Demand before capacity
Review interval consumption, operating hours and planned load changes. Separate electricity used on site from possible exports and confirm which meter receives the generation.
Commercial PV
Put generation where
your building can use it.
Assess rooftop PV against the operating load, the available space and the electrical connection—not roof area alone.
Operating context
Start with the objective.
A workable site
Review roof condition, structure, plant and access zones, shading, cable routes and switchboard capacity. Resolve lease, ownership and connection constraints early.
Comparable proposals
Compare layouts, equipment, generation assumptions, export conditions, electrical works, monitoring, warranties and maintenance on the same scope.
Selection framework
Make the assumptions explicit.
Site information
Plans, roof condition, access and existing electrical information.
Operating evidence
Available interval data, current tariffs, operating hours and expected changes.
Decision criteria
Energy recipient, capital-work timing, ownership responsibilities and acceptable disruption.
System integration
Connect the whole building.
System connections
From generation to building use.
- PV arrayDC generation
- PV inverterConverts DC to AC
- Main switchboardAC connection point
- Plant + tenancy loadsElectricity used on site
At the switchboard: ↔ Grid↔ Optional battery + inverter
Design notes
Storage is shown as a separate AC-coupled branch. Metering, protection and isolation are omitted. Backup requires a separately designed arrangement. This is not a construction drawing.
Before a proposal
Prepare the project evidence.
Bring the site location, available electricity data, current equipment information and the intended outcome. Record missing information and confirm the assessment scope before relying on a system size or financial estimate.
A building-first approach to commercial solar
Load before capacity.
Load before capacity
System sizing begins with the building’s energy demand and operating profile.
Building constraints
Roof area, structure, access, switchboards, metering and export constraints influence the design.
Comparable proposals
Clearly defined assumptions allow commercial solar proposals to be compared properly.
Integrated energy
Where relevant, rooftop PV can be assessed together with BIPV and battery storage.
Read the proposal
Generation is not the same as savings.
kW / installed rating
The rated capacity describes equipment under specified conditions. It is not the building’s annual electricity supply.
kWh / energy over time
An estimate needs site orientation, shading and loss assumptions. Compare expected generation with interval demand to distinguish direct use, export and curtailed energy.
Financial case / explicit assumptions
Separate avoided purchases from export revenue. Include the actual tariff, connection conditions, maintenance and replacement assumptions; test changed prices and loads instead of relying on a single payback figure.
Further reading: Australian Government / Solar system sizing ↗