The essentials in 30 seconds
- Flexible vs rigid: flexible (Solbian, Sunbeam, Renogy) = adaptable bimini/awning/curved deck, efficiency -10 to -15% vs rigid, lifespan 8-12 years. Rigid (Victron 140W, BlueSun) = maximum efficiency, lifespan 20-25 years, requires flat surface (rear arch, stern mast, bow deck).
- Sizing rule of thumb: 1 Wp of panel for 1 Ah of raw lithium bank. 200 Ah lithium = 200 Wp minimum, 400 Ah lithium = 400 Wp minimum. Double if offshore cruising without daily engine charging.
- MPPT controller mandatory: never use PWM in 2026, efficiency loss 25-30%. Victron SmartSolar MPPT 100/30 (~ 140 € HT) up to 400 Wp, 100/50 or 150/100 for large banks.
- Typical ROI: 200 Wp sailboat summer cruising = output ~ 80-100 Ah/day in June-August. Savings on generator or shore power = payback 4-6 years.
- Complete budget 40-foot sailboat: 200 Wp rigid + MPPT + installed wiring = ~ 1,200-1,600 € HT. 400 Wp flexible bimini = ~ 2,500-3,200 € HT.
Solar has become the #1 renewable energy source for recreational boating. Simpler than a wind generator, more efficient than a hydrogenerator at anchor, quieter than a genset. But choosing between flexible and rigid impacts efficiency, durability, and aesthetics.
This article distinguishes the two families, presents the brands distributed by Skysat, and provides a workshop verdict by program. For battery bank sizing, see our sizing method article.
The two families — flexible vs rigid
Flexible
Photovoltaic cells under sealed polymer film, up to 30° curvature possible. Brands: Solbian (Italy, premium, ~ 6-9 €/Wp), Sunbeam (Germany, mid-range, ~ 4-6 €/Wp), Renogy (China/USA, entry-level, ~ 2-4 €/Wp).
Rigid
Monocrystalline cells under tempered glass + aluminum frame. Brands: Victron (pleasure craft reference, 140 W = ~ 200-280 € HT), BlueSun (Asia, mid-range), Solara (Germany, premium marine).
Flexible panels — technical details
- Advantages: adaptable to bimini/awning/curved deck, lightweight (2-4 kg/m²), no windage, discreet appearance.
- Limitations: efficiency -10 to -15% vs rigid at equivalent power, lifespan 8-12 years (polymer film degrades), irreparable if punctured.
- Required surface: ~ 1.3 m² for 200 Wp Solbian.
Rigid panels — technical details
- Advantages: maximum efficiency, lifespan 20-25 years, mechanical robustness, lowest cost per Wp.
- Limitations: requires flat surface (rear arch, stern mast, bow deck), weight 8-12 kg/m², windage underway, less discreet appearance.
- Required surface: ~ 1.1 m² for 200 Wp Victron.
MPPT controller — why it's mandatory
The charge controller converts panel voltage (variable 14-22 V to 12 V bank) using two technologies:
- PWM (Pulse Width Modulation): outdated, simple, efficiency 70-75%. Unacceptable in 2026.
- MPPT (Maximum Power Point Tracking): modern, efficiency 95-98%. Bonus: automatically adjusts optimal voltage based on irradiance.
Skysat distributes MPPT only. Reference: SmartSolar MPPT 100/30 (~ 140 € HT) up to 400 Wp, 100/15 (~ 84 € HT) for small installs ≤ 200 Wp.
Sizing based on lithium bank
Rule of thumb: 1 Wp panel for 1 Ah raw lithium bank.
- 100 Ah lithium bank → 100 Wp minimum.
- 200 Ah lithium bank → 200 Wp minimum.
- 400 Ah lithium bank → 400 Wp minimum.
- Offshore without daily engine charging → double (1 Wp for 0.5 Ah).
2026 model comparison chart
| Model | Type | Power | Surface | Price HT |
|---|---|---|---|---|
| Victron 140W | Rigid mono | 140 Wp | 1.25 × 0.67 m | ~ 280 € |
| Solbian SP 144Q | Flexible mono | 144 Wp | 1.40 × 0.70 m | ~ 950 € |
| Sunbeam Tough 160W | Flexible mono | 160 Wp | 1.40 × 0.80 m | ~ 720 € |
| BlueSun 200W rigid | Rigid mono | 200 Wp | 1.55 × 0.80 m | ~ 220 € |
| Victron MPPT 100/30 | Controller | 400 Wp max | — | ~ 140 € |
Practical installation on sailboats
Skysat workshop rules
- Proper wire sizing: 200 Wp at 12 V = 17 A nominal → 4 mm² wire minimum, length ≤ 5 m.
- Series fuse on panel output: 25 A for 200 Wp, 50 A for 400 Wp.
- Blocking diode: integrated in modern panels. Check datasheet.
- MPPT ventilation: dissipates 10-15 W at full load, do not install in a closed cabinet.
- VictronConnect MPPT programming: lithium LFP profile, absorption voltage 14.4 V, float 13.5 V.
3 real-world workshop cases
Case 1 — Bénéteau Oceanis 40, 200 Wp rigid rear arch
2024 refit: 1 × Victron 140W + 1 × BlueSun 60W mounted on stainless steel rear arch + MPPT 100/30. Measured output June-August: 90-100 Ah/day Mediterranean, 70-80 Ah/day Atlantic. Total install: 1,350 € HT.
Case 2 — Lagoon 42 catamaran, 400 Wp flexible bimini
2 × Solbian 200W flexible panels on fixed bimini + MPPT 100/30 + Cerbo GX integration. Installation time 6 hours workshop (bimini fabric + wiring). Summer output 180-200 Ah/day. Total install: 2,800 € HT.
Case 3 — IMOCA racing sailboat, 600 Wp semi-rigid
3 × custom 200W semi-rigid panels each + 2 × MPPT 150/45 dual-zone. Offshore output 250-300 Ah/day. Material cost ~ 4,500 € HT.
FAQ — Solar panels for sailboats in practice
How many Wp do I really need?
Rule: 1 Wp / 1 Ah raw lithium bank. 200 Ah bank = 200 Wp minimum. Double for offshore without daily engine charging. No need for more unless high consumption like air conditioning/watermaker.
Solar in winter layup?
Yes, useful to maintain lithium bank charge without intervention. 100 Wp rigid + MPPT is enough to offset BMS self-discharge over 6 months.
Portable folding panels?
Good as occasional backup (stopover, solo anchoring) but not for permanent use. 60-100 Wp folding panel + EcoFlow case ~ 250-400 € HT, useful as backup.
Is solar enough offshore?
In tradewind transatlantic (15-25 knots, near-permanent sun), 400 Wp + 200 Ah bank = possible full autonomy without engine. In polar transat, no — hydrogenerator or wind generator needed as backup.
Which MPPT for which bank?
MPPT 100/15 up to 200 Wp. MPPT 100/30 up to 400 Wp. MPPT 150/45 up to 600 Wp. MPPT 250/100 up to 1,200 Wp (rarely needed in pleasure craft).
Skysat distributes Victron Energy and BlueSun. Solbian and Sunbeam available on special order. 2026 HT prices are indicative distributor prices.
