Zonnepanelen blijven rendabel na einde salderingsregeling, blijkt uit nieuw onderzoek

PhD student Carlotta Masciandaro and Professor Machiel Mulder from the University of Groningen (RUG) used a simulation model based on 2021 data to map the distribution of costs between households with and without solar panels. Their research, published in the scientific journal Energy Economics, analyzes the effects of the net metering scheme on energy bills.

Key Findings

• The net metering scheme shifts part of the electricity bill from households with solar panels to those without.
• Households without solar panels pay 14% more for their electricity bill due to the scheme, while households with solar panels pay 74% less.
• This inequality arises because households without solar panels pay energy tax on their total consumption, whereas solar panel owners do not pay tax on their net consumption after netting annual production against usage.

Impact of Net Metering

• Under net metering, electricity production is valued at the same price as consumption, with households paying only for their annual net consumption.
• Without net metering, households would pay one price for electricity drawn from the grid and receive a lower price for surplus energy fed back into the grid.

Policy Changes

• The Dutch government will abolish the net metering scheme on January 1, 2027, citing unequal cost distribution and lack of incentives for immediate solar energy use.
• Without net metering, the payback period for solar panel investments will increase from just over 5 years to approximately 9 years.
• Despite this, solar panels remain a viable long-term investment, with a technical lifespan of 15–30 years.

Financial Implications

• Households with solar panels currently save about €690 annually due to net metering; this will drop to €385 after 2027.
• Annual savings of €250 are needed to recoup installation costs.

Cost Components Analyzed

• The study examined three cost components of electricity bills: supplier costs, grid management costs, and energy taxes.
• All costs are assumed to be passed on to households under a budget-neutral approach.

Supplier Costs

• The electricity price rises from €0.11 to €0.12 per kWh due to increased renewable energy capacity, despite the merit-order effect lowering wholesale prices.
• Higher balancing costs arise from uncertainty in predicting household consumption, leading to additional expenses for energy suppliers.
• Suppliers also face higher costs from reimbursing households for surplus energy, prompting the introduction of feed-in tariffs.
• Households without solar panels pay 7% more to their energy supplier, while those with solar panels see a 93% reduction in their bill due to lower grid consumption.

Grid Management Costs

• Grid expansion due to solar panel installations increases annual grid management costs from €190 to €196 per household (a 3% rise).
• All households bear these costs equally, regardless of solar panel ownership, as mandated by the Dutch Authority for Consumers & Markets (ACM).
• Total estimated investment for grid expansion is €51 million, based on 2021 solar panel installations.

Energy Taxes

• Net metering reduces the tax base, as households with solar panels pay energy tax only on net annual consumption.
• The Dutch government lost an estimated €550 million in revenue in 2021 due to this reduced tax base, leading to a 37% increase in the energy tax rate (from €0.08 to €0.11 per kWh).
• Households without solar panels pay 32% more in energy taxes, while those with solar panels see a 91% reduction.

Regional and Housing-Type Variations

• Detached homeowners without solar panels are most adversely affected, while semi-detached homeowners with solar panels benefit the most.
• Solar panel yield varies by region, with sunnier areas offering greater savings.

Post-2027 Compensation

• From 2027, households with solar panels will receive a guaranteed feed-in tariff for surplus energy, set at a minimum of 50% of the supplier’s electricity price until 2030.
• This tariff ensures solar panels remain profitable, with annual savings of €385, though the payback period will extend to over 9 years.
• Transparency in feed-in tariffs is crucial for informed investment decisions, and long-term policy clarity is recommended.

Alternative Tariff Structures

• A net billing system, compensating surplus energy at 25% of the average wholesale price, could distribute costs more equitably.
• Converting energy tax from a per-kWh rate to a fixed household fee would limit cost increases for non-solar households to 2%, though this shifts the tax’s purpose away from discouraging consumption.