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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 Austria

Regulation determines the limits and tariffs this calculator works with.

No guaranteed feed-in tariff — the price is negotiated

Austria has no equivalent of the German statutory tariff. What you receive for surplus is set by your electricity supplier.

Typical range
3–11 ct/kWh
Guarantee
none in law

This is the largest economic difference from Germany. The calculator works with an average — get a concrete offer before relying on it.

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Remuneration usually tracks the exchange price, sometimes at a discount, sometimes fixed for one or two years. It can change substantially when the contract ends — in either direction.

For the economics this means self-consumption counts for even more than in Germany. Sizing an array close to your own demand is more defensible here than there.

OeMAG's market premium offers a subsidised route for larger systems, but it is tied to tenders and rarely relevant for households.

Zero VAT for systems up to 35 kWp

Supply and installation of photovoltaic systems up to 35 kWp carry no VAT.

VAT
0 % up to 35 kWp

The measure was introduced for a limited period and has been amended more than once. Check the current window before placing an order.

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The threshold is higher than Germany's. The zero rate removes the old construction of opting into standard taxation to reclaim input tax and then reverting to the small-business scheme.

The relief covers systems on or near residential buildings, and on buildings serving the public good.

Federal subsidy plus provincial subsidy

Heating replacement and photovoltaics are subsidised federally, with the provinces adding their own programmes on top.

Subsidy levels and application windows change more often in Austria than in Germany and are partly budget-dependent.

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Switching from a fossil heating system to a heat pump attracts a federal grant that can approach full funding for lower-income households. The provinces add their own budgets, whose size and conditions vary considerably.

Because federal and provincial support stack but each has its own deadlines and caps, it pays to check both applications before commissioning the work.

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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