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Amperecalc

Cost & footprint

When has your investment paid for itself?

Payback is more than investment divided by savings. Rising electricity prices shorten it; degradation and operating costs lengthen it. This calculator models both across the full horizon.

How we calculate

Calculation model

  1. 01

    For each year the benefit is escalated by the price increase and reduced by degradation, net of operating cost.

  2. 02

    Break-even is the year in which cumulative cash flow first exceeds the investment — interpolated within the year.

  3. 03

    Net present value discounts all future payments to today, using your discount rate as the alternative return.

  4. 04

    The internal rate of return is found numerically as the rate at which net present value becomes zero.

Good to know

  • The discount rate should reflect the return you forgo — a savings rate for equity, the loan rate for debt.
  • A positive net present value means the investment beats your alternative.
  • Payback period alone is a weak criterion, because it ignores everything after break-even.

Law & subsidies

What applies in Switzerland

Regulation determines the limits and tariffs this calculator works with.

Export remuneration: every grid operator decides for itself

There is no national tariff. What you receive for exported electricity is set by your local utility — and the national spread is more than threefold.

Typical range
4–16 Rp./kWh
Set by
around 600 grid operators
National flat rate
does not exist

This is the single most consequential number in the whole calculation, and the one no calculator can know for you. Look up your utility's tariff before ordering a system.

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Two neighbouring municipalities can differ by ten centimes per kilowatt hour. On a typical system exporting 4,000 kWh that is 400 francs a year — over twenty years, more than the price of a battery.

Since the revision of the Energy Act a minimum price applies, based on avoided costs. It does not remove the spread, it only limits it from below.

In practice: where remuneration is high, a large array pays. Where it is low, almost only self-consumption counts — which moves storage and load shifting to the front of the queue.

A one-off payment instead of an ongoing tariff

Switzerland supports photovoltaics with a single investment contribution rather than a running feed-in tariff.

Base contribution
flat per system
Capacity contribution
per kWp, degressive
Administered by
Pronovo AG
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The one-off payment typically covers a meaningful share of the investment and is paid after commissioning. Unlike the German scheme it creates no recurring income — after that, the economics rest entirely on self-consumption and the local export tariff.

Systems with little or no self-consumption can apply for the high one-off payment, which compensates for the reduced benefit.

Many cantons and municipalities add contributions of their own.

This compilation is orientation, not legal advice. Rules in this field change several times a year — check the linked primary source before you invest, or ask a certified specialist.
See all regulatory topics

Frequent questions

Answered briefly.

What price escalation is realistic?

German household electricity prices have risen by about three percent a year on average over the past two decades, with considerable swings. Three percent is a cautious assumption; run zero percent as a sanity check.

Net present value or internal rate of return — which should I look at?

Net present value if you want to know how much money the investment brings you in absolute terms. Internal rate of return if you want to compare it against other investments.

Do I have to account for degradation?

For solar modules yes, though at 0.4 to 0.5 percent a year it is small — over 20 years roughly equal to two years of price escalation. For batteries, capacity fade matters considerably more.

Balcony solar calculator

Yield, self-consumption and savings for your postcode and orientation.

Rooftop PV calculator

Yield, self-sufficiency and return of a rooftop array over 25 years.

Heat pump calculator

Running cost, investment, subsidy and payback in a direct comparison.

All results are model calculations based on your inputs and statistical reference data. They do not replace individual professional planning.

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