What makes the cut

  • Proven: years on the market and many real installs.
  • Supported: a warranty the company honors and support you can reach.
  • Best value: worth the money over its whole life.
  • Right-sized: sized for your darkest month, not the average.
  • Sun data: NASA POWER long-term monthly averages, for panels tilted at latitude (homes and cabins) and flat (van and bus roofs). A ZIP code uses the center of its 3-digit ZIP area, and a shared location the nearest ZIP-area center, so the sun is local to your area, not just your state. The state table uses each state's 2020 Census center of population. The full table.

Where the information comes from

  • Long-term owner builds on YouTube, forums and blogs, linked on every guide.
  • Owner reports from readers running the gear.
  • Manufacturer spec sheets and warranty terms.
  • Independent tests and teardowns.

Keeping it current

Every guide and pick shows when it was last reviewed. Changes are logged on What changed. Reader ideas that change a pick get credited.