Transition to a flexible energy grid: how we tackle grid congestion

Traffic jams on the electricity grid

‘Grid congestion is like a traffic jam on the electricity network,’ explains TNO expert Hanna van Sambeek. ‘It occurs when more is demanded from the grid than it can handle. This can be due to excessive supply at a given moment or excessive demand. The energy transition is driving both supply and demand for electricity up, making grid capacity insufficient at peak times in more and more locations.’

Grid congestion affects all levels of the electricity network: high-voltage (the motorways), medium-voltage (provincial roads) and low-voltage (local streets to the front door). There are several ways to reduce congestion problems, which essentially boil down to expanding capacity or using the grid more efficiently.

Expanding grid capacity

Reinforcing the grid is the most obvious solution, but it takes years and requires huge investments, as materials and space have become scarcer and more expensive, and there is a shortage of skilled workers.

Grid operators and governments are collaborating through the National Action Plan for Grid Congestion (LAN) to speed up permits and construction, optimise infrastructure use and encourage flexible consumption.

Efficient use of grid capacity

‘Generating energy locally with solar panels and using heat pumps supports the energy transition, but the current network was not designed for this,’ says Hanna. ‘Heat pumps switching on en masse and large numbers of cars charging around six in the evening put heavy strain on the grid. A solution is flexibility: better matching electricity supply and demand.’

This is exactly what TNO has been researching for years in national and European projects, translating knowledge into practical applications.

Flexibility and end users

Through energy efficiency and flexibility we can better balance consumption and feed-in (generation). This allows us to use existing infrastructure more efficiently and enables further electrification. Four concrete examples follow below.

Smart home energy management (HEMS)

Managing capacity more efficiently on the low-voltage grid is one way to avoid grid reinforcement. TNO developed the European protocol S2, enabling all kinds of electrical devices from different suppliers to communicate with a Home Energy Management System (HEMS).

Solar panels, home batteries, charge points and heat pumps place a heavy load on the grid, but smart control and coordination can unlock major gains.

For example, S2 allows your car to charge more slowly when the heat pump needs more power. Or the grid operator offers a reduced network tariff if you can demonstrate that you help to relieve the grid.

Flex in the built environment

Flexibility with EVs and heat pumps is often available, but not yet sufficiently utilised. Some 80% to 92% of household consumers are willing to make flexibility from devices such as heat pumps, EVs, home or neighbourhood batteries and solar panels available to prevent congestion, provided the right incentives are in place.

These results come from the Built Environment Electrification (GO-e) project. In GO-e, TNO worked with grid operators, technical universities and market parties to investigate how smart flexibility services can relieve the electricity grid.

For the first time, the GO-e consortium provides detailed insight into the potential of flexibility as a solution to grid congestion in the built environment. The project shows there is a high risk of congestion in some low-voltage networks if nothing changes in the coming years.

Energy hubs

A growing number of businesses on industrial estates are joining forces to decarbonise together. This reduces dependence on fossil fuels, cuts CO₂ emissions and helps to relieve the overloaded grid. In so-called energy hubs, they can organise the generation and use of green electricity in a smart way.

The “Working together in energy hubs” roadmap from the Netherlands Enterprise Agency (RVO) offers businesses, residents, neighbourhoods, grid operators and policymakers an overview of options, translates barriers into actions and provides practical guidance to get started.

Behavioural change

Consumers can contribute through behavioural change. This is already happening in many places where residents take the initiative to work with their neighbourhood on sustainability.

More than 700 local energy communities, with around 120,000 participating citizens, play an essential role in meeting climate targets. Locally generated and used energy avoids costly transport over the grid and thereby reduces the need for reinforcement.