Manufacturing is where rooftop solar economics are usually strongest and the engineering most demanding. High connected load, high tariffs, and long operating hours make the case; the constraints are shift patterns, electrical infrastructure, and the cost of any unplanned interruption.
What this segment needs
A plant's shift pattern determines almost everything. A single-shift daytime operation matches generation closely and achieves high self-consumption. A three-shift operation has a large night load that solar cannot reach without storage, though the daytime portion may still be substantial enough to justify a large system. Sizing follows the load curve, not the roof.
Engineering considerations
Manufacturing sites are frequently on HT connections with their own transformer, so interconnection is a different exercise than an LT rooftop tie-in and involves protection coordination and, often, utility review. Demand charges are a significant part of an industrial bill, and whether solar reduces them depends on coincidence with peak. Power factor, harmonics from existing drives, and the interaction between inverters and plant equipment all need assessment rather than assumption.
Karnataka context
Industrial consumers in Karnataka face relatively high tariffs with meaningful demand charges, which strengthens the case. Accelerated depreciation is typically available for commercial and industrial installations and materially affects the after-tax return, though the applicable rate should be confirmed with your finance team. Plant shutdown windows are usually fixed well in advance and become the anchor for the whole commissioning schedule.
Common mistakes to avoid
At industrial scale the expensive mistakes are electrical and schedule-related:
- Sizing on total consumption without separating daytime from night-shift load
- Treating HT interconnection as equivalent to a small rooftop grid tie
- Overlooking power factor, harmonics, and interaction with existing variable-speed drives
- Planning commissioning outside the plant's fixed shutdown windows
- Assuming demand charges will fall without verifying when peak demand actually occurs
What we recommend
Start from the load curve broken down by shift, and from your last twelve months of demand data rather than energy alone. Establish the interconnection approach early, because HT tie-in drives both cost and timeline. Then build the commissioning schedule backwards from your planned shutdown window.
Common questions
- Does solar work for a three-shift operation?
- The daytime portion is offset, which can still be a large absolute saving on a high-consumption plant. Night shifts continue on grid supply unless storage is added, which is rarely economic at that scale.
- Will solar reduce our demand charges?
- Only where generation coincides with your recorded peak. It reliably reduces energy charges. Demand charge impact must be checked against your actual demand profile.
- How is HT interconnection different?
- It involves protection coordination, metering at HT, and usually more utility review than an LT rooftop connection. It affects both cost and timeline and should be scoped early.
- Can we claim accelerated depreciation?
- Industrial installations are generally eligible under prevailing rules. The applicable rate and your specific tax position should be confirmed with your finance team.
- When should commissioning happen?
- During a planned shutdown. Tie-in requires a controlled outage, and aligning it with an existing shutdown avoids any production loss.
Talk to our engineering team for a solar assessment.
We will review your consumption, roof, and site constraints before recommending any capacity.