Glasgow's Clyde river could help Scotland lead renewables

The potential for district heating networks in Glasgow is said to be more than twice that of Edinburgh and four times that of Aberdeen.

Glasgow’s heat demand is one fifth that of all Scotland’s settlements put together. At least half of the heat demand could be met by sourcing heat from the River Clyde and its tributaries.

A report by greenspace Scotland suggests the high density of public owned buildings across the city makes it feasible for public assets to act as the first nodes that, over time, become linked together to create a heat network covering much of the city. 

Water is said to be a more efficient heat source than the air or ground. 

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Scotland remains bottom of the European league for renewable heat with just 7% of demand being met from low carbon sources. The cheap price of gas and the fact policy is entirely reserved to Westminster is said to be one of the biggest barriers to an expansion of renewables.

As the host city for the 2021 UN Climate Conference, COP26, experts say Glasgow has the “ambition, political drive, economic strength and cohensive community”to lead the way.

River catchments act as giant solar heat collectors. As these ‘heat highways’ pass through urban areas, some of the heat can be extracted by submerged pipes and boosted in temperature by large scale heat pumps.  

The heat can then be distributed to surrounding buildings through sub-surface pipes known as district heat networks.

Many European countries including Austria use the technology, while in Copenhagen 98 % of all existing buildings are connected to district heating networks.

A £15m water-sourced  system is now operational at the former John Brown shipyard in Clydebank, which is being cleared for thousands of homes.

The system will cut West Dunbartonshire’s CO2 emissions by more than 4,000 tonnes each year for the next 40 years, making Clydebank one of the greenest towns in Scotland and could eventually be used to power the Golden Jubilee hospital.

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“It’s not a new idea," said Dave Pearson, a director of Star Refrigeration Ltd, which was recently involved in a project in Norway.

"It’s just a lot more convenient to burn oil, gas, coal and trees.

"There is about two and half times as much heat in the River Clyde as the entire city centre area need, maybe a bit more.

“We’ve got an air quality crisis and gas is the biggest culprit. The problem with gas is that the particles are very small so they get very deep into people’s lungs and very quickly into the bloodstream and create problems ranging from lung disease, to heart disease and also very worryingly Alzheimer’s.

“Obviously the focus is on transport but the particulates from gas are much much more pervasive, in getting into the body and damaging it. There is no safe lower limit. 

“The running costs (of water power) are probably about 75% of the life-cycle cost of the heat pump so it’s all about how much electricity costs.

"The challenge we have got is the UK has some of the most expensive electricity in Europe and it’s got some of the cheapest gas.

"To a very large extent, created by the government. So they put a lot of tax onto electricity and practically no tax on gas and that has been discussed as needing to change.

Research suggests using urban rivers and greenspaces to generate heat would be the equivalent in reducing harmful emissions of taking 1.7 million cars (or 60% of Scotland’s car fleet) off the road for a year.

Julie Procter, Chief Executive of greenspace scotland said: "Wind turbines are now a familiar sight producing clean, green electricity and Scotland has an enviable track record in shifting to renewable sources of electricity.

"However, we remain bottom of the European league for renewable heat with just 7% of our heat demand being met from low carbon sources.

"The Green Heat in Greenspaces study shows that Scotland has huge natural reserves of heat locked up in its water bodies and greenspaces, yet we have barely scratched the surface in terms of their utilisation.”

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While there is high reliance on gas in towns and cities, experts point towards Fort William in the Highlands, Scotland’s biggest town, which has no supply.  A plan to introduce a mains was rejected last year and there is said to be interest in exploring other sources.

John Maslen, greenspace scotland’s ParkPower Programme manager said: “The Scottish Government have got very limited powers in this areas because the whole gas situation is entirely reserved.

"However keen they are to move policy away from fossil fuels and gas, they are really heavily reliant on what the Westminster government wants to do in this area.

"The Clyde offers the biggest single opportunity largely due to the huge heat demand of Glasgow.  If we could get a large scale scheme going in Glasgow this could have a major impact on Scotland as a whole."

The Scottish Government’s recent draft Heat in Buildings Strategy indicates that to meet 2030 climate change targets the country will need to move one million homes off the mains gas grid, together with 50,000 non-domestic buildings, and convert 167,000 buildings that are currently off the mains gas grid to greener sources of heat.

A government spokesman said: "Heat pumps and heat networks have huge potential to reduce emissions in our homes and buildings by providing more efficient, environmentally-friendly solutions.

"In February, Scotland became the first country in the UK to legislate to support the growth of heat networks. That legislation will help cut emissions, reduce fuel poverty and create green jobs by accelerating the deployment of heat networks.

Councillor Anna Richardson, City Convener for Sustainability & Carbon Reduction at Glasgow City Council, added: “As the world’s attention focuses on Glasgow for COP26 over the coming months, innovative low-carbon heat solutions like this demonstrate how the city can address its 21st Century challenges.”