First Solar Series 6 Procurement Checklist: Area, Shipments & Battery Worth

What This Checklist Is For

If you're an EPC or independent power producer getting ready to source a large ground-mount solar project, I'm guessing you don't need another engineering lecture. You need to know what to ask before signing the module purchase agreement. Since I took over purchasing in 2020, I've been the person who manages procurement for a 40-person EPC firm, placing roughly $15M in solar equipment orders every year across 18 vendors. I report to both operations and finance. This is the six-step checklist I pull out whenever someone says 'First Solar' is the safe choice.

It's built for utility-scale or commercial-scale buyers. If you're also wondering whether a solar battery is part of the plan, Step 4 covers that. If not, skip it and get back to the module area question, because that one is easy to get wrong.

1. Confirm the First Solar Series 6 Module Area Before You Get Too Attached to the Price

Here's the boring question that saves money: what is the First Solar Series 6 module area? Not the approximate frame size, not the quote number. The area. For the Series 6 Plus, that's roughly 2.87 square meters, which works out to about 7.8 feet by 4 feet per module. It drives racking spacing, land use, container loading, and even how many cleaning passes your O&M team needs. If you design a string layout around a different footprint, you will end up with a full BOM that doesn't fit. That's expensive. Period.

Verify current dimensions from the First Solar Series 6 datasheet. In recent revisions, the dimensions have held close to 2385 mm × 1205 mm, but the datasheet revision number in your contract should match the physical module.

I don't have hard data on how many fixed-tilt layouts get redone because of this, but based on the procurement files I've reviewed, my sense is it's more common than people admit. I wish I had caught it on my first project; what I can say anecdotally is that 15 minutes with the actual datasheet would have saved us a redesign fee.

2. Compare First Solar Shipment Data With Your Construction Window

The next line item on my checklist is 'first solar shipped gw q2 2024.' In Q2 2024, First Solar shipped 3.7 GW. That tells me the factory is actually producing and executing orders. But the same quarter ended with about 66 GW of total backlog (as of Q2 2024, at least). Translation: modules are moving, but future production slots are not empty. If you haven't reserved capacity, the delivery date can drift, and a drifting module delivery can push out the entire energization schedule.

Take it from someone who has signed a supply agreement on a Friday afternoon under deadline pressure: get a guaranteed delivery month in writing, including a penalty that actually hurts. This worked for our team because we tied liquidated damages to our planned grid connection month. Your mileage may vary if your crew can easily reschedule, but for a fixed-price EPC, slip dates are poison.

One side note: the 66 GW backlog figure is from the company's Q2 2024 earnings release. By the time you read this, the number may be different. Use the most recent report in your own risk review.

3. Ask Whether Bifacial Solar Panel Technology Actually Fits the Site

Every RFP these days seems to include 'bifacial solar panel technology' as a default requirement. Bifacial modules can capture reflected light and boost energy yield on the right site. But First Solar's CdTe product line is monofacial right now. The Series 6 and Series 7 are not bifacial modules. If your site selection was based on bifacial gains from elevated racking over white sand, you're ordering the wrong product from First Solar.

I can only speak to our project history. We've built on compact, moist-soil sites where bifacial gains would have been forgettable; there, First Solar's temperature behavior and low degradation made more sense. For a wide-open desert site with high albedo, bifacial c-Si deserves a real analysis. My job is not to protect a marketing narrative. It's to match the physical module to the physical site.

Bottom line: don't make 'bifacial' an automatic checkbox. It's a site-specific decision, not a virtue signal.

4. Decide If a Solar Battery Is Worth It After You See the Load Profile

Now for the question most people actually want to answer: 'is a solar battery worth it?' I hear it in every internal kickoff, usually followed by the phrase 'battery lithium battery storage' on the approval form. Behind the awkward term is a straightforward question: will the battery sell or avoid energy at a price greater than its cost?

A lithium-battery add-on made sense for us on one project because the utility imposed demand charges from 4 p.m. to 9 p.m., and net metering was being phased out. Those two facts created a revenue gap that a battery could fill. On another project, there was no demand charge, the PPA took all the output, and a battery would have been a metal box that sat idle. That's not anti-storage; that's arithmetic.

If you're asking whether a solar battery is worth it for a single facility, run the load profile first. I don't have hard data on your utility tariff, but based on the storage quotes I've processed, honestly, the payback almost always comes from demand-charge reduction or time-of-use arbitrage. Without those, a lithium battery just adds cost, maintenance, and interconnection complexity.

Use your utility's most recent rate schedule and interconnection agreement, not a national average. Battery economics are hyper-local.

5. Calculate the Total Cost Over 25 Years, Not the Efficiency One-Pager

First Solar doesn't win the datasheet efficiency contest. The Series 6 Plus is around 16% module efficiency, while some c-Si modules push past 21%. What matters more in a 25-year PPA is degradation. First Solar's published annual degradation rate is under 0.5%. A module with 21% efficiency but 0.8% degradation can lose its energy advantage by year ten.

I wish I had tracked our first-year performance by string and row in every project. What I can say anecdotally is that low-degradation modules make the finance model easier to close, because lenders care about year-25 production, not the glass that shines in a booth. That's worth money. Simple.

6. Put Performance Remedies Into the Supply Contract

This is the step most buyers ignore, and it's the one that has burned me. We saved $30,000 by taking a lower quote from a vendor without clear performance remedies. Ended up spending $70,000 on testing, replacement modules, and a second crane mobilization. That 'budget' decision made me look bad to finance and delayed the project. Every solar module needs a contract clause that answers three questions: what measurement standard defines a failure, who pays for removal and reinstallation, and how long does the claim window stay open?

First Solar has strong field data and a real warranty, but the warranty still has to be specific in your contract. If a supplier says 'we'll discuss later' for those three questions, treat it as a red flag. Trust me on this one.

Three Mistakes I Keep Seeing in Solar Procurement

1. Ordering by weight instead of crate dimensions. For First Solar Series 6, the module area is about 2.87 m², but the packaging design is what determines shipping costs. Get the loading plan before you compare freight bids.
2. Adding a lithium battery after the electrical design is locked. Even a modest storage system changes inverter sizing, switchgear, and often the interconnection application. 'We'll add a battery later' sounds flexible until the stamped drawings are done.
3. Using a generic c-Si inverter curve for CdTe modules. First Solar modules have different I-V characteristics. The inverter MPPT window must match the actual Series 6 datasheet, or you'll get clipping and underperformance before you start.

Bottom Line

This checklist is not a substitute for engineering, legal review, or current manufacturer documentation. It's a procurement habit: confirm area, confirm shipment timing, question bifacial by default, run the storage math, model degradation, and write down performance remedies. That's it. The details are dry, but they're what keep a project from going sideways.