Electricity from heat pumps, combined with a shift to renewables in district heat networks, emerged as the winning technologies to drive the Finnish capital’s transition to carbon neutrality by 2035.
Finland has “a very strict target” to become carbon neutral by 2035 and the same goal applies to its capital city, said Kaisa-Reeta Koskinen, manager at the Carbon Neutral Helsinki project.
Helsinki has a huge challenge decarbonising its district heating system, which is currently entirely fuelled with coal and gas, she told a EURACTIV virtual event on 20 May.
District heating systems are networks of hot water pipelines that distribute heat directly to people’s homes. Once installed, they are versatile enough to be fed with any locally-available source of energy, making them an invaluable asset in the energy transition.
“More than 90% of buildings in Helsinki are connected to the district heating system,” which is powered by two coal and two gas combustion plants, Koskinen said. And even though those are efficient cogeneration facilities – producing electricity and heat at the same time – the related carbon emissions will have to be completely eliminated by 2035.
In addition, coal will be banned from energy production in Finland as of 2029, which makes the decarbonisation challenge even more daunting, Koskinen said.
To reach its goals, the city launched a competition with a €1 million prize for those who will find the best solution to decarbonise the Finnish capital’s heating system.
Biomass was quickly ruled out because of the added pressure this would have placed on Finland’s forestry sector, Koskinen said. So this left Helsinki with one option – electrification.
“The electrification of heating is a very clear trend,” Koskinen told the EURACTIV webinar.
“At the moment we’re looking at deep geothermal, heat pumps and waste heat from industrial and other sources,” she explained when asked by EURACTIV to elaborate on the alternatives to coal and gas in Helsinki’s district heating system.
“It’s very clear that a big part of the solution is going to be heat pumps,” she said, adding that “the future of district heating and heating overall is going to be a combination of distributed and centralised heat production”.
Phasing out coal
Helsinki’s case is not isolated. Heat networks today are based largely on fossil fuels like coal and gas, which is “not consistent” with Europe’s climate ambitions, said Paul Voss from industry association Euroheat & Power, which represents the district heating sector.
“Obviously, that’s not the future,” he told participants at the EURACTIV webinar. “Ten years from now there won’t be any coal left in Helsinki, and I think you’ll see that pattern repeated across Europe,” Voss said.
That decarbonisation process is likely to take longer in Eastern EU countries, however, Voss admitted. District heating networks there were developed during the communist era and many of them are still running entirely on coal.
But even that is changing rapidly. Across the European Union, “coal has actually rapidly declined and renewable’s share has tripled from 10% in 2009 to 30% in 2018” in the cogeneration industry, said Hans Korteweg, Managing Director at COGEN Europe, an industry association.
According to him, further gains can still be made by switching district heating systems to gas. In Germany, the city of Kiel was able to reduce emission by 70% “just by switching from coal to flexible gas” solutions like natural gas, biomethane and hydrogen, he said.
“Many of the existing combined heat and power plants in Europe can be refurbished at quite a low cost to accept varying shares of hydrogen,” Korteweg said, adding that the rough abatement cost is estimated at €5-€8 per tonne of CO2. “And there are many examples of cities in Italy and Poland where they combine waste heat CHP and heat pumps” to reduce the emissions of district heat systems, he added.
The beauty of district heat networks is that they can instantly switch thousands of homes to new heating sources without changes to the distribution infrastructure, while providing “cheap storage” for the energy system as a whole, Voss said. “We can pick up excess renewables production and use that to power big heat pumps or big boilers and provide balancing services,” he explained.
According to Voss, solutions will vary depending on local circumstances and availability of renewables or waste heat from nearby factories. “I hope we can use a lot more waste heat from data centres, factories, solar thermal, geothermal, and power-to-heat,” he said.
Gas as a transitional fuel
In Poland, state-owned company PGE has made plans to replace coal-based CHP systems with fossil gas that will be gradually replaced by renewable and low-carbon gases such as biomethane and hydrogen.
“We will use gas as a transitional technology in our pathway to climate neutrality. This means that gas-fired turbines that are built today will be able in the future to use CO2-free gases only,” said Piotr Czembor, from PGE, which supported the EURACTIV event.
“The PGE group strategy assumes that by 2030, more than 70% of energy sources in heat production will be zero or low carbon. And after that, we plan to deploy CHP units using zero emission fuels,” Czembor said.
However, fuel switching won’t be cheap, he added, saying access to finance will be key for PGE to make investments into new CHP plants and district heat networks.
“Therefore, from our perspective it is important that gas as a transitional fuel will be recognised as environmentally sustainable. Otherwise, the cost of financing such investments will be much higher,” he warned.
Robert Nuij, an official at the European Commission’s energy directorate, said large amounts of funding will be available to member states via the EU’s €750 billion recovery plan. “And member states can definitely use the money available to support district heating,” he said.
By now, 22 EU member states have submitted national recovery and resilience plans to the European Commission. For Poland, €170 billion will be available in total under the EU budget and recovery plan.
But Koskinen insists that those investments must be future-proof. “We don’t have the luxury for a transition period anymore,” she said, stressing that investments in heating systems being made now will still be up and running in 25 years.
“We have to get rid of fossil fuels fully, and quite quickly,” she said. “If at this point we start investing into fossil fuels, even if they are not as bad as coal, it is going to be a bad investment.”
> Watch the full video of the EURACTIV event below:
[Edited by Benjamin Fox]