The number of data centres in the UK is set to increase by almost a fifth, according to figures shared with BBC News.

Data centres are giant warehouses full of powerful computers used to run digital services from movie streaming to online banking – there are currently an estimated 477 of them in the UK.

Construction researchers Barbour ABI have analysed planning documents and say that number is set to jump by almost 100, as the growth in artificial intelligence (AI) increases the need for processing power.

The majority are due to be built in the next five years. However, there are concerns about the huge amount of energy and water the new data centres will consume.

Some experts have warned it could drive up prices paid by consumers.

More than half of the new data centres would be in London and neighbouring counties.

Many are privately funded by US tech giants such as Google and Microsoft and major investment firms.

A further nine are planned in Wales, one in Scotland, five in Greater Manchester and a handful in other parts of the UK, the data shows.

While the new data centres are mostly due for completion by 2030, the biggest single one planned would come later – a £10bn AI data centre in Blyth, near Newcastle, for the American private investment and wealth management company Blackstone Group.

It would involve building 10 giant buildings covering 540,000 square metres – the size of several large shopping centres – on the site of the former Blyth Power Station.

Work is set to begin in 2031 and last for more than three years.

Microsoft is planning four new data centres in the UK at a total cost of £330m, with an estimated completion between 2027 and 2029 – two in the Leeds area, one near Newport in Wales, and a five-storey site in Acton, north-west London.

And Google is building a data centre in Hertfordshire, an investment worth £740m, which it says will use air to cool its servers rather than water.

By some analyses, the UK is already the third-largest nation for data centres behind the US and Germany.

The government has made clear it believes data centres are central to the UK’s economic future – designating them critical national infrastructure.

But there are concerns about their impact, including the potential knock-on effect on people’s energy bills.

It is not known what the energy consumption of the new centres will be as this data is not included in the planning applications, but US data suggests they can be considerably more powerful than older ones.

Dr Sasha Luccioni, AI and climate lead at machine learning firm Hugging Face, explains that in the US “average citizens in places like Ohio are seeing their monthly bills go up by $20 (£15) because of data centres”.

She said the timeline for the new data centres in the UK was “aggressive” and called for “mechanisms for companies to pay the price for extra energy to power data centres – not consumers”.

According to the National Energy System Operator, NESO, the projected growth of data centres in Great Britain could “add up to 71 TWh of electricity demand” in the next 25 years, which it says redoubles the need for clean power – such as offshore wind.

Bruce Owen, regional president of data centre operator Equinix, said the UK’s high energy costs, as well as concerns around lengthy planning processes, were prompting some operators to consider building elsewhere.

“If I want to build a new data centre here within the UK, we’re talking five to seven years before I even have planning permission or access to power in order to do that,” he told BBC Radio 4’s Today programme.

“So you’re starting to see some of these AI workloads move into other countries, where the UK has always been a very important hub.”

UK deputy prime minister Angela Rayner has overturned some local councils’ rejection of planning permission for data centres, citing their importance to the country’s infrastructure and the government’s growth push.

There are also growing concerns about the environmental impact of these enormous buildings.

Many existing data centre plants require large quantities of water to prevent them from overheating – and most current owners do not share data about their water consumption.

Stephen Hone, chief executive of industry body the Data Centre Alliance, says “ensuring there is enough water and electricity powering data centres isn’t something the industry can solve on its own”.

But he insisted “data centres are fixated with becoming as sustainable as possible”, such as through dry-cooling methods.

Such promises of future solutions have failed to appease some.

In Potters Bar, Hertfordshire, residents are objecting to the construction of a £3.8bn cloud and AI centre on greenbelt land, describing the area as the “lungs” of their home.

And in Dublin there is currently a moratorium on the building of any new data centres because of the strain existing ones have placed on Ireland’s national electricity provider.

In 2023 they accounted for one fifth of the country’s energy demand.

Last month, Anglian Water objected to plans for a 435-acre data centre site in North Lincolnshire. The developer says it aims to deploy “closed loop” cooling systems which would not place a strain on the water supply.

The planning documents suggest that 28 of the new data centres would be likely to be serviced by troubled Thames Water, including 14 more in Slough, which has already been described as having Europe’s largest cluster of the buildings.

The BBC understands Thames Water was talking to the government earlier this year about the challenge of water demand in relation to data centres and how it can be mitigated.

Water UK, the trade body for all water firms, said it “desperately” wants to supply the centres but “planning hurdles” need to be cleared more quickly.

Ten new reservoirs are being built in Lincolnshire, the West Midlands and south-east England.

A spokesperson for the UK government said data centres were “essential” and an AI Energy Council had been established to make sure supply can meet demand, alongside £104bn in water infrastructure investment.

Additional reporting by Tommy Lumby