Flexibility is the key for net zero

UKPN to reveal flexibility tender results

Grid operators look for inertia solutions

“TSO of the North” project under discussion

Local Electricity Bill supported by MPs

Grid flexibility is a crucial tool for the electricity system to reach carbon neutrality and it is already becoming business as usual, market experts said in a Climate Action webinar this week.

The cost of solar and wind power has plummeted - making a sound case for renewable energy - but variability must be addressed for high levels of deployment to be reached.

“Today’s challenge is not the availability of technology, it’s integrating high shares of wind and solar in the power system. Grid flexibility is key to the cost-effective use of renewables,” said Roland Roesch, Deputy Director of the Innovation and Technology Centre at the International Renewable Energy Agency.

Flexibility could save customers in Great Britain up to £40 billion by 2050, according to a study by Imperial College London.

Distribution Network Operators are already procuring flexibility through tenders and using new platforms. UK Power Networks will announce the results of its latest flexibility tender this week, said Stathis Mokkas, the DNO’s Energy Markets Lead. Up to seven year contracts worth £27 million were available in last month’s tender, for up to 170MW capacity. This is a longer duration contract than the first rounds in 2019, and the bid size has been brought down to 50kW to facilitate increased participation. This is driven by the DNO’s principles to improve accessibility to flexibility markets, to be a neutral market facilitator and commitment to use flexibility markets when efficient.

UK Power Networks was the first DNO to use Piclo Flex, an independent flexibility marketplace. Last year it contracted 45.1MW of cumulative capacity, and puts its success down to having a clear framework, with transparency on size and location in terms of requirements and indicative revenues for providers. UK Power Networks is also working with other DNOs through the Open Networks project at the Energy Networks Association to standardise and facilitate flexibility markets. It also has an ongoing trials with National Grid ESO to resolve voltage issues at the transmission system. In addition, it is developing a new market to facilitate the connection of additional renewables on the network. Also, it conducts trials with third parties such as Kaluza, another software platform connecting home devices and electric vehicles, to reduce pressure on the grid at peak times. By 2030 there could be more than 10 million EVs on UK roads, so how to transmit signals and incentivize flexibility is a big question.

Transforming the grid from centralised hubs of large power plants into a decentralised network of thousands of micro generators is like building a ship while at sea, said Carolina Tortora, Head of Innovation Strategy at National Grid ESO, which runs the England and Wales transmission grid and is responsible for market operation starting from an hour before real time. Testing new technologies should not be rushed, but meeting the pledge to be able operate a carbon neutral electricity grid by 2025 and a whole energy system by 2050 is a significant challenge. National Grid’s Future Energy Scenarios study estimates if all vehicles are electrified an additional 5 - 20GW of demand could be added depending on various factors, an increase of around 9 to 30% over current peak demand.   

At the same time, the intermittency of renewables makes supply harder to forecast and monitor as it is embedded in the distribution network, making cooperation between the transmission and distribution system operators crucial.

Consumption patterns are also more unpredictable, which calls for a bottom up approach to changing market design, said Richard Sarti, Director of Marketing and Sales at NODES, a European marketplace for decentralised flexibility. Many countries have an unfavourable regulatory framework for flexibility projects with incentives for investment in physical assets prioritised over operational expenditure such as software upgrades, although the UK has introduced a total expenditure system. Successful flexibility markets will also depend on the willingness of industry to investigate flexibility solutions before conventional grid reinforcement, and whether system operators allocate innovation funding to embark on projects. Regulatory sandboxes to trial innovative projects should be continued, Sarti said.

A new challenge system operators will face as the share of renewables increases is a decrease in inertia. When large power stations stop working, the turbines take a while to stop turning, meaning that electricity does not suddenly shut off. But this is not the case with small renewable plants.

National Grid ESO takes a three-pronged approach to tackling such challenges based on regulatory, network and market solutions. It has already recalibrated the system to be able to withstand greater frequency excursions. Secondly it is looking at synthetic options such as supercapacitors and hydro-compensators to simulate inertia without providing any active power to the grid. Thirdly it is conducting market-based innovation projects, looking at how to forecast and value inertia from for example wind farms and batteries.

Putting storage on a level playing field with other sources of generation will be key to managing inertia, said Sarti. Digital technologies including artificial intelligence and blockchain will facilitate the transition, making access to data a priority.

There are two extremes for the future development of a flexible grid run entirely on renewables. One is developing a globally interconnected grid that could bring power from resource-rich but geographically isolated areas such as the Sahara desert via high voltage lines, and the other is a local peer-to-peer community network relying on embedded small generators. The future grid in Great Britain may be a combination of the two, Tortora said, and there are many projects at the EU level looking at interconnectivity. One idea being mulled is the “TSO of the North” proposal with an offshore TSO commonly run by the UK, Norway, Germany and the Netherlands.

Meanwhile non-profit campaign group Power for People has gathered support from 132 MPs for a Local Electricity Bill to encourage and enable the local supply of electricity. Although the global climate meeting COP26 had to be postponed to 2021 due to the COVID-19 pandemic, political pressure to decarbonise the electricity system remains strong and this underpins the need for flexibility.