A group of Dutch companies has joined forces to develop a comprehensive alternative to gas-fired CHP (Combined Heat and Power), ensuring that affordable electricity, heat, and CO₂ remain available. Voltiris and TNO are taking the lead on this initiative. With the help of an MOOI subsidy, the companies will collaborate over the next three years. The goal? To shape the future energy supply for greenhouse horticulture.
The acronym MOOI stands for Mission-Driven Research, Development, and Innovation (Missiegedreven Onderzoek, Ontwikkeling en Innovatie). Kaz Vermeer from Voltiris explains that the Dutch-Swiss company, which developed a special solar panel system for greenhouses, saw opportunities for a horticulture project within this broader subsidy program.
The subsidy program is designed to support strategically important innovations. To qualify for funding, a project must fit within one of the designated innovation themes. In the case of the Voltiris project, this theme is "Multi-use of space for renewable electricity production on land."
© Kaz Vermeer
The project partners at the kick-off
Tracking the sun
Voltiris has developed a system in which solar panels are not placed on the greenhouse roof but installed inside the greenhouse. The system consists of small solar panels and spectral filters placed at the top of the greenhouse. These filters allow PAR light (Photosynthetically Active Radiation) to pass through to support plant growth, while other light frequencies, including infrared, are reflected and concentrated onto photovoltaic panels. This not only protects plants from excessive heat radiation but also generates energy. Since the PAR light is transmitted, no shadow is created. The installation moves throughout the day to follow the sun's path, optimizing energy production.
"Because we track the sun, our power generation profile is more consistent compared to fixed-panel systems. By following the sun, we can start generating electricity earlier in the day and continue for longer. This dual-axis tracking system produces up to 35% more energy annually than static solar panels."
The MOOI project focuses on large-scale decentralized production and consumption of solar energy in greenhouse horticulture. By installing solar panels inside greenhouses, the approximately 10,000-hectare greenhouse area in the Netherlands can be better utilized. There are already greenhouses with solar panels in the Netherlands, but these often block significant amounts of sunlight, leading to discussions about which crops can still be grown underneath.
Voltiris' research at Delphy has shown that bell peppers can be grown under the panels. Project partners have calculated that Dutch greenhouse horticulture has the potential to provide 5 gigawatts of solar PV capacity, a 25% increase compared to the current national capacity.
Scaling up
Now that the subsidy application has been approved, the project partners can move forward. In addition to Voltiris and TNO, the project includes Horconex, Skytree, Delphy, Lingezegen Energy, Division Q, and Hortivation. Advisory support is provided by Harvest House, Capturam, Rabobank, 3M, Glastuinbouw Nederland, and the Netherlands Enterprise Agency (RVO).
The first phase of the project focuses on scaling up the production and installation capacity of Voltiris' spectral-filtering panels. This year, pilot trials will be conducted at Division Q's Broeikas facility, which is also equipped with bubble-based cavity wall insulation, and at Lingezegen Energy. In 2026, a large-scale 1-hectare demonstration will take place in an existing greenhouse within the Lingezegen Energy cooperative.
"We believe that at least one hectare is needed to demonstrate that our innovation works on an operational scale."
Beyond this project, Voltiris is also working on practical installations with various growers in the Netherlands and Belgium. In April, installation will begin for a 1-hectare cherry tomato project in Switzerland. Voltiris' technology has been further developed in recent years:
The already minimal shadow effect of the system has been reduced by 10-15% through smaller aluminum components.
System output has been further optimized by improving light concentration on the solar panels.
"In the early years, we invested a lot of time in fundamental system development. Now that the system is ready for real-world use, we are scaling up. Collaborative projects like this, along with our commercial installations, are crucial for expansion."
Behind the meter
Kaz emphasizes that the project is not just about Voltiris' solar panel system: "This is a system-wide innovation. A key part of the project is gathering insights from all partners. Questions we address include: What is needed for installation in a greenhouse? What kind of specialists are required? Do workers need specific training? The goal is to implement the innovation as broadly as possible."
The research involves a combination of hardware and software. TNO will investigate how to optimally manage large-scale solar energy generation.
"The goal is to use as much electricity as possible behind the meter, as this is financially beneficial for growers and aligns with grid operators' strategies for managing network congestion."
To achieve this, TNO is developing algorithms that will be tested in small-scale trials this year. By next year, the aim is to scale up to a 1-hectare site, ensuring minimal electricity is fed back to the grid and maximizing on-site usage. The project partners intend to share the energy optimization algorithms and management system with the market.
© Kaz VermeerVoltiris' system in practice
Replacing CHP
Growers play a crucial role in this project. "We are looking at applications for individual growers as well as cooperatives like Lingezegen Energy. Their involvement is exciting." Linzegen Energy is actively working on future energy sources, and solar power generation with Voltiris' system fits perfectly into their strategy. "Electrification is increasing. Electricity can be used for heat pumps to replace natural gas heating or for CO₂ capture from ambient air using Skytree's system, instead of relying on CO₂ emissions from CHP plants."
The project will run for three years, until the end of 2027.
"We're thrilled that so many partners have joined and are enthusiastic about this project. RVO also took notice. It's exciting to see how what started as an ambitious idea has turned into a concrete collaboration with top horticulture players, shaping the future of energy supply in greenhouse horticulture. The future requires action!"
For more information:
Voltiris
kaz.vermeer@voltiris.com
www.voltiris.com/