Energy Stack

Working tools

Tools.

Calculators that show their working. No round numbers, no marketing-friendly outputs, no postcode form that just sends your details to an installer.

Solar

Solar payback estimator

Inputs: roof orientation, tilt, shading factor, your tariff and your consumption shape. Output: a year-by-year breakdown including degradation, with the assumptions visible.

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Battery

Battery sizing

Drop in your evening load shape. The calculator returns the smallest battery that captures most of your shiftable energy, not the largest one your installer can sell you.

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EV charging

EV running cost

Smart-tariff overnight charging compared against standard rates and against an ICE equivalent. Includes home losses and degradation.

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Heat pumps

Heat loss estimator

A rough check on the survey number your installer is quoting. Useful for spotting an oversized quote, not a substitute for a proper room-by-room calculation.

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