The EnergySage Equipment Rating System

About our Equipment Rating System

In 2015, we launched the first iteration of our equipment rating system with the assistance of the National Renewable Energy Laboratory (NREL) so solar shoppers could easily understand and compare their solar equipment options.

Since then, the rating system has undergone several updates to keep pace with advancing solar technology. We believe the latest iteration provides a more accurate and granular evaluation of the equipment available in the market and will help both shoppers and installers differentiate products.

How does EnergySage evaluate equipment?

We developed our Equipment Rating System over years of research—including interviews with manufacturers, financiers, solar installers, and homeowners—to understand what truly differentiates the best products from the rest. Our rating logic reflects today’s equipment standards, including advancements in efficiencies, improvements in warranty offerings, and more.

We give a categorical rating for each piece of equipment, ranging from "Poor" to "Excellent". Categorical ratings are based on numerical scores assigned to each piece of equipment. Those Numerical scores are assigned according to criteria across multiple categories including, performance, warranties, durability, and more. Eventually, those numerical scores will all be out of 100; for now, they will be out of 95 for inverters and batteries, and 90 for solar

A curve is applied so the highest-rated equipment gets a score of 100. Here's how the numerical scores relate to the displayed categorical scores:

Rating	Score
Poor	0 to 19
Fair	20 to 39
Good	40 to 59
Very Good	60 to 79
Excellent	80 to 100

Numerical scores don’t appear in our marketplace today but, pending user research, we are considering adding them in 2025.

Some products on our marketplace may currently appear as "Unrated". Our Equipment Rating System focuses on evaluating the most commonly quoted solar panels, inverters, and batteries, and we are committed to continuously expanding our coverage.

Solar panel rating criteria

Performance (30 points)
- Panel efficiency
- Output per square foot
- Temperature coefficient
Warranty (25 points)
- Product warranty length
- Power warranty length
- Power warranty at year 25
- Additional criteria related to labor, shipping, and more
Durability (25 points)
- Wind load
- Snow load
- Advanced certification and testing
- PVEL top performer tests
Manufacturing (15 points)
- ISO certifications
- [Coming later] Manufacturing location

[Coming later] Installer input (5 points)

Inverter rating criteria

Performance (35 points)
- CEC efficiency
- Voltage performance
- Decibels of sound
- Max inverter loading ratio
System customization (10 points)
- Temperature operating range
- Enclosure rating
Capabilities (15 points)
- Optimization level
- Additional capabilities related to generator integration, fleet management, and more
Warranty (15 points)
- Inverter warranty length
- Communication equipment warranty length
- Additional criteria related to labor, shipping, and more
Certifications (20 points)
- National grid connection standards
- Updated grid connection standards
- Additional certifications

[Coming later] Installer input (5 points)

Battery rating criteria

Performance (35 points)

- Roundtrip efficiency
- Usable capacity
- Largest possible battery capacity in one system
- Peak power output
- Continuous power output
- Battery chemistry
- Power density

System customization (25 points)

- Enclosure rating
- Operating altitude
- Discharge temperature (high and low)
- Smallest building block size
- Weight
- Cubic feet
- Additional customization
Capabilities (15 points)
- Generator integration
- Inverter integration
- Islanding capability
- Additional capabilities

Warranty (20 points)

- Warranty length
- Annual degradation
- Cycles/throughput
- Additional criteria related to labor, shipping, and more

Where can I find the rating of a particular piece of equipment?

You can find the rating for a particular product in our Buyer’s Guides:

Where do consumers see equipment ratings?

Consumers can see ratings for equipment on

Product details pages
Buyer’s guide lists and comparison view (linked above)
All quote views (quote details, quote list, and quote comparison)