‘In Scandinavia it is a common wisdom that you can tell a lot about a person from their woodpiles’ (Lars Mytting, ‘Norwegian Wood’). As a result, when travelling in that part of the world, the elaborate creations that you see show just how culturally important stores of energy have remained.
A serendipitous combination of climate and geography mean that in the UK we do not experience the same low winter temperatures as many of our Northern European neighbours. We have also seen the benefit of the post-war construction of a centralised energy system and the discovery of natural gas in the North Sea. This, combined with the impact of the Clean Air Act, which required many of us to stop using coal to heat our homes, has made natural gas our dominant energy source for heating.
Until recently, despite the loss of our coal bunkers, we were still storing energy in our homes, in inconveniently large tanks of water that took up space that could be used to store things other than energy. The advent of combi-boilers has dealt with this problem, removing the hot water tanks and freeing up our airing cupboards.
As a consequence, storing energy has lost its cultural relevance in our society. Other than when we refill the petrol tanks in our cars, we have lost the connection between the energy we use and the need to gather and store that energy that is epitomised by the gathering and stacking of wood to see you through the winter.
As a society, we have not, however, lost the need to store energy, it’s just that we have become reliant on the ‘system’ to do it for us. Energy storage has been moved ‘upstream’. We rely on the inherent storage, the ‘line pack’, in our gas system to deliver incredible resilience, coping with massive swings in demand as everyone in the country turns on their heating each morning. It also copes with huge variability in demand as temperatures change from day to day.
We have also had significant stores of energy in our electricity system. There are the well known pumped storage schemes, which act as a balancing mechanism, providing important back up capabilities to see us through peaks in demand. However, more significant from a system perspective have been the energy stored in nuclear fuel rods and piles of coal, available for release whenever it is needed.
Things are changing… and they need to, as we start to recognise the full impact that our love affair with fossil fuels is having on our environment – both the quality of the air that we breathe and the climate change impacts of greenhouse gas emissions.
As we close our ageing fleet of coal-fired power stations we are replacing them with low carbon alternatives such as renewables, but these bring their own problems as many of them create a variability in supply that does not match our variations in demand for energy. In the electricity sector, the current solution to this issue is to use gas-fired power stations to balance the system, but this can only be a temporary solution – gas is still a fossil fuel and unless we are going to capture and store the CO2 it produces, it cannot remain part of the mix if we are to meet our climate change obligations.
An increasing use of gas creates another problem, it places additional pressure on the storage capability and system resilience provided by our gas grid. Whilst we can be reassured that our current system is large enough to supply the volumes of gas we use to both produce electricity and to heat our homes, is it still large enough to provide all the energy storage expectations we are now placing upon it? The gas system’s inherent storage capabilities were designed to replace the coal bunkers outside our homes, we are now asking it to also replace the large piles of coal that sat outside our power stations. If it doesn’t have the capacity for this, who will be willing to make the large, long-term investments needed to remedy the situation, particularly when other investors are busy looking for solutions that can reduce our reliance on gas by 2050 to meet our greenhouse gas emission targets?
There is no doubt that as a society we need to start seriously re-thinking the way we store energy. In the past we all had domestic stores of energy that made an important contribution to the overall system. Maybe the solutions need to become more localised again.
There is lots of work being done on batteries, but in reality this is focussed on enabling the electrification of our cars and not on meeting the storage needs of the whole system. Connecting transport to electricity will help, but it also increases the complexity of the system, creating commercial opportunities but also unintended consequences which may not always improve things.
Batteries for cars are an example of a store of energy that is being designed and optimised to meet a specific need. Maybe it is time to look for additional solutions that place the store of energy at other points of need, particularly where there is a need for heat – the major challenge for our energy system. It may even be time to start looking at how we can share that storage capacity at a community level – a sharing economy is likely to make the implementation of the solutions far cheaper for all of us.
We need to take pride in our ‘woodpiles’ again they are part of what helps our society to function… after all, ‘you can tell a lot about a [society] from [its] woodpile’.