Decarbonising heat is a challenge – but one that the industry can solve. The best place to start is by doing the basics: measuring, managing and optimising instead of working on assumptions, says ADE director Tim Rotheray.
My role involves a lot of speaking with people about the future energy system. Increasingly central to that is the discussion of the decarbonisation of heating. When talking about heat I seem to encounter two views. The first is ‘it’s easy, just insulate buildings and then put heat pumps everywhere’. The other view is ‘it’s all so hard, how are we going to get into all those buildings and homes, no one is prepared to pay for the energy efficiency measures’.
This first, ‘it’s all easy’ view is normally made by those in the power sector, experts in electricity who apply the logic that works well there into heat. Power is a standardised commodity. Heat is not. People have personal views about what they like. In homes, some like the direct heat from a radiator in a room where others prefer the gentle pervasive heat from underfloor heating.
In industry, reliability of heat supply may be valued over almost everything else. Industrial heat users often invest in costly back up plant just to give that security of supply. I visited an industrial member of the ADE which had three boilers each the size of small house ticking over just in case they lost their main heat source. This site was proud of having steam supply for 13 years with no interruptions. Each of the users, from industrial and commercial through public sector to domestic, are different.
Another challenge to oversimplifying heat is that it is generally not part of a wider network. Unlike power, excess heat cannot simply be sold off. This is why domestic solar power is more appealing than solar heating. Once the hot water tank is full there is no grid to sell your excess to. Our approach to heat cannot be the same as that of power.
That said, the ‘it’s all too hard’ is the more dangerous view to put forward. Yes, there are real obstacles. Seeing how changes will be made in every home, office and industrial complex to improve efficiency and change fossil fuelled plant can seem daunting. But if we, the industry, keep telling the media, the government and parliamentarians how hard it all is, do we really think it will encourage them to act?
I’d suggest a better approach is to admit that there are challenges but also as an industry to declare with confidence that we can do this. We can deliver zero carbon heat to homes, offices and businesses.
But where do we start? The first point of call is knowing what is going on. And we do not. Astonishingly, the heating sector does not know very much about heat use. People give figures for the heat demand of a home, office or high street store but it is not based on real data for that home or office. It is based on myriad assumptions. We assume the efficiency of boilers, the heat losses through walls and windows, and the effectiveness of radiators. All these assumptions are based on tests, some are lab conditions, others real world but not on real live data for that property. For roughly half the energy we use in our economy, we don’t really know where it goes.
Compare this with cars – most car owners can tell you how many miles get they get a tank of fuel and how much it costs to fill. Their costs will differ from the manufacturers test figures due to location (hilly or flat) driving style (gentle of aggressive) and the type of journey (urban or rural). The car driver has accurate real-life data based on their own circumstances. This knowledge can inform their next car choice.
Rather than being focussed on cost effective performance the industry is most worried about there not being enough heat and they don’t have the data to know. The absence of data combined with the risk of installing something that may not be enough for the freak cold blast means we routinely oversize. Boilers, pumps, piping are all oversized. You may not think this matters; after all, better to have and not need than need and not have. But it has profound economic and carbon impacts. Because we pay for connections based on assumed use new hospitals can end up paying too much for their gas contract, reducing money for frontline services.
Heat networks, designed based on assumptions from the traditional heating industry, have been routinely oversized. This oversizing of heat networks leads to the stories of common areas of apartment buildings overheating because of oversized pipes. And in the home with a gas boiler, an oversized condensing boiler means overheated radiators and the central heating water returns to the boiler too hot for them to ‘condense’. This condensing action can reduce gas use by up to 10% – but it only works if the system is well sized and managed.
Measure, manage, optimise
Much of the industry keeps telling government that decarbonising heat is very challenging. The truth is that we have oversized assets which are wasting energy and carbon. The first step is very simple. All that is needed is data monitoring – like in-room thermostats and data on the flow temperature of boilers – to optimise performance. More importantly if we started gathering these data, they could be used to ensure that heat pumps, heat networks and efficiency measures could be appropriately sized and installed. Good data is the first step on the route to good heating.
Rather than telling all who will listen how hard it is, why don’t we start telling them what we can do – right now, with traditional systems. Because ultimately if we don’t tell them how we can do it, eventually someone else will – and they will take your business with it.