A process that never stops
Pulping, refining, pressing and drying run as one continuous line, driven by motors and pumps. The load is large and steady, so a mill uses every unit its solar produces, but most of its energy still comes from the grid and, during outages, a generator.
Which source served the load, and what it cost
A mill’s bill is really several bills: grid units at off-peak and peak rates, generator units at the cost of fuel, and free solar units. WattEY meters grid, generator and solar separately, so the mill sees which source carried the line each hour and what each unit cost, the starting point for cutting it.
