Why New Solar Panels Lose Power: LID vs LeTID Explained

LID vs LeTID in solar panels showing the difference between light induced degradation and elevated temperature induced degradation in photovoltaic cells.

Noticed an early drop in solar output? An engineer breaks down LID vs LeTID degradation, affected cell types, and what manufacturers test for. LID and LeTID are two specific, well-documented degradation mechanisms that cause a measurable output drop in certain solar cells shortly after installation, before performance stabilizes. Neither is a manufacturing defect — they’re … Read more

Solar Panel Degradation: How Much Power Do Panels Really Lose in 25 Years?

Solar Panel Degradation showing long-term photovoltaic power decline.

Solar panel degradation rate explained by a registered engineer — real year-by-year output decline data across every major cell technology. Every solar panel produces slightly less power in year two than year one, and slightly less again in year three, in a slow, predictable decline that continues across the system’s entire operating life. This isn’t … Read more

Solar Panel Temperature Coefficient: Why Heat Kills Performance

Solar Panel Temperature Coefficient showing how rising panel temperature affects photovoltaic power output.

 Solar panel temperature coefficient explained by a registered engineer — real hot-climate performance data and which technology handles heat best. Temperature coefficient is the single most consequential number on a solar panel datasheet that most buyers never think to ask about, and it’s also the reason a hot, sunny climate doesn’t automatically mean maximum solar … Read more

N-Type vs P-Type Solar Panels: Honest Comparison

N-Type vs P-Type solar panels installed on a residential rooftop.

N-type vs P-type solar panels explained by an engineer — real efficiency and degradation differences, and which one actually matters for buyers. N-type and P-type refer to how a silicon wafer is chemically doped, and it’s become a genuinely important spec-sheet distinction over the past few years as N-type has moved from a niche premium … Read more

Polycrystalline Solar Panels: Worth Buying in 2026?

Polycrystalline solar panels installed on a large commercial rooftop under bright sunlight.

Efficiency, cost, and real-world performance data for polycrystalline solar panels — where they still make engineering sense in 2026. I still get this question on nearly every residential site visit: “Just give me the cheapest solar panels that work.” More often than not, homeowners are referring to polycrystalline solar panels. The honest engineering answer in … Read more

Is Buying Used Solar Panels a Mistake? An Engineer’s Honest Verdict

Professional solar engineer in a hard hat and safety vest using a multimeter to test the open-circuit voltage (Voc) of a used solar panel junction box at a warehouse.

Thousands of used solar panels hit the US market daily. Before you buy, learn the “red flags” that indicate a dying module and how to test for 90% efficiency. As a solar engineer with years of experience in designing, testing, and installing photovoltaic systems, I’ve seen both the value and risks of the secondary solar … Read more