De Groene Mient is a socio-ecological housing project in the Vruchtenbuurt district of The Hague, where 33 households largely meet the energy-neutral standard. They generate solar energy far beyond their own needs during sunny periods, so they have decided to share their excess electricity with the other Vruchtenbuurt households. A wonderful idea, which also presents significant organisational and technical challenges. The Future Urban Systems research group and the Mission Zero centre of expertise contribute their knowledge to this initiative.  
The 33 households in De Groene Mient want to share the energy they generate with 300 other households in Vruchtenbuurt. This hits two marks with one arrow, as Rizal Sebastian, Professor of Future Urban Systems, explains: “While renewable energy is abundant in De Groene Mient, few residents in the remainder of Vruchtenbuurt have solar panels. Through their initiative to share the excess of their sustainable energy with other neighbourhoods, De Groene Mient can help provide affordable energy and overcome energy poverty across the district. At the same time, Vruchtenbuurt can help De Groene Mient. Due to overcapacity issues of the electricity grid – or grid congestion – feeding locally generated energy into the grid subjects to costs. De Groene Mient can avoid these unwanted costs by sharing their energy surplus with their neighbours. The ultimate goal is to share energy on a larger scale both within the district and beyond.” 

Smart data and energy storage 
To realise these plans, pioneers in Vruchtenbuurt founded the local energy cooperative Sterk op Stroom. Last year, the cooperative received special permission from the Dutch government to become an energy supplier for the next 10 years as part of the innovation experiment programme. “This opportunity challenges them to fulfil this new role professionally,” says Senior Lecturer Fred Zoller. “The most obvious aspect is technology. Renewable energy is not available 24/7, so we need to think about ways to achieve a proper match between supply and demand. Data and AI play an important role in this respect. For example, appliances and devices that can automatically switch on when plenty energy is available.”  

Local energy storage is another indispensable component of the plans. Fred: “This might include a neighbourhood battery, or a parking square for smart charging of shared electric vehicles (EVs) with a bi-directional capability.”

Solving mobility problems with energy 
Last February, the research group participated in the national Synergy Hackathon at Green Village, TU Delft. Students, researchers, companies and neighbours gathered to explore possible solutions, and proposed the smart parking and charging station. “Since the Vruchtenbuurt district simultaneously struggles with a major parking problem, the idea of working with shared EVs emerged”, Researcher Noelle Choong explains. “Access to shared EVs could enable some residents to get rid of their private cars. Moreover, the batteries of these shared EVs with a bi-directional capability can serve as flexible storage within the smart grid.”  

How can car batteries be a part of the smart grid? Noelle clarifies how this would work: “Usually, you charge an electric car with more energy than you consume during a daily drive, allowing the excess energy in the car’s battery to power your TV in the evening or run the dishwasher.”
Residents are the key to success 
A wide range of solutions and possibilities are conceivable, and now it’s a matter of testing the various options to see what works. “Trust in the local community and in the technology is essential,” says Fred. “If we start working with a data-driven approach, everyone needs to understand what that entails. It is still unclear which systems and products we will end up with, but to succeed, we need to keep everyone involved in the development. By continuously analysing data and exploring new scenarios, we can show people how much energy they can potentially save. Using these insights, we hope to get more residents on board.” 

Resident symposium 
On 28 June residents will come together to discuss various options during a symposium. In preparation, Noelle is currently analysing various datasets on aspects such as neighbourhood energy consumption. “We will present several scenarios”, she explains. “Like the impact on the smart grid if residents would do their laundry an hour later than usual. How would they feel about making that change?” 

Step by step 
The Sterk op Stroom cooperative currently has about 300 members. “These are the frontrunners, enthusiasts who are eager to contribute ideas and participate,” Rizal explains. “To make local energy sharing in a decentralised system into a success, we need at least 3,000 households to sign up for the so-called democratic energy contract. This growth will come naturally once the initial results become apparent – I am convinced of that.” Fred adds, “In addition to the smart electricity grid with a smart parking and charging station, we are investigating a smart multi-commodity grid for sharing electricity and heat. This will enable the project to grow step by step and make a real contribution to decentralising our energy systems.” 

This applied research project in collaboration with local residents is made possible by innovation subsidies from the City of The Hague, especially the subsidy programme for higher-education awarded to The Hague University of Applied Sciences and the subsidy for local community in the ‘Energie uit de Wijk Challenge’ awarded to Sterk op Stroom. The project has been incorporated as a Climate Deal in The Hague’s Climate Agreement launched on 10 April 2024, which is an implementation of the EU Mission towards 100 Climate-Neutral and Smart Cities by 2030.