Harry
Queen news: Windsor Castle is estimated to have the next highest energy bill of £393,523
"These units convert natural gas into electricity, with the heat produced by this process being used to provide heating and hot water.
"As a result, Combined Heat and Power reduces the Royal Household's greenhouse gas emissions, energy costs and reliance on the National Grid."
The Queen is also due to make Balmoral Castle in Scotland more sustainable, after winning permission for a 2MW hydroelectric turbine to generate £650,000 worth of power.
Any surplus energy will be sent to the National Grid, according to a report in The Daily Telegraph.
Britons BACK Queen as Meghan and Harry row erupts [POLL]
Whisper it quietly but Britain is becoming ASHAMED of the Royal Family [OPINION]
Queen to skirt around inheritance tax through loophole via Charles [INSIGHT]
Queen news: Meghan and Harry's former home is estimated to have the the lowest energy costs of the ten royal homes surveyed
Queen news: Prince Charles has installed solar panels at Clarence House
Balmoral Castle already has one hydroelectric turbine in place, which provides 100kW of power, as reported by The Herald newspaper in Scotland.
Prince Charles, who continues to campaign on environmental issues having done so for several decades, has also installed solar panels at Clarence House, while he also uses low-energy light bulbs and has improved the insulation at his properties, according to the website of the Prince of Wales and Duchess of Cornwall.
Frogmore Cottage, the former home of Prince Harry and Meghan Markle before they moved to the US, is estimated to have the the lowest energy costs of the ten royal homes surveyed at £10,575.
They are also reported to have installed a green energy unit when they lived there to provide eco-friendly heat, hot water and electricity
Queen news: Royal Family UK residences
But Uswitch.com has estimated that moving to their 1,350 square metre home in Santa Barbara has increased Harry and Meghan's energy bills to £12,418 a year because of the cost of air conditioning and operating their swimming pool.
The price comparison website cites the US Energy Information Administration estimating that four percent of domestic energy use in California is for air conditioning, 25 percent for water heating, 27 percent for space heating, and 44 percent for appliances, electronics and lighting.
It added that assuming that water heating and space heating use gas, and air conditioning and other appliances use electricity, this equates to the average domestic energy bill comprising 38.4 percent gas and 61.6 percent electricity.
Sarah Broomfield, energy expert at Uswitch.com, said “The Royal Family have gone to great lengths to make their palaces and castles more sustainable, but the age and size of these homes mean they still require a lot of energy to run.
“Whatever type of home you live in, palace or not, there are lots of ways to keep our energy consumption down.
“Turning off lights when you leave the room, turning off appliances at the plug when they’re not in use, and adding draught-proofing are small changes that can all add up to big savings on your energy bills.
“Switching tariffs is another great way to keep those utility bills down.
"If you’re on a standard variable tariff, you can save money by switching, so it is always worthwhile doing a search online and comparing energy deals.”
Buckingham Palace declined to comment when contacted by Express.co.uk.