Start with the daytime load.
Solar generation is most valuable when the facility can use it as it is produced. A monthly electricity bill is not enough to establish this. The project team should understand the daytime load profile, weekly operating pattern, seasonal variation and any planned changes in production.
Sizing against available roof area alone can create excess generation during low-load periods. The commercial treatment of that excess depends on the applicable regulations and supply arrangement, so the load and the export framework must be studied together.
The roof is an engineering input, not just an area.
A usable rooftop must be assessed for structural capacity, sheet or slab condition, access, drainage, fire and maintenance pathways, shading and the location of existing services. Different roof zones may support different layouts or require remedial work.
The design should also consider how equipment will be installed safely and how the roof will continue to be maintained after commissioning. A layout that maximises module count but restricts access can create long-term operating problems.
Integration determines whether the system operates reliably.
Solar connects to an existing electrical network. The project therefore needs a clear understanding of transformers, switchgear, protection, metering, cable routes, earthing and the point of interconnection.
The single-line diagram, protection philosophy and equipment ratings should be checked against the proposed system. Generation forecasts are important, but they do not replace electrical integration and commissioning discipline.
Evaluate the complete business case.
Project economics should reflect realistic generation, degradation, losses, downtime, maintenance, financing where relevant and the actual tariff components displaced by solar. A simple comparison between project cost and the headline electricity rate can overstate savings.
Management should review the expected saving, payback, major assumptions, risk allocation and responsibilities for performance. The best project is not necessarily the largest one; it is the one whose technical design and commercial case remain credible under realistic operating conditions.
What management should take away
- Use interval load data to establish how much solar the facility can absorb.
- Complete structural, access and electrical assessments before fixing project capacity.
- Model savings against the tariff components actually displaced by solar.
- Make generation assumptions, responsibilities and performance risks explicit before approval.