City Conversations – Gridlocked
Wednesday 22 January 2020, 6.00 – 8.00pm
The Building Centre, Store Street London WC1E 7BT
The UK’s plan to achieve net zero CO2 by 2050 relies heavily on a decarbonised electricity grid. Increasing demand for electricity as a result of major energy users from transport to heating migrating to electricity will lead to an inevitable stress on supply and distribution. Many questions still need to be answered. Can we continue our successful decarbonisation of the grid or does its fundamental nature need to change? How do we deal with long term demand and varying demand according to different users at different times of the day and throughout the year. In particular what do we do about heat – is it right that designers are now designing all-electric domestic heating systems? Or will this put too great a burden on future grid infrastructure. Should we be looking to heat network systems, non-fossil fuel alternatives for heating buildings and, in particular, continuing to use our existing gas distribution system?
What is the future of the electricity grid? On the one hand there is a movement which proposes that we meet our carbon targets by moving to more localised systems and reducing our dependence on the grid. Others feel that a more global grid system might be the answer.
Built Environment professionals need to start making decisions now regarding how to heat and cool the existing building stock and ensure that all buildings meet the requirements of a zero carbon world in the future.
In a complex world, sometimes the answer lies in a simple concept. According to Bob Lowe we must engineer a system where the trajectory of the demand curve eventually meets and falls below the arc of the decarbonised energy supply curve. The key here is that demand needs to fall – the grid cannot supply all our current needs even without electric vehicles and a forest of heat pumps warming our new homes. It is still the improvement of existing building stock that holds the key and the heating of this stock at current peak levels of demand, if converted to electrical load, would far exceed what the grid could deliver.
We know what to do and the direction of change towards decarbonisation of the grid gives grounds for optimism according to Lowe, his own predictions from 10 years ago now proving to be woefully pessimistic. If the current rate of change towards a decarbonised grid were to continue we would have no problem reaching the zero carbon target of 2050. The questions that must be constantly asked is ‘can we continue to change at this rate? Does decarbonisation destabilise the consistency of supply? Renewables can be more variable according to the weather conditions. Given that CO2 is a global issue can the rest of the world follow suit?’
In particular, with a growing heat component of the demand side, will the grid capacity need to grow and can the system cope?
Bill Watts showed us a classic graphic of heat and electricity demand during an annual cycle in the UK. This emphasized the large heat demand during winter in northern hemisphere countries and the difficulty we will have in fulfilling that demand with electricity. Scientists and engineers need a plan to bridge that gap without fossil fuels and advise policy makers on what will work. There have been several schemes that attempt to show that the abundance of solar power on a global scale is the source to exploit. But how to move the energy from locations of high insolation to the places where there is demand during the winter months. The idea of a supergrid linking North Africa and Europe has been on the table for many years now. Political instability is one issue that may have slowed its deployment. Although our electricity grid is more linked to the continent than we might imagine, the infrastructure required to supply winter demand is massive. Watts leans towards the strategy put forward by the Climate Change Commission, the use of hydrogen. This involves the conversion of electrical energy to this gas and subsequent transportation and reconversion back to heat and electrical energy.
The jury may still be out on whether hydrogen can achieve this. The size of the hydrogen molecule make it far more difficult to contain than natural gas and it is difficult to liquefy. According to the US Department of Energy’s Office of Energy Efficiency and Renewable Energy, ‘using today’s technology, liquefaction consumes more than 30% of the energy content of the hydrogenand is expensive.’
There was little discussion about the principle of the power grid itself. The idea of bigger and more integrated worldwide system was generally accepted and there were few advocates of a smaller scale system or off grid communities from either the panel or the audience. But we know there are risks in this, as nuclear power becomes a smaller component of the electricity mix and power outages such as those that occurred on a national scale is 2019 may become more frequent with a more varied and unpredictable
But building more localised systems for heat is what Vatenfall believe is a vital component of reaching ‘fossil-free living within one generation’ – the company’s stated mission. Using the Scandinavian model, the company looks to solve the heat demand through distributed heat networks, although the essence of what they do is to provide a system’s response to local supply and demand. To achieve true energy efficiency this micromanaged approach looks in detail at heat sources – such as industrial processes – and ensures this can be shared though a ‘heat grid’ system. This is in contrast to the direction that some developers are going with, for example, new build domestic flats, where autonomous individual air source heat pumps are the proposed solution – without even considering any systems network, such as a suggestion from the audience that local parks might make a ‘ground source’ for heat.
Spare a thought then for the property developer who needs to deal with these varying strategies at the coalface. The problem for a developer such as Berkeley Homes, some of whose schemes may be very large and very extended in timescale, is the changing regulatory and technical frameworks in which they might find themselves throughout a project. It is not easy to be successful if the local plan demands heat networks at the beginning of a project while at the same time professional advisers are recommending heat pumps. In Richard McGibbon’s view the developer is well placed to look after the demand side; it would probably be better to devolve responsibility for the supply side to the market that could be for example a local ESCO. In his view the problem is compounded by claims from manufacturers of technology that are sometimes not substantiated.
McGibbon suggested that we might need to be able to sell the idea of lower levels of comfort – justified by his own example, six months with a broken boiler and no heating and hot water as a result; but generally demand reduction needs to be planned for through investment in building fabric improvements. In the existing building stock, this is still a tough nut to crack as initiatives such as The Green Deal showed; but without a coherent plan we may be in for a metaphorical ‘cold shower’ anyway, if the grid cannot support the heating and, increasingly, cooling demands of the existing building stock.
A final thought from a journalist, Tom Whipple of The Times, engaged and concerned like the rest of us, observing all these arguments, reviewing the technology advances and trying to make sense of whether we should be optimistic or pessimistic. “It is very unlikely that we are going to become a less-energy-consuming civilization, so we are going to have to find other ways of generating our energy…I think that if we haven’t sorted out nuclear fusion in 50 years time, we might well be in trouble.”
In conclusion, we should not underestimate the scale of the emergency and continue to monitor the rates of change in both decarbonised supply and demand reduction. The grid seems to be the big constant in future energy plans, expanding to a more global network with time. We still need to develop localized energy systems. In the same way, we need to live with competing approaches to heat supply until the technology becomes better understood. We need to decide whether hydrogen will be an important component to supply our energy. We need to consume less which may mean we have to accept lower levels of comfort.