No grid expansion despite more solar power: BFH researchers point to solutions

05.09.2023 The growing number of PV systems poses a challenge for the stability of the electricity grid. What solutions are already available as an alternative to costly grid expansion, is the topic of a discussion paper published by researchers from the Laboratory for Photovoltaic Systems at Bern University of Applied Sciences BFH.

One focus of Switzerland’s Energy Strategy 2050 is on the rapid expansion of renewable energies. Photovoltaics (PV) will account for the majority of this. However, the planned output of all PV systems (around 40–50 GW) would overload the electricity grid during load peaks, which is why there is often talk of the need to expand the grid, although, expanding the network takes a great deal of money and time. Moreover, it does not solve the problem that there is an oversupply of solar power throughout Europe at the same time as peak production by PV systems in Switzerland. This means that the load peaks cannot be absorbed by the grid and probably cannot be exported due to the lack of consumers. In a discussion paper, researchers from the Laboratory for Photovoltaic Systems at the Bern University of Applied Sciences BFH propose alternative solutions for integrating large amounts of solar power into the grid without having to expand the grid. This paper was developed within the scope of SWEET EDGE, the national research project. SWEET EDGE’s main goal is to model energy systems of the future for cities, the Swiss Plateau and the alpine regions, to identify the challenges involved and to respond to them with recommended courses of action wherever possible.

Kein Netzausbau trotz mehr Solarstrom: BFH-Forschende zeigen Lösungen

Framework conditions need adapting

In their discussion paper, the researchers write that most of the solar power could be absorbed by intelligent, decentralised systems. These include battery storage systems or electric cars, for example. Suitable products and solutions are available on the market and have been used in various projects for many years. However, in order for these systems to provide reliable relief for the electricity grids and enable increased PV capacity without additional excessive grid load, the researchers say that two factors in particular need to change. Firstly, the absolute feed-in priority of solar power must be placed in the proper context. This means that there should be no right to feed load peaks into the grid when they are not relevant in terms of energy but are challenging and uneconomical for the overall system. Secondly, grid operators and regulators must allow decentralised, flexible systems and encourage grid-serving behaviour by offering an appropriate incentive system.

Implementation can begin

The question of how to successfully connect PV systems to the grid with a high proportion of solar power is one that concerns a number of different stakeholders, such as distribution grid operators and installation companies, but also PV system operators and politicians. The discussion paper with the possible solutions was presented to representatives of all stakeholders to solicit their feedback. The next step is for the researchers at BFH and the entire SWEET EDGE consortium to gather further feedback from the participating industries. They want to become involved in the discussion of grid integration, gain additional experience and collect best practice examples, with the aim of publishing a revised, even more broadly supported version of the discussion paper. In addition, the authors of the discussion paper hope that certain of the ideas will be adopted and implemented right away.

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