by Power & Sun Beta version
Solar panels across open land at sunset

Finland

Solar estimate for Helsinki

Satellite-measured irradiance: 988 kWh/m²/year. A 100 kWp rooftop in Helsinki generates about 95 MWh a year.

Yield
949 kWh/kWp/year
Performance ratio
86%
Mean air temperature
7.0 °C
Sunniest of 132 cities
No. 127

Sunlight through the year

Jun is the strongest month at 6.19 kWh/m² a day and Dec the leanest at 0.09. Air temperature runs from -7.1 to 18.9 °C. Source: typical year from PVGIS-SARAH3, at 14 m above sea level. The 100 kWp figure is the estimator’s, for a flat roof with open sky, and carries a band of about plus or minus fifteen per cent.

We do not print a tariff for Helsinki: rates differ by utility and customer class, so the estimator below uses the rate from your own bill.

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Helsinki is filled in. Add your roof and your rate.

1 What kind of system? This decides which of the questions below are worth asking.
2 Where it is, and what the roof is like The sunlight at your coordinates is the largest input to everything that follows.
Shape
Anything shading it?
3 What you use, and what it costs Your own tariff, so the saving is yours rather than an average.
An off-grid or hybrid system is sized against what you use, so one of these is needed. Solar beside generators is sized against the load they carry, so one of these is needed.
When do you use most of it? This decides how much of the generation you use rather than export.
Add a battery? Without one, solar can carry about 60% of the daytime load. With one, the sets rest through the day and into the evening.

Nothing is stored. No account, no email, no follow-up unless you ask.

Energy figures only — no price, and not a quote. This estimate shows what a system could generate and what that energy is worth at the tariff you give. It never prices a system: a price comes from an engineer after a site survey. The figures are estimates under our engineering disclaimer. What you enter here is not stored. If you send an enquiry, we keep your details to answer it and delete an enquiry that does not become a job after 24 months — see the privacy notice.

Your estimate appears here

Answer the three sections and press Work it out.

  • An array sized to your roof and your load
  • Generation from the real sunlight at your coordinates
  • Storage sized for backup, or for days off grid
  • What it is worth at your own tariff
Run a free estimate

What it is not

WattGro is project software, not an engineer. Every number is an engineering estimate until a qualified engineer has surveyed the site and signed the design. The public estimator never prices a system.

How we build

Every product here is built multi-country from the first line: your currency, your tax rules, your language. Every product starts free, with no card. Built in Dubai by L K Verma and a small team, for people and businesses whose lives run across borders.