Understanding manufacturing solar sizing
Why manufacturing usage runs higher than a warehouse
Manufacturing facilities run motors, compressors, conveyors, and process equipment continuously, while a warehouse mostly just stores goods with minimal active load. That's why light manufacturing commonly runs 15 to 25 kWh per square foot a year, roughly double or more what a comparable warehouse uses. Check the warehouse solar sizing calculator to see that comparison directly with a similar-sized building. The DOE's Better Plants program helps manufacturers benchmark and reduce exactly this kind of energy intensity across their operations.
When heavy manufacturing changes the picture
Yes, heavy manufacturing with large motors, furnaces, or continuous process lines can run 30 to 60 kWh per square foot a year or more, well above the light manufacturing range this calculator assumes by default. Use your actual utility bills for an accurate estimate if your facility runs energy-intensive equipment like welding, casting, or heat treating, since the built-in default will understate usage for those processes. The solar panel calculator in our system sizing section can help translate whatever corrected usage figure you land on into an actual panel count.
Addressing demand charges separately from usage
Solar reduces the usage-based portion of your bill directly, but demand charges driven by short equipment startup spikes need a battery or load management strategy to address. Check the demand charge reduction estimator to see how much of your bill comes from demand charges specifically before assuming solar alone solves the whole problem, and the payback calculator once you have a final system size, or the battery storage sizing calculator if demand charges are a major factor. Cross-check this against roof space vs. output estimator before deciding.
What kind of offset to expect
A meaningful share, though usually not all of it. A 60,000 sq ft light manufacturing facility using about 20 kWh per sq ft a year needs roughly 835 kW to fully offset usage, while an 80% usable roof share caps the system at about 686 kW, covering about 82% of usage. That's a strong offset, landing between what a warehouse and an office building typically achieve. The U.S. Energy Information Administration's commercial buildings energy survey is a useful benchmark for comparing your building's usage intensity against national averages, and the roof space vs. output estimator in our system sizing section covers the same roof-to-output tradeoff from a residential angle. If demand charges are a big part of your bill, the battery storage size calculator in our Battery & Storage section can show whether a battery would shave your peak enough to pay for itself.