What do you know about Denmark? For the average person we’d imagine you’ve heard of Lego, bacon, vikings and QI host Sandi Toksvig. But how about district and communal heating?

Now we’ll be honest, we didn’t much about it either, but it is being proposed by Gemserv to meet the island’s heating needs by providing an economical, low carbon solution.

What is It?

Starting with the basics, district and communal heating, also known as heat networks, is a system of delivering heat to several buildings from a centralised point. Essentially imagine that instead of having a boiler in your flat or house, you share one with your neighbours too.

They can vary anywhere from two buildings sharing a heating system (aka a communal heat network), all the way up to much larger (aka district heating).

Are They Viable?

The Gemserv report says that as of 2018, only 6% of heat demand worldwide was supplied via district heating. But where it is used, such as in Denmark, the system results in benefiting from economies of scale, which Gemserv says ‘in some cases delivering savings of up to 30% on annual costs’.

It adds: ‘The positives are further compounded by the use of demand aggregation – cooling and heating needs can work in tandem to reduce waste and improve efficiency. Furthermore, the separation of generation and consumption means that system changes can be made without huge amounts of upheaval or replacement.’

Our Island

Germserv says that ‘incredibly valuable in meeting the net-zero targets of the island’. If this was a route that was taken, it says they could be used in some of the more densely populated parts of the island providing low carbon power that is competitively priced compared to traditional fuels.

The tech arounds these networks has developed a lot in recent years and they can operate at lower temperatures and deliver heat via heat pumps or lower-grade waste heat.

Environmentally, if people moved directly from a gas boiler to heat-pump-powered district heating could potentially save 62% in carbon emissions, which Germserv says could rise to 99% by 2040.

Its report further goes on to say that there are potentially 28 financially viable heat networks on the island. It adds: ‘Notably, those networks with higher theoretical heat densities should deliver lower costs of heat to consumers. However, there is no guarantee that consumers will sign up to heat networks, even if they are available. In their modelling scenarios for the UK’s sixth carbon budget, Element Energy hypothesises that uptake could be as low as 50% in some cases.’

Who Fancies A Danish?

Many people will pour scorn on whether this can work on a large scale, we turn now to the test case, Denmark (hence the Lego and bacon). Denmark services 63% of its citizens via heat network, the third-highest across the world, behind only Latvia (65%) and Iceland (92%).

Germsev says: ‘One key to their success is arguably the high percentage of networks that are operated by consumer-owned, non-profit cooperatives. These in turn are regulated by a heating association (Danish District Heating Association), ensuring regulatory oversight for both providers and consumers. This then contributes towards low levels of energy poverty, reduction of fuel imports, and carbon emission reductions.’

Furthermore, looking at the example of Samsø, where 75% of households use biomass-generated district heat, while another island, Bornholm, is investing in the technology and aims to be carbon neutral in the next few years.

What’s the But?

Of course there’s a but. This isn’t a miracle cure. If these networks were rolled out, they would need to be built and this would likely be disruptive and expensive.

Germserv says that on island, the estimated capital expenditure would be £136,994,372. An average cost per property of £10,556. There is no way to dance around that figure, we could almost build two ferry terminals for that. Or provide regional swimming pools for many, many years.

What Needs to be Considered?

Obviously the costs are large upfront, but the evidence based on Denmark means the potential benefits need to be looked at. After all there are few upfront capital costs for cleaner energy that are going to be cheap, but then again Pulrose Power Station infamously cost a lot more than its initial £185m budget and involved some rather dodgy loans, so where there is spending, there is risk.

We also need to look at how homes etc would be serviced with a network, the report provides pictures like the ones below, but would you really want a pipe running between every hose on your road? Alternatively of course, they can go below the ground, but this would involved digging up so many miles of road it would make the prom look like a pothole job.

There is much more in the Gemserv report on this option and other potential energy solutions for the island , which we’ll be looking at in the coming days. You can read more below or by opening it up here.

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