Utah Plug-In Solar Bill HB 340

Background

Utah’s HB 340 made history in the US by legalizing plug-in solar. Plug-in solar (also called balcony solar) is widely used in Europe, especially Germany, and now there is a movement to legalize plug-in solar in the US.

When I use the term “legalize” here, it’s a bit of a simplification because there are already manufacturers in the US that sell plug-in solar systems. For example, Craftstrom will sell you a system today with a UL 1741 certified inverter and their proprietary NEC Smart Plug designed to protect home wiring. There are companies that are attempting to solve all the safety and compliance problems surrounding plug-in solar ahead of formal US state regulations. The bills that I track on this site provide clarity for consumers, manufacturers, and utilities.

What does HB 340 say?

If you would like to read the full text of the bill yourself, you can view it here. It is actually quite short, but I will summarize the key points and provide some added context and commentary.

Key Points

1. It modifies the rules around residential solar by creating a new category for small portable solar generation devices

2. Creates exemptions from interconnection requirements for portable solar generation

3. Establishes basic safety requirements for portable solar generation devices

4. Provides liability protection for electrical corporations

5. It defines an inverter as a device that is UL1741 certified and “operated in accordance with the latest revision of IEEE1547, as amended”

6. It defines a “Portable solar generation device” as a device that:

   • “has a maximum power output of not more than 1,200 watts”
   • “is designed to be connected to a building’s electrical system through a standard 120-volt alternating current outlet”
   • “is intended primarily to offset part of the customer’s electricity consumption”
   • “meets the standards of the most recent version of the National Electrical Code”
   • “is certified by Underwriters Laboratories or an equivalent nationally recognized testing laboratory”

7. It exempts portable solar generation devices from interconnection agreements

8. Portable solar generation devices are not subject to the net metering requirements

9. The electrical corporation (utility) may not require consumers to obtain permission before installing or using a portable solar generation device, charge a fee related to the system, or require any additional controls or equipment. The utility is not liable for any damage or injury caused by the device

10. The bill took effect May 7th 2025

Commentary

What Products Qualify?

The current problem in the market is that no plug-in system as a whole is certified by Underwriters Laboratories (UL). You can find component parts that are UL certified. For example, inverters that are UL 1741 certified, and the solar panels may be certified under a different standard, but no systems have yet been certified under UL 3700, which is the new standard that covers plug-in solar systems as a whole. While no system has UL 3700 certification yet, Craftstrom claims compliance at the component level through individually certified parts. Ecoflow sells products with the note “Due to restrictions under the H.B. 340 Solar Power Amendments, this product is only available for sale and plug-and-play installation in Utah.”. It’s unclear to me whether component-level certifications fully satisfy the bill’s requirements. I’ve seen arguments that there are no legal products in Utah because no products are UL 3700 listed, but in practice companies are selling products in Utah and other states and people are buying them.

Renter Access

Another gap in the Utah bill is that it does not stop landlords or apartment complexes from prohibiting these systems. In my apartment lease, it states that I am not allowed to put anything on my balcony except for furniture and plants, essentially. So for many renters, it’s unlikely that they would be able to take advantage of plug-in solar unless they have more permissible leases.

Excess Energy Production

The bill also does not explicitly address what happens in the case that someone produces more electricity than they consume. The bill states that the device “is intended primarily to offset part of the customer’s electricity consumption”, but what happens if the customer goes on vacation and their panel generates a surplus and sends it to the grid? Some systems are designed for “zero export,” meaning they will stop production before exporting energy to the grid, but others are designed just to shut off in an outage as a safety measure.

Looking Forward

In upcoming posts, I hope to look at some of the other bills to see how they differ from Utah’s and if they solve some of these gaps. I’d also like to cover the safety challenges of plug-in solar in more depth. I think that as the market matures, we will start to see UL 3700 certified systems, and consumers will have more clarity. Until then, I would warn anyone installing one of these systems to use caution. If you are buying an inverter make sure it is UL 1741 listed, use a dedicated circuit, and follow manufacturer instructions. Some people are saying that plug-in solar is a disaster and the solar panels will be blown off in the wind, turning into flying guillotines. Some are saying that using plug-in solar will result in widespread fires. I think these claims are hyperbolic, but there are real safety concerns that have not been fully addressed because the market is so new in the US. Anyone saying plug-in solar is 100% safe because it is widespread in Germany is also not understanding the full picture of the market realities. With energy prices rising, plug-in solar is gaining a lot of interest. It will be an interesting movement to watch.