Draft Heat Networks Delivery Plan

In short, more ambition needs to be considered. We already know from our own experience that some actions of the Scottish Government and local authorities have been constraining the potential to develop heat networks. Other priorities, such as building homes more quickly, even if they are of lower quality, have been prioritised.

From the information supplied in the draft document, heat networks supply is currently in the low single digits of percentage of the population in Scotland. From Euroheat & Power, 2017 Country by Country, Share of citizens served by district heating in percent, more than half of 24 European countries supply approximately 25% of their population from district heating, with a quarter achieving very close to, or significantly more than, 50% of their population from district heating. The UK appears at the bottom in that listing.

Clearly, from these empirical examples, it is possible to supply many times what is currently suppled from heat networks in Scotland. The question is, moving forward, how would district heating now compare with the currently available alternative options?

Analysis, such as available from the link below, is that a new district heating system is highly competitive with respect to heating price when compared to individual heating solutions, and that is before environmental and other society wide costs, such as electricity grid reinforcement, of the alternatives, is considered. This holds true even for lower energy homes in quite sparse heat networks.

https://www.danskfjernvarme.dk/groen-energi/analyser/03052018-the-competitiveness-of-district-heating-compared-to-individual-heating

It should be noted that 4th generation district heating technology is still advancing, and by using water at lower temperatures and still better pipe systems, heat losses are minimised and district heating becomes feasible in still more places.

The example of Denmark is a usefully comparable one to Scotland.

We believe there has exists a Memorandum of Understanding between the Government of the Kingdom of Denmark and the Scottish Government on cooperation in the areas of decarbonisation of heating systems, district heating and energy efficiency in buildings?

https://www.gov.scot/publications/decarbonisation-of-heating-systems-district-heating-and-energy-efficiency-in-buildings-mou/
Nearly two thirds of homes in Denmark get their heating from a network.

While there may be additional geographical constraints in Scotland, the extensive nature of heat networks across Denmark, and the small scale of many networks in Denmark and other Nordic countries, the evidence is this should not be exaggerated.

Much of the existing networks in Denmark, and elsewhere, have also neither taken advantage of the latest technology now available, nor had the same environmental incentives that we now understand.

We need to be more ambitious in Scotland, and not so constrained in our current thinking. Currently, we would suggest the total potential of district heating in Scotland is not the limiting factor on short to medium term targets. It is the capacity to develop the infrastructure in the medium term, and the constraints in mindset in the short term, that will determine what targets can be set, and met or exceeded.

We are acutely aware in our own circumstance, and Sustainable Cupar’s own zero carbon district heating proposal that made it to the final 10 of the Scottish Government’s Local Energy Challenge Fund (LECF), that given the good words the Scottish Government has said, that it is implementation of policy at the Scottish Government and local authority level that has most hampered the development of our proposal.

It is instructive to note in early Local Heat and Energy Efficiency Strategy work (Phase 1 Pilots, Technical Evaluation Report, September 2019), the methodology there saying, “There are two key steps when identifying a potential district heating network; identifying anchor loads and assessing the heat density of the area.” And then the commentary on how that worked out saying, “It is interesting to note that across all of the pilots, we did not identify any immediately implementable district heating networks by employing the core methodology outlined above.”

The use of a 4MWh/m/year linear heat density benchmark has been ridiculous, and we would suggest in some circumstances its use has not complied with Part 4 of the Climate Change (Scotland) Act 2009. Taking a local example of a proposed development by a national housebuilding company (Persimmon), the heat energy use they give for the homes they propose there is an average of 5.6MWh/year. Working the equation the other way, as we should rightly expect those involved in this area to be able to do, this gives just 1.4m of pipe per home with which to connect up an entire heat network. That’s just not physically possible to do. Is the Scottish Government, and local authorities, that use such a benchmark figure (we would name Fife Council), really saying that district heating is impossible in such situations, and does not merit any investigation? How then have they actually managed it in reality in Denmark, and other Nordic countries?

We have noted a number of independent scientific papers referring to a 0.2MWh/m/year figure being used in Denmark, as to what may be cost effective. Perhaps with the Scottish Government’s memorandum of understanding with the Danish Government on this issue it would have information on this? Such a figure is also more consistent with a level where research indicates environmental criteria would favour district heating over individual systems.

We would also question the fixation with anchor loads, particularly in the case of new build development, where installing the heat network infrastructure can be significantly less costly. A sufficient number of homes is sufficient.

As a different, but not unrelated point, it is perhaps necessary to question the use of 5th generation in the draft document?

5th generation is generally regarded as a more radical departure from previous generations, and not simply being a lower temperature operation. It involves concepts such as, the the same network providing both cooling as well as heating, a decentralised concept where each connected building is a contributor to the network, as well as being supplied from it (with no requirement for a separate energy centre), potentially bidirectional flow, and a network temperature close to ground temperature.

It is perhaps closer to the concept of a shared ground loop for individual ground source heat pumps, than traditional heat networks.

4th Generation district heating also encompasses ULTDH (ultra low temperature district heating), as well as LTDH, where the network supply temperature can be significantly below 50C. The cut off between the two (LTDH/ULTDH) is usually taken to be where the building cannot safely take domestic hot water (DHW) simply via a heat exchange from the network supply.

This is not to say which (4th or 5th generation) may be the better solution in particular circumstances.

If district heating, as evidence suggests, is in many cases more cost effective than individual heating systems, this in itself has capacity to reduce fuel poverty.

In comparison to our current ways of supplying heat, which tend to export the money people pay for heat out of their local economy, district heating, based on local renewable sources of energy, has the capacity to retain more of that money in the local economy.

This has the capacity to reduce poverty in two ways, possibly both in the amount of money people have to pay for their heat, and in their ability to earn more.

Community and co-operative ownership of the district heating system can enhance that benefit, and further mitigate against any exploitation of any monopolistic nature of district heating.

Promotion of community involvement, control, and ownership of district heating systems should be favoured, and promoted as a priority.

Again we would question a fixation with anchor and non-domestic buildings.

Not too large new housing developments can be sufficient for a heat network, and all the stages really need to be undertaken at the same time in such a situation.

Whilst agreeing with the general direction of the building hierarchy, we would again question the fixation with individual anchors buildings and non-domestic buildings. A new build housing development of sufficient size (which need not be that big) should also be right there at the top of the hierarchy.

Cost effectiveness is important because it directly relates to what people have to pay for their heat, but as indicated in the draft there are other factors, including our obligations to reduce emissions.

In the likes of traditional tenements and townhouses, decarbonising the heat supply itself via a heat network may be the most cost effective option. Their linear heat density is also likely to be high. Such properties should therefore also be very high on the Building Hierarchy.

An approach that has worked in other countries is to directly assure demand, particularly in relation to new development, by requiring appropriate development to use a heat network for their heat supply.

To a significant extent this ability should already exist within Scottish Government and local authority planning policy.

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We agree with developing an approach towards appropriate existing buildings being moved to a heat network, but the cost to those involved, and sufficient support for that, has to be a very serious consideration.

In the meantime, as new build may be the most cost effective way to increase the number of properties connected to a heat network (and without disruption to existing occupants), and provide the assurance of demand that would make it cost effective for existing buildings to convert, the failure to require this under current planning policy, where it already reasonably could be done so, needs to be strongly addressed.