WHERE there is waste muck, there is heat. Scientists have long thought they could capture the relative warmth of sewage.

Now engineers in Stirling are getting ready to open the UK’s first low-carbon energy hub which uses waste water.

Scottish Water aims to heat several public buildings, including a school, a leisure centre and a stadium, through a mixture of cutting-edge technologies, including heat pumps, at its sewage works at Forthside.

Their £6 million scheme, which has financial backing from Stirling Council and the Scottish Government, was visited by First Minister Nicola Sturgeon yesterday ahead of its switch-on next month.

Ms Sturgeon said: “Earlier this year Scotland became one of the first countries in the world to acknowledge the fact that we are facing a global climate emergency, and it is only right that we take appropriate action.

“I am proud of the bold, innovative and world-leading policies we are implementing to address the climate crisis we face. The Stirling District Heat Network project is a fantastic example of this, using waste water to help provide energy to local public buildings and businesses.

“It is a great demonstration of how we can work collaboratively to make a real difference.”

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The new energy hub consists of a conventional natural gas combined heat and power (CHP) engine, heat from a waste water heat pump system, thermal stores and back-up gas boilers for the district heating network. The CHP engine generates heat for the public buildings and electricity for the sewage plant and the waste water heat pumps.

The heat from waste water technology, provided by SHARC Energy Systems, uses a heat recovery unit to separate liquid and solid waste, which is returned to the treatment process.

A heat exchanger transfers the heat from the waste water to the clean water using a closed loop system.

A heat pump increases the temperature of the water, which is then delivered to the district heat network.

The average temperature of the heat in waste water is between 15 and 21 degrees centigrade.

The heating network will include the Peak Leisure Centre, Forthbank Stadium, St Modan’s High School and organisations such as Zero Waste Scotland and Volunteer Scotland.

Scottish Water chief executive Douglas Millican said: “Sustainability is vital for homes, businesses and services, and using the energy from waste water is a great example of using resources to their maximum benefit.

“This new scheme in Stirling will go a long way towards helping reduce our carbon footprint and protecting the environment.”

Leader of Stirling Council, Scott Farmer, said: “Making Stirling the first place in the UK to harness this mix of cutting-edge renewable technologies shows Stirling Council is determined to lead the way on tackling climate change by reducing our carbon emissions and improving energy efficiency.

“This innovative initiative will deliver cost-saving benefits to the council and residents, generate additional income for many years to come and benefit communities in the form of regeneration and jobs in the growing renewables sector.”

Several public and private sector organisations are working to wean Scotland off gas-only heating.

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Electric heat pumps – essentially reverse fridges – are being developed on an industrial scale across the planet.

In Clydebank, local authorities hope to use pumps to capitalise on the relative warmth of the local river to heat a new neighbourhood. Scotland has Europe’s worst record on renewable heat.

Statistics earlier this year revealed the country – despite an excellent record on clean electricity – remains dangerously dependent on burning climate-change causing gas to stay warm.

Only six per cent of all heating in Scotland is sustainable, just one 10th of the proportion in Sweden, the best performing nation in the EU-28.

Scottish Power reckons renewable electricity output, however, must quadruple to develop clean heating and transport.