Energy Guide

Commercial solar and batteries

How to check a commercial solar proposal

What should we check before accepting a commercial solar proposal?

A credible proposal should separate observed site facts, design assumptions, modelled generation, commercial forecasts and unresolved approvals. Compare offers on consistent consumption, degradation, price, export and maintenance assumptions, and make the supplier state what remains subject to survey or network approval.

Written by Energy Guide editorial team · Specialist review: Pending · Source checked:

Separate fact from forecast

Mark which inputs came from bills, interval data, drawings, a site survey or a model. Ask for the weather dataset, losses, degradation, self-consumption and export assumptions behind annual generation and savings.

Define the delivered scope

Confirm design, equipment, access, scaffolding, structural work, connection application, metering, monitoring, commissioning, documentation, training and maintenance. Record exclusions and dependencies explicitly.

  • Survey and structural responsibility
  • Planning and property consents
  • Network application status and limits
  • Product and workmanship warranties
  • Generation or performance commitments
  • Insurance and fire-risk requirements
  • Operations, maintenance and fault response

Stress-test the commercial case

Test lower generation, delayed commissioning, changed electricity prices, reduced site demand and early property exit. A simple payback figure is not enough where contracts, equipment and occupation extend over many years.

Sources

These sources support the explanation above. Check the linked source for current rules and eligibility.

Related questions