Glossary of terms
Plain-English definitions of the terms you'll encounter in HB 395 and plug-in solar generally. Hover or tap any term to view an expanded breakdown.
A
- Anti-islanding Hover to expand
- The automatic disconnection of a small generator from the grid within milliseconds of a utility outage, protecting line workers from energized wires.
HB 395 & Technical Breakdown
Under Virginia HB 395 and IEEE 1547 / UL 3700 standards, anti-islanding is a mandatory safety mechanism. When power grid voltage or frequency drops below threshold limits (such as during a storm outage or transformer failure), the microinverter shuts off AC output within milliseconds. This prevents 'islanded' power generation that could send dangerous high-voltage backfeed into disabled power lines where utility technicians are working.
B
- Backfeed Hover to expand
- Electricity flowing back from a customer's system into the utility grid. HB 395 systems are designed to minimize backfeed.
- Behind-the-meter Hover to expand
- Generation that offsets the customer's own consumption before the utility meter measures it. HB 395 systems are strictly behind-the-meter.
HB 395 & Technical Breakdown
Backfeed occurs when a balcony solar panel produces more instantaneous wattage than the residence's active appliance load is consuming. Under Virginia's HB 395, plug-in systems operate behind-the-meter up to 1,200 W AC. Because HB 395 systems are not eligible for net-metering credits under § 56-594, any excess exported backfeed flows into the local distribution grid without financial credit, which is why matching system capacity (e.g., 400W–800W) to your base daytime household load maximizes financial ROI.
HB 395 & Technical Breakdown
Behind-the-meter (BTM) systems sit on the customer's side of the utility billing meter. Electricity generated by a plug-in balcony panel is consumed immediately by nearby active household appliances (refrigerator, Wi-Fi router, TV, HVAC fan). The utility meter simply registers lower net kWh import from the grid during daylight hours, reducing your monthly electric bill without needing a meter swap or complex utility billing setup.
D
- Disclosure label Hover to expand
- A standardized HB 395 information sheet that manufacturers must ship with every compliant product starting July 1, 2026, including the UL 3700 certification number.
HB 395 & Technical Breakdown
Required under § 55.1-1234.1 of the Virginia Code starting July 1, 2026, the HB 395 disclosure label must be permanently attached to the equipment and included in retail packaging. It displays the manufacturer's name, system model, UL 3700 certification file number, maximum rated AC output (capped at 1,200 W), and a standardized consumer notice stating that the unit meets Virginia safety regulations.
H
- HB 395 Hover to expand
- Virginia House Bill 395, enacted in 2025, the Commonwealth's statewide framework for plug-in solar.
- HOA Hover to expand
- Homeowners association — a governing body for a planned community. HB 395 limits HOA authority to prohibit plug-in solar.
HB 395 & Technical Breakdown
Passed by the Virginia General Assembly and signed into law in March 2025, HB 395 creates the nation's most comprehensive legal framework for plug-in balcony solar. It establishes dual implementation dates: July 1, 2026 for retail equipment compliance (UL 3700 & disclosure labels) and January 1, 2027 for full consumer protection rights that prevent landlords and HOAs from placing unreasonable bans on compliant systems.
HB 395 & Technical Breakdown
Under Code of Virginia § 67-701.1 (added by HB 395), HOA declarations and bylaws cannot prohibit a homeowner or tenant from installing a compliant plug-in solar system in exclusive-use areas (such as private balconies, patios, or fenced yards). While HOAs retain architectural review powers over color and mounting aesthetics, any restriction that increases installation cost by more than 10% or decreases system performance by more than 10% is void as a matter of public policy.
I
- Interconnection Hover to expand
- The formal agreement and equipment connecting a customer-owned generator to the utility grid. HB 395 systems do not require interconnection.
- Inverter Hover to expand
- Hardware that converts panel DC output to household AC. HB 395 systems use a microinverter rated at 1,200 W AC or less.
HB 395 & Technical Breakdown
Traditional rooftop solar requires a formal Interconnection Agreement (IA) filed with utilities like Dominion Energy or APCo, involving engineering review fees, meter replacements, and multi-week approval waiting periods. HB 395 specifically exempts compliant plug-in systems (UL 3700 certified, 1,200 W AC or less) from interconnection agreements — treating them as standard plug-in appliances rather than grid-interconnected utility generators.
HB 395 & Technical Breakdown
Solar panels generate direct current (DC) electricity, whereas household outlets run on 120V 60Hz alternating current (AC). The inverter performs this power conversion, synchronization with household voltage, and continuous grid safety monitoring. For HB 395 compliance in Virginia, the inverter must be a module-level microinverter rated at 1,200 watts AC peak output or less.
K
- Kilowatt-hour (kWh) Hover to expand
- The standard unit of electricity consumption — one kilowatt drawn (or produced) for one hour.
HB 395 & Technical Breakdown
A kilowatt-hour is the billing unit used on your utility statement. In Virginia, residential electricity costs roughly 12 to 14 cents per kWh. A 400W balcony solar panel operating in typical Virginia sunlight (averaging 4.5 peak sun hours daily) generates about 1.4 to 1.8 kWh per day, which equates to roughly 500 to 650 kWh annually — saving around $70 to $90 per panel on your annual power bill.
M
- Microinverter Hover to expand
- A small inverter mounted on or near each solar panel, converting DC to AC at the panel level. Required for HB 395 compliance.
HB 395 & Technical Breakdown
Unlike bulky central string inverters used on commercial roofs, microinverters are compact, weatherproof units (about the size of a paperback book) mounted directly behind individual balcony panels. Microinverters allow each panel to operate independently, preventing shade on one section of your balcony railing from reducing energy production across the rest of the system.
N
- NEC Hover to expand
- National Electrical Code, the model electrical-safety code adopted (with amendments) by Virginia. HB 395 systems are designed to comply.
- Net metering Hover to expand
- A billing arrangement that credits a customer for grid-export electricity. HB 395 systems are not eligible for net metering.
HB 395 & Technical Breakdown
The National Electrical Code (NEC Article 705) governs interconnected electric power production sources. HB 395 ensures that compliant plug-in systems adhere to NEC safety requirements — including rapid shutdown, overcurrent protection, and ground-fault circuit interrupter (GFCI) compatibility — without requiring dedicated circuit rewiring for standard 120V household outlets.
HB 395 & Technical Breakdown
Under Code of Virginia § 56-594, traditional rooftop solar systems earn bill credits for excess electricity fed back to the grid. HB 395 explicitly excludes plug-in balcony solar from formal net metering schedules to eliminate utility meter swap fees and complex billing tariffs. Plug-in systems offset immediate daytime energy use behind-the-meter.
P
- Plug-in solar Hover to expand
- A solar generator small enough to connect via a standard household outlet, without an electrician or interconnection agreement.
HB 395 & Technical Breakdown
Also called a balcony power station, plug-in solar is a portable, self-contained renewable energy unit comprising 1 to 4 solar panels, an integrated UL 3700 microinverter, mounting brackets, and a regular 120V wall plug. It is designed for DIY assembly in 30 minutes on balconies, decks, or terraces without structural drilling or high-voltage wiring.
R
- Reasonable restriction Hover to expand
- A condition a landlord or HOA may lawfully impose on an HB 395 install — without significantly increasing cost or decreasing performance.
HB 395 & Technical Breakdown
Defined under Virginia Code §§ 55.1-1234.1 and 67-701.1, a 'reasonable restriction' allows property managers or HOAs to specify mounting placement (e.g., inside balcony railings rather than protruding outward), cable routing cleanliness, and non-reflective frame colors. However, restrictions that prevent installation entirely or reduce energy yield by more than 10% are legally unenforceable.
S
- SCC Hover to expand
- Virginia State Corporation Commission, the agency responsible for administering HB 395's notification form and dispute process.
HB 395 & Technical Breakdown
The State Corporation Commission (SCC) regulates Virginia's public utilities. Under HB 395, the SCC convenes a stakeholder work group to publish the standardized statewide customer notification form and oversees utility compliance, ensuring Dominion Energy, APCo, and electric co-ops adhere to uniform plug-in solar reporting procedures.
U
- UL 1741 Hover to expand
- The legacy safety standard for inverters in hard-wired rooftop solar. Not sufficient on its own for HB 395 compliance.
- UL 3700 Hover to expand
- The safety standard HB 395 requires for plug-in solar systems, covering anti-islanding, backfeed, thermal performance, and ground-fault protection.
HB 395 & Technical Breakdown
UL 1741 (Standard for Inverters, Converters, Controllers and Interconnection System Equipment) evaluates traditional rooftop solar inverters wired directly into main breaker panels. While UL 1741 governs anti-islanding and grid protection, it does not include plug-in outlet safety requirements, touch-safe pin de-energization, or integrated enclosure testing required by UL 3700.
HB 395 & Technical Breakdown
UL 3700 is the specialized national safety standard created specifically for plug-in solar power systems. It mandates that when the plug is disconnected from the wall outlet, the male prongs de-energize in under 0.1 seconds to prevent electrical shock. Starting July 1, 2026, all plug-in solar equipment sold or installed under HB 395 in Virginia must be certified to UL 3700.