The increasing complexity of the electricity system as more renewables are integrated creates a new dimension that calls for much greater cooperation between system operators. This was one of the key messages that emerged from the Smart Grid Flexibility conference in London this week.
While growing renewable sources of generation overcompensates for fossil fuel and nuclear generation capacity that will be lost, but due to the intermittent nature of wind and solar availability is not guaranteed, warned Andreas John, head of system management at one of the four German TSOs 50Hertz.
Around 65% renewable penetration is forecast for 2023 in the 50Hertz transmission system area. “Sooner or later it will not be enough. I’m really concerned how we will bridge the gap between available generation and customers´demand in future,” John said. “An increased line loading in addition to new lines are difficult to realize, it makes the razor blade we are dancing on a little bit sharper.”
In one scenario of Germany´s grid development plan to realize the tnergy transition an extra 11,600km of transmission line needs to be constructed, which is a massive cost burden. “Grid tariffs can only go in one direction – upwards,” he said.
Assets to control power flows such as phase shifting transformers, HVDC interconnections, dynamic line rating and grid boosters will stretch the limits of the grid, but these will increase complexity. As the share of renewable generation increases it is no longer enough to rely on previous concepts, and a philosophy change is needed, he added. Operational schemes must be adapted, operators’ skills must be extended and SCADA/EMS functionality must be developed rapidly to support the energy transition. “Vendors claim to have the solution and understand the system operators’ challenges but when it comes to the crunch they shrug their shoulders,” John said.
TSOs have a large number of moving targets to comply with in a short time horizon, John continued. For example in Germany there is a Grid Expansion Acceleration Act (NABEG) reforming redispatch procedures which must be complied with by October 2021. While there are many vendors offering flexibility products, these will not be enough to solve all the challenges without cooperation from renewable generators and distribution system operators. As traditional power plants are phased out more alternative reactive power and voltage management is required, and it is still unclear whether reactive power compensation devices are covered under the operators’ asset base, or will come under a market regime.
The four German TSOs are now working on a €10 million automated system management project involving Friedrich-Alexander-Universität Erlangen-Nürnberg called InnoSys 2030, funded by the Federal Ministry for Economic Affairs and Energy. This will help to integrate renewables, but the added complexities will likely take their toll on the system, John concluded. “What we are doing is live surgery on a living system in which our entire welfare is dependent.”
Other system operators speaking at the event strongly agreed that further cooperation and flexibility projects are required. “If we don’t coordinate, the regulator will coordinate us, so we have an incentive to coordinate,” said Yvonne Ruwaida, business strategist at Vattenfall Distribution. In Sweden there is a need to use flexibility due to grid constraints in the TSO grid, she said. “It is not so much too much production but too much load that is the challenge. A modern revenue regulation incentivising the use of smart grid solutions is needed to unlock flexibility. Also the understanding that there is no one-size-fits-all. Flexibility can be used for both congestion management in different voltage levels and balancing on the system level by coordinating and not by competing.” Vattenfall is participating in the EU Horizon 2020 flexibility project CoordiNet, which has three large-scale demonstrators implemented by both the DSO and TSO in Sweden, Spain and Greece.
Energy producers also increasingly see flexibility as key to their strategy. Norwegian renewable energy producer Agder Energi is working on a number of initiatives, CEO of Agder Energi Fleksibilitet Rune Hogga, such as partnerships with Microsoft and Cognizant, and he is also chairman of the board of NODES, a flexibility platform jointly owned with Nordpool. The Engene flexibility pilot with Microsoft uses the Azure cloud solution architecture in the medium voltage grid to forecast load and renewable supply and then uses algorithms to determine optimal dispatch of resources. In one case it allowed a €5 million investment to be deferred, Hogga said.
NODES is an integrated energy marketplace offering local flexible power resources to DSOs and TSOs. It has a parameter-based structure rather than using fixed products, which means it can be adapted for the microgrid, DSO or TSO level. The Norwegian TSO Statnett is also engaged with the NORFLEX project, which demonstrates the use of local flexibility in the grid areas of Agder Energi Nett, Glitre Energi and Møre Nett using the NODES marketplace.
Several studies are trying to estimate the value of flexibility in deferring grid investment. Scottish and Southern Electricity Networks (SSEN) will soon issue a paper with consultants Frontier Economics on a method to quantify how to compare network reinforcements with flexibility services. French DSO Enedis estimated the value at between €5/kW/year and €24/kW/year in a 2017 paper, although noting that the valuation of the flexibilities depends greatly on how they are implemented.
Another initiative discussed at the Smart Energy Forums conference is Internet of Energy (IO.Energy), which aims to facilitate the development of new energy services in Belgium by focussing on consumers using digital and technological innovation. Founding members include Belgian system operators Elia, Fluvius, Resa, ORES and Sibelga.
Many flexibility projects will call for greater engagement from customers, but the challenge will be how to encourage participation when the financial incentives are likely to not be sufficient, and few are willing to relinquish control over their freedom to use energy whenever they like.