Solar boat: how far can you go on sunshine? PEHN, PonTOM, Silent Yachts and Sunreef compared
From a 5 m lake boat to a 40 m catamaran: what the solar panels deliver compared with motor and battery, and why no yard states a solar-only range.
How far a solar boat can go on sunshine alone is something not a single yard in this comparison puts a number on. Working through their own figures, the solar panels deliver at most 3 to 21 % of the motor power in full sun. A solar boat therefore runs on its battery and tops it up along the way. It only manages without a charging point at slow speed or with breaks.
Which solar boats are available in Europe?
Two groups: small lake boats of around 5.5 m from Austria and Germany, and large catamarans from 18 m from Italy and Poland. In between, we found no series-built boat with published data.
| Boat | Length | Solar (peak) | Battery | Motor according to the yard | Price from |
|---|---|---|---|---|---|
| PEHN 530 (solar option) | 5.30 m | 0.168 kWp | 3 kWh AGM or 4.8 kWh lithium | Kräutler 0.8 or 1.6 kW | €29,790 (website) or €41,800 incl. VAT (2025 brochure), solar €1,990 extra (PEHN, brochure) |
| PonTOM Defender 5.6 Solarboot M3 | approx. 5.60 m (frame) | 0.96 kWp | 5 kWh (or 10) | Torqeedo Cruise 6.0 RS, 6 kW | on request (Kiebitzberg) |
| Silent Yachts 60 | 18.86 m | 16.8 kWp | 354 kWh | 2 × 164 kW continuous, 130 kW generator | on request (Silent Yachts) |
| Silent Yachts 80 | 24.38 m | 22.4 kWp | 354 kWh (or 708) | 2 × 200 kW continuous, 2 × 75 kW generator | on request (Silent Yachts) |
| Sunreef 100 Eco (sailing catamaran) | 28.65 m | up to 45.1 kWp | 770 kWh | 2 × 180 kW | on request (Sunreef, battery) |
| Silent Yachts 120 Explorer | 36.74 m | 40 kWp | 624 kWh | 2 × 720 kW | on request (Silent Yachts) |
| Sunreef 40M Explorer Eco | 40 m | up to 40 kWp | approx. 920 kWh | 2 × 540 kW, 2 × 480 kW generators | on request (Sunreef) |
PEHN's figures do not match: the website says from €29,790 without mentioning VAT, the 2025 brochure from €41,800 including 20 % Austrian VAT. Ask for the current price before you buy. Sunreef also contradicts itself: for the Sunreef 100 Eco, the launch announcement gives 49 kWp and 2 × 360 kW, and for the 40M the text says 50 kWp. We show the figures from the model pages. For the 60 and 80 Sunreef Power Eco motor yachts, the yard publishes too little data for the table. None of the four yards lists prices in pounds or a UK dealer; Silent Yachts' only official sales partner in Europe is in Greece (Silent Yachts).
Why does no yard state a range on solar power?
Because the panels are small compared with the motor. We divided the panels' peak output by the motor power, both taken from the yards' own figures:
| Boat | Solar ÷ motor power | Solar ÷ battery |
|---|---|---|
| PEHN 530 with 0.8 kW motor | 21 % | 0.168 kWp for 3 kWh |
| PonTOM Defender 5.6 | 16 % | 0.96 kWp for 5 kWh |
| Silent Yachts 60 | 5 % | 16.8 kWp for 354 kWh |
| Silent Yachts 80 | 6 % | 22.4 kWp for 354 kWh |
| Sunreef 100 Eco | 13 % | 45.1 kWp for 770 kWh |
| Silent Yachts 120 Explorer | 3 % | 40 kWp for 624 kWh |
| Sunreef 40M Explorer Eco | 4 % | 40 kWp for approx. 920 kWh |
A panel only reaches its peak output (kWp) under ideal conditions. Even then, the sun covers only a fraction of the full motor power. At slow speed, however, a motor needs much less than its maximum output, so the solar share is larger. Kiebitzberg writes that the panels at times charge more than the motor uses (Kiebitzberg), but gives no speed for this. PEHN writes that the boat can run “purely on solar and mains power” (PEHN). Silent Yachts and Sunreef advertise “Unlimited Range” but state no conditions for it (Silent Yachts, Sunreef), and the large models carry a generator.
How far does a small solar boat go on a full battery?
PEHN states at least 40 km on battery for all its boats, 2 hours at full throttle or up to 6 hours at half speed (PEHN FAQ). That is a battery figure, not a solar figure. Kiebitzberg gives no range for the PonTOM. Our charging map for electric boats shows where you can charge on the way.
What sets the PEHN 530 and PonTOM apart?
- Design: The PEHN 530 is a classic open lake boat for 5 people, weighing 390 kg empty according to the data sheet. The PonTOM is an aluminium pontoon for up to 9 people or 800 kg payload; the hull alone weighs approx. 800 kg (PEHN, Kiebitzberg).
- Solar: On the PonTOM, 0.96 kWp is standard, almost six times the PEHN's 0.168 kWp option.
- Licence: In the UK, private pleasure craft need no licence (RYA). On the Continent, the PEHN 530 with 0.8 to 1.6 kW stays below the limits in Germany, Austria and Switzerland. The PonTOM with 6 kW is licence-free in Germany up to 7.5 kW, but not on Lake Constance or in Austria. Details in our guide electric boat without a licence.
- Buying: Both sell directly from the yard, PEHN on the Attersee, Kiebitzberg in Havelberg with sales agents in Hamburg and Denmark. Both boats have CE category D (sheltered waters).
Sources and image rights
- Images
- Lena Netkach / Pexels (conditions)
- Checked
- 27 October 2026 by Andreas Lakeberg
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