Who Created the First Solar Panel? 6 Steps to Evaluate Solar Panel Suppliers

Who Created the First Solar Panel?

The photovoltaic effect was discovered by French physicist Edmond Becquerel in 1839. The first actual solar panel, though, arrived in 1883, when American inventor Charles Fritts pressed a very thin layer of gold onto selenium. Fritts’ panel converted less than 1% of incoming sunlight into electricity. Enough to prove the concept; not enough to power much else.

In 1954, Bell Labs researchers Daryl Chapin, Calvin Fuller, and Gerald Pearson created the first practical silicon solar cell at around 6% efficiency. That silicon-cell heritage is still the basis for most crystalline PV modules sold today.

If you landed here because you’re evaluating First Solar panels or other modules for a commercial or utility-scale project, the history matters for one reason: making a solar panel that produces electricity stopped being difficult a long time ago. The hard part is choosing a solar panel supplier that can deliver consistent quality at scale, back its products for 25 to 30 years, and stay financially stable long enough to honor that commitment.

I’m a quality compliance manager at First Solar. I review every module batch before it is released to customers—roughly 120 batch releases a year. In 2025, I rejected about 2% of first-production batches due to specification deviations. This article is the checklist I would run if I were on the buying side: comparing solar panel suppliers, reviewing a PV module distributor agreement, or trying to decide between a manufacturer and an OEM private-label arrangement.

Who Should Use This Checklist

This six-step checklist is for volume buyers:

• EPCs evaluating module suppliers for a tender;
• project developers procuring modules directly or through a distributor;
• procurement teams working with manufacturers on large-scale supply agreements;
• distributors deciding whether to carry a manufacturer brand or launch their own private-label product.

If you are replacing a few panels on a rooftop, this is more process than you need. If you are buying thousands of modules, the steps below will catch the issues that do not show up in the first quote.

Step 1: Confirm Who Actually Manufactures the Module

The brand on the label is not always the factory that made the module. That distinction matters more as the market grows.

Suppliers fall into roughly three categories:

• Direct manufacturers that own production lines and sell under their own brand, such as First Solar’s thin-film modules.
• Distributors that buy finished modules from one or several manufacturers and resell them under the original manufacturer’s brand.
• Private-label or OEM arrangements, where a seller contracts a factory to build modules under the seller’s own brand. The seller controls the brand; the factory controls the production quality.

All three can work. But the legal structure matters: when comparing PV module OEM vs private label options, the question is not which brand sounds more professional. It is which legal entity signs the product warranty, and what financial resources stand behind it.

I used to assume that a recognizable brand also owned its factory. I stopped assuming that after almost signing a supply agreement with a company that turned out to be a marketing operation built entirely on OEM production. The modules were acceptable, but the warranty was only as strong as the contract between the brand and its OEM factory. If that relationship collapsed, the buyer would have been left trying to claim directly against a factory that had no contractual duty to us.

Before you go deep into pricing, ask for the factory name, location, and the legal name of the manufacturing entity. It should be in the contract, and it should match the name on the warranty.

Step 2: Look Beyond the Certificates

Most suppliers will show IEC 61215 and IEC 61730 certificates. Necessary, yes. Sufficient, no.

Those certifications are type approvals. They prove a sample design passed standardized lab testing. They do not prove that the tens of thousands of modules you receive will match that sample.

Ask the supplier how they control consistency in production. Useful questions:

• What share of modules receives electroluminescence (EL) testing at end of line? One hundred percent is increasingly common; if they only sample, find out the sample rate.
• How often is the flash tester calibrated, and what tolerance does it hold compared to a certified reference module?
• Can they share a power-bin histogram from a recent production lot? A distribution clustered near the bottom of the bin tells a different story than one clustered in the middle.
• What is the internal reject rate for visual defects, and what counts as a visual defect?

I do not care if a salesperson can recite the datasheet from memory. I care whether traceability records can connect a specific module serial number back to its production date, shift, and test data. If the supplier cannot do that, their quality system is probably not at the level their brochure suggests.

Step 3: Translate Degradation and Warranty Terms Into Money

Two quotes can both say “30-year linear power warranty” and still be very different products. The details matter, and they have a direct financial impact.

Here is a simple example. Supplier A offers a 450 W panel with 0.45% annual degradation. Supplier B offers a 455 W panel with 0.55% annual degradation. By year 25, Supplier A’s panel is still at roughly 399 W under its warranty curve; Supplier B’s panel is at roughly 392 W. The higher starting power loses to lower degradation over the asset’s life.

On a 50 MW project, a difference of 0.1% annual degradation can change energy yield by millions of kilowatt-hours across 25 years. That’s real revenue.

Before comparing warranty wording, ask:

• Does the linear warranty start at delivery, at interconnection, or after the first year of operation?
• What exclusions apply to glass, frames, junction boxes, and connectors?
• Who pays for replacement module logistics, labor, and downtime in a warranty claim?
• Is the claims process handled locally, or do you have to ship modules to another continent?

I read warranty claims for a living. Honestly, most buyers do not read these clauses until they have a problem, and by then it is usually too late to negotiate anything.

Step 4: Compare Total Cost Per Delivered Kilowatt-Hour

If the procurement conversation stops at price per watt, the analysis is incomplete. Total cost of ownership includes:

• module price;
• freight, insurance, tariffs, and port handling;
• project-design differences caused by module dimensions and weight;
• degradation and temperature performance over 25 to 30 years;
• expected failure and replacement rates;
• the financial stability of the warranty provider.

The lowest $/W module can lose its advantage by the time freight, tariffs, and degradation differences are included. I’ve had suppliers tell me their module was “basically the same” as a competitor’s because the datasheet looked similar. It was not. The temperature coefficient, power tolerance, and warranty language were different.

A full LCOE model may be overkill for comparing every quote. But for a shortlist of finalists, run the yield calculation properly. The point of total-cost thinking is to compare delivered energy, not delivered hardware.

Step 5: Ask About Transport, Storage, and Receiving Inspection

This step gets skipped more than any other, yet it is where solar panel suppliers and buyers end up in their most expensive disagreements.

Large-format glass modules can develop microcracks before they reach the site. They can be invisible at a glance while still reducing performance, and they tend to get worse over cycles of heat and cold. If you sign the delivery receipt before inspecting, then open the crates later and find cracks, proving who caused the damage becomes your problem.

I remember a project where a customer received a container with cracked corner glass on about 6% of the modules. The trucking company said the crates were fine when loaded. The supplier’s loading photos looked acceptable. Nobody had inspected at delivery, so everyone had a plausible story and nobody had clear liability. Had the buyer taken photos and opened a few crates before signing, the situation would have been easier to settle.

Before you order, ask the supplier:

• What is the maximum stacking height for pallets during transport and storage?
• Are modules shipped upright, and what is the recommended orientation in the container?
• Can they provide written handling instructions for the freight forwarder?
• Do they allow third-party pre-shipment inspection at the factory?

At delivery, do not wave the truck away. Photograph the container and pallets before unloading. Open at least a few boxes in front of the driver. If possible, arrange EL spot testing on a sample before accepting the batch. It becomes way more expensive to argue about damage after the driver leaves.

Step 6: Look at the Financial Health of the Warranty Provider

A 30-year warranty from an organization that will not survive 30 years is a marketing document, not protection.

When reviewing a supplier or distributor, take time to check:

• production volume history and capacity utilization;
• audited financial statements or credible credit reports;
• ownership structure and whether a parent-company guarantee backs the warranty;
• their track record of honoring warranty claims;
• whether they hold local spare-module stock or a clear plan for replacements.

The last point is not hypothetical. In 2022, freight and logistics shocks made replacement parts expensive and slow. The suppliers that had local warehousing and credible spare-module programs were the ones that kept projects and O&M teams satisfied.

I did not fully understand the financial side of module selection until I watched a module brand disappear after its backer ran into trouble. The modules kept producing. The warranty effectively did not.

If you buy through a PV module distributor, ask whether the distributor has the contractual right to file a manufacturer warranty claim on your behalf. If you buy private-label modules under an OEM agreement, ask directly: if the brand stops operating, which legal entity is responsible for warranty replacements, and where is the financial guarantee? If the answer is vague, have an attorney review that clause before you sign.

Common Mistakes to Avoid

• Comparing only $/W. It ignores logistics, performance, degradation, warranty, and administration overhead.
• Assuming “same specifications” means the same module quality. Different factories have different tolerances, test coverage, and process control.
• Skipping receiving inspection. A note on the bill of lading is cheap; a legal dispute is not.
• Buying a private-label module without confirming who holds the warranty and the assets behind it.
• Waiting until after signing to ask how warranty claims will work. Ask before the order is placed.

Looking back, I should have insisted on third-party EL testing before accepting the first batch from one of my early suppliers. At the time, it felt like an unnecessary expense on a project that was already over budget. One undetected microcrack issue cost us a rework and weeks of delay—a result that made the inspection fee look trivial.

Charles Fritts didn’t have to choose among suppliers in 1883. Today, you have plenty of choices. Run the six steps above and keep the total-cost frame in mind, and you will lower the chance of letting a low sticker price hide a much higher real cost.