Most residential solar panels sold in 2026 are rated around 430 to 470 watts, and the most efficient home panels now convert roughly 23% to 24% of sunlight into electricity. Larger commercial panels can top 600 watts, but they are too big and heavy for most homes. For a San Diego roof, the better question is which panel produces the most usable power from the space you have.
Why has panel wattage gone up?
In 2022, about 400 watts was a standard home panel; today 430 to 460 watts is the norm. Newer cell designs, including N-type heterojunction (HJT), TOPCon and back-contact cells, get more power from the same footprint. Higher-wattage panels mean fewer panels for the same system size, which helps on smaller or oddly shaped roofs.
Is the highest-wattage panel the best choice?
Not always. Wattage is measured in lab conditions, and real production depends on heat, shade and how the panel ages. Three specs matter as much as the number on the label:
- Temperature coefficient: how much output drops as the panel heats up. Lower is better on hot inland afternoons.
- Degradation rate: how much output the panel loses each year. Premium panels lose about 0.25% a year.
- Shade tolerance: split-cell designs keep producing when vents, chimneys or trees shade part of the panel.
Which panel does Stellar Solar install?
Stellar Solar installs the REC 460 Alpha Pure-RX, a 460-watt heterojunction panel with efficiency up to 22.6%, a low temperature coefficient of -0.24%/°C and degradation of about 0.25% per year. It is not the single highest-wattage panel on the market, but its heat performance and shade handling deliver strong real-world output on San Diego roofs.
What happened to the SunPower 415?
An earlier version of this article named the SunPower 415 and A-Series as the highest-wattage panels available in 2019. SunPower Corp. filed for bankruptcy in August 2024. SunPower-branded panels were made by Maxeon Solar Technologies, which spun off from SunPower in 2020 and has said it will continue to honor its panel warranties. If you already have one of those systems, Stellar Solar can still service or expand it. See what to do if your solar company goes out of business.
How many panels does my home need?
That depends on your electricity use, your roof and whether you add a home battery. We size every system from your actual SDG&E bills, then fit the layout around required setbacks and fire-access pathways.
Get a free, no-pressure quote and we will design a system around your roof and your SDG&E usage.
