NerdWallet’s overall ratings for solar panel companies are weighted averages of ratings in the following categories:
• Responsiveness to service requests. • Customer satisfaction.
• Pricing transparency.
• Warranty coverage, including for workmanship and equipment. • Performance guarantee. • Customer service options.
Data collection and review process
NerdWallet reviews the largest residential solar companies in the U.S. based on market share and search volume (as a proxy for consumer interest). We gather information from companies’ websites and contact companies if further information is needed.
The final output produces star ratings from poor (1 star) to excellent (5 stars). Ratings are rounded to the nearest half-star.
Information updates
Our writers and editors review providers on an annual basis. Throughout the year, we may maintain contact with providers and update any changes to their offerings.
Factor weightings
The weighting of each rating factor is based on our team’s assessment of which features are most important to consumers and which ones impact the consumer experience in the most meaningful way.
The review team
The review team comprises writers and editors who cover solar products and services. Each writer and editor follows NerdWallet’s strict guidelines for editorial integrity. The combined expertise of our team is infused into our review process to ensure thoughtful evaluation of products and services from the customer's perspective.
Responsiveness to repair requests
Solar companies that provide the time frame in which they dispatch technicians for repair requests are rated accordingly. If providers don’t disclose a timeline for repairs, they are given the lowest score.
Customer satisfaction
NerdWallet averages the customer review scores for companies from three sources: the Better Business Bureau, SolarReviews (a review site that collects consumer reviews of solar panel companies) and ConsumerAffairs (a consumer review site). The higher a company’s average customer satisfaction score, the higher its score in our rubric.
Pricing transparency
Companies that provide quotes immediately and without requiring a consumer to provide contact information receive higher scores than those that require consumers to wait to be contacted by a sales representative.
Warranty coverage
NerdWallet looks at solar companies’ standard warranties, including workmanship and equipment warranties. We evaluate what is covered in each warranty and their terms. Factors that affect a company’s score for warranties include length of a warranty, type of coverage, inclusion of labor and difference in coverage for leasing or PPA customers compared to customers who purchase or finance systems. Companies that vary their warranty coverage or terms by location are scored according to the coverage and terms that are consistent for all customers.
Performance guarantee
NerdWallet considers differences in solar companies’ performance guarantees, including length of a performance guarantee, the guaranteed production or output during the last year of the contract and if a performance guarantee is tied to a required subscription plan. We also look at how performance guarantees differ for each company in regard to different agreement types. Companies that offer solar panels with better performance guarantees for 25-year terms will score better in our rubric than those with lower performance guarantees or terms for less than 25 years.
Customer service options
NerdWallet considers how easily consumers can contact customer support and make service requests. The easier this process is for consumers, the better a company will score in our rubric.
Regulatory or legal action
The final category is unweighted and discretionary. A solar company’s rating may be adjusted down if it has faced governmental regulatory action or major legal action in the past five years for practices NerdWallet deems harmful to consumers.