Year 2025 saw many changes in the energy landscape, not all of which were positive for those of us concerned with the need to rapidly reduce carbon emissions. One item that emerged with good press, however, was the introduction and expansion of “Balcony” or “Plug-In” solar photovoltaic (PV) systems in the United States. KQED provided a report on these systems in July, the New York Times and Washington Post ran articles in August, Sierra Club (on line) reported in November, and the San Francisco Chronicle reported on them on Christmas day; solar industry press also provided coverage.
So what is this technology and does it really provide environmental and (for the buyer) economic benefit? This blog summarizes the good (many) and the caveats (there are some uncertainties).
The typical balcony solar system is comprised of one to four portable solar PV panels, with a mounting system and inverter (to convert the direct current generated by the panels to alternating current used in the home). Their benefit (relative to traditional roof-mounted panels) is that they are lighter weight than traditional roof-mounted panels, lower cost, and simpler to install (and move about). The cost of these systems is substantially lower than a full rooftop installation, making them attractive to a greater number of customers who would like to obtain solar PV benefits, but can’t afford (or whose circumstances don’t allow) a full-scale rooftop system.
Their relative portability is seen as a benefit for renters, though homeowners too are opting for these due to their simplicity of installation and lower cost. The fact these systems plug into existing home wiring (requiring a standard ground-fault circuit interrupter (GFCI)-protected outlet on a dedicated, breaker-protected circuit) substantially simplifies installation as does the fact they needn’t be roof mounted so can be located (and moved) as convenient. All of which lowers cost.
Existing PV system owners can also benefit from these low-cost systems to supplement their existing production. California’s current Net Energy Metering (NEM) agreement allows owners under NEM 1.0 and 2.0 to expand their systems by 10% or 1 kW, whichever is greater, while remaining on their current NEM tariff, without moving to the less favorable NEM 3.0.
The technology is not new, it’s been slowly imported. These systems have been sold in Germany for decades, with almost a million legally installed, and more not formally (legally) registered; up to 25 other European nations have legalized these systems. In the United States, Utah has legalized them, while several other states have legislation in process (New York, Pennsylvania, New Hampshire and Vermont based on recent press reports).
Editor’s note: Senator Scott Weiner has introduced SB 868 – Electricity: portable solar generation devices to quickly advance the legality of balcony solar.
Economic and Environmental Benefits
A balcony solar system can be a good investment. As example, consider a basic 2-panel, 800 kW system; several vendors provide such systems including Brightsaver and Craftstrom. (Brightsaver provides free pick-up at their Richmond facility north of San Francisco; otherwise delivery charges (only to Bay Area locations at the time of this writing) are additional. Price for a 2-panel, 800 W system on their website (early 2026) is quoted at $1,988, including delivery, some installation support and tax.)
Such a system, if installed in the Bay Area with south-facing orientation, and optimal tilt (38 degrees), should produce about 1,280 kWh of electricity over its first year. If this offsets PG&E-supplies electricity which averages about $0.44 per kWh for residential customers, savings would be $560 per year. At this rate, the buyer earns-back the cost of their system in 3 ½ years… an attractively short time! Different orientations and tilts (and shading effects of nearby trees or structures) could all reduce the annual production, and lengthen the payback estimate.
Despite more sun, a similar system in southern California has a longer payback due to the lower average electrical rates. This same system, installed south-facing with optimal 34 degrees tilt, would produce about 1,360 kWh per year. But as a typical Southern California Edison (SCE) residential rate is only $0.30 per kWh, annual savings is $410, resulting in a 5-year payback. For LA Department of Water & Power (LADWP) customers, with a typical residential rate of $0.22 per kWh, annual savings would be only $300 year, resulting in a 6 ½ year payback period. Despite these differences, all these payback periods are shorter than realized by traditional rooftop systems.
Both these examples assume the owner will fully utilize the electricity produced—likely if the house consumes significant electricity during daylight hours. But if everyone is away during the day with only the refrigerator, modem and heating/air conditioning running, the electricity produced may or may not be fully utilized. Whether any excess flows to the grid and whether the homeowner gets credit is still murky- some inverters will prevent this for safety reasons and/or to avoid utility interconnection agreements and fees (see Caveats, below). Adding batteries will help maximize the captured energy; they could be discharged in the evening helping avoid higher-cost electrical rates; these are widely available as options.
Environmental benefits are significant and are another motivation for many who invest in solar PV systems. For these benefits, the results are the opposite of the economic ones; Southern California customers would be making a greater environmental impact than those in PG&E territory. As PG&E sources 90% or more of its energy from carbon-free sources, its CO2 content per kWh is less than one-tenth the national average (0.8 lbs CO2/kWh), so self-generating 1,280 kWh with a balcony solar system is replacing only 100 pounds of CO2 annually, about that sequestered by 5 smaller trees! Information on carbon content for Southern California electricity is more ambiguous, but it appears that an 800 W balcony system as discussed would reduce emissions in SCE territory by 375 pounds of CO2 (17 trees worth), and by 500 lbs CO2 (22 trees) in LADWP territory.
The Caveats
There are clear benefits to these balcony systems—their low cost and flexibility open an entirely new market to clean-energy and solar PV system ownership. There are, however, a few concerns that arise as one considers these prospects.
The first concern is shorter panel warranties. Traditional rooftop panels are manufacturer warrantied for 25, 30 or more years; balcony system warranties appear to be of 10-year duration. Likely the panels will function longer, but the longer one has redress against premature failures, the more comforting.
The second concern is the unknown cost of installation and electrical upgrades. If one has a recently installed deck or patio, likely they have had an outdoor GFCI outlet installed for lighting or other purposes. (Though this may or may not be on its own circuit breaker.) But if you’re in an older property, you may not have such an advantage. In this latter case, to meet the stated installation requirements, a buyer would need to have such a circuit installed, with wiring or conduit as conditions and location dictate. This work can be done by any electrician, but it will add to your cost. Running the wire from the PV inverter into the house to plug into a wall outlet is physically do-able, but does not meet the minimum safety requirements of a system installation. Such an action-of-convenience could result in an overloaded circuit and safety/fire hazard. And even if you have an outdoor GFCI outlet, you need to assure it’s on its own breaker to avoid overloading and tripping the breaker due to multiple devices.
Finally, code-compliance, permitting and interconnection uncertainties need to be resolved. First among these is approval: electrical products in the United States are confirmed safe with the independent Underwriters Laboratory “UL” seal of approval. While individual components meet this standard, fully assembled systems have not as yet. (It reportedly is in process.)
Uncertainty exists as to whether owners need to obtain utility connection approval before they can connect their systems. Interconnection agreements are required with your utility if you plan to feed electricity to the grid: these support safety and reliability of the grid. Locally, KQED reported PG&E’s claim that registering a connection should only take an hour of time, with a fee between $100 and $800 and approval time of three days. We have not heard sufficient anecdotal information to know the accuracy of this claim. Utah’s enabling legislation specifies such agreements are not required for plug-in systems rated at less than 1,200W (1.2 kW) as long as they are UL certified and have anti-islanding features for safety– perhaps California will eventually move in the same direction. As some of the inverters prevent electricity flow to the grid, the need for an interconnection agreement is not apparent.
Similarly, it’s uncertain what (if any) local permits are required (as is the case for the installation of traditional rooftop systems). At this time, it appears that vendors leave this part of the process to the buyer / homeowner. Anecdotal evidence suggests compliance varies; this issue needs further clarification and a process appropriate to the simplicity of the technology.
In summary, it’s not surprising that all questions related to introduction of this new (to the US), distinctive technology have not as yet been immediately answered. Likely these concerns will be clarified during 2026. As the awareness and installation of these balcony systems expand, their benefits will be more widely experienced. These systems increase accessibility of cost-effective solar PV systems for renters and homeowners, further increasing renewable sourcing, decreased carbon emissions and energy independence. They clearly have a bright future.
More Information
Several sources and reports are cited; others were identified as part of the research for this post. A few that were particularly useful include (as of January 2026):
An extensively detailed analysis of costs, benefits and general installation guidance.
An information source in the UK with a summary of systems available in the US (priced in dollars) and discussion of related issues such as rebates and safety standards.
A detailed discussion of the concerns that have been raised about NEC and UL compliance
Cites benefits, but also notes the industry is still in a “regulatory grey area”
Major vendor sites include the following; others can be found on search engines:
AP Systems
Former Silicon Valley start-up now Texas-based that reportedly has sold over 4 million microinverters. Their EZ1 microinverter plugs into a wall outlet, connecting 2 solar panels.
Brightsaver
San Francisco Bay Area based company offering a wide variety of system sizes and batteries. Free pick up is available at their Richmond, CA warehouse.
EcoFlow
A wide selection of battery storage systems and panels. This global start-up is based in Shenzhen, China, with a US office in the San Francisco Bay Area.
GismoPower
Appears to be primarily fixed and mobile carport-sized systems. Not clear their delivery outside Florida.
Zoltux
San Francisco-based start-up funded on Kickstarter offers a plug-in PV system starting at $1199 with the claim of 5 minutes installation time.
COP30: The Reviews Are In! by Amy Quirk