The net result of the increase in renewables expected over the next decade and more is “much greater volatility in the power system,” increasing the need for flexible resources, including energy storage.
This is a key finding of an economic study released earlier this week by Bloomberg New Energy Finance and commissioned by Eaton in partnership with the Renewable Energy Association. The study is titled Beyond the Tipping Point: Flexibility Gaps in Future High-Renewable Energy Systems in the UK, Germany and the Nordics.
Economic tipping points mean renewable energy will account for more than half of electricity generation by the mid-2020s in the UK and Germany, according to BNEF. At the same time, the cost of generating energy from wind and solar is expected to more than half from today’s levels by 2040.
The study says that “future energy systems in the UK and Germany with very high levels of variable renewable generation must be complemented by flexible resources, including energy storage.” With increased wind and solar generation, there will be some periods of time where renewables along are able to meet power demand, Eaton says in a press release. However, there will be long gaps that cannot be filled by wind or solar, and current demand response and energy storage technologies cannot fill these gaps.
Eaton says it commissioned this study “to understand the size of the challenge before exploring possible policy and technology responses, which will be the focus of the second part of the study to be released in early 2018.”
Although pumped storage hydropower is not specifically mentioned in this press release, Eaton does say the because of its large hydropower capacity, the Nordic energy system can add renewables without struggling with the seasonal gaps and increased volatility mentioned above.
The study says that a 78% renewable (11% solar and wind) scenario in 2040 is achieved without introducing large amounts of volatility or curtailment. This is thanks in part to the hydrological cycle in the Nordics, where water inflow is at its lowest during winter and at its highest during spring and summer, while wind power is higher over the winter and lower over the summer.
In fact, the report indicates that this region of the world may have “substantial spare flexibility available for export via interconnectors to support the high-variable renewables British and German markets.”