The global battery market could be worth €250 billion per year from 2025 onwards according to the European Commission, and batteries are likely to play a key role in decarbonising the road transport sector. Coupled with digital technologies, there is a huge opportunity to increase the flexibility and reliability of the grid to allow more renewables to be integrated. But the production and use of batteries is expensive, and can have some negative environmental impacts.
Engerati spoke with Patrick Clerens, secretary general of the European Association for Storage of Energy (EASE) about the challenges and opportunities presented by energy storage, the different technologies, and a recent Commission consultation on the sustainability of batteries.
E: How can storage contribute to the energy transition?
PC: It is more accurate to say it will be the backbone of the energy transition. Firstly, carbon neutral sources like wind turbines, solar PV are variable renewables. The integration of more renewables needs storage as at the moment flexibility and balancing services is mainly done by burning something when you need it.
Demand-side management means one has to shift consumption while keeping the same standard of living. So storage is really the backbone allowing all this and providing different technologies for the transition.
In addition, electrical system stability typically relies on inertia from hydropower or thermal generators rotating masses, meaning tonnes of metal revolving at high speed to keep the heartbeat of the electricity system at 50 Hertz. When something happens there is a lot of mass to slow down and it takes time to change the heartbeat. The big issue is we are losing more and more rotating masses, and so you need very fast reacting “synthetic inertia”. This and other system services, such as power quality and voltage control, will also have to be provided by storage systems. On top of this, it will also bring renewables into other sectors, for example power to gas, heating and cooling, transport, to make the energy transition a reality.
E: What are the most common storage technologies actually being built today?
PC: Currently around 96% of storage is pumped hydro and of the remaining 4%, by far the biggest share is lithium-ion. But the system is changing. You have days in winter when it’s very cold and there’s no wind, so you need seasonal storage that lasts for weeks and months. Technology such as compressed and liquefied air, or flow batteries are therefore needed. These can contain a lot of energy. Then you have innovative projects such as balloons in the sea, using gravity, carbon nano-tubes, ultra-capacitors – we will see a lot of technology evolving in the next few years, and it’s not today we can say we have a clear winner. Solid-state batteries, for example those being developed by French battery maker Saft, are a promising future technology, since they will have a higher energy density and less risk of spontaneous combustion.
E: What are the growth projection rates for storage in Europe?
PC: We expect the storage market to continue to grow in 2019 and 2020, but at a slower rate than in the previous three years due to the short-term saturation of some front-of-the-meter markets, and the maturing of the large German residential market. Storage capacity in Europe will reach 5.5GWh by 2020, according to our European Market Monitor on Energy Storage released in March. New growth drivers will emerge as the Clean Energy Package is enacted and we expect E-mobility to become a significant new application for stationary energy storage to support the charging infrastructure.
E: What are the technology challenges, in terms of sourcing materials, disposal of old batteries, etc?
PC: With certain technologies such as liquid air there are few issues, but with batteries – as all electronic devices – you need to source the materials and then dispose or recycle. We have responded to a public consultation by the European Commission on the sustainability of batteries and we have a report on our website in which we explain how the use of second life batteries could have a positive economic and environmental impact, if the risks are properly managed. There is a real focus the sustainability of batteries in Europe, but raw materials, e.g. the ‘rare earth’ minerals are not so rare at all, it is just a cost issue. Also lithium is available for example in Europe, where an Austrian company is developing a mine.
E: What are the regulatory challenges to further deployment of storage?
PC: Not all services that could be provided by storage are remunerated. For example, you need as indicated synthetic inertia, but at the moment it is provided for free by the system, but this will stop. So this product should be tendered. And the European regulatory framework does not allow long-term contracts for balancing services, which hampers investment. In some countries such as the Czech Republic energy storage cannot be connected as a stand-alone device to the grid. And some system operators de-rate batteries, in other words they will not remunerate the full capacity of the battery. But this is discrimination against a technology as there could be a problem with any power plant, and in informal discussions the Commission accepts that this is not fair.
E: Which countries have the most progressive policies?
PC: The countries doing the most are the ones that feel the heat… such as the UK and Ireland, which are islands with limited connection, and undergoing what the European continent will undergo in a few years in terms of system challenges related to integrating a large amount of renewables for the size of the country. There are drivers in the Clean Energy Package for new national policies, the framework will be an incentive to have more storage, such as allowing consumers to participate in the energy system, the so called “prosumer”, who can bid in flexibility markets, maybe via an aggregator. One can now also have a contract where you are exposed to the wholesale price, which allows the consumer to charge the batteries when prices are negative. Also, since renewables bid into the day-ahead market and provide what they bid for, they will need energy storage or other firming options to honour their bids.
E: Are there any particular success stories you can share with us?
PC: There are many, some of which are highlighted in our report Storage4EU. We showcase many innovative projects by companies such as Uniper, GE, Enel, Iberdrola, Voith, Terna, EDF, Highview Power, Maxwell, Engie, NGK, CENER, BSEF and SAFT. Islands are particularly interesting. There is a Dutch island in the Caribbean called St Eustatius which is powered for several hours a day entirely with renewables and storage, which is an achievement as many of these islands are run mainly on diesel.
E: How will storage facilities operate within new flexibility markets?
PC: Flexibility and scarcity markets are the two markets that need to develop. Flexibility is only procured at the transmission level – it should be procured at the distribution level as well as there is more and more need to bring these markets down to that level. Energy storage will be on of the biggest contributors to flexibility in these markets. The added value is its very fast reaction. We will have a workshop on isolated energy systems and how flexibility will be provided on 21st November in Brussels.
EASE is also supporting ERA-Net SES with its Smart Energy Systems Conference 2019, which will be held in Belgium from 7th-10th October.