The UK and Germany will need more flexible backup capacity as more than half of their electricity generation will come from renewables in the 2020s, a study by Bloomberg New Energy Finance (BNEF) released during the COP 23 climate conference in Bonn states.

The rapid growth in variable renewables will lead to much greater volatility in the power system, challenging inflexible ‘baseload’ generators and creating opportunities for new flexible sources, says the study Beyond the tipping point: flexibility gaps in future high-renewable energy systems in the UK, Germany and the Nordics.

The study was commissioned by power management company Eaton in partnership with the UK-based Renewable Energy Association (REA).

“As wind and solar become the cheapest options for power generation, the race is on to develop and deploy the flexible resources that will complement them,” said Albert Cheung, head of global analysis at BNEF.

In both Germany and the UK, there will be certain days and even whole weeks where all power demand can be met by renewable generation. But in certain weeks and months, low wind speeds coinciding with cloudy skies will still require other generation sources to meet the majority of demand.

The issue this week has led to friction in exploratory coalition talks for a fourth government under German Chancellor Angela Merkel.

Green Party representatives demand a faster energy transition and a coal exit in order to still reach Germany’s 2020 climate targets, while politicians from Merkel’s Christian Democrats (CDU) and their Bavarian sister party, the Christian Social Union (CSU) reject a coal exit and claim it would lead to imports of nuclear and coal-fired power from France and Poland on days of little wind and sun.

The BNEF study, however, says while longer power gaps cannot be filled with demand response and current energy storage technologies, the increase in RE as early as 2030 will create a “very challenging environment for ‘baseload’ technologies that benefit from running at a constant stable output, such as nuclear, coal and lignite.”

Flexible power technologies such as energy storage and gas will have an advantage, as the can quickly respond to power supply gaps. BNEF says, adding that a fleet of flexible resources will need to be maintained to fill the gaps, including interconnectors and dispatchable renewable technologies such as bioenergy.

In the future, long-term storage solutions such as hydrogen may come into play too, the study says.

“Eaton commissioned this economic 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,” said Louis Shaffer, distributed energy segment manager, Europe, Middle East and Africa Region at Eaton.

“These solutions could include continued promotion of smart metering, reforms to increase market openness and transparency for all grid ancillary services and long-term grid service contracts and pricing schemes. We will also analyse the benefits of various policy options for the future of the energy market that include battery storage,” added Shaffer.

The Nordics do not experience the significant growth in system volatility as Germany or the UK power gaps can be balanced with an abundance of hydro-electric power.

Transition

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