Storage and smart grids: hype or future of energy systems?

In the ATELIER Lighthouse City Amsterdam pilot, the Republica buildings will have diverse forms of storage: thermal seasonal storage in an Aquifer Thermal Energy Storage (ATES) and a large battery. They have different functions:in the ATES, heat from the buildings in the summer will be stored in an underground aquifer and used again to heat the buildings in winter. As Amsterdam has a clear seasonal heat demand, seasonal thermal storage is logical. In the Netherlands, this is already a proven technology and economically feasible for application in new office buildings. The future challenge for dense areas in Amsterdam is to keep systems small and optimise at area level instead of at building level so that underground systems do not hinder each other.

The battery is used to balance the electricity demand of the buildings with its own solar production and supply at low energy prices in the timeframe of one or two days. Occupants of the buildings will be stimulated to trade and use the flexibility to lower energy use and costs. Since the battery is servicing all buildings, a smart grid between the buildings to balance supply and demand is needed. This is still very innovative since battery prices used to be high and electricity prices are not fluctuating enough. Also, under the current electricity law in the Netherlands, this type of trading is not allowed. To facilitate the energy transition, experiments like these are temporarily allowed to learn from.

Also, in the second ATELIER Lighthouse City Bilbao, the pilot has an ATES and batteries, but since this is refurbished and not newly built, the outside climate and the electricity market are different. Comparisons will show pilot behaviours under different circumstances. We will take the lessons from these pilots to generalise and help our six Fellow Cities and further interested cities.

Storage and smart demand response can also help lower investments in the grid by reducing peak demand. Not only can this save money, but Dutch grid operators currently have a waiting time of sometimes years for grid reinforcement and not enough people to speed up. The business case is getting more positive for storage due to these timelines and less so by the avoided investments.

In the future electric vehicle, car batteries can be part of the smart energy system. Cars are parked 90% of the time, so, from a technology perspective, it’s a no brainer to use the battery for storage and flexibility in the electricity grid as well. However, to do it technically and be able to use all these small entities with all these different owners, that is still a big challenge. Future will tell what type of optimisation will be politically preferable, the one with lowest investment, with lowest societal costs or lowest CO₂ emissions, or all of them?

How all these smart systems can be technically controlled, governed and still be economical will hopefully be shown in the ATELIER project. In the meantime, we simulate these systems both in our lab and in computer models to predict behaviour when the pilots are ready, but also under other circumstances and locations to find optimal conditions for the future. I am sure we will learn a lot from these pilots in the coming years.

Dr. Renée Heller (AUAS), e.m.b.heller@hva.nl

Picture Credits: Unsplash