Commercial Solar Guide

Why commercial solar is different from residential

Commercial solar installations involve fundamentally different considerations from domestic ones: larger system sizes, three-phase electrical infrastructure, grid connection requirements, business case development, procurement procedures, and — in many cases — multiple stakeholders.

The financial analysis is also different. Commercial solar is assessed on its impact to business operating costs, capital expenditure planning, EBITDA, depreciation, and increasingly on ESG (Environmental, Social and Governance) credentials. These are not factors in a domestic installation.

This guide covers the key considerations for businesses, commercial property owners, and organisations considering solar and battery storage — without assuming prior technical knowledge.

Financial returns for commercial solar

Commercial electricity rates in the UK typically range from 18–30p/kWh depending on contract terms, usage volume and market conditions. Solar-generated electricity has an effective cost of approximately 4–6p/kWh over the system's 25-year life. Every unit of solar electricity your business uses instead of buying from the grid saves the difference.

For businesses with high daytime electricity consumption — manufacturing, food production, offices, cold storage, commercial kitchens — solar self-consumption rates of 70–95% are achievable. For businesses with lower daytime consumption, battery storage can shift generation to periods of higher use.

A typical 50 kWp commercial system in West Sussex generates approximately 47,500–52,500 kWh per year. At a grid rate of 25p/kWh and 80% self-consumption, that is approximately £9,500–£10,500 per year in electricity bill savings. A 100 kWp system roughly doubles this.

Commercial projects with higher consumption or grid export via Smart Export Guarantee (SEG) may achieve payback in 5–8 years. Systems sized specifically for self-consumption typically achieve 6–10 years. Battery storage adds complexity to the ROI calculation but improves it for businesses with predictable peak usage outside solar generation hours.