Scenarios of large volumes of non-dispatchable renewable technologies in the electrical systems are arousing concern over the need for storage, in order to avoid losses from dumping. This would not be a problem if there is balanced growth between dispatchable and non-dispatchable renewables and fortunately, in countries such as Spain, unlike Central Europe, this will indeed be possible.
GTM Research has recently published a study which estimates that energy storage capacity will reach 21,600 MWh by 2022, without counting the technology that currently and will most probably in future lead the storage of power to be used as electricity.
Spain is the global leader in energy storage in new renewable technologies thanks to CSP which, after large hydropower, is the leading storage technology for renewable power electricity, according to data from ‘Global Energy Storage’, released by the US Department of Energy, as analysed by Protermosolar. Spain’s CSP plants with storage enjoy 6,850 MWh in electricity storage capacity over 18 installations. Following Spain, countries with battery technologies and CSP plants, are the US, with 5,200 MWh; South Africa, with 2,600 MWh; and China with 1,000 MWh.
At global level, the storage capacity of CSP plants in operation and under construction amounts to 22,150 MWhe, while the rest of the technologies, including batteries, remain at a far lower level given that together they only total 6,600 MWhe. The analysis also highlights that molten salts technology for power generation purposes is, at global level, well above other alternatives such as batteries.
CSP is the only dispatchable renewable energy source with prices currently between 50 and 60 €/MWh, as demonstrated by contracts awarded in recent international tenders.
Storage in CSP plants has investment costs of around 40 €/kWh of equivalent installed electricity capacity, while the price of battery systems, taking into account the battery pack and the balance of system, are 10 times higher.
Storage is integrated into the CSP plants themselves so that their power generation can follow demand requirements. The availability of dispatchable plants is essential for any electrical system, rather than having to make additional investments to try and make use of the dumped power produced due to a greater penetration of non-dispatchable renewables plants.
But also that volume of storage could, with a very modest investment, be able to make use of dumped wind power, which usually coincides with days with little sunshine, with 40% efficiency.
In the recent tender in Dubai for a 700 MW output to be dispatched between 4 pm and 5 am the following morning, solar PV technology was unable to compete due to a lack of product and price, so CSP was awarded the contract as it was cheaper than combined cycles. Today, CSP plants represent the most competitive technology for utility-scale power plants with several hours of storage, according to Protermosolar.
The future deployment of CSP exclusively depends on plants with storage and countries such as China and Dubai (UAE) will shortly become the new global leaders in energy storage, thanks to the 1,400 MW and 700 MW, respectively, which are currently under construction.
For Luis Crespo, President of Protermosolar, “it is hard to understand how with these references and the costs at which CSP plants could be rolled-out in Spain, that the Committee of Experts has not taken CSP into account in the future generation mix. This very committee envisions 80,000 MW of non-dispatchable renewable technologies, which will be impossible in both technical and investment terms. Such a volume will need a very high level of back-up from conventional power plants, which contradicts the basic concept of the Energy Transition. There needs to be a balanced mix of solar technologies (solar PV and CSP) that enables faster progress towards decarbonising, without increasing costs for the system, with PV generation working during daylight hours and CSP during the evening and at night, thanks to its storage and back-up capacity“.