Heat, extracted from the waters of the Clyde via giant water-source heat pumps, is one of the key elements in Glasgow City Council’s plan to bring heat to 66% of households via district heating. Water-source heat pumps are also integral to many other local authority plans.

But the expert behind the pioneering water-source heat pump network that heats homes in West Dunbartonshire's  Queens Quay, says that the cost of electricity means that it is “not financially viable to repeat that project”.

“There is,” said Dave Pearson, sustainability director at  Star Refrigeration which  installed the Queens Quay pump, “more heat in the Clyde than is required to heat Glasgow.

"But the electricity cost to run big heat pumps is so bloated compared to the cost to make electricity from wind farms.

“The UK Government has created a pricing model for electricity which is counter-productive to their own decarbonisation with electrification policies”.

Mr Pearson pointed out that it is 7p/kWh to make electricity as a wind farm but“more than 30p/kWh to "buy it two miles down the road". "That’s crazy," he added, "when you think of that versus gas at 7p/kWh.”

But the potential of combining windfarm electricity with industrial-sized clean heat pumps, he noted, is huge and could result not only in decarbonised heat, but also "less wasted electricity, less cost to balance the grid, cleaner air and a huge tax revenue boost”.

Certain  areas will lend themself best to such networks. These are, said Mr Pearson: “Any area with big enough buildings (three-storey or more) and within a neighbourhood (not a solo house on a hill) will find the lowest cost of decarbonisation would be to join a heat network.”

The Herald: Queens Quay energy project at ClydebankQueens Quay energy project at Clydebank (Image: Star Refrigeration)

But the huge power of heat networks can only be realised, he said, if the issues around cost of electricity are resolved.

The Queens Quay project went online in November 2020 and supplies heat to council offices, the Titan Enterprise Centre, Clydebank Leisure Centre and Queens Quay House Care Home as well as  a social housing development and the new Clydebank Health Centre, 

It is also not only the Clyde that could deliver such heat. Many cities and neighbourhoods, Mr Peerson noted, could generate heat from bodies of water, since “over 80% of Scotland’s heat demand is within 1000m of open water”.

Among the virtues of water-source heat pumps, he said, is that the heat is "easy to get at". “It’s not as warm as other sources, but it is less risky, which is what developers want. So don’t go digging holes and opting for geothermal if you have a big river nearby."

He added: “Some sources of heat get overblown because they are whacky or trendy or being pushed by vested interests ahead of more mundane but viable options. ‘Keep it simple’ is a good mantra.”

READ MORE: The Scottish council plans for heat pump and district heating networks

READ MORE: Glasgow council heat pump and heat networks plan revealed

Already Scotland is home to many district heating networks, but most of them are powered by fossil fuels. “We are slowly,” Mr Pearson said, “stopping doing the wrong sort of district heating- broadly speaking burning stuff, especially fossil fuels. But even Energy from waste is being seen for what it is: burning second-hand fossil fuels in the form of trash.”

Politicians, Mr Pearson said, have yet to fully embrace and enable this potential - which reaches beyond heating itself. 

He said: “Sir Keir Starmer (and most of the other politicians) are still arguing the toss over how much the government will have to spend or choose to spend on green infrastructure. They have it around the wrong way. The question should be: How much tax revenue will they earn and how much expenditure will they save if they create policies that see pension funds invest in green infrastructure?”

To enable a transition to heat networks Mr Pearson is calling for politicians to enable the following; “Demand certainty, which will come from the Local Heating and Energy Efficiency Strategies, as long as there is a sensible price of heat dictated.

"Currently there isn’t and there is no obligation on even the public sector buildings to join district heating if offered to them. However, it is impossible to offer a sensible price of heat until electricity pricing is sensible.

"It will only be viable to deploy clean district heating if the price of electricity is rationalised. It would need to be about 10p/kWh to make the price of heat about 7p/kWh (roughly cost of gas).”

He added: “Get both windfarms and big heat pumps right and you drop billions of pounds into the Scottish economy. I’m seeing enough signs to be optimistic but enough slow progress to think we will blow it.”

Helen Melone, Senior Policy Manager at Scottish Renewables, said:  “At a time where the heating of buildings makes up 50.6% of Scotland’s energy use and heat has been described as one of the most difficult sectors to decarbonise, the rapid deployment of heat networks, an enabler of low-carbon heat, will be critical to help us meet our climate change targets.

“However, many heat network developers are put off from investing in this infrastructure due to the high cost of electricity to run heat pumps. Closing the cost between heating with gas and heating with electricity is a challenge facing all of the UK but one that needs addressed urgently if we are to meet our challenging climate change targets.”

A Department for Energy Security and Net Zero spokesperson said: “Our plans to Power Up Britian include rebalancing gas and electricity costs, so even more consumers can make the switch to cheaper and more energy efficient green products, like heat pumps.”

"We are continuing to develop our approach and the potential impacts of rebalancing across technologies and consumers are being fully considered. We will provide further information in the coming year.”