Featured · Power, grid and money
What is net metering?
What net metering means: your supplier offsets solar you feed back against what you draw. The scheme ends on 1 January 2027. Here is what changes.
Knowledge base. From watt-peak to heat pump, explained in plain language.
34 articles · 13 terms explained in brief
Where do you start? Pick your situation and we put the explainers in order.
- 01
Your quote is on the table
Watt-peak, inverter capacity, expected yield: a quote is full of terms you only need to understand once. These explainers help you check whether the numbers fit your roof and your usage.
- 02
Net metering is ending and you feed in power
With the net-metering scheme on its way out, what your exported power earns is changing. Read how net metering works, which charges suppliers apply and whether a dynamic contract suits you.
- 03
You are considering a home battery
A battery only pays off when the numbers add up. Start with costs and payback time, compare life with and without a battery, and see what smart grid control means for your situation.
- 04
From gas boiler to heat pump
Whether a heat pump suits your home mostly comes down to insulation and your heating system. First test whether your house is ready, then choose between hybrid and all-electric.
All explainers. By topic, with what each one covers.
- What does a home battery cost? From €5,445A home battery from SolarFast starts at €5,445 including VAT and installation. Prices per capacity (around 5 to 25 kWh), price level September 2026.
- Which home battery do I need? How to find the right sizeWhich home battery do I need? Evening and night use sets the kWh. Then your fuse box (single or three phase), solar surplus and inverter come into play.
- A home battery without solar panels: does it pay?A home battery without solar panels charges at cheap hours and discharges at expensive ones. When that pays, what you need and when waiting is smarter.
- Where to place a home battery?The best place for a home battery, room by room: shed, garage or attic, and why the crawl space is out. With fire service advice and our fitting practice.
- Backup power with a home battery: how it worksBackup power with a home battery only works with a backup provision. What stays on: the fridge, or the whole meter cupboard.
- Home battery subsidies: what exists?No national home battery subsidy in the Netherlands. What exists: VAT refunds under conditions, local schemes, EIA for businesses and Warmtefonds loans.
- How home battery VAT refund worksHome battery VAT refund: if your battery trades in power, you can reclaim the VAT on purchase and installation. Conditions, steps and KOR timing.
- Double energy tax on your home batteryFrom 2027 your home battery can cost you energy tax twice: when it feeds grid power back. When it does, when it does not, and what the cabinet is doing.
- Smart grid controlGrid control and net-aware charging: how your supplier steers your charger, home battery or heat pump, what you notice and whether you get paid.
- Electricity imbalance market: what it isThe electricity imbalance market is where TenneT settles deviations per quarter-hour. A home battery can follow those prices via your supplier.
- Home battery and inverter safely online: how to do itA home battery, inverter or charger is usually online. What you arrange yourself (updates, password, wifi) and which EU rules apply from 2027.
- Buying solar panels: what to look forBuying solar panels: quote, inverter, warranty, meter and installer. How to compare quotes fairly.
- How many solar panels do I need? The calculationWork out in three steps how many solar panels you need. For 4,000 kWh you land around 11 panels of 435 Wp, depending on your roof.
- Solar panel yield per year and per monthSolar panel yield: 0.85 to 0.9 kWh per watt-peak per year. That yield splits by month: high in summer, low in winter.
- Solar panels on a flat roof: ballast, layout and yieldHow much ballast you need on a flat roof depends on wind zone and the roof, not a fixed kilo figure. South or east-west sets the layout.
- Solar panels on a dormer: what is possible?Solar panels on a dormer: they often fit on its flat roof, and above, beside or below it on the main roof. Structure and shade decide what is possible.
- Solar panel sizes and weightSolar panel weight on roof tiles: about 20 to 25 kilos each. Common sizes and how many genuinely fit on your roof.
- Cleaning solar panels: when is it worth it?Cleaning solar panels? Usually unnecessary: rain does the work. When it pays off (flat roofs, bird droppings), how to clean safely and the upkeep that matters.
- VAT on solar panels: 0% and when to fileOn solar panels on or at your home you pay 0% VAT. When you may still have to file: as a freelancer, above 15,000 Wp or after moving. With the KOR pitfall.
- What is net metering?What net metering means: your supplier offsets solar you feed back against what you draw. The scheme ends on 1 January 2027. Here is what changes.
- Feed-in payment: what you get for exported solar powerThe feed-in payment is what your supplier pays for exported solar. Who sets the rate, and what changes when net metering ends.
- Grid congestion: what still fits your homeWhat grid congestion means, what you notice at home, and how to check what still fits your connection. Soft postcode check plus the capacity map.
- Single-phase or three-phase: upgrade needed?How to recognise your power connection and what fits on it. Plus when upgrading for a heat pump, EV charger or home battery is needed, and what it costs.
- Home energy management system (EMS) explainedHome energy management system (EMS) explained: how it steers solar panels, home battery, heat pump and EV charger on your own surplus and hourly prices.
- Energy independence: more solar self-consumptionBecoming energy independent starts with self-consumption: more own power by day, a home battery for the evening and smart use. You stay on the grid.
- Financing energy upgrades: loan or mortgageFinancing solar panels, a home battery or a heat pump? Compare the Energiebespaarlening, extra mortgage room and savings, with conditions and a worked example.
- How much electricity does air conditioning cost per day?A fixed air conditioner (single split) uses about 0.7 kWh per hour of cooling. A simple sum and three examples show what a day of cooling costs.
- Insulation for a heat pump: what do you need?Is your home insulated well enough for a heat pump? Run the 50-degree heating test, see which insulation pays off first and choose hybrid or all-electric.
- Heat pump subsidy: ISDE for air-to-waterISDE applies to air-to-water heat pumps, not to air-to-air. Who can apply, which documents you need and how to apply in eLoket after installation.
- How many kWh does a heat pump use per year?A heat pump's yearly electricity use depends on your heat demand and the SCOP, for an 8 kW unit or a hybrid too. How to run the numbers yourself in kWh.
- Underfloor heating and heat pumps: ideal match?Why underfloor heating and a heat pump work so well together, when radiators are enough and what fitting it in an existing floor involves.
- How much noise does a heat pump make?A heat pump outdoor unit may cause at most 40 dB at the neighbours. What that limit means, how the sound feels in practice and what placement does.
- Charging your car on your own solar powerWith a smart charger your car charges on your solar surplus. How surplus charging works, where the lower limit sits and what it saves.
- A charger in your owners' association: how to get it doneA charger at your parking spot in a Dutch VvE often needs approval today. How to approach it, what the 2017 model rules allow and which law is coming.
Terms from A to Z
Quick look-up
What a word means, in a sentence or two. Want to know more? Read the full explainer.
- COP and SCOP
- How much heat a heat pump delivers per kWh of power. The SCOP is that figure averaged over a heating season.
- Full explainer COP and SCOP
- Diversity factor
- Not everything in your home runs at full power at the same time. This factor lets you check whether everything fits on your connection.
- Full explainer Diversity factor
- Dynamic energy contract
- You pay the current power price by the hour or quarter-hour instead of a fixed rate.
- Full explainer Dynamic energy contract
- Feed-in
- Power your solar panels send to the grid when you generate more than you use. Your supplier settles this through net metering or a feed-in payment.
- Read on: What is net metering
- Feed-in charges
- What your supplier charges for the power you feed back to the grid.
- Full explainer Feed-in charges
- Home battery lifespan
- How long a battery lasts, expressed in charge cycles and warranty years.
- Full explainer Home battery lifespan
- Inverter
- Converts the direct current from your panels into the alternating current you use at home.
- Full explainer Inverter
- kWh (kilowatt-hour)
- 1,000 watts for one hour. You read your usage and your yield in kWh.
- Full explainer kWh (kilowatt-hour)
- kWp (kilowatt-peak)
- One thousand watt-peak. Useful for larger systems: a 4,000 Wp installation is then written as 4 kWp.
- Read on: What is Wp (watt-peak)
- Optimizer
- A small box per panel that limits shade loss and shows the yield per panel.
- Full explainer Optimizer
- P1 port
- The data port on your smart meter. It lets you read your usage and feed-in yourself, for example for an energy monitor or home battery.
- Read on: What is net metering
- Self-consumption
- The share of your self-generated power that you use in your own home straight away. The higher your self-consumption, the less you draw from the grid.
- Read on: Energy independence
- Watt-peak (Wp)
- The peak output of a solar panel under standard test conditions.
- Full explainer Watt-peak (Wp)
How we write these explainers. No sales talk.
- From practiceWith examples from the roofs and meter cupboards our installers work with.
- Rules checkedWe check rules and policy against the official source before they go into an explainer.
- Up to date on the blogRates and news that change fast live on the blog, so these explainers do not go stale.
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