What is a Tier 1 Solar Panel?

A Tier 1 solar panel is a panel that is made by a manufacturer that has been rated as Tier 1 by a reputable independent PV industry analyst.

Tier 1 is the highest (best) tier, and means that the analyst who ranked it believes that the module manufacturer scores well on lots of criteria including:

1. Experience
2. Financial position
3. Manufacturing scale
4. Deployment scale
5. Durability & quality
6. Technical Performance
7. Vertical integration
8. Insurance and backing
9. Service and support

While "Tier 1" status is a proxy for quality, there are a number of Tier 1 brands that I would not install on my own home.

Thus, my advice is to stick to brands on my recommended chart, instead of looking for whether or not a brand is "Tier 1"

I have written in detail about Tier 1 rankings here.