The UN-accredited non-governmental organization International Solar Energy Society (ISES) has been working on renewable energy issues since 1954. With vast experience in this field, ISES specialists see benefits where others think they are impossible. Europe has access to unlimited energy storage resources, ISES is confident, but even industry experts turn a blind eye to this unique source.
Pumped storage power plant in Spain. Image source: Sirbatch, Wikimedia
ISES experts say that pumped storage power plants (PSPPs) are this supposedly infinite resource for clean energy storage. A whole range of misconceptions obscure the potential of PSPPs: the small number of such plants, the need for many dams on rivers, the large area of flooded land, high water consumption, environmental damage and high capital costs for PSPPs. All of these are misunderstandings of the essence and principles of operation of pumped storage power plants, the organization says. Getting rid of these misconceptions can radically change the approach to energy storage in Europe.
The issue of energy storage in the EU is important because renewable electricity generation is extremely uneven geographically and seasonally. Wind is usually dominant in the north, while solar power plants dominate in the south. The storage capacity must be sufficient to survive weeks without sun and wind. Pumped storage power plants can be an ideal solution for this purpose.
Conventional batteries can easily provide short-term energy storage – up to several hours – with a high output power of the GW level. Pumped storage power plants, in turn, can provide long-term energy storage – up to several days, covering the need for stored volume by up to 95%. Together, these two sources can become a comprehensive solution to the problem of interruptions in renewable energy.
ISES experts have created a European atlas of potential sites for pumped storage power plants with a capacity of 2 to 5,000 GWh. Preference was given to sites with large differences in elevation and the shortest sections for discharging water for power generation. The atlas presents sites for 820,000 pumped storage power plants with a total storage capacity of 86 million GWh, which is equivalent to 2 trillion electric vehicle batteries.
The atlas includes premium sites (priced AAA and AA) and lower-quality sites (priced A, B, C, D and E). Premium sites for pumped storage are characterized by high heads (over 500 m), small dams, short pressure tunnels, high volumes (over 40 GWh) and long operating lives (over 100 hours). There are over 6,000 premium sites for pumped storage in the atlas, with a total storage capacity of around 1,100 TWh, which is around 40 times more than required for a fully electrified and decarbonized Europe.
Capital costs for high-quality, long-life energy storage systems are in the range of $8–$25 per kWh. For example, Australia’s Snowy 2.0 energy storage system (Class AA) costs around A$12 billion for 350 GWh of energy and 2.2 GW of capacity (160-hour storage). This equates to $22 per kWh, which is much lower than the cost of batteries for a system that lasts 100 years.
According to experts’ calculations, 150 GWh of pumped storage capacity located outside national parks does not require the construction of new dams on rivers, and the extensive network of high-voltage transmission lines in the EU will allow facilities to be located in almost any area without having to worry about the need to pull in energy infrastructure from afar.
The land requirements for the pumped storage plant are quite modest. The total flooded area would be 60 km² (0.6 m² per person), which is 100 times smaller than the area occupied by the solar power plants that would be supported by the pumped storage plant and 20 times smaller than the parking area occupied by 100 million cars. The capital cost of this system of five of the most powerful pumped storage plants to cover Europe’s needs is about €100 billion and represents a huge opportunity for local economic development. This amounts to only €1,000 per person for the opportunity to use the pumped storage plant for 100 years.
Five such sites are capable of providing electricity to all of Europe for several days.
As for concerns about water consumption, the water consumption for pumped storage is low because the same water is circulated between reservoirs for 100 years. In arid areas, a small amount of water may be needed to replace evaporation losses. The amount of water needed for the initial filling and to replace evaporation losses is a few liters per person per day, equivalent to a 20-second morning shower.
The environmental impact of PSPPs is low due to the absence of new dams on large rivers, low land and water requirements, no electrochemical processes, long service life (100 years) and a large choice of off-river locations (avoiding risky scenarios).
Global solar and wind capacity in the EU is being installed six times faster than everything else combined. Electrification of transport, heating and industry will double or triple electricity demand. Fortunately, off-the-shelf solar, wind and pumped storage solutions are available to decarbonise Europe at an affordable price, something that all stakeholders need to pay close attention to.