Is it time to answer those awkward questions on CHP and district heating?
Bill Watts of Max Fordham says that CHP and district heating are a short-term fix that isn't even working. And while London 'mandates' them, other solutions are overlooked.
There is a growing disquiet surrounding the installation of Combined Heat and Power (CHP) and district heating systems in new-build developments. Current policy from the GLA under Chapter Five of the 2015 London Plan, alongside encouragement from DECC, almost mandates their inclusion to get planning approval, but data supporting their effectiveness is so scant it’s almost scandalous.
Like many other engineering consultants, Max Fordham has been working on district heating and CHP schemes throughout the UK for some time. This includes working with existing systems, designing them ourselves, and reviewing reports and designs by other consultants.
In our experience, it’s a fact that existing CHP and district heating systems are generally more expensive to run, consume more energy and issue more CO2 than an equivalent “conventional” system.
For older systems, this normally leads to the recommendation to rip them out and replace with local boilers. For new systems installed in the last four years or so, it leads to a problem for registered social landlords who thought they were getting a system that wasn’t that much more costly than the conventional heating systems that they have been used to.
The hapless residents have to pay what is asked of them, with no opportunity to enter the marketplace for competition on prices. I find it staggering that such a basic utility as heat can be provided by a completely unregulated, monopoly supplier who can charge what they like.
Even when we have been obligated to include these technologies in our own designs, we can only make the projects make sense from the point of view of CO2 consumption if we suspend our professional disbelief and simply input the manufacturer’s data and discount any system losses.
Like death and taxes, system losses are inevitable, as is overly optimistic manufacturer’s data. If we add calculated losses, it sends CO2 consumption north of those from conventional systems. And that’s before allowing for additional factors that can be difficult to mitigate – such as workmanship and sub-optimal operation.
The dearth of data relating to the effectiveness and efficiency of CHP and district heating means that unless you are in an energy service company (ESCO), you don’t know exactly what the heat losses are from these systems, except that we know they are much higher than we have been led to believe. If the CHP and district heating industry fails to indicate what those losses are, it makes predicting the viability of these systems very difficult.
"The dearth of data relating to the effectiveness and efficiency of CHP and district heating means that unless you are in an energy service company, you don't know exactly what the heat losses are from these systems, except that we know they are much higher than we have been led to believe."
The decision to install CHP and district heating, as promoted by the government and as good as mandated by the GLA to gain planning approval, is based on reports by consultants that purport their effectiveness. But a cursory examination in these reports of the calculations made for losses, efficiency and run times indicate an at best naïve understanding of engineering.
The carbon-saving argument for gas CHP is based on the current carbon intensity of grid electricity. The case rapidly falls away, however, as the grid decarbonises, which is the avowed aim of the government, by switching from coal to gas, nuclear and renewable electricity.
Even the rabid proponents of CHP and district heating schemes admit that their idealised zero loss systems will not save carbon in a few years. This is not a viable long-term strategy.
When we discuss these reports with the authors there is a general agreement that the figures don’t really stack up but hey, the client wants an easy passage through planning, so just put it in.
We’ve even experienced examples where the more far-sighted proponents suggest that developers should install PV arrays to offset the additional CO2 that the district heating and CHP will produce. You couldn’t make it up!
The government has been sold on the idea of these systems as the panacea to future energy woes and the growing impact of global warming. The more curious are beginning to question these figures and do the calculations based on more empirical evidence, expressing an alternative view and suggesting, quite rightly, that all is not well in the garden. But to question this too ardently, in London at least, will jeopardise planning approval for a client, so compliance is the safest option.
Another intangible that affects the performance of these systems, leading to results that are far worse than we calculate, is the quality of the installation. There are no statutory requirements for any installation standards or performance standards, so one should not be surprised at the outcome.
Somewhat belatedly the industry has produced some design guidelines that could improve the quality of the installations, but there is no legislation to back this up and no performance targets stipulated. Without defined targets, a requirement to publish data, or a need to be competitive with other sources of heat, one can’t see the industry hurrying to change.
So why are we doing this?
Policy makers will, in private, tell you that they don’t really care about the costs or the losses. They are aware of the problems but are happy with the price paid for the infrastructure and the additional running costs and the increase in CO2 emissions. They’ll tell you the bigger picture is that, in the future, all these systems will be fed with low carbon heat.
Will you please tell us, what are the sources of this low-carbon heat you are forecasting over the next 25 years? This policy is making things worse – we are using more energy, we are wasting more energy, we are producing more CO2, developers are paying more to install systems they don’t need, owners are paying more for their flats as a result, tenants are paying for heat they don’t need at a price they can’t shop around against.
It is a scandal – and we are blithely tolerating it at a time when fuel poverty, energy security and housing affordability are looming issues threatening our way of life. All this, on the unresolved promise that the additional CO2 we are releasing today will one day be “paid back” in an as-yet unarticulated future.
While this district heating circus plays out, it sucks money from the job of better insulating buildings to not need heat in the first place. The irony is that reducing the amount of heat a building needs will actually increase the proportion of heat lost in a district heating system, making it less economically viable and more environmentally damaging.
District heating, therefore, is not a friend of insulation. Until we get some answers to how we are going to heat and power Britain I suggest we make use of our cash to insulate well and reduce the demand for heat, and therefore use very little of it.
Bill Watts is a senior partner at Max Fordham LLP