Solar equipment, without the hype
Brand matters less than salespeople suggest. Installer quality, a fair price and solid warranties matter more. Here's what's actually being installed, what the specs mean, and which companies have had trouble.
Solar panels
Efficiency, warranties, degradation and which companies are financially solid.
11,566 certified models · 177 brands
Inverters
Microinverters vs string vs optimizers, warranties and replacement costs.
1,131 certified models · 85 brands
Home batteries
Usable capacity, power, chemistry, warranties and whether one pays off.
652 certified models · 62 brands
What's actually being installed
Share of residential systems installed since 2024, from 465,486 public installation records (LBNL Tracking the Sun and California DGStats).
Solar panels
Inverters
Home batteries
Battery shares come from a smaller sample (11,099 systems) outside California.
What actually matters
Installer quality matters more than panel brand
- Most residential system failures and roof leaks come from installation workmanship (wiring, connectors, flashing, conduit), not the panel model.
- Workmanship warranties range from 1 to 25 years. 10+ years is a good benchmark. They are only as good as the installer's solvency (SunPower's August 2024 Chapter 11 and Sunnova's June 2025 bankruptcy left many customers without workmanship or service support).
- Ask whether the installer uses its own crews or subcontractors, its NABCEP certifications, how long it has been in business, and who services the system if it closes.
- Manufacturer labor reimbursement programs (REC ProTrust, Qcells, Enphase) often depend on certified installers, so ask for the actual warranty PDF.
A warranty is only as good as the company behind it
- Panasonic (2025 exit), LG (2022 exit), Meyer Burger (2025 insolvency) and Maxeon (2026 judicial management, US imports blocked) all show that a 25-40 year paper warranty depends on the company's survival.
- Prefer brands that are financially stable and have a US legal entity and service presence. Ask whether a third-party warranty insurance policy backs the manufacturer warranty.
- Meyer Burger sold its US equipment and laid off all US staff in 2025, so claims from US customers have little practical recourse.
What 'Tier 1' really means (and how it's misused)
- The BloombergNEF Tier 1 list is a financial bankability ranking: manufacturers whose own-brand, own-factory modules were used in at least 6 different non-recourse bank-financed utility projects over 2 years.
- It is NOT a quality, reliability or warranty rating, and BNEF itself says it should not be used that way.
- Salespeople often say 'Tier 1 panels' to suggest premium quality. Nearly every mainstream Chinese brand is Tier 1.
Independent reliability testing (PVEL / RETC)
- Kiwa PVEL's 2026 Scorecard (May 2026) named 43 Top Performer manufacturers; 87% of manufacturers and 61% of BOMs had at least one failure, a record high.
- No single model/BOM was a Top Performer in all tests in 2026, a first in the Scorecard's 12 editions.
- 26% of BOMs broke under mechanical load testing and 45% of manufacturers had a major delamination failure. Thin glass and larger formats are blamed.
- Testing is voluntary and paid for by manufacturers, so absence does not mean failure. Results apply to a specific bill of materials (BOM), and the panels you get may be made from a different BOM.
- RETC's PV Module Index is a similar annual third-party test program.
Efficiency vs cost per watt
- Efficiency only matters when roof space is limited. On a large roof, a 20.5% panel and a 23% panel produce the same kWh per installed watt.
- Compare quotes by $/W (total price / DC watts), not $/panel. 2026 US residential installed cost typically about $2.50-$3.50/W before incentives (check the latest EnergySage/LBNL data).
- Premium IBC/HJT/back-contact panels cost more per watt. The extra cost pays off mainly on small roofs or in very hot climates.
Temperature coefficient and degradation
- Temperature coefficient (Pmax) is typically -0.24 to -0.26%/C for HJT, -0.29 to -0.30%/C for TOPCon, and -0.34 to -0.37%/C for older PERC. Panels lose more output per degree in hot climates with a larger negative number.
- Linear performance warranties for N-type panels usually guarantee 87-92% at year 25-30 (0.25-0.4%/yr). P-type PERC is typically 84-86% at year 25 (~0.55%/yr).
- Real-world median degradation (NREL) is about 0.5%/yr across older fleets. New N-type tech claims less, but UVID (UV-induced degradation) in TOPCon is an emerging concern flagged by PVEL in 2026.
MLPE (microinverters/optimizers) pros and cons
- Pros: panel-level monitoring, reduced shading/mismatch losses, NEC 690.12 rapid-shutdown compliance, no single point of failure (micros).
- Cons: more electronics on a hot roof (each failure needs a roof visit), higher $/W, and component lock-in.
- String inverters with simple rapid-shutdown devices (Tigo TS4-F, APsystems RSD, Tesla MCI) are cheaper and fine for unshaded, simple roofs. Expect to replace a string inverter once in 25 years ($1,500-$3,000).
- Warranty: micros 25 yr (Enphase), optimizers 25 yr + inverter 12 yr (SolarEdge), most string inverters 10-12 yr.
Batteries: what matters
- Check usable kWh (not nominal), continuous kW (determines how many loads run at once), and surge/LRA (whether the HVAC can start).
- LFP chemistry dominates in 2026 (safer, longer cycle life) over NMC.
- Battery warranties are limited by years AND throughput (MWh) or cycles, with an end-of-warranty retention of 60-70%. Read both limits.
- AC-coupled batteries are easy to retrofit to existing solar. DC-coupled hybrids are more efficient for new installs.
- Whole-home backup often needs 2+ batteries or load management. A smart panel or Meter Collar can avoid a main panel upgrade.
US manufacturing, domestic content, FEOC and UFLPA
- 'Made in USA' panels usually mean US-assembled modules with imported cells. US cell production is only now ramping: Canadian Solar's Indiana HJT plant (July 2026), T1 Energy's Austin plant (first cells targeted Q4 2026), Qcells Cartersville (targeted end of 2026), and Silfab Fort Mill (idled Aug 2026).
- UFLPA detentions have hit Qcells (2025), Maxeon (2024-2026) and others. Supply disruptions can delay installs.
- FEOC (foreign entity of concern) rules under the 2025 budget law restrict tax credits for third-party-owned (lease/PPA) systems that use Chinese-linked components. Ask whether lease/PPA pricing depends on equipment that meets these rules.
- Meyer Burger's Arizona plant closed in May 2025. Waaree bought its module tools.
Racking, flashing and roof warranties
- Flashing types: traditional metal flashing slid under shingles (e.g., IronRidge FlashFoot2, EcoFasten), micro-flashing/butyl-sealed (QuickBOLT), flashless sealant mounts (Roof Tech), tile hooks/replacement tiles, and standing-seam clamps (S-5!) that need no penetrations.
- Racking warranties (often 25 years) cover the hardware, NOT roof leaks. Leak coverage comes from the installer's workmanship/roof-penetration warranty.
- Ask: Will installing void my roofing manufacturer's warranty? Is there a separate roof-penetration warranty, and how long? Do you seal into rafters (not just decking)? Who handles removal/reinstall for a future re-roof, and what does it cost (typically $2,000-$5,000+)?
- If the roof has less than 10 years of life left, re-roof before installing solar.
Red flags in equipment pitches
- 'Tier 1' presented as a quality guarantee.
- 'Free solar' / 'government program' framing for a lease or PPA.
- Selling discontinued brands (Panasonic, LG, Meyer Burger) or Maxeon/SunPower-branded panels without disclosing the company's status.
- Quoting only panel brand and wattage without naming the inverter, battery and racking models.
- Highlighting a 30-40 year warranty without saying who backs it or what labor is covered.
- Claiming a battery provides 'whole-home backup' without a load calculation.
- Oversized production estimates. Check them with NREL PVWatts.
- Pressure to sign the same day, or dealer fees added to loans (often 20-30% hidden in the price).