Our utility-scale solar and battery storage facility, a 350 MW single-axis tracker array with four-hour battery storage and a collector substation, was delivered under an EPC contract with a power purchase agreement behind it. That agreement carried a commercial operation date and penalties for delay. Looking back, the schedule worked because it was built on production rates, not on area dates.
The rate told us the date
Grading, piling, tracker and module work moved across thousands of acres. On a site that size, a small daily shortfall compounds into weeks. Piling, tracker and module crews were planned by daily rate, and the schedule flagged any block falling behind within a week, early enough to add a crew or move one from a block that was ahead.
On a job this size, a hundred piles a day is the whole story. We watched the rate, and the rate told us the date.
Site manager, Jacob Wiseman
Every shipment tied to a block
Modules, trackers, inverters and transformers came from different suppliers, each with its own long lead time. Every shipment was tied in the schedule to the block it served. When a container ran late, the effect showed up on a specific block and a specific energization date, not as a vague supply problem, and crews could be resequenced to blocks whose material was on site.
Energized in twelve blocks
- Block by block. The array was commissioned in 12 blocks in sequence, so the first megawatts reached the grid while later blocks were still being built.
- Interconnection held. Protection and control testing was planned with the utility months ahead, to hold the fixed energization window.
- On date. Commercial operation was reached on the date in the agreement.
The lesson we carry to every large site: measure production daily, tie every delivery to the work it feeds, and give the owner the same view of the rate that the field has.
