District heating systems can be zero carbon and cut energy bills – two major selling points that energy giant Vattenfall believes should persuade all housebuilders to connect to local networks, says Anthony Harrington.

WHEN you consider that district heating networks in have been around since the 1970s in Scandinavia, it is perhaps sobering to realise how far the UK in general, and Scotland in particular, is behind the curve.

Around 22 percent of all Scotland’s carbon emissions come from home heating. Yet the fact is that schemes which utilise local sources of waste heat can be either zero or close to zero greenhouse gas emitters. Some networks include heat pumps, be they ground, air or water pumps, which are powered electricity, but if supplied by renewable energy then it can be a zero-carbon solution.

This makes district heating schemes a great low carbon solution for new build housing estates. However, as Jenny Curtis, Director of Commercial and Development at Vattenfall, explains, there is as yet nothing that requires developers to investigate connecting to district heating systems, even if there is a heating network that runs right past their latest development.

“Free choice is great, but it is not always the most sensible way of implementing major changes,” Curtis says. “When the UK switched from analogue to digital TV, the government simply mandated the change, and that was 100% effective in driving the transformation to digital. We need something similar for district heating,” she suggests. It is perhaps astonishing that at a time when Scotland is already following England in announcing the end of the road for gas combi boilers the choice of whether or not to link up a new built estate to an available district heating system is still left up to the developer.

“Decarbonisation of heat requires a mixed economy, with investment in the most effective tech for each local region. This should align incentives for developers and building owners and unlock investment, with the result that costs could be driven down by as much as 30%. This means lower bills for households whilst slashing carbon emissions” she says.

Though it is not yet at the point of mandating connections to district heating systems if one is available to a development the Scottish Government is taking important steps to promote heat networks. In February, The Heat Networks (Scotland) Bill was approved, which provides the first UK regulatory framework for district heating.

As the Bill itself says, its aim is to encourage the greater use of heat networks in Scotland (the key term being ‘encourage’ rather than ‘mandate’). The Bill covers issues such as the granting of licenses, making applications and setting up heat network zones.  The point of the Bill, as Curtis explains, is to address the fact that so far, heat networks providers, unlike other utilities providers, have not been regulated. The Bill is designed to set up license and regulation arrangements for Scotland. Crucially, it’s hoped that bringing regulation to the district heating sector will inspire consumer confidence and increase demand.

“The new Scottish legislation is a welcome step in the right direction. It sets a precedent in Scotland which we hope the rest of the UK will follow,” Curtis says. Government support will help unlock the ability for district heating networks to be delivered at scale, which is when they are most cost effective and make the biggest impact on carbon reductions.

Vattenfall’s biggest district heating systems have hundreds of thousands of homes attached. “We have major scale networks in Amsterdam, Berlin and Uppsala, and our Amsterdam system, for example is targeted to provide heating to 100,000 homes by 2025” she points out.  

“Beyond the challenge of getting the right supportive regulatory framework in place, what we really need to get large scale district heating schemes established in the UK is for the energy industry to work much more closely with the property industry,” she says.

“Rolling out district heating is more cost effective for all concerned – from the plot developer to the end customer served with heat – if the pipes of the system are installed at the same time that the infrastructure for a new development of a few thousand homes is being built. This is for two reasons. Firstly because the cost of other heating equipment that would otherwise have been installed can be used to offset the cost of the heat network. Secondly, because you avoid having to pay twice for digging up the road to install the pipes.”

“Conversely, it is much more costly to come and install district heating when the housing development is already built sometimes referred to as ‘retrofitting’ You will need to dig up the roads to lay the district heating pipes without the benefit of sharing that cost with other utilities. In addition, the home owners will have already paid for alternative heating systems that might still have many years of operating life left before they need to be replaced. Both of these points mean that it will be much more difficult for the heat network to be commercially viable in this retrofitting only case”.

One of Vattenfall’s most recent Scottish projects is the 50/50 joint venture between the Swedish government backed group and Midlothian Council.  The JV has created a new Energy Services Company, ESCo, to deliver low carbon, green energy projects across the Midlothian Council area. The first project will be a low carbon district heating network supplying the new Shawfair town in the north of the council area on the outskirts of Edinburgh.

Zero Waste contractor FCC Environment, which operates the councils’ Energy from Waste facility near Millerhill, will supply low carbon heat to the Vattenfall district heat network. The EfW is fuelled by residual waste collected by Midlothian, Edinburgh and East Lothian councils. 

The proposed Shawfair development will see 4,000 new homes, businesses and retail outlets in a landscaped environment surrounding a new town centre and railway station, provided with heat from the project. The district heating network is expected to save over 2,000 tonnes of CO2 per year, the equivalent of taking 1,200 petrol/diesel cars off the road.

This article is brought to you in association with Vattenfall.