When to Buy First Solar Panels (And When to Wait) — A Buyer's Guide Based on 3 Real Scenarios

There’s No Universal Answer — But There Is a Right Answer for Your Situation

If you’re searching for “where to buy First Solar panels” or wondering if their Series 6 or Series 7 modules fit your next project, you’ve probably already seen plenty of generic advice. “Buy the best quality.” “Wait for the best price.” “Just lock in your backlog now.”

Here’s the thing: none of those answers are wrong. But they’re also not right — for everyone.

I’ve been handling procurement for large-scale solar installations for about 5 years now. I’ve personally made (and documented) 4 significant mistakes, totaling roughly $120,000 in wasted budget. Three of those were directly related to timing — when I bought, not even what I bought.

So let me break it down into three practical scenarios. Figure out which one describes you, and your decision gets a lot clearer.

Scenario A: You’re Starting a New Greenfield Project (12+ Months Out)

What I’ve Seen Work

If you’re in early-stage development — land secured, interconnection studies underway, but financing not fully closed — you have time. And time is your biggest advantage.

My recommendation: Do not buy yet. Instead, get an allocation letter or a capacity reservation from First Solar. Lock in pricing for Series 7, but don’t pay deposits until your financial close is solid.

Here’s why: In 2023, I watched a developer commit to a 200 MW order of Series 6 Plus modules 14 months before COD. When their financing fell through in month 10, they lost a $400,000 deposit. The modules sat in a warehouse. They were eventually sold at a 12% discount to another developer. That’s $48,000 gone, and it took 6 months to unwind.

“I knew I should wait for financial close before ordering. But my EPC pushed me to ‘secure the supply chain.’ That was the one time the verbal agreement got forgotten. $400k lesson.”

What to do instead: Ask First Solar for a non-binding capacity reservation (they do offer these for large projects). Use that to support your financing application. Only convert to a binding PPA when you have committed financing. This way, you get priority allocation without taking on financial risk too early.

What the Data Says

According to First Solar’s Q4 2024 earnings call (source: First Solar investor relations, Feb 2025), their global backlog stood at 80.2 GW as of year-end 2024. That’s significant — it means waiting a few months for financial certainty won’t necessarily leave you without supply, but it’s getting tighter. Their average lead time for Series 7 modules (as of early 2025) is roughly 8–10 months for new orders.

Scenario B: You Have a Firm PPA and a Tight COD Timeline (6–9 Months Out)

What I Learned the Hard Way

This is the most common trap. You have a signed PPA, your EPC says “we need modules in 6 months,” and everyone panics.

Here’s my hard-learned truth: Buy now, but don’t buy blind. I once assumed “same specifications” meant identical performance across different series. Didn’t verify. Turned out Series 6 and Series 7 have different string inverter compatibility requirements. We had to re-engineer the string layout on a 50 MW site, costing $12,000 in redesign fees and a 2-week delay.

Your checklist before buying:

• Confirm module dimensions and weight for your tracker system (First Solar Series 7 uses a different frame than Series 6)
• Verify electrical compatibility with your inverter string sizing — Series 7 has a slightly different I-V curve
• Get written confirmation on delivery milestones, not just a promised date
• Ask about the 0.5% annual degradation warranty — is that for Series 6 or Series 7? It varies by product line

In 2024, a colleague of mine skipped the final review on a 100 MW Series 6 order because they were rushing and “it’s basically the same as last time.” It wasn’t. The panels had a slightly different junction box location, which required re-routing combiner boxes. $15,000 in retrofitting costs. Missed the deadline by 5 days.

Why Quality Matters Here

When you’re on a tight timeline, you can’t afford the wrong modules. That’s when the “quality as brand image” argument kicks in. The First Solar name means something in the utility-scale world — but only if the modules are specified correctly for your project. If you get it wrong, your client won’t blame the module; they’ll blame you. And rightly so.

Scenario C: You’re a Developer With Flexibility (9–15 Months Out, No Rush)

The Surprise I Didn’t Expect

This is where I have mixed feelings. On one hand, waiting for the “right moment” can save money — First Solar has historically offered volume discounts for large, early commitments. On the other hand, prices have been trending up through 2024 due to material costs and factory ramp-up timelines.

The surprise wasn’t the price trend. It was how much hidden value came with buying early — not just pricing, but allocation priority. In Q2 2024, a developer I know committed to 300 MW of Series 7 modules 18 months before COD. They got a 5% discount off the list price, free shipping for the first 50 MW, and priority allocation during a supply crunch later that year. That last point alone saved them from a 3-month delay.

My honest take: If you have flexibility and are confident about your project timeline, buying early (with a reasonable deposit) is the smarter play. The risk of price increases outweighs the risk of committing too soon — especially given First Solar’s backlog is still growing.

“Part of me wants to wait for the best deal. Another part knows that tight supply doesn’t reward waiting. I compromise by buying with a small deposit and delaying final payment until 6 months before delivery.”

How to Figure Out Which Scenario You’re In

Here’s a simple diagnostic:

• Your project is more than 12 months from COD and financing isn’t closed: You’re in Scenario A. Don’t buy yet. Secure a reservation.
• You have a signed PPA and your EPC says 6–9 months: You’re in Scenario B. Buy now, but verify specifications first. That $12k re-engineering cost I mentioned — it’s avoidable.
• You have flexibility and are confident in your timeline: You’re in Scenario C. Early commitment with a small deposit is your sweet spot.

If you’re still unsure, ask yourself one question: Would a 3-month delay in module delivery kill your project? If yes, you need to prioritize speed over price. If no, you can afford to optimize for cost. Simple.

Final Thought: Don’t Let Perfect Be the Enemy of Good

Look, I’m not saying there’s one right way to buy First Solar panels. But after watching (and causing) $120k in avoidable losses, I can tell you this: the most expensive mistake isn’t buying too early or too late. It’s buying without a plan that fits your specific timeline, financing, and technical requirements.

Take 30 minutes to map your project timeline against the scenarios above. It saved my team from repeating a $400k error.