Small Wind Turbine ROI 2025/26
Calculate payback period and ROI for a small-scale wind turbine installation in the UK. Enter turbine rated output, site wind speed, annual generation estimate, installation cost and Smart Export Guarantee (SEG) income to model profitability over the turbine lifetime.
Key Inputs
- Turbine rated output in kW (up to 50kW for SEG eligibility)
- Site mean annual wind speed (m/s) — from NOABL wind speed database or site assessment
- Estimated annual generation (kWh) — from manufacturer power curve and site data
- Installed cost including tower, foundation, grid connection and planning
- SEG export rate in pence per kWh (typical: 3–15p/kWh in 2025/26)
- Annual self-consumption saving (if on-site use)
- Annual maintenance and insurance cost
What You'll Get
- Annual electricity generated (kWh)
- Annual SEG export income
- Annual self-consumption saving
- Annual maintenance cost
- Net annual income
- Simple payback period
- 20-year cumulative return
Important Notes — 2025/26 Rates & Caveats
Small wind turbines are eligible for the Smart Export Guarantee (SEG) up to 50kW installed capacity. UK onshore small wind average capacity factors are 20–30% for well-sited rural turbines. A 15kW turbine at 25% capacity factor generates approximately 32,850kWh/year. Installed costs range from £20,000 for a 5kW building-mounted turbine to £100,000+ for a 50kW free-standing turbine (including tower and groundworks). Planning permission is typically required. Turbines near residential buildings face restrictions under permitted development. MCS certification is required for SEG eligibility (systems up to 50kW). Offshore or large-scale wind is not covered by this calculator.
Frequently Asked Questions
What is a typical payback period for a small wind turbine in the UK?
Payback periods for small wind turbines (5–50kW) in the UK in 2025/26 are typically 10–20 years at current SEG export rates. At 5p/kWh SEG, a 15kW turbine generating 30,000kWh/year earns £1,500/year in export income. At an installed cost of £80,000, payback from SEG alone takes over 50 years. However, if 60% of generation is self-consumed at the prevailing electricity rate (28p/kWh), total annual benefit is approximately £5,500, giving a payback of 14–15 years. Site wind resource is the single biggest variable.
Do small wind turbines need planning permission in the UK?
Most small wind turbines require planning permission from the local planning authority. Permitted development rights for micro-wind turbines (under 3.8m blade diameter, building-mounted, single turbine, residential) exist in England, but planning applications are still frequently needed for free-standing and larger turbines. Wind turbines in National Parks, AONBs and conservation areas face stricter controls. Many rural planning authorities are broadly supportive of small community or farm wind turbines, particularly post-2022 when national energy security became more prominent in planning policy.
What is the Smart Export Guarantee (SEG) and how much does it pay for wind power?
The Smart Export Guarantee (SEG) requires licensed electricity suppliers with 150,000+ customers to offer a tariff for electricity exported to the grid from small-scale renewables, including wind turbines up to 50kW. SEG rates are set commercially by suppliers — in 2025/26, fixed rates are typically 3–6p/kWh. Dynamic/agile export tariffs from Octopus Energy can achieve 15p/kWh or more at peak times. To qualify, the installation must be MCS-certified and have a meter capable of measuring export. The SEG replaced the Feed-in Tariff (FiT), which closed to new applicants in 2019.
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