THE Scottish Government’s Draft Heat in Buildings Strategy consultation document, published last month, emphasises that homes and workplaces account for around 21 per cent of Scotland’s total greenhouse gas emissions.

‘We can and must make very significant progress towards eliminating emissions from the way we heat our buildings over the next decade and reduce them to zero by 2045,’ it says, also pointing to heating solutions that are ‘widely used in other European countries and are now gaining a growing share of the market here in Scotland – but for many of us, they remain unfamiliar’.

In Shetland in fact, some of those methods were applied more than 20 years ago when the Islands’ Council and the Shetland Charitable Trust, in a far-sighted move to implement sustainable heating investments that benefited the community, studied examples of successful waste-to-energy schemes elsewhere, particularly those in Denmark.

The Council and Trust initiated the main elements of Shetland Heat Energy and Power Ltd (SHEAP) in 1997, with the first customer connected the following year.SHEAP heats more than 1200 homes and buildings in the capital Lerwick.

These include schools, care homes and a hospital heated through an exchanger that enables heat to be transferred from the insulated hot water mains ito a separate pipework in the buildings, giving customers access to central heating whenever they need it and unlimited hot water.

The main source of energy is the Energy Recovery Plant (ERP) run by Shetland Islands Council that enables waste to be transformed into over 6 MW/hr of heat by burning 23,000 tonnes of waste per year.

It should be noted that there is no mains gas in Lerwick that SHEAP has to compete with. Around 80 per cent of Scottish homes are heated by mains gas but the Scottish Government Heat in Buildings Strategy wants mains gas phased out as it is a fossil fuel.

Located at a latitude roughly the same as the Southern tip of Greenland and slightly north of St Petersburg in Russia it’s hardly surprising that heat is a priority in the Shetland Islands. 

Derek Leask, executive director at SHEAP highlights the challenge: “On average we have much lower temperatures than the rest of the country across the year,” he says. “And with significantly windier conditions the wind chill is higher, and a large proportion of the population in Shetland are still suffering from fuel poverty”.

The Herald:

Executive director at Shetland Heat Energy and Power Ltd (SHEAP), Derek Leask, believes more support is needs for consumers who want to transition from heating systems powered by electricity  to more eco-friendly and cost-effective district heating   

 

He says that that Scotland has taken a positive approach to addressing climate change and carbon reduction in order to protect the future of our children and grandchildren. “This is an important document that sets out the vision we have to achieve buildings with zero carbon emissions and it’s good that district heating networks are seen as having an extremely positive role in achieving this goal.”

He does, though, believe that an issue that perhaps hasn’t fully been addressed is the fact that 50 per cent of houses in Shetland are still heated by electricity – which is expensive and not particularly environmentally friendly as this comes from an oil fired power station as Shetland is not on the national grid.

He explains that to connect to a district heating network requires a building to have a ‘wet system’ installed. This involves radiators or underfloor heating through which hot water is pumped around the building. Hot water comes from the heat exchanger which instantly heats the cold water from the mains avoiding the need for a hot water tank.

“If you have a heating system with conventional heaters you have to replace that whole internal system with a system of pipes that can transport the hot water around your house which can be expensive for most consumers.

“And while there is financial support available for them to be connected to the district heating system, consumers also need help to convert from traditional electrical systems, such as storage heaters, into wet systems that can be powered using low-carbon or renewable energy.”

In the UK, fossil fuel (and nuclear) power stations dump half or more of the energy consumed into the atmosphere or nearby sea – unlike in Scandinavia where the waste heat is distributed into district heating networks.

Even renewable sources of electricity represent added cost, he adds. “The means of generating renewable energy comes predominantly from wind power, mostly onshore but increasingly offshore, and as soon as that electricity reaches the grid the amount that Scottish Hydro Electric Power Distribution (SHEPD) charges consumers to transmit it across their network is nearly as expensive as the energy itself. 

So to use this energy in a heating network is not cost effective as things currently stand. “There has been something of a lack of attention to that and while we all support the move to low carbon and renewables, that renewable energy isn’t cheap. There’s a lot of support for heat pumps in this document but these pumps still need to be operated by electricity.”

The question remains then, how to address the cost to consumers if we are going to make this massive transition to eliminating emissions from the way we heat our buildings over the next decade. “Domestic customers in Shetland and Scotland can now get zero-interest loans or grants from Home Energy Scotland which is useful support and we’re waiting to hear if Zero Waste Scotland will do the same for commercial users,” Leask explains.

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SHEAP’s Energy Recovery Plant burns domestic, commercial and industrial waste

 

“But the Domestic Renewable Heat Incentive (RHI) scheme is closing to new accreditation applications in March 2022 and while existing schemes will continue to get it I’m not sure if there’s anything else in the pipeline to replace RHI – and meanwhile there are inequalities between the way electricity companies and district heating companies are charged for commercial rates with district heating networks which are generally more community focused and greener, currently losing out.”

Leask suspects that while the Scottish Government is enthusiastic about the proven value and potential for district heating systems, because the islands have been successfully implementing the technology now for two decades now, the Lerwick project has tended to become somewhat forgotten about. “We were the first in Scotland to go down the road to install a successful scheme that covers most of the town. It is relatively recent that government is seeing the benefit of district heating networks in the fight against climate change.

“So we spend a lot of time discussing policy and ideas and innovation with Dansk Fjernvarme, the Danish District Heating Association and meet regularly with its member companies because they are several years ahead of us, with almost every local municipality having a district heating scheme.”

In Denmark over 60 per cent of the population is connected to a district heating network. The country embarked on a transition to district heating after the 1973 oil crisis as it needed to become more energy efficient and less dependent on fuel from elsewhere.

SHEAP is also looking to innovations in Shetland in the cyclical economy, with a project making fuel from fish oil found in salmon biomass which is removed from the food chain (fish which die before being ready to harvest), an environmentally friendly energy source.

Lerwick Power Station is installing a new turbine from which SHEAP also hopes to take waste heat generated which will be an efficient and affordable heat option while a thermographic drone survey was carried out in January to improve the resilience and longevity of the district heating pipe network.

“While we’re pleased to see the publication of this consultation document – and clearly a lot of thought and work has gone into it – the key is translating that into real action,” says Leask.