Solar Power for Factories: Engineering, Not Just Panels

Industrial sheds are built to keep weather out, not to carry arrays. Purlin spacing, section capacity, sheet condition and existing loads all determine what can go up there and how it must be fixed.

A structural survey comes before any layout drawing. Where the roof will not carry a ballasted array, the options are elevation, reinforcement, or a ground-mounted plant on adjacent land. On a site with spare land the ground-mounted option is frequently better engineering regardless — optimum tilt, easy cleaning, and no structural compromise for twenty-five years.

Fixing detail matters as much as capacity. A poorly sealed penetration in a factory roof is a leak over a production line, which is a far more expensive problem than the generation it enabled.

Two identical factories with identical roofs can have paybacks a year or more apart purely because of when they run. A two-shift operation consuming steadily through daylight self-consumes almost everything it generates. A single-shift unit that closes at weekends exports a meaningful share at a lower credited value.

This is why we size from twelve months of consumption data with the load pattern examined, not from roof area. Capacity beyond what the load absorbs during generation hours earns less, and at industrial scale that difference is large in absolute terms.

Factories are electrically noisy. Welding plant, VFDs, large motors and unbalanced loads create an environment that affects how inverters behave and how protection should be set. An installation designed for a clean commercial supply will produce nuisance tripping and, in the worst cases, equipment stress.

The point of connection is a design decision. Depending on sanctioned load, transformer capacity and existing utilisation, a plant may connect at LT into a main panel with sufficient headroom, or need an HT interface with its own transformer and protection scheme. That study happens before the design is fixed, not after.

At an industrial tariff around ₹9 a unit with strong self-consumption, a 100 kW plant generating 1,60,000 units a year saves roughly ₹14,40,000 annually against an indicative installed cost of ₹40 to ₹50 lakh — a simple payback of three to four years before tax treatment.

Accelerated depreciation improves that materially for a profit-making entity. We provide the generation model and the cost; the depreciation and cash-flow treatment belongs with your finance team, because it depends on your tax position rather than on the plant.