Energy storage has always been central to the way we ‘do work’ in Britain. Traditionally people stored wood to heat and cook in their homes and even used icehouses to store ice to chill food, drinks and rooms in hot summers.  Large-scale coal mining developed during the Industrial revolution and from the 18th century to the 1950’s coal provided a main source of primary energy for homes, industry and transportation.

Throughout most of the nineteenth century and the first half of the 20th century a second revolution enabled gas to be manufactured from coal for lighting, heating, and cooking, later substituted by mined natural gas. Coal was stored in heaps and gas, later oil, in tanks that could provide weeks or months of energy reserves for the nation. Now all that is changing because:

• Privatised energy companies no-longer see the boardroom profit in storing large reserves of fuels so we tend to have days rather than weeks or months of UK fossil fuel storage.
• We are increasingly moving to renewable electricity generated by water, wind and sun, driving the need for storage to balance the Intermittency of their supply.
• As energy demands rise and fossil fuels are becoming scarcer, more costly and geopolitically insecure we can simply no longer afford to throw away energy, eg the 60-70% of heat thrown into the atmosphere from the cooling towers of inefficient coal-fired power stations. Waste energy must become stored/reused energy.
• The global environmental impacts of burning fossil fuels make it unethical to not derive as much energy value from each energy source as possible – making storage imperative.

So why does the government not heavily invest in storage, rather than pouring billions into subsidising artificially low fossil fuel prices that depress the wider value of energy and dis-incentivises investment in storage? Conservative politicians demonstrate no will to force utilities to increase their storage capacity, and the stranglehold of the ‘Big Six’ on energy supply and demand systems means that private schemes to increase local or national storage find it hard to get a foothold in energy markets. Building Regulations could be used to leverage thermal storage technologies into new and existing housing but again there is no will to do so and quite the contrary: over ten million UK homes have already replaced their water heaters and hot water tanks with combi-boilers, so eliminating distributed storage capacity and significantly reducing distributed grid-scale heat storage nationally. Going too, pushed out by the regulations and SAP, are the often popular storage radiators that so effectively used cheaper, excess night electricity to keep traditional masonry homes warm during the day.

Despite the apathy of the big utilities towards storage (as with solar – it potentially eats into their profits) and that of their friends in government, energy storage is a big new hot ticket in town, stimulating the growth of a wide range of new energy storage technologies for everything from buildings to heavy industry, transport and IT networks. A recent ‘backcasting event’ explored alternative visions of how Scotland could be 100% run on renewable energy by 2030 . Each Vision – from ‘Big Energy’, to a ‘Scotland-wide’ system to local ‘autarkic’ micro-grids – needed storage so ICARB  then hosted a follow-on workshop on ‘energy storage’ that provided a real insight into progress in the field. Klaus Vajen showed us exemplars from Germany of building integrated solar systems, providing everything from daily to annual solar hot water stores. Ebbe Munster gave us two examples of solar hot water storage systems built at the community level in Denmark, using borehole thermal energy storage at Braedstrup and a huge hot water storage pit in Marstal. Marco Masoero showed us thermal energy storage systems, district heating and cooling schemes using storage and outlined a range of ‘power to fuel’ technologies being developed there.  Hendrik Lund from Denmark expounded his vision for directing the renewable generation revolution into one dominated by conversion of electricity into heat, gas and transport systems to provide storage at the grid level.

Autarkic, self-reliant micro-grids with embedded renewables, are most efficient when demand and supply are synchronised. Eddie Owens of Heriot Watt University showed how three alternative communities in Findhorn, Scotland; Damanhur, Italy and Tamera in Portugal are able to produce up to 20% more value from energy generated locally by employing: a) more accurate weather/energy forecasting algorithms and b) persuading householders to modify their behaviours to use more of their own local energy with information from a user-friendly energy quality interface and different prices for red, amber and green energy supplies.

Six expert workshops covered 1) thermal energy storage; 2) energy storage media like phase change materials, chemicals and solids; 3) grid level energy storage systems, including pumped storage; 4) hydrogen fuel cells; 5) batteries and 6) control systems for grid and storage optimisation. You can see a detailed report of the event and its workshops on the ICARB website  and look through the presentations. ICARB also held a conference to explore carbon accounting methods and approaches for communities and cities which included discussion of accounting for embedded storage.

I am finishing this piece in Edinburgh, thirteen minutes into a power outage and I’m very glad my computer has a good battery and the open fire has warmed the large marble mantel piece before me. So – ‘this affects you how?’ – if you haven’t already thought about how to integrate as much energy storage into your own home and lifestyle as possible – perhaps this is a good time to do so!

Sue Roaf