My Honest Take on First Solar: Not the Cheapest, But the Smartest Long-Term Bet for Utility-Scale Solar
If you're evaluating modules for a utility-scale project and your only metric is $/Watt, you're leaving real long-term value on the table—especially if you're not factoring in First Solar's low degradation rate and the reliability of their thin-film technology. After comparing proposals from three major module suppliers—including First Solar and two Tier-1 crystalline silicon (c-Si) manufacturers—for a 200-MW solar farm we broke ground on last year, I can tell you: the initial price quote from First Solar (their Series 6 Plus, around $0.28/W) was roughly 10-15% higher than the c-Si bids. But when I ran the full lifecycle cost, including annual degradation and O&M impacts, the total cost of ownership (LCOE) favored First Solar by 5-7% over 25 years.
That’s the kind of analysis that makes a procurement manager look good to both the CFO and the operations team. Here’s how I got there.
Why My First Impression Was Wrong (and What Corrected It)
When I first saw the pricing from First Solar, my gut reaction was: why pay more for a panel with lower nameplate efficiency? The Series 6 Plus has a module efficiency of about 18-19%, while the leading monocrystalline PERC panels from the c-Si camp hit 21%+. That’s a significant difference in power density, and on a 200-MW site, it means roughly 5% more land needed to achieve the same nameplate capacity. More land equals more civil works, more racking, longer cables. Not good for the budget.
I was about to dismiss First Solar as a premium-priced option without a clear advantage. But our technical lead—a veteran solar engineer who’d been in the industry since the Solyndra days—suggested we dig deeper. He said, “Look at the degradation curves, not just the nameplate ratings.”
The Data That Changed My Mind
Annual degradation rate is the single most underappreciated metric in module procurement. People assume all Tier-1 modules degrade at roughly the same rate—around 0.5% to 0.7% per year. But First Solar's long-term data promises an average of less than 0.5% per year for their CdTe modules. Many top c-Si panels are rated for 0.55% to 0.65% under standard test conditions, but real-world field data (I've seen NREL reports and internal project data from a 150-MW installation in California) often shows 0.6% to 0.8% for c-Si in hot, humid climates.
That 0.2% to 0.3% difference per year compounds massively over 25 years. On a 200-MW plant generating 350 GWh annually, a 0.2% difference in degradation means roughly 70 MWh less energy production in year 25 alone. At a PPA price of $40/MWh, that’s $2,800 in lost revenue per year—just from the degradation gap. Over the entire project life, the difference totals tens of thousands of dollars.
That alone shifted the levelized cost of energy (LCOE) comparison back in First Solar’s favor, even factoring in the higher upfront module cost and increased land requirements.
I Learned This the Hard Way in 2021
I'll be honest: I almost made a different choice on a smaller project (50 MW) back in 2021. I went with a cheaper c-Si option based on initial $/W pricing and a compelling financing offer. The modules performed reasonably well for the first 3 years. But by year 4, the degradation tracking showed a clear 0.7% annual slope, higher than the datasheet’s projected 0.55%. The project’s cash flow projections started looking tight. I still have the Excel model saved—it's a reminder that short-term savings can become long-term headaches.
On the 200-MW project I mentioned earlier, I ultimately went with First Solar Series 6 Plus. That decision was made in Q3 2023, and our commissioning was in Q2 2024. So far, the performance data matches their claims. I’m tracking actual degradation quarterly (note to self: need to do the Q1 2025 analysis).
What About the Series 7 TR1?
For my project, the Series 6 Plus was the right fit—it was available at the promised price and delivery schedule. The Series 7 TR1, which was announced with higher efficiency (around 21%), was still ramping up production, and our timeline didn't allow for the wait. Based on what I’ve seen from their investor relations and product roadmaps, the TR1 could be a game-changer for projects where nameplate density matters—like sites with limited acreage. I've heard the price point is competitive, but I don't have a confirmed quote to share (this was accurate as of late 2024, and the market changes fast—verify current pricing with your First Solar rep).
Not Everything is Perfect: The Boundaries
Before you think I'm a First Solar fanboy, let me tell you where their product doesn't excel. First, the land use issue I mentioned: if your site is land-constrained (like a brownfield in a dense area), lower efficiency means fewer MW per acre. You might be better off with high-efficiency c-Si modules there. Second, while First Solar's technology handles high temperatures well, it can also have slightly lower performance in very low-light conditions compared to the best bifacial c-Si panels. Finally, the upfront cost reality: if your project has a hard capital budget cap and you cannot secure financing that accounts for LCOE, the higher initial $/W might simply be a blocker. In those cases, going with a quality c-Si vendor might be the pragmatic choice.
So here's my bottom line: For large-scale, ground-mount projects where you have room to optimize and a 20+ year horizon, First Solar's CdTe modules can deliver better long-term economics despite a higher initial ticket. Don't let the lower nameplate efficiency fool you—the degradation data and manufacturing quality make them a strong contender. And if you're doing a project that can accommodate the extra land, it's often the smartest choice.
Above all, the way you evaluate your module suppliers will set the tone for the project’s financial performance for decades. Spend the time on the LCOE model, not just the unit price. In so doing, you get to balance the near-term budget and long-term reliability. That’s the kind of procurement work that builds a reputation.