Best solar panels for a van roof: 13 rigid and flexible panels compared by W/m², €/W and weight
· 14 min read
For a flat roof with room, buy Offgridtec’s Mono V2 panels: 100 or 200 W at ≈ €0.63–0.64 per watt with a 10-year product warranty and the numbers printed. For a short roof, pay for density — the SunPower-cell SPR-100 or the EcoFlow 175. For a curved roof, the choice is a €90 Renogy ETFE you may replace, a BougeRV CIGS that tolerates heat and shade, or a Solbian that does everything at a price I could not capture. Thirteen panels, eight rigid and five flexible, ranked on watts per square metre of roof, price per watt, watts per kilo and product warranty from published datasheets — with voltage class, coefficients and the disagreements between each maker’s own pages shown as reported.
I have not measured these panels on a roof; the method box says what the score is. The planner part is the point: the solar-roof post already counts how many fit on your van, and every panel here is a rectangle you can lay on that roof in VanPlot next to the fan.
Best value per watt
Offgridtec Mono 200 W V2 (30 V, black frame)
≈ €0.64 per watt, 197 W/m², 10-year warranty — 200 W down one side of the roof for ≈ €128.
Overall 7.9 / 10 · 11.2 kg · ≈ €128
Best overall rigid 100 W
Offgridtec Mono 100 W V2 (23 V, black frame)
925 × 560 mm, 6.2 kg, ≈ €63, 10 years and the coefficient printed.
Overall 7.7 / 10 · 6.22 kg · ≈ €63
Lightest rigid per watt
EcoFlow 175 W Rigid (TOPCon)
175 W at 5.6 kg and 195 W/m² — TOPCon cells, if EcoFlow has it in stock.
Overall 6.8 / 10 · 5.6 kg · ≈ €149
Most watts per m²
Offgridtec SPR-100 120 W (SunPower back-contact)
120 W back-contact in a 100 W footprint: for the van where the roof, not the budget, is the limit.
Overall 6.8 / 10 · 6.5 kg · ≈ €189
Best flexible, price aside
Solbian SP 144 (Maxeon back-contact, semi-flexible)
144 W at 1.9 kg and 177 W/m² on a 2 mm laminate — the flexible reference, price not captured.
Overall 6.0 / 10 · 1.9 kg · price n/p
Best 12 V-class 175 W
Victron BlueSolar 175 W-12 V Mono (SPM041751200)
Vmp 19.4 V, 668 mm wide, 25-year power warranty with the figures printed.
Overall 5.7 / 10 · 11 kg · ≈ €133
Best budget flexible
Renogy 100 W 12 V flexible ETFE (EU model)
≈ €90, 1.9 kg, 2 mm, 12 V class: the cheapest way onto a curved roof.
Overall 5.3 / 10 · 1.9 kg · ≈ €90
Best walkable flexible
WATTSTUNDE WS100EFX Marine (semi-flexible, alu-backed)
4 mm aluminium-backed laminate you can stand on once bonded, 12 V class.
Overall 4.0 / 10 · 3.1 kg · ≈ €317
Best for curved roofs and shade
BougeRV Yuma 100 W CIGS flexible
CIGS that bends 360° and shrugs off heat and partial shade, with a 10-year warranty.
Overall 3.6 / 10 · 1.47 kg · ≈ €260
The comparison
| # | Product | Overall | Watts per m² of roof (W/m²) | Price per watt (€/Wp) | Watts per kg (W/kg) | Product warranty (years) | Voltage class, coefficient, warranty terms (as reported) | W × H × D | Weight | Price |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Offgridtec Mono 200 W V2 (30 V, black frame) Best value per watt rigid, 30 V class (MPPT) | 7.9 | 197 8.3 | €0.64 10.0 | 17.9 0.4 | 10 y 10.0 | Vmp 30.8 V, Imp 6.5 A, Voc 36 V; 22.3 % cells; −0.38 %/°C; 10-year product, ≥ 80 % at 25 y; 30 V class — MPPT only (Offgridtec) | 1720 × 35 × 590 mm | 11.2 kg | ≈ €128 |
| 2 | Offgridtec Mono 100 W V2 (23 V, black frame) Best overall rigid 100 W rigid, 23 V class (MPPT) | 7.7 | 193 7.8 | €0.63 10.0 | 16.1 0.1 | 10 y 10.0 | Vmp 23.9 V, Imp 4.2 A, Voc 28 V; 22.3 % cells; −0.38 %/°C; 10-year product, ≥ 80 % at 25 y; 23 V class — needs an MPPT on 12 V (Offgridtec) | 925 × 35 × 560 mm | 6.22 kg | ≈ €63 |
| 3 | EcoFlow 175 W Rigid (TOPCon) Lightest rigid per watt rigid, N-type TOPCon | 6.8 | 195 8.0 | €0.85 9.1 | 31.3 2.6 | 5 y 2.9 | Voc 25.5 V, Vmp 21.9 V, Imp 8 A; 25 % claimed; ≈ 5.6 kg; coefficient not published (EcoFlow) | 1176 × 30 × 762 mm | 5.6 kg | ≈ €149 |
| 4 | Offgridtec SPR-100 120 W (SunPower back-contact) Most watts per m² rigid, IBC cells, 12 V class | 6.8 | 211 10.0 | €1.57 6.3 | 18.5 0.5 | n/p — | Vmp 19.8 V, Imp 6.05 A, Voc 23.35 V; ~24 % back-contact cells; warranty and coefficient not shown; the SPR-120 SLIM (1,435 × 415 mm) is a different panel that retailers mix up (Offgridtec) | 1055 × 35 × 540 mm | 6.5 kg | ≈ €189 |
| 5 | WATTSTUNDE WS100M (SOLA Frame Mono 100 Wp) rigid, 12 V class | 6.5 | 190 7.4 | €1.09 8.2 | 17.2 0.3 | n/p — | Vmp 20.8 V, Imp 4.81 A, Voc 24.8 V; 18.8 % cells; the successor SOLA Frame is quoted at 1,135 × 510 mm by solarkontor; warranty and coefficient not shown (WATTSTUNDE) | 1030 × 35 × 510 mm | 5.8 kg | ≈ €109 |
| 6 | Solbian SP 144 (Maxeon back-contact, semi-flexible) Best flexible, price aside semi-flexible, IBC cells | 6.0 | 177 5.7 | n/p — | 75.8 10.0 | 5 y 2.9 | Vmp 25.3 V, Imp 5.7 A, Voc 30 V; 24–25.9 % cells; −0.38 %/°C; walkable only when fully bonded; 5-year limited warranty (Solbian) | 1490 × 2 × 546 mm | 1.9 kg | n/p |
| 7 | EcoFlow 100 W Rigid (ZMS331) rigid, IP68 | 5.8 | 174 5.3 | €0.66 9.9 | 16.1 0.1 | 5 y 2.9 | Voc 20.3 V, Vmp 17.1 V, Imp 5.9 A (most sheets; some listings say 21.6 / 18 V / 5.56 A); 23 % claimed; coefficient not published (EcoFlow) | 980 × 30 × 586 mm | 6.2 kg | ≈ €66 |
| 8 | Victron BlueSolar 175 W-12 V Mono (SPM041751200) Best 12 V-class 175 W rigid, 36-cell 12 V class | 5.7 | 176 5.6 | €0.76 9.5 | 15.9 0.0 | 5 y 2.9 | Vmp 19.4 V, Imp 9.03 A, Voc 23.7 V; −0.45 %/°C; 25-year power warranty, 90 % at 10 y, 80 % at 25 y (Victron) | 1485 × 30 × 668 mm | 11 kg | ≈ €133 |
| 9 | Renogy 100 W 12 V Mono, compact (EU model) rigid, 36-cell 12 V class | 5.7 | 178 5.8 | €1.10 8.1 | 15.6 0.0 | n/p — | Vmp 20.4 V, Imp 4.91 A, Voc 24.3 V; 22 % cell efficiency; −0.37 %/°C on the US sheet; power warranty 95 % at 5 y, 90 % at 10 y, 80 % at 25 y; EU product-warranty years not shown (Renogy) | 1062 × 35 × 530 mm | 6.4 kg | ≈ €110 |
| 10 | Renogy 100 W 12 V flexible ETFE (EU model) Best budget flexible semi-flexible mono, ETFE | 5.3 | 150 2.3 | €0.90 8.9 | 52.6 6.2 | 5 y 2.9 | Vmp 18.9 V, Imp 5.29 A, Voc 22.5 V; 15 % module efficiency; 1,219 × 546 × 2 mm (the US revision is 1,093 × 582 × 3 mm, 2.4 kg); 5-year materials warranty (Renogy) | 1219 × 2 × 546 mm | 1.9 kg | ≈ €90 |
| 11 | WATTSTUNDE SOLA Flex Mono 100 Wp semi-flexible mono PERC, ETFE | 4.5 | 169 4.7 | €1.67 5.9 | 48.5 5.5 | 3 y 0.0 | Vmp 28.6 V, Imp 3.49 A, Voc 34.32 V; ≥ 22 % cells; flexes up to 30 %; 3-year warranty; 28 V class — MPPT only (WATTSTUNDE) | 1595 × 3.1 × 370 mm | 2.06 kg | ≈ €167 |
| 12 | WATTSTUNDE WS100EFX Marine (semi-flexible, alu-backed) Best walkable flexible semi-flexible, aluminium plate, walkable when bonded | 4.0 | 198 8.4 | €3.17 0.0 | 32.3 2.8 | n/p — | Vmp 18 V, Imp 5.31 A, Voc 20.9 V; 35 cells, > 20 %; IP65; walkable when glued to a solid surface; fraron 970 × 520 × 4 mm / 3.1 kg vs camperpower ≈ 1,200 × 500 mm / 4.5 kg; warranty not shown (WATTSTUNDE) | 970 × 4 × 520 mm | 3.1 kg | ≈ €317 |
| 13 | BougeRV Yuma 100 W CIGS flexible Best for curved roofs and shade flexible thin-film, adhesive | 3.6 | 132 0.0 | €2.60 2.2 | 68.0 8.7 | 10 y 10.0 | Vmp 24 V, Imp 4.21 A, Voc 30.5 V; bends 360°; 1.47 kg on the DE page, 4.54 lb (2.06 kg) on the US page; 10-year product, 25-year performance; coefficient not published (BougeRV) | 1096 × 1.5 × 689 mm | 1.47 kg | ≈ €260 |
How these are rated — and what I did not do
I have not run these units side by side. This is a spec-sheet comparison: every number in the table is a manufacturer or retailer figure, linked per product and checked September 2026. Where makers publish energy figures under different conditions they are shown as reported and kept out of the score, because a number measured at 32 °C cannot be ranked against one measured at 25 °C. What can be ranked fairly is arithmetic on published dimensions, weight, capacity and price — the things that decide whether a unit fits your layout, what it costs you in payload, and what it costs per litre. That is what the score is.
Each metric is scaled 0–10 across this set (best = 10, worst = 0), then weighted:
- Watts per m² of roof (W/m²) — 35 % (higher is better)
- Price per watt (€/Wp) — 35 % (lower is better)
- Watts per kg (W/kg) — 15 % (higher is better)
- Product warranty (years) — 15 % (higher is better)
- Watts per m² uses the panel's outside length × width; it is the metric that turns the solar-roof post's panel count into watts. Rigid and flexible panels are in one table because a van roof has to choose between them.
- Price per watt uses the street price named per product; the EcoFlow 100 W is half its 2-pack price; the Solbian SP 144's 2026 price was not captured and it is scored without it.
- Temperature coefficient, efficiency claims and cycle-of-life warranty percentages are shown as reported and not scored — only five panels publish a coefficient.
- Product warranty years were not shown for the Renogy 100 W (EU page), WATTSTUNDE WS100M and EFX, and the Offgridtec SPR-100; those four are scored over three metrics.
- Manufacturer pages could not be opened from this build environment this run; figures come from the makers' published datasheets and listings as indexed, cross-checked between retailers, with every disagreement shown in the product's reported line. Model churn is real: EcoFlow has no 220 W rigid, WATTSTUNDE no WS200M, and Renogy's EU and US 100 W panels are different sizes.
No affiliate links: product links go to the manufacturer or the spec page the numbers came from. If a spec here is wrong, tell me and I will fix it and note the change.
How to choose: the roof decides, then the controller
Start from the roof, not the watts. The solar-roof post counts how many 1,060 × 530 mm panels fit on each of 85 van variants, and the answer is usually four to eight, minus one for a fan. That count is the budget; the table above tells you how to spend it. If the roof is short (a Transporter, a Vito, a Trafic), density wins: the Offgridtec SPR-100 puts 120 W where a Renogy puts 100, the EcoFlow 175 puts 195 W/m² down. If the roof is long (an L3 or L4), price per watt wins and the Offgridtec Mono V2 panels are the cheapest reliable watts here. If the roof curves — a high-top, a pop-top, a classic — it is flexible or nothing, and the choice is between a cheap Renogy ETFE you may replace, a BougeRV CIGS that tolerates the heat, and a Solbian that does both at a price.
Then the controller. Seven of the thirteen panels here are 23–31 V class. On an MPPT controller that is a non-issue and often an advantage (higher voltage, thinner cable, earlier morning start); on a PWM controller it throws a third of the panel away. Size the controller for the array’s Voc in the cold — a 36 V-Voc panel in series pairs is 72 V before the winter correction — and read the battery and solar sizing post for what the watts actually deliver per season: 400 W is ≈ 1.5 kWh a day in June and 0.75 in October.
Heat and shade are the numbers not in the headline. Roof cells run at 60–70 °C in summer, so −0.37 to −0.45 %/°C is 15–18 % off the nameplate at noon; only five panels here publish the coefficient. A fan or a roof rack shading one cell string drops a crystalline panel hard and a CIGS or back-contact panel less. Put the fan at the rear and the panels forward of it, or accept one panel in its morning shadow — the roof-fan guide has the fan heights.
Weight is small but high. Four rigid 100 W panels and rails are ≈ 30 kg on the roof, 2 m up; the weight post shows what that does to the centre of mass next to a 20 kg battery low in the bench. Every panel here is a rectangle you can place on the roof in the planner, with the fan, to see the shadow strip before you drill.
The panels, in order
1. Offgridtec Mono 200 W V2 (30 V, black frame)Best value per watt
Overall 7.9/10 · 1720 × 35 × 590 mm (35.5 L outside) · 11.2 kg · ≈ €128 (€128 g-part.de, Sep 2026; geizhals.de from €129.28) · reported: Vmp 30.8 V, Imp 6.5 A, Voc 36 V; 22.3 % cells; −0.38 %/°C; 10-year product, ≥ 80 % at 25 y; 30 V class — MPPT only (Offgridtec)
≈ €0.64 per watt, 197 W/m², a 10-year product warranty and the coefficient printed on a German datasheet. It is a 1,720 × 590 mm, 30 V-class module — a long, narrow panel that runs down one side of the roof past a fan, on an MPPT only. Measure the flat roof between the ribs before buying: 1.72 m is longer than most people think.
Reasons to buy
- 200 W for ≈ €128 — €0.64 per watt
- 590 mm wide: a long narrow panel that runs down one side of the roof past a fan
- 10-year product warranty
Reasons to avoid
- 1,720 mm long: measure the flat roof between the ribs first
- 30 V class, MPPT only
- 11.2 kg on the roof, high up
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: offgridtec.com, offgridtec.com, geizhals.de.
2. Offgridtec Mono 100 W V2 (23 V, black frame)Best overall rigid 100 W
Overall 7.7/10 · 925 × 35 × 560 mm (18.1 L outside) · 6.22 kg · ≈ €63 (€63.02 offgridtec.com / g-part.de, Sep 2026 (sale €52.96)) · reported: Vmp 23.9 V, Imp 4.2 A, Voc 28 V; 22.3 % cells; −0.38 %/°C; 10-year product, ≥ 80 % at 25 y; 23 V class — needs an MPPT on 12 V (Offgridtec)
The 100 W panel that wins on the spec sheet: 925 × 560 mm, 6.22 kg, ≈ €63, 10 years, −0.38 %/°C. The catch is the 23 V class (MPPT only) and the 560 mm width, which puts one across a narrow roof strip where a 510 mm WATTSTUNDE fits two. At this price, buy an extra one.
Reasons to buy
- ≈ €0.63 per watt with a 10-year product warranty
- 925 × 560 mm — 137 mm shorter than the Renogy for the same 100 W
- German shop, German datasheet with the coefficients printed
Reasons to avoid
- 23 V class: PWM controllers waste a third of it, MPPT only
- 560 mm wide — two do not fit across a 1.1 m roof strip
- Sale prices move weekly; the list is €63
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: offgridtec.com, offgridtec.com, g-part.de.
3. EcoFlow 175 W Rigid (TOPCon)Lightest rigid per watt
Overall 6.8/10 · 1176 × 30 × 762 mm (26.9 L outside) · 5.6 kg · ≈ €149 (€149 eu.ecoflow.com, Sep 2026 (listed sold out at the time)) · reported: Voc 25.5 V, Vmp 21.9 V, Imp 8 A; 25 % claimed; ≈ 5.6 kg; coefficient not published (EcoFlow)
5.6 kg for 175 W: the lightest rigid panel per watt in the guide, TOPCon cells, 195 W/m². It is 762 mm wide — one across on most vans — and was sold out on the EU site when I checked. EcoFlow publishes no coefficient and a 5-year warranty.
Reasons to buy
- 175 W at 5.6 kg — the lightest rigid panel per watt in the guide
- 195 W/m² on the roof, the densest here
- Vmp 21.9 V: still MPPT-friendly on a 12 V bank
Reasons to avoid
- 762 mm wide — one across on most vans, not two
- Sold out on the EU site when checked
- Coefficient and long-term power warranty not published
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: eu.ecoflow.com, enfsolar.com.
4. Offgridtec SPR-100 120 W (SunPower back-contact)Most watts per m²
Overall 6.8/10 · 1055 × 35 × 540 mm (19.9 L outside) · 6.5 kg · ≈ €189 (€188.60 schnell-und-sicher-handelskontor.de, Sep 2026; €223.70–259 elsewhere) · reported: Vmp 19.8 V, Imp 6.05 A, Voc 23.35 V; ~24 % back-contact cells; warranty and coefficient not shown; the SPR-120 SLIM (1,435 × 415 mm) is a different panel that retailers mix up (Offgridtec)
The most watts per square metre here: 120 W back-contact in the Renogy-100's footprint, 12 V class. At ≈ €1.57 per watt it only makes sense when the roof is the constraint and not the budget — a short van with a fan and an air conditioner. Warranty not stated in the listings I could read, so it is unscored on that metric.
Reasons to buy
- 120 W in the Renogy-100's footprint: +20 % from the same roof
- Back-contact cells, 12 V class
- Shade-tolerant cell layout
Reasons to avoid
- ≈ €1.57 per watt — the roof has to be the constraint
- Warranty not stated — unscored
- Two SPR names, two shapes; order by dimensions
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: offgridtec.com, solar-autark.com.
5. WATTSTUNDE WS100M (SOLA Frame Mono 100 Wp)
Overall 6.5/10 · 1030 × 35 × 510 mm (18.4 L outside) · 5.8 kg · ≈ €109 (€109 powerdude.de (WS100M-A), Sep 2026; €119.90 solarcamp24.de) · reported: Vmp 20.8 V, Imp 4.81 A, Voc 24.8 V; 18.8 % cells; the successor SOLA Frame is quoted at 1,135 × 510 mm by solarkontor; warranty and coefficient not shown (WATTSTUNDE)
The German camper-shop staple, 510 mm wide — the narrowest 100 W rigid panel here and the one that fits two across a 1.1 m strip. 12 V class, 5.8 kg, ≈ €109. It is mid-transition to the SOLA Frame with a 1,135 mm length, the cells are the least efficient in the guide, and the warranty was not shown; scored on three metrics.
Reasons to buy
- 510 mm wide: the narrowest 100 W rigid panel here — two across a 1.1 m strip
- 5.8 kg, hollow-chamber frame, 12 V class
- The German camper-shop staple; kits with cable and controller
Reasons to avoid
- Warranty not stated in the listings I could read — unscored
- 18.8 % cells, the lowest efficiency in the guide
- Model in transition: WS100M vs SOLA Frame dimensions differ by 105 mm
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: media.wattstunde.de, solarkontor.de, geizhals.de.
6. Solbian SP 144 (Maxeon back-contact, semi-flexible)Best flexible, price aside
Overall 6.0/10 · 1490 × 2 × 546 mm (1.6 L outside) · 1.9 kg · price n/p (2026 list not captured; 2022 list €1,188 excl. VAT) · reported: Vmp 25.3 V, Imp 5.7 A, Voc 30 V; 24–25.9 % cells; −0.38 %/°C; walkable only when fully bonded; 5-year limited warranty (Solbian)
The flexible panel that matches rigid density: 144 W at 1.9 kg and 177 W/m², Maxeon back-contact cells, the coefficient and warranty published. The price is the reason it sits mid-table — I could not capture the 2026 list, and the 2022 one was ≈ €1,188 before VAT — so it is scored without it. For a curved roof that must carry real power, it is the reference.
Reasons to buy
- 144 W at 1.9 kg — 76 W per kilo, the best in the guide
- 177 W/m²: the flexible panel that matches rigid density
- The marine reference; coefficient and warranty documents published
Reasons to avoid
- Price not captured this run (2022 list was ≈ €1,188 excl. VAT) — excluded from its score
- 24 V class, MPPT
- Not to be walked on unless bonded to a rigid surface
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: solbian.eu, solbian.eu, solbian.eu.
7. EcoFlow 100 W Rigid (ZMS331)
Overall 5.8/10 · 980 × 30 × 586 mm (17.2 L outside) · 6.2 kg · ≈ €66 (€131 per 2-pack eu.ecoflow.com, Sep 2026 (sold only in pairs)) · reported: Voc 20.3 V, Vmp 17.1 V, Imp 5.9 A (most sheets; some listings say 21.6 / 18 V / 5.56 A); 23 % claimed; coefficient not published (EcoFlow)
≈ €0.66 per watt in a 980 × 586 mm, 6.2 kg panel with an IP68 box, sold in pairs on the EU site. Two sets of electrical figures circulate and no coefficient is published; the datasheet set (Vmp 17.1 V) is the one to plan with.
Reasons to buy
- ≈ €0.66 per watt and 6.2 kg
- 980 × 586 mm, pre-drilled mounting holes
- IP68 junction box
Reasons to avoid
- Sold in pairs only on the EU site
- Two sets of electrical figures in circulation
- No temperature coefficient published
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: eu.ecoflow.com, vieffetrade.eu.
8. Victron BlueSolar 175 W-12 V Mono (SPM041751200)Best 12 V-class 175 W
Overall 5.7/10 · 1485 × 30 × 668 mm (29.8 L outside) · 11 kg · ≈ €133 (€132.74 ebromsolar.at, Sep 2026; €173.40 eBay.de — no large DE shop price surfaced) · reported: Vmp 19.4 V, Imp 9.03 A, Voc 23.7 V; −0.45 %/°C; 25-year power warranty, 90 % at 10 y, 80 % at 25 y (Victron)
The 12 V-class 175 W panel: Vmp 19.4 V, 668 mm wide so two sit side by side on a 1.4 m roof, a 25-year power warranty with the retention figures printed. It is also 11 kg and −0.45 %/°C, the heaviest per watt and the most heat-sensitive of the rigid panels, and its poly twin has the same size. ≈ €133 from an Austrian shop; larger German shops did not show a price this run.
Reasons to buy
- 175 W in a 668 mm-wide panel: two side by side on a 1.4 m roof
- True 12 V-class (Vmp 19.4 V) — works on PWM as well as MPPT
- Victron's 25-year power warranty with the figures printed
Reasons to avoid
- 11 kg — the heaviest per watt of the rigid panels here
- −0.45 %/°C: loses more on a hot roof than the PERC panels
- Poly twin (SPP041751200) has the same size and a different price — check the code
In the planner: pick Solar panel and choose the preset “Victron BlueSolar 175 W” — it drops in at these dimensions and this weight, so the fit and the axle load are checked before you order. Specs: victronenergy.com, enfsolar.com, ebromsolar.at.
9. Renogy 100 W 12 V Mono, compact (EU model)
Overall 5.7/10 · 1062 × 35 × 530 mm (19.7 L outside) · 6.4 kg · ≈ €110 (€109.99 de.renogy.com, Sep 2026 (promo pages lower)) · reported: Vmp 20.4 V, Imp 4.91 A, Voc 24.3 V; 22 % cell efficiency; −0.37 %/°C on the US sheet; power warranty 95 % at 5 y, 90 % at 10 y, 80 % at 25 y; EU product-warranty years not shown (Renogy)
The panel the solar-roof post counts in fours and eights: 1,062 × 530 mm, 6.4 kg, 12 V class, 22 % cells. It costs ≈ €1.10 per watt against €0.63–0.66 for Offgridtec and EcoFlow, and Renogy's EU page does not state product-warranty years, so it is unscored there. Brackets, cables and second-hand units are everywhere.
Reasons to buy
- 1,062 × 530 mm: the panel the solar-roof post packs 4–8 of on a van
- 6.4 kg, 12 V class, 22 % cells
- The most common single panel in van builds — brackets and cables everywhere
Reasons to avoid
- EU page does not state product-warranty years — unscored on warranty
- ≈ €1.10 per watt against €0.53–0.65 for Offgridtec and EcoFlow
- Renogy's US, UK and EU 100 W SKUs differ in size and coefficient
In the planner: pick Solar panel and choose the preset “Renogy 100 W compact” — it drops in at these dimensions and this weight, so the fit and the axle load are checked before you order. Specs: de.renogy.com, enfsolar.com.
10. Renogy 100 W 12 V flexible ETFE (EU model)Best budget flexible
Overall 5.3/10 · 1219 × 2 × 546 mm (1.3 L outside) · 1.9 kg · ≈ €90 (from €89.99 de.renogy.com, Sep 2026) · reported: Vmp 18.9 V, Imp 5.29 A, Voc 22.5 V; 15 % module efficiency; 1,219 × 546 × 2 mm (the US revision is 1,093 × 582 × 3 mm, 2.4 kg); 5-year materials warranty (Renogy)
The cheapest way onto a curved roof: ≈ €90, 1.9 kg, 2 mm, 12 V class, 546 mm wide. 15 % module efficiency means 150 W/m², and glued crystalline panels are the ones that crack and delaminate after a few summers — Renogy's 5-year materials warranty is the bet. The EU and US revisions are different sizes.
Reasons to buy
- The cheapest flexible panel here at ≈ €0.90 per watt
- 1.9 kg, 2 mm, 12 V class
- 546 mm wide: two across a 1.1 m roof
Reasons to avoid
- 15 % module efficiency, 150 W/m²
- Crystalline cells on a glued sheet run hot and crack over years — the known flexible-panel failure mode
- EU and US revisions are different panels
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: de.renogy.com, renogy.com.
11. WATTSTUNDE SOLA Flex Mono 100 Wp
Overall 4.5/10 · 1595 × 3.1 × 370 mm (1.8 L outside) · 2.06 kg · ≈ €167 (€167.23 solarcamp24.de, Sep 2026) · reported: Vmp 28.6 V, Imp 3.49 A, Voc 34.32 V; ≥ 22 % cells; flexes up to 30 %; 3-year warranty; 28 V class — MPPT only (WATTSTUNDE)
A 370 mm-wide strip — 1,595 mm long — that fits the roof between a rib and a fan where no other 100 W panel goes. 22 % cells, 2.06 kg, 28 V class. The 3-year warranty is the shortest in the guide and ≈ €1.67 per watt is the price of the shape.
Reasons to buy
- 370 mm wide: the strip that fits between a roof rib and a fan
- 2.06 kg, 3.1 mm
- 22 % cells on a flexible sheet
Reasons to avoid
- 1,595 mm long for 100 W
- 3-year warranty — the shortest here
- 28 V class
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: media.wattstunde.de, solarkontor.de, solarcamp24.de.
12. WATTSTUNDE WS100EFX Marine (semi-flexible, alu-backed)Best walkable flexible
Overall 4.0/10 · 970 × 4 × 520 mm (2.0 L outside) · 3.1 kg · ≈ €317 (€317 mc-wohnmobile.de, Sep 2026) · reported: Vmp 18 V, Imp 5.31 A, Voc 20.9 V; 35 cells, > 20 %; IP65; walkable when glued to a solid surface; fraron 970 × 520 × 4 mm / 3.1 kg vs camperpower ≈ 1,200 × 500 mm / 4.5 kg; warranty not shown (WATTSTUNDE)
The flexible panel you can stand on once it is bonded, on a 4 mm aluminium-backed laminate, 12 V class. By its datasheet it is the densest 100 W here (198 W/m²); by another retailer it is 1,200 × 500 mm and 4.5 kg. ≈ €3.17 per watt and no stated warranty put it near the bottom of a table that cannot score 'walkable'.
Reasons to buy
- The flexible panel you can stand on once it is bonded
- 198 W/m² — the densest 100 W here, by its datasheet dimensions
- 12 V class, no frame, 4 mm
Reasons to avoid
- ≈ €3.17 per watt
- Two retailers, two sizes and weights
- Warranty not stated — unscored
Not a planner preset yet; place a generic item and type these dimensions and weight in. Specs: fraron.de, mc-wohnmobile.de.
13. BougeRV Yuma 100 W CIGS flexibleBest for curved roofs and shade
Overall 3.6/10 · 1096 × 1.5 × 689 mm (1.1 L outside) · 1.47 kg · ≈ €260 (€259.99 de.bougerv.com (regular €299.99), Sep 2026) · reported: Vmp 24 V, Imp 4.21 A, Voc 30.5 V; bends 360°; 1.47 kg on the DE page, 4.54 lb (2.06 kg) on the US page; 10-year product, 25-year performance; coefficient not published (BougeRV)
Last on the score and first for a roof that curves or sits in partial shade: CIGS thin film that bends 360°, 1.5 mm thick, 1.5–2 kg depending on which BougeRV page you read, a 10-year product warranty. It pays for that with 132 W/m² — 689 mm wide for 100 W — and ≈ €2.60 per watt. The planner preset uses the older 1,080 × 660 mm size.
Reasons to buy
- 1.5 mm thick and 1.5–2 kg: glues to a curved roof with nothing above the sheet metal
- CIGS tolerates partial shade and heat better than crystalline flex
- 10-year product warranty — unusual for a flexible panel
Reasons to avoid
- ≈ €2.60 per watt
- 132 W/m²: 689 mm wide for 100 W
- 24 V class: MPPT, and two published weights
In the planner: pick Solar panel and choose the preset “BougeRV Yuma 100 W flexible” — it drops in at these dimensions and this weight, so the fit and the axle load are checked before you order. Specs: de.bougerv.com, bougerv.com.
FAQ
Rigid or flexible solar panels on a van roof?
Rigid if the roof is flat enough and you can accept 30–35 mm of frame plus brackets: €0.63–1.10 per watt, 5–10-year product warranties, glass that survives hail and years of heat. Flexible if the roof curves, you need to keep the profile under 5 mm, or weight matters more than money: 1.5–3 kg per 100 W, €0.90–3.17 per watt, and — for glued crystalline panels — a known failure mode from heat cycling that CIGS (BougeRV) and back-contact laminates (Solbian) handle better. The solar-roof post has how many of each fit on your van.
How many watts of solar fit on a van roof?
With rigid 100 W panels (≈ 1,060 × 530 mm) edge to edge: 400–500 W on a medium van such as a Ducato or Sprinter L2, 500–700 W on an L3, 600–800 W on an L4, minus one panel for a roof fan on most bodies. Denser panels change that: the Offgridtec SPR-100 puts 120 W in the same footprint, the EcoFlow 175 W puts 195 W/m² on the roof, and a 370 mm-wide SOLA Flex fills the strip beside a fan that nothing else does.
What does the voltage class mean — 12 V, 23 V, 30 V panels?
A 36-cell '12 V' panel (Vmp 18–21 V: Victron, Renogy, WATTSTUNDE WS100M, EFX) charges a 12 V bank through a PWM or MPPT controller. Panels with Vmp 23–31 V (Offgridtec Mono V2, BougeRV Yuma, Solbian, SOLA Flex) need an MPPT controller, which converts the surplus voltage into current; on a PWM they lose a third of their output. Any modern build uses MPPT, so the class mostly matters for series wiring and controller input limits.
How much do solar panels weigh on a van roof?
Rigid 100 W panels are 5.8–6.4 kg; 175–200 W rigid panels 5.6 kg (EcoFlow TOPCon) to 11–11.2 kg (Victron, Offgridtec 200). Flexible panels are 1.5–3.1 kg per 100 W. Four rigid 100 W panels plus rails are around 30 kg on the roof, which is high up and matters for the centre of mass — the weight post covers it.
What is the temperature coefficient and does it matter on a van?
How much output drops per degree above 25 °C cell temperature. A van roof in July runs cells at 60–70 °C, so a panel rated −0.45 %/°C (Victron BlueSolar) loses about 18 % at 65 °C and one rated −0.37 %/°C (Renogy 100) about 15 %. Only five panels here publish it; it is shown, not scored.
Which solar panel does the planner use?
VanPlot's roof presets are the Renogy 100 W compact (1,062 × 531 mm), Victron BlueSolar 175 W (1,485 × 668 mm), a 200 W rigid at 1,650 × 670 mm and the BougeRV Yuma 100 W flexible (1,080 × 660 mm); any panel here can be placed by typing its dimensions and weight into a generic panel. The roof view shows the fan, the panels and the shadow strip together.
