Company lists · Data refreshed September 2026

Top 25 Solar testing and certification labs based in the United States

RevenueBase identified 56 solar testing and certification labs headquartered in the United States as of September 2026 and tracks 1,189 professional contacts across them, including 485 with verified work emails. Phoenix is the largest hub.

This list covers solar testing and certification labs headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 18, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 18, 2026 86% judged on-target in blind review
56Companies
1,189Contacts tracked
485Verified emails
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The 25 largest solar testing and certification labs based in the United States

Ranked by team size
Top 25 of 56 solar testing and certification labs based in the United States, ranked by team size, largest first. Data refreshed Sep 18, 2026. RevenueBase Smart Search rates how each company's information relates to solar testing and certification labs: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceHouston, United StatesHQ checked Sep 18, 2026501-1,000442 contacts →

Partial evidence

“SPL is a leading provider of compliance and testing services for Environmental, Energy, and other end markets.”

Source: RevenueBase Database · checked Sep 18, 2026
2Strong evidenceBaltimore, MD, United StatesHQ checked Sep 18, 2026201-500180 contacts →

Strong evidence

“Eurofins Electrical & Electronics North America is a leading testing and certification laboratory, providing a unique array of testing services and accreditations for regulatory…”

Source: RevenueBase Database · checked Sep 18, 2026
3Strong evidenceSand City, CA, United StatesHQ checked Sep 18, 202651-200116 contacts →

Strong evidence

“GroundWork Renewables is the leading provider of high-quality meteorological (MET) data and ISO-accredited PV lab testing to give solar plant owners complete situational awareness…”

Source: RevenueBase Database · checked Sep 18, 2026
4Strong evidenceNapa, CA, United StatesHQ checked Sep 18, 202611-5046 contacts →

Strong evidence

“Kiwa PVEL is the leading reliability and performance testing lab for downstream solar project developers, financiers, and asset owners around the world.”

Source: RevenueBase Database · checked Sep 18, 2026
5Partial evidenceAlpine, UT, United StatesHQ checked Sep 18, 202611-5041 contacts →

Partial evidence

“Wyssling Consulting is the #1 Residential Solar Engineering company in the industry.”

Source: RevenueBase Database · checked Sep 18, 2026
6Partial evidenceNew Castle, PA, United StatesHQ checked Sep 18, 202611-5037 contacts →

Partial evidence

“Applus Keystone+ specializes in streamlining the burden of regulatory compliance testing.”

Source: RevenueBase Database · checked Sep 18, 2026
7Indirect evidenceRound Rock, TX, United StatesHQ checked Sep 18, 202611-5030 contacts →

Indirect evidence

“Starting in January of 2022, PTI becomes a part of the Nemko Group.”

Source: RevenueBase Database · checked Sep 18, 2026
8Partial evidenceYork, PA, United StatesHQ checked Sep 18, 202651-20019 contacts →

Partial evidence

“As an independent, accredited, third-party test laboratory, Molimo is dedicated to providing clients with a high quality testing experience, complete with the fast and accurate…”

Source: RevenueBase Database · checked Sep 18, 2026
9Partial evidencePineville, NC, United StatesHQ checked Sep 18, 202611-5018 contacts →

Partial evidence

“Sapphire Technical Solutions is an ISO-17025 accredited photometric, radiometric and power efficiency testing laboratory as well as an equipment manufacturer.”

Source: RevenueBase Database · checked Sep 18, 2026
10Strong evidenceLincoln, NE, United StatesHQ checked Sep 18, 202611-5016 contacts →

Strong evidence

“NCEE Labs, founded in 1998, provides FCC, CE, and worldwide EMC/wireless testing, Product Safety, Reliability, and X-Ray testing, as well as wireless certification to large and…”

Source: RevenueBase Database · checked Sep 18, 2026
11Indirect evidenceNew Cumberland, PA, United StatesHQ checked Sep 18, 202611-5015 contacts →

Indirect evidence

“Keystone was founded as a National Fenestration Rating Council (NFRC) licensed Inspection Agency in 1998 by Former President, Marcia Falke, building on her more than 25 years…”

Source: RevenueBase Database · checked Sep 18, 2026
12Strong evidenceGlenside, PA, United StatesHQ checked Sep 18, 202611-5014 contacts →

Strong evidence

“Since inventing the world’s first Solar Simulator in 1967, Solar Light Company, LLC has been a global leader in laboratory-grade light science instrumentation and testing…”

Source: RevenueBase Database · checked Sep 18, 2026
13Strong evidenceFremont, CA, United StatesHQ checked Sep 18, 202651-20014 contacts →

Strong evidence

“RETC is an independent testing and certification laboratory specializing in solar and energy storage products.”

Source: RevenueBase Database · checked Sep 18, 2026
14Strong evidenceRemote, United StatesHQ checked Sep 18, 20261-1012 contacts →

Strong evidence

“PV Letters provides structural certification letters for solar installers in the United States.”

Source: RevenueBase Database · checked Sep 18, 2026
15Partial evidencePhoenix, AZ, United StatesHQ checked Sep 18, 202611-5012 contacts →

Partial evidence

“At Print Pro AZ, we are at the forefront of innovation in the solar labeling industry.”

Source: RevenueBase Database · checked Sep 18, 2026
16Partial evidenceSouth San Francisco, CA, United StatesHQ checked Sep 18, 20261-108 contacts →

Partial evidence

“At Amplify Energy, we evaluate and improve the quality and performance of solar power generation facilities in order to maximize financial returns for system owners, buyers, and…”

Source: RevenueBase Database · checked Sep 18, 2026
17Strong evidenceAustin, TX, United StatesHQ checked Sep 18, 20261-108 contacts →

Strong evidence

“ESTEC Solutions provides Equipment Safety Testing, Evaluation and Consultation Solutions to Semiconductor, Flat Panel Display and Solar Panel Equipment Manufacturers.”

Source: RevenueBase Database · checked Sep 18, 2026
18Partial evidenceSpringfield, MO, United StatesHQ checked Sep 18, 20261-107 contacts →

Partial evidence

“Peace of Mind, Investment Protection, Performance Assurance Ethical Third-Party Verification that Builds Trust: Think of us as an independent advocate for solar customers that…”

Source: RevenueBase Database · checked Sep 18, 2026
19Indirect evidenceSanta Barbara, United StatesHQ checked Sep 18, 20261-106 contacts →

Indirect evidence

“Angstrom Designs is a diverse group of engineers who focus on systems design for automated instrumentation, control, test and measurement.”

Source: RevenueBase Database · checked Sep 18, 2026
20Strong evidenceCouncil Bluffs, IA, United StatesHQ checked Sep 18, 202611-506 contacts →

Strong evidence

“Lab Certifications and TAB Testing: BalCon is an industry leader who has been ensuring equipment efficiency and safety for over 25 years.”

Source: RevenueBase Database · checked Sep 18, 2026
21Partial evidencePhoenix, AZ, United StatesHQ checked Sep 18, 202611-503 contacts →

Partial evidence

“Independent NVLAP Accredited Testing Laboratories for LM-79, ISTM (In-Situ), Photometrics (Photometry & IES Files), colorimetry and Electrical Measurements.”

Source: RevenueBase Database · checked Sep 18, 2026
22Indirect evidenceCorona, CA, United StatesHQ checked Sep 18, 202611-503 contacts →

Indirect evidence

“Electrical Services For Today’s Changing Technologies” Integrated Power & Lighting, Inc.”

Source: RevenueBase Database · checked Sep 18, 2026
23Strong evidenceMoorpark, CA, United StatesHQ checked Sep 18, 20261-103 contacts →

Strong evidence

“Photo Emission Technology offers a variety of turn-key electronic systems for Solar Cell Testing to help improve efficiency for commercial solar cells.”

Source: RevenueBase Database · checked Sep 18, 2026
24Indirect evidenceAllentown, PA, United StatesHQ checked Sep 18, 20261-102 contacts →

Indirect evidence

“Your Partner in Quality Photometrics LightLab International Allentown, LLC is an ISO-Accredited laboratory specializing in personalized, highly accurate measurements of lighting…”

Source: RevenueBase Database · checked Sep 18, 2026
25Strong evidenceLawrenceville, GA, United StatesHQ checked Sep 18, 20261-102 contacts →

Strong evidence

“RE Innovations LLC was imagined and created in April 2019 by Joseph M Spossey with the simple goal of providing innovative product development, design, testing and certification…”

Source: RevenueBase Database · checked Sep 18, 2026

Showing 25 of 56 solar testing and certification labs based in the United States

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Solar testing and certification labs based in the United States at a glance

As of Sep 18, 2026
40.8%Verified-email coverage
21.2Average contacts per company
11-50Median size (employees)
5.4%Largest-city concentration · Phoenix
Sep 18, 2026Page data refreshed

Companies by employee count

1-10
25
11-50
23
51-200
6
201-500
1
501-1,000
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 56 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among solar testing and certification labs, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “solar testing and certification labs”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names solar testing and certification labs), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among solar testing and certification labs, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 485 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 18, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names solar testing and certification labs, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many solar testing and certification labs are there based in the United States?

RevenueBase identified 56 solar testing and certification labs headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

SPL, headquartered in Houston, tops this list with the largest team on record.

Which city has the most solar testing and certification labs?

Phoenix leads with 3 headquartered companies, followed by Austin (2) and Buford (2).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 485 verified decision-maker contacts tracked across these 56 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 18, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.