A study by the Netherlands Authority for Consumers and Markets (ACM) has found that energy suppliers in the Netherlands can differentiate between households with and without solar panels in their rates, as long as the differentiation is based on the additional costs incurred. The study focused on four major energy suppliers - Budget Energie, Vattenfall, Eneco, and Engie - who supply electricity to over half of Dutch households.

The extra costs for suppliers related to households with solar panels include higher purchasing costs, higher imbalance costs, and costs associated with the net metering scheme. ACM concluded that the rates charged by these suppliers to households with solar panels were based on these additional costs and were consistent with the law.

Despite charging higher rates to households with solar panels, the study found that the suppliers do not achieve higher margins overall, as they also charge lower rates to households without solar panels. ACM highlighted the need for suppliers and energy-comparison companies to make it easier for consumers with solar panels to compare contracts effectively.

ACM will continue to monitor the evolution of feed-in costs and the differentiation in rates between households with and without solar panels in the consumer energy market. The authority plans to conduct more follow-up studies if necessary to ensure compliance with regulations.

In a separate report, ACM's monthly Monitor on the consumer energy market revealed an increasing number of households opting for fixed contracts, although the growth rate has slowed compared to previous periods. In April, 55% of consumers had fixed contracts, 42% had variable contracts, and the remaining households had dynamic contracts. The number of households with dynamic contracts is steadily increasing, while the rate of consumers switching contracts remained low in March.