The hardest part of running materials for a 50 MW utility-scale solar project isn't picking the right vendors — it's sequencing the deliveries so the EPC's installation crew never stops working. We've coordinated material releases for solar projects from Yuma County to the Apache Junction corridor, and the same three release-timing failures show up over and over. Here's what they look like and how to dodge them.
The three releases that kill solar schedules
- MV cable arrives before the trenches are open — cable sits on a job-site reel rack baking in the sun for 4–6 weeks, jacket degrades, contractor blames the supplier
- Transformers arrive late — pad-mounts have a 22–30 week lead time and one missed milestone delays final commissioning
- Inverters and switchgear ship too early — equipment with ESS storage gets stored outdoors waiting for energization, BMS batteries lose state-of-charge, warranty issues
Release 1: medium voltage cable — sync to trenching
A typical 50 MW project needs 30,000–60,000 feet of MV cable (15kV or 35kV) for collector lines. That's $400K–$900K in cable just sitting in reels if it shows up before trenches are dug. UV degradation of the jacket starts within 2–3 weeks of desert sun exposure on uncovered reels.
Better approach: split the order into two or three releases tied to civil progress milestones. Release 1 ships when 30% of trenches are open. Release 2 at 60%. Final release at 90% trenched. Coordinates with the EPC's project schedule, keeps cable cold and covered until pull-day.
We typically pre-position only the high-volume "trunk" runs in Release 1 — the cable that goes into the longest, deepest trenches first. CME Wire and Priority Wire both honor staged-release POs without surcharge if scheduled at PO time.
Release 2: pad-mount transformers — start ordering on Day 1
Pad-mount and substation transformers are the longest-lead items on every utility-scale solar project we've supported. JST Power pad-mount lead time in 2026 runs 22–30 weeks for 1500 kVA and larger, 18–24 weeks for 500–1000 kVA, and 14–18 weeks for under 500 kVA. ABB, Howard Industries, and Cooper Power are similar.
On a project with a Q3 2026 commercial operation date, transformers should be PO'd no later than Q4 2025 — and ideally engineered and submitted in Q3 2025. Yes, that's before the EPC has finished detailed design. Yes, we've seen projects miss COD because the team waited for "final design" before placing the transformer PO.
Mitigation tactic: place the PO with a 30-day pause window for final spec confirmation. The factory holds the slot, you have 30 days to confirm primary/secondary voltages, taps, BIL, and impedance. We help our solar EPC clients structure these "soft-locked" POs to protect the schedule without committing to a wrong spec.
Release 3: inverters and switchgear — wait for substation readiness
Counterintuitive but critical: don't take delivery of expensive inverters and switchgear until the site is energization-ready. A 1500V SMA or Sungrow inverter on a $250K reel is more valuable than the contractor's pickup truck — and storing it outdoors in 110°F desert heat for 6 weeks while the utility works on substation tie-in is asking for warranty problems.
Equipment with battery energy storage (BESS) is even worse. Lithium iron phosphate cells lose calendar life rapidly above 95°F. We've seen claims rejected because the equipment sat outside the temperature spec for 4+ weeks before commissioning.
Better: schedule equipment delivery to align with utility tie-in milestones. Ask the EPC to share their substation energization plan with the supply chain manager — most don't, and that's where the gap forms. Tech Energy America regularly attends substation tie-in coordination meetings on behalf of our solar clients.
Material-release checklist — what to specify in the EPC contract
- Staged release schedule tied to civil and substation milestones (not arbitrary dates)
- On-site storage requirements — covered, ventilated, off-ground for cable; conditioned space for inverters with BESS
- Maximum on-site dwell time per equipment category before warranty risk
- Liquidated damages on early/late releases — if the supplier ships early without authorization, who pays storage?
- Release authority — clear chain of command, single point of contact for go/no-go on each release
What we provide solar EPCs in Arizona
Tech Energy America serves as a staged-release distribution partner for solar EPCs across Arizona and New Mexico. We hold MV cable, conduit, transformers, switchgear, and balance-of-system materials at our Scottsdale facility and release per the EPC's schedule. Avoids on-site storage liability and lets the EPC pull just-in-time.
For multi-phase projects (e.g., 50 MW broken into three 17 MW phases), we segment the inventory into project-specific bins so there's no cross-allocation confusion when phase 2 starts before phase 1 commissions.
Related reading
- Our commercial solar EPC capabilities
- JST Power transformers we distribute
- More articles on the Tech Energy America blog
Running materials for a solar EPC?
Talk to us early — even before final design — about staged release planning. We'll save you weeks on COD.
📞 Call (480) 910-0867✉ Email Solar EPC Team