Toolbox

All calculators.

Nine tools covering the whole household energy transition — from the first balcony module to a heat pump. Each one calculates live and shows its model.

Solar & storage

Popular

Balcony solar calculator

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

Open

Rooftop PV calculator

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

Open

Battery calculator

The economically optimal capacity, not the largest one.

Open

Cost & footprint

Payback calculator

Net present value, internal rate of return and break-even for any energy investment.

Open

Tariff comparison

Standing charge, unit rate and bonus netted out over two years.

Open

New

Consumption audit

Consumption broken down appliance by appliance — with savings in euros.

Open

Carbon footprint

Electricity, heat, mobility and diet — and what each measure actually achieves.

Open

Mobility

Popular

EV charging costs

At home, at a public charger, at a rapid charger — and against a combustion engine.

Open

Heating

Heat pump calculator

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

Open

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