Electricity prices as scenarios, not forecasts

Short answer #

Use at least cautious, central and high price paths. A higher grid-price assumption raises avoided cost but can also make heat-pump and charging operation more expensive.

Important variables #

• Investment after support
• Useful energy, efficiency and degradation
• Energy prices and tariff
• Horizon and discount rate

Worked example #

€0.34/kWh grows to about €0.414 after ten years at 2%, or €0.554 at 5%.

Break-even: What changes the result? #

Test the main driver as a cautious, central and optimistic range. Also check whether the ranking reverses at a crossover or remains robust across the range.

Common mistakes #

• Treating subsidy or tariff as certain
• Omitting losses and degradation
• Confusing simple payback with return

Sources & assumptions

• KfW Bankengruppe — Heizungsförderung ab 21. Juli 2026 (2026-08-17)
• RATIOXA — Methodology and formulas (2026-08-17)