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Reel volumes on solar EPC projects
Solar EPC sites empty a steady flow of DC, collection and fibre cable reels, and steel reels with time-limited credits. How to estimate the count from packing lists and plan laydown and pickups.
Updated
On a utility-scale solar site, cable arrives on a schedule tied to blocks or arrays, and empty reels pile up just as steadily. The reels range from small plywood spools of PV wire to large nailed reels of medium-voltage collection cable. If the conductor is heavy, they can be steel reels with a charge on the invoice. Plan reels in the logistics plan, the way you plan cable laydown.
Estimate the count before the first delivery
You don't need an industry rule of thumb, because the project already has the numbers. Every cable line on the purchase orders or packing lists gives a length per reel and a total. Divide one by the other, then group the result by reel type and size:
- PV and DC string wire: usually many small reels, often plywood.
- DC feeder and AC collection cable: larger nailed-wood reels, the size range that take-back programs and reel buyers want.
- Medium-voltage and heavy conductor: may ship on steel reels. Log the serial numbers.
- Fibre for SCADA and communications: fibre reels. See fibre reels.
Plan the laydown
Put the counts into yard math to get the footprint stood on flange, and the share of a 53 ft trailer each size takes. For example, a 66 in reel like Southwire's A-76 covers about 30 sq ft on its own and weighs about 473 lb empty, so a hundred of them is a large yard.
Protect steel reel credits
Long builds and early deliveries are where steel reel credits get lost. Southwire credits a returned steel reel in full only within 12 months of shipment, and its policy allows a deferral period to be negotiated at quotation for larger projects or shipments ahead of the project start. Negotiate it in the cable contract. Then log every steel reel serial at receiving and send return requests in writing as reels empty. Steel reel returns.
Schedule pickups at milestones
Programs and buyers send a truck for a full load, so schedule pickups by count, not by calendar. Pick a trigger, such as "when a 53 ft trailer's worth of one size is staged," and request the pickup when you reach it. Remote sites need the trailer route and turnaround spelled out in the request. Clear the yard completely before demobilisation, because reels left behind become the landowner's problem.
Questions
How do I estimate how many reels a solar project will produce?
Add up the reel count on the cable packing lists or purchase orders. Each line gives length per reel and total length, so reels = total length / length per reel. Then group by reel size.
Can steel reel charges be deferred on a long project?
Southwire's steel reel policy says a reel charge deferral period can be negotiated at quotation for larger projects or early shipments. Ask at the time of quote, not after.