UL 3700 or UL 1741? The certification your state's plug-in solar law asks for

Short answer

Every state plug-in solar law so far points to independent safety testing, but they don't all name the same thing. Of the 9 state laws in force or signed, 3 name UL 3700, the new plug-in-specific standard; 1 names UL 1741, an inverter standard; and 5 ask for a listing by an independent testing lab without naming either.

Check what your state's law names before you buy. The table below quotes each law's wording.

What each state's law names

The standard column is the law's own requirement, as we recorded it from the statute. 9 laws are in force or signed, and 2 bills are still pending.

Certification named in each state's plug-in solar law

3 of 9 state laws in force or signed name UL 3700.

Certification named in each state's plug-in solar law. 3 of 9 state laws in force or signed name UL 3700.
State Status Standard named in the law Names UL 3700? Size cap Effective Source
ColoradoLegal Legal Labeled and listed by an NRTL; outage protection No 1,920 W Aug 12, 2026 dre.colorado.gov
MaineLegal Legal Listed or certified to UL 3700, or to a comparable standard by an NRTL; or configured to the National Electrical Code as adopted in Maine Yes 1,200 W Not verified yet legislature.maine.gov
MarylandLegal Legal UL or equivalent NRTL No Not verified yet May 12, 2026 mgaleg.maryland.gov
UtahLegal Legal UL or equivalent NRTL; current NEC; outage protection No 1,200 W May 7, 2025 le.utah.gov
VermontLegal Legal UL 3700 or equivalent NRTL, and IEEE 1547-2018 Yes 1,200 W Jul 1, 2026 legislature.vermont.gov
ConnecticutSigned, not in force yet Signed, not in force yet UL or equivalent NRTL and UL 1741; NEC, IEEE 1547, State Building Code No 1,200 W Oct 1, 2026 cga.ct.gov
New HampshireSigned, not in force yet Signed, not in force yet Certified by an NRTL to nationally recognized safety standards for distributed energy resources and plug-in solar systems No 1,200 W Jan 1, 2027 gc.nh.gov
New JerseySigned, not in force yet Signed, not in force yet UL 3700 or comparable standard(s) by an NRTL; outage protection Yes 1,200 W Mar 1, 2027 pub.njleg.gov
VirginiaSigned, not in force yet Signed, not in force yet NRTL (29 CFR 1910.7); current NEC; outage protection No 1,200 W Jan 1, 2027 law.lis.virginia.gov
CaliforniaAwaiting governor Awaiting governor Bill pending: no requirement in force yet – – – leginfo.legislature.ca.gov
New YorkPassed the legislature Passed the legislature Bill pending: no requirement in force yet – – – nyassembly.gov

"Names UL 3700?" is worked out from the wording: yes when it contains "3700". "Not verified yet" means we haven't read that part in the statute. Laws change; each state's page has the detail and the date we checked it. All 50 states and DC.

UL 1741 and UL 3700, side by side

Both are UL documents, but they were written for different things.

UL 1741 compared with UL 3700
QuestionUL 1741UL 3700
What it is A UL standard for inverters, converters, controllers and interconnection equipment for distributed energy resources such as solar. UL An Outline of Investigation for interactive plug-in photovoltaic equipment and systems. UL Solutions launched a certification program based on it on Jan 8, 2026. UL
Written for Equipment for stand-alone or grid-connected power systems, "intended to be installed in accordance with the National Electrical Code". UL describes traditional solar as permanently installed and inspected by professionals. UL Plug-in systems, which connect to household circuits through a plug and receptacle rather than being wired in. UL
What it covers The inverter, converter, controller or interconnection equipment the listing names. For grid-connected equipment it is used together with IEEE 1547 and IEEE 1547.1. UL Construction, performance and labeling. UL says it requires features that mitigate accidental contact with hazardous electric parts, promote safe installation, protect against overloads and prevent current from flowing in the wrong direction. UL
What to check A kit can have a UL 1741 microinverter without the whole plug-in kit having been evaluated. The listing covers the product it names. It covers equipment as well as systems, so check whether a listing names the whole kit or one part of it.

We only state what these sources say. We don't quote technical limits such as trip times or wattages from either document.

"UL" isn't the only lab

OSHA recognizes 21 Nationally Recognized Testing Laboratories (NRTLs), including UL LLC, CSA Group, Intertek, TÜV Rheinland and TÜV SÜD (OSHA's current list, counted Sep 29, 2026). Where a state's law asks for an NRTL, or "UL or an equivalent", any lab on that list is one.

How to check a kit before you buy

  1. Look for the lab's mark and a file or certificate number on the product and its spec sheet, not just the letters "UL" in an ad.
  2. "Compliant with", "meets" or "designed to" a standard is not the same as "certified" or "listed" by a named lab.
  3. Check what the listing covers: the whole plug-in kit, or only the microinverter.
  4. Look the number up in the lab's own directory. For UL, that's UL Product iQ, which has a basic search you can use without an account. For other labs, open the lab's page from OSHA's list; each has a "Certification Listing Website" link (UL's, for example).
  5. Match it to what your state's law names in the table above.

Landlords, utilities and the kit

A few laws add rules about who may put a kit up or what the kit must tell you. These are the ones we've read in the statute:

  • New Jersey, landlords: Can't prohibit use within the leased premises (incl. balcony/patio) if the tenant pays the electric bill; reasonable restrictions; 14 days' written notice with documentation; indemnity may be required.
  • Vermont, landlords: Tenant gives 10 days' notice; landlord may respond within 10 days with reasonable restrictions, including requiring a licensed electrician at the tenant's cost. No electrical work without landlord permission.
  • Virginia, landlords: Landlords with more than 4 units can't prohibit an exterior install; reasonable restrictions; tenant gives 7 days' notice with documentation. Not for RUBS-billed units.
  • Connecticut, power sent to the grid: Device must warn that generation above on-site use is charged as usage unless the meter allows net metering.

Other states' laws are silent on these points, or we haven't read that part yet; each state page says which.

Legal where you live?

Your address, the way your panels face and your utility's rate.

See what a kit would save on your balcony →

Sources and method

The state table is generated from our state-law data each time this page loads, so it changes when a law does. The newest state check in it is from Sep 29, 2026. The other sources were opened and read on Sep 29, 2026:

General information, not legal or electrical advice. Follow your kit's instructions and your state's rules.