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Free UK Energy & Renewables Calculators 2026

Solar PV installer margins, heat pump job profitability, BUS grant impact, EPC assessor pricing, ECO4 funded insulation, battery storage and small-scale renewables ROI — updated for 2025/26. Free to use, no account needed.

UK Renewable Energy Sector 2025/26

The UK renewable energy installation sector is growing rapidly driven by the Boiler Upgrade Scheme (BUS), ECO4, the Smart Export Guarantee (SEG) and the Clean Heat Market Mechanism (CHMM) from 2025. These calculators help solar PV installers, heat pump contractors, EPC assessors, insulation installers and small-scale renewable developers quickly model job margins, grant impacts and ROI without specialist software.

Frequently Asked Questions

What is the BUS grant for heat pumps in 2025/26?
The Boiler Upgrade Scheme (BUS) provides £7,500 towards the cost of an air source heat pump or biomass boiler in England and Wales in 2025/26. The grant is paid to the MCS-certified installer, who reduces the customer price accordingly. The scheme is managed by Ofgem. Ground source heat pumps receive the same £7,500 grant.
Is MCS certification required for solar PV installers?
Yes. MCS (Microgeneration Certification Scheme) certification is required for solar PV installers who want their customers to access the Smart Export Guarantee (SEG) tariff, which pays for electricity exported to the grid. MCS certification is also required for heat pump and battery storage installers wanting to access BUS grants. MCS annual certification body fees typically cost £1,500–£3,000/year.
What is the ECO4 scheme and when does it end?
ECO4 (Energy Company Obligation 4) is a government scheme requiring large energy suppliers to fund energy efficiency improvements in low-income and fuel-poor households. Eligible measures include cavity wall insulation, loft insulation, external wall insulation (EWI), heat pumps and boiler replacements. ECO4 runs until March 2026, after which a successor scheme (ECO5 or GBIS extension) is expected. Installers working on ECO4 projects must be TrustMark registered and PAS 2030 certified.
What is the Smart Export Guarantee (SEG) rate in 2025/26?
The Smart Export Guarantee (SEG) requires licensed electricity suppliers with 150,000+ customers to offer export tariffs for small-scale renewable generators (up to 5MW). Rates vary by supplier — in 2025/26, typical SEG export rates range from 3p to 15p/kWh depending on the tariff (fixed vs dynamic/agile). Octopus Agile export can achieve higher rates at peak times. Installations must be MCS-certified to qualify.