Start with measured demand
Use interval electricity data and distinguish space heating, hot water, cooling, pool circulation and other loads. State occupancy and seasonal changes. A floor area, bedroom count or annual bill alone cannot establish the right inverter, battery or heat-pump size. Check supply capacity, phases, starting loads and simultaneous operation before specifying equipment.
Model generation at the property
Use a stated weather dataset, module plane, shading survey, temperature model and loss assumptions. Nameplate power is measured at defined test conditions, not a promise of continuous output. For example, twelve 500 Wp modules total 6 kWp at those conditions; that arithmetic alone says nothing about annual yield or the appropriate AC inverter size.
Compare the complete scope
Give each bidder the same measured demand, drawings, access information and performance objectives. Compare exact equipment variants, routes, mounting, protection, controls, enabling works, tests, documents and taxes. Mark exclusions and provisional items separately. A lower headline price or a larger nominal system does not establish better value.
Agree responsibilities and scheduling
Confirm who handles the survey, design, any community consent, municipal procedures, electrical registration and distributor or supplier submissions. Requirements depend on the property and installation. Equipment availability, safe access, enabling work and third-party decisions affect the schedule. Ask how faults, disruption and support requests will be handled; do not infer attendance hours from a website contact form.
Keep a commissioning record
Agree the inspections, measurements, settings and documents applicable to the installation. Retain equipment identification, as-built diagrams, protection details, test results, operating instructions and handover records. Monitoring access is useful, but an app displaying generation is not proof of electrical safety, completed registration or an active export-compensation contract.
Read the surplus-compensation contract
Under simplified compensation, exported energy and imported energy are accounted for separately within the applicable billing arrangement; the credit is limited by the eligible imported-energy value. It does not automatically remove all fixed charges or taxes. A retailer's virtual-credit product has separate terms and is not a physical battery or a universal net-metering entitlement.
Read the current official programme
Identify the exact scheme, responsible authority and current text before assuming a percentage, ceiling or deadline. Check applicant and property eligibility, eligible equipment and costs, energy evidence, application sequence and completion dates. An expected programme is not an open call, and an earlier year's approval does not establish current availability.
Make financial assumptions explicit
Compare the actual installed quote with interval self-consumption, imports, exports, contracted prices and applicable credit limits. Include losses, fixed charges that remain, maintenance, replacement, finance and taxes. Treat incentives as conditional until their applicable requirements and, where required, award decisions are established. A simple cost divided by annual benefit is not a forecast or a guaranteed payback.
Documents and reference links
Check the current version and applicability. These links do not establish failure rates, LIT credentials or an outcome for your property.
Company contact
Ben HaydenPrepare for a useful assessment
Provide the location, objectives, existing models, plans or safely taken photos, and measured demand. Confirm scope, availability, assessment fees and responsibilities before booking.