In most cases, solar panels gradually lose efficiency over time and produce progressively less energy each year. (The annual rate of this decline should be under one percent.)
After a specified number of years, the panel should still be able to generate the same amount of power as when it was first installed, according to the warranty. Most product warranties are for a minimum of 10 years and can be as long as 25 years, while power warranties often last for 25 years.
Because of its importance, the inverter system will be covered by its own warranty. On average, people live between 10 and 25 years. The racking system must last for at least two decades in possibly harsh climates.
The warranty should be at least 20 years long and batteries should be included. It’s an expensive part, so read the fine print before you buy. A 10-year warranty is standard on both the Tesla Powerwall and the Sunrun Brightbox.
Avoid being coerced into making a purchase.
It’s not always a red flag if the sales representative you’re meeting with is eager to close the deal because many respectable solar installers offer commissions to their sales personnel. Yet, high-pressure sales tactics are a clear indication that a company values quantity over quality in its business operations.
Some red flags to keep an eye out for include
When a company:
• tells you that solar will be great for your home while other companies tell you otherwise;
• pushes you to go with “no-money-down” financing schemes (leases and PPAs);
• pressures you to sign a contract quickly rather than letting you carefully study it on your own;
• preys on the elderly
Read the Better Business Bureau’s documented cases of consumer dissatisfaction with major national installers like Vivint Solar, Sunrun, and SolarCity (Tesla) to learn more about their questionable sales tactics. The best solar panel installers in your area aren’t aiming to expand into a national powerhouse, but rather to remain locally based and focus on providing exceptional service.