Fotovol

Solar panel calculator

How many kW you need, what it costs, when it pays back

Calculate in 30 seconds how many kW of solar panels you need on your roof, the estimated cost in lei, and the value after the Casa Verde subsidy. Start from your monthly consumption (on your electricity bill) and adjust for EVs, heat pump, or extra AC units. For a contractual figure request a quote or read the help guide.

Advanced calculator

Advanced calculator — detailed sizing

Look on your electricity bill.

Panel brand (preference)

These numbers are indicative only. Only an installer visiting your home can tell you exactly how many panels will fit and how they'll be positioned on your roof.

See how panels would fit on your roof

Enter dimensions and watch panels pack onto a top-down preview, with compass + tilt + occupancy controls.

Brand directory by tier — what you will be looking at

Panels

Inverters

Batteries

How the solar panel calculator works

The calculator gives you three numbers from your input: recommended system capacity in kWp, estimated total cost in lei, and what portion of that cost the Casa Verde subsidy could cover. It starts from your average monthly consumption in kWh (on your electricity bill) and adjusts for electric vehicles, heat pumps, and extra AC units. The output also reflects your panel-tier preference (top, mid, low) and an optional storage battery.

Assumptions behind the numbers

The calculation uses an average yearly production of ~1,250 kWh/kWp for south-facing systems, varying between 1,150 and 1,400 kWh/kWp depending on the county and roof tilt. The electricity price defaults to a representative Romanian residential tariff for 2026; if your tariff is different, the payback period scales linearly. The maximum subsidy considered is 20,000 RON, the AFM Casa Verde cap. Cost ranges use mid-market prices for residential kits and already account for the reduced VAT regime applied to home installations. Panel degradation (~0.5%/year) and maintenance fall outside the calculator's scope.

From estimate to real decision

The number is a sanity-check anchor for installer conversations, not a binding price. Use it to compare 2–3 quotes: if one is 30% above the estimate, ask why; if it's lower, check the equipment (panel tier, inverter brand, battery type). A real number needs an on-site assessment of orientation, tilt, electrical panel, and distance to the meter. Read more in how much a solar system costs and how Casa Verde works, or request a personalized quote. To estimate how many panels fit on your roof, use the positioning estimator.

Frequently asked questions

How much do I save with solar panels?
Depends on your consumption and tariff. A typical Romanian home with 4,000–6,000 kWh/year consumption saves 4,000–7,000 RON/year at a ~1.3 RON/kWh tariff. Enter your real monthly kWh in the calculator for a personalized number.
How long until a solar system pays back?
Without subsidy: 7–10 years; with Casa Verde: 4–6 years. Varies with tariff, consumption, and system size. If the tariff rises, the payback period shortens automatically.
Does the calculator include the Casa Verde subsidy?
Yes, if you tick the option, the calculator deducts the 20,000 RON cap from the total cost. The subsidy isn't automatic — you must apply separately at AFM when the program opens. See the Casa Verde guide for details.
How does the electricity price affect payback?
Directly and linearly. At constant consumption, a 20% tariff increase boosts annual production value by 20% and shortens payback proportionally. If tariffs fall (unlikely long-term in Romania), payback lengthens.
Can I sell excess energy?
Yes, via prosumer status. In Romania's current model, excess fed into the grid offsets consumption at the same tariff (simplified net metering) over a year. The calculator assumes this model — for details see what it means to be a prosumer and check your supplier's offer.
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