Rooftop and carport solar for Eastern Province facilities: what the rules allow, and three checks before you sign

Many private sites in the Eastern Province (factories, hotels, malls, hospitals and schools) have large roofs and open car parks, and carry their heaviest electrical load in the hot daylight hours, when solar produces most. The framework for small-scale solar lets them put that to use.

What the framework allows

The regulatory framework for small-scale solar PV systems was issued by the electricity regulator (then the Electricity and Cogeneration Regulatory Authority, ECRA; today the Saudi Electricity Regulatory Authority). It lets a consumer connect a grid-tied system of 1 kW to 2 MW for each premises. It works by net billing: energy the system sends to the grid is credited to the electricity bill.

Two further limits shape the size of a system: a consumer's systems within one service area may total no more than 5 MW, and a system may be no larger than the premises' contracted load. The distribution company installs a bidirectional meter, and a system above 100 kW also needs a separate generation meter, at the consumer's cost.

Three checks before you sign

Installer quotes often differ widely in size, yield and price, and are hard to compare. Three checks make them comparable.

First, size against your daytime load. Energy used on site replaces energy bought from the grid, and that is where it is worth most. A system sized to fill the roof rather than to match the load sends more to the grid and earns less from each kilowatt-hour.

Second, yield at P90, not only P50. P50 is the yield expected in a typical year; P90 is the yield exceeded in nine years out of ten. A business case that still holds at P90 is one a board can approve with confidence.

Third, savings at your actual tariff. Work from your own bills and tariff category, not from an average, and include the cost of the generation meter for a system above 100 kW.

What to have ready

Twelve months of electricity bills for each account in scope, with interval data if the meter records it; each account's tariff category and contracted load; and drawings or photographs of the roofs and car parks. With these, a feasibility study sizes the system against real consumption rather than an estimate.

Where GH fits

GH does independent feasibility. We do not sell, supply or install equipment, and we take no installer commission. For one site we answer how much solar fits, the yield at P50 and P90, the savings under your tariff and the payback, and we write a specification that qualified installers can tender against. Your installer builds the system and files the connection application.