The Busbar

Solar · The Lead

Renogy launches an N-Type bifacial panel series for off-grid and RV roofs

On 12 June, Renogy rolled out a new line of N-Type (TOPCon) bifacial solar panels in 100W, 200W and 400W ratings, sitting alongside its existing 250W and 590W bifacial models. The pitch is higher cell efficiency — around 25%, on 16-busbar cells — plus rear-side generation, with Renogy claiming up to roughly 14% extra energy from the back of the panel versus conventional PERC and an 80% bifaciality factor. It's aimed squarely at off-grid, RV and overland users. How much of that rear-side gain you actually see, though, depends entirely on how the panel is mounted — which is the subject of this week's Background.

Renogy consolidated its rigid-panel range around N-Type cells on 12 June, launching a bifacial series in 100W, 200W and 400W ratings (a 320W variant is also listed) to join the 250W and 590W bifacial panels already on the books. The move follows the wider industry shift away from p-type PERC toward N-Type TOPCon cells, which run a little more efficiently, degrade more slowly, and hold output better as they heat up — all of which matters on a roof that bakes in the sun all day.

The headline number is bifaciality. Renogy rates the cells at roughly 25% efficiency on a 16-busbar layout and claims the glass-backed panels generate about 14% more energy from reflected light hitting the rear, citing an 80% bifaciality factor against traditional PERC. The company frames the series for "off-grid and distributed energy" — RV, overland, marine and remote-infrastructure use — and lists the 100W from around $106, with pricing scaling by wattage. "At Renogy, we believe every ray of sunlight carries value — and every inch of space should work," the company said in its launch release.

Two caveats worth keeping in front of the marketing. First, the rear-side gain is real only when light can reach the back of the panel: a module flush-mounted on a white RV roof sees very little of it, while a tilted ground array over gravel or snow sees a lot. Second, for most mobile installs the genuine upgrade here is the front side — higher efficiency per square foot and a better temperature coefficient — not the bifacial bonus. Renogy was an early mover putting bifacial panels into mobile setups back in 2023; this is the company standardising on the cell technology rather than a new trick. We dig into whether bifacial pays off on a van roof below.

Find on Amazon →

Sources

Firmware

Victron's Click & Design ESS tool now speaks 120V split-phase

Victron updated its browser-based Click & Design tool on 17 June to support 120V and 120/240V split-phase systems built around MultiPlus-II and Quattro inverter/chargers — the configuration North American installers actually use. The free tool (a Victron Professional login is required) lets you lay out a solar ESS step by step and simulate a year of performance against real irradiance data. Until now it was 48V/230V-centric, so US and Canadian designers were largely locked out.

Victron extended its Click & Design tool on 17 June to cover 120V and 120/240V split-phase systems using MultiPlus-II and Quattro models — closing a gap that had made the tool largely academic for the North American market. Click & Design is Victron's step-by-step web app for sizing a solar ESS: you pick inverter/charger, PV array and battery, and it simulates roughly a year of operation using actual solar data for the location, so you can see how often the system would hit empty or spill PV before you order hardware.

Split-phase support matters because that's how virtually every US and Canadian off-grid and backup install is wired — two 120V legs for 240V loads. With the tool previously oriented around 48V/230V single-phase European systems, designers on this side of the Atlantic were stuck doing the sizing by hand or in spreadsheets. The tool remains free behind a Victron Professional account.

Sources

Industry

Intersolar Europe opens in Munich — balcony all-in-ones and Victron's next GX

Intersolar Europe runs 23–25 June at Messe München, and the pre-show announcements point to two themes that touch the off-grid world. Budget LiFePO4 makers are pushing up-market into plug-and-play balcony storage: WattCycle is showing a 10kWh all-in-one with 2.5kW/5kW bidirectional output and a built-in MPPT, and Ampace is launching a 15,000-cycle residential pack. On Victron's stand (B4.150), the genuinely new items for mobile and off-grid builders are a cost-reduced Nucleo GX, a 4G GlobalLink 530, and a GX 'Opportunity Loads' feature that dumps surplus solar into flexible loads once the battery is full.

Intersolar Europe opens in Munich on 23 June, and while the show floor is dominated by grid-tied residential storage, a few threads reach the mobile and off-grid reader. The clearest is budget LiFePO4 brands moving up the value chain: WattCycle — better known for sub-$200 drop-in batteries — is unveiling a 10kWh plug-and-play balcony all-in-one with 2.5kW and 5kW bidirectional options, integrated MPPT and a microinverter interface, while Ampace launches a residential pack it rates at 15,000 cycles. Both are home-storage products, but they signal where the cheap-cell supply chain is heading.

On Victron's stand (B4.150), most of the lineup is already familiar, but three items are worth noting for builders: the Nucleo GX, a cost-reduced GX comms centre that drops VE.Bus and HDMI while keeping core monitoring; the GlobalLink 530, a 4G remote-monitoring device pitched on better global coverage; and GX Opportunity Loads, a Venus OS feature that automatically diverts excess PV to flexible sinks — EV/e-bike charging, hot water, pool heating — once the battery is full, instead of curtailing. The high-voltage three-phase Multi HS19 Solar is slated for summer.

Sources

Safety

Marine How To: that CE mark on your cheap inverter might be meaningless

A 20 June Marine How To piece warns that the legitimate European CE (Conformité Européenne) mark is widely imitated by a near-identical 'China Export' logo that carries no compliance or safety assurance at all. The article points specifically at the cheap end of the DC world — inverters, MPPT controllers, battery chargers and diesel heaters — and argues a logo is not evidence of testing. Its practical advice: ignore the symbol and instead look for a Declaration of Conformity, EMC test reports, a named manufacturer with a real address, and actual support.

Marine How To published a useful reminder on 20 June: the marks stamped on budget DC gear are not the same as having been tested. The piece centres on the genuine CE (Conformité Européenne) mark and its near-twin, an unofficial "China Export" logo with the letters spaced more tightly together, which looks almost identical but certifies nothing. The author names the usual suspects — inverters, MPPT charge controllers, battery chargers and diesel heaters — as the products where the fake mark turns up most.

The argument is simple and worth internalising before the next cut-price Amazon purchase: "a logo is not evidence." What is evidence, per the article, is a Declaration of Conformity you can actually read, technical specifications, EMC test reports, an identifiable manufacturer with a physical address, and support you can reach. None of that is a guarantee either, but it's a far better filter than a symbol anyone can print. This is opinion from a respected marine-electrical source rather than a regulatory notice — but it's the kind of opinion that saves a cabin fire.

Sources

Marine How To — Safety Marks That are Scams (20 June 2026)

The Background · Market Analysis

Does bifacial solar actually pay off on a van roof?

This week's Renogy launch leans hard on bifaciality — the panel's ability to make power from light hitting its rear. It's a real effect, and on the right mount it's worth money. On the wrong mount, which describes most RV roofs, it's close to free marketing. Here's how to tell which one you have.

A bifacial panel is rated by two numbers: its front-side wattage, and a bifaciality factor — the fraction of front efficiency the rear cells deliver under equal light. Renogy quotes 80%, which is typical for a good N-Type module. But that factor only describes the cells' potential. The actual rear-side yield is governed by how much light reaches the back, and that comes down to three things: the albedo (reflectivity) of whatever is behind the panel, the air gap between panel and surface, and how much of the rear is shaded by mounting rails, the roof itself, or the structure underneath.

The flush-mount problem

Stick a bifacial panel flat against a van or RV roof on low-profile brackets and you have defeated the feature. The rear faces a surface a few centimetres away, in its own shadow, with almost no light getting in from the sides. Real-world rear-side contribution in that configuration is typically in the low single digits of percent — sometimes effectively zero. You paid for glass on the back and a heavier panel, and you're running it as a monofacial module. A white roof helps a little by bouncing some light into the gap; a dark roof helps not at all.

Where it does pay

Bifacial gain shows up when the panel is tilted and raised over a reflective surface. A ground-deployed array on a portable stand over light gravel, concrete or sand can pick up 5–15%; over fresh snow, considerably more. Tilt legs on a roof rack that lift the panel several inches and angle it toward the sun also open up the rear to ambient and reflected light. The pattern is consistent: the more the panel behaves like a free-standing module with sky and bright ground behind it, the more the second number on the datasheet turns into real amps.

So is the new Renogy series worth it for a mobile build? Possibly — but mostly for the front side. N-Type TOPCon cells give you higher efficiency per square foot (useful when roof space is the binding constraint), a flatter temperature coefficient (useful when the panel is pinned to a hot roof), and slower long-term degradation. Those benefits apply regardless of mounting. The bifacial bonus is a genuine extra only if you tilt, lift, or ground-deploy. Buy the panel for the cells; treat the rear-side number as a bonus you have to earn with your mounting, not a spec you automatically collect.

Sources

Community Pulse

What the forums are talking about this week

The week's mobile-DC chatter was less about kit and more about the appliances hanging off it. On r/vandwellers, an owner posted a Dometic SRE 0080 compressor fridge throwing a 4-blink error code — an ECU fault with the compressor refusing to run — and the thread turned into the usual diagnostic ladder: confirm supply voltage at the compressor under load, check for low-voltage cut-out from a sagging house bank, then suspect the electronic control unit itself. It's a good reminder that "the fridge died" is often a wiring or voltage-drop problem before it's a compressor problem.

Separately, a "Zero Breeze customer service warning" thread collected owner complaints about support on the popular battery-powered DC air conditioner — a recurring theme with niche 12V/24V cooling gear, where the hardware ships before the support operation scales. Both are signals, not verified findings: treat them as places to start your own diagnosis, not conclusions.

Threads

Product Radar

New and notable components announced or launched this week

N-Type Bifacial Solar Panel Series (100/200/250/400/590W) — Renogy

Solar

Rigid bifacial panels on ~25%-efficiency 16-busbar N-Type TOPCon cells, with glass backsheet for rear-side generation (claimed up to ~14% extra vs PERC, 80% bifaciality).

From ~$106 (100W); scales by wattage Available now via renogy.com and distributors Find on Amazon →

Front-side efficiency and temperature behaviour are the real wins on a roof; the rear-side bonus only pays if you tilt or ground-deploy.

Multi HS19 Solar — Victron Energy

Inverter

High-voltage three-phase 15kW inverter/charger with integrated MPPT charge controllers, aimed at larger stationary and hybrid systems.

Not disclosed Slated for summer 2026

Three-phase and HV PV put this above most mobile builds, but it's the direction Victron's larger off-grid range is heading.

Balcony Solar Storage All-in-One (10kWh) — WattCycle

Battery

Plug-and-play balcony storage with up to 10kWh LiFePO4, 2.5kW/5kW bidirectional output, integrated MPPT, microinverter interface and hybrid on/off-grid operation.

Not disclosed Shown at Intersolar Europe 2026 (Booth C4.251); availability TBA

A budget cell brand reaching for the all-in-one segment — residential, but a signal worth watching.

PR-S3 Elite — Ampace

Battery

Residential energy-storage pack rated at a 15,000-cycle lifespan, well above the typical 6,000–10,000-cycle home battery.

Not disclosed Launched at Intersolar Europe 2026 (Munich, 23–25 June)

Cycle-life claims this high are marketing until independently tested, but the number is the headline.