Energy & electricity on board
On long voyages, every kilowatt hour counts – energy represents comfort, freedom, and safety all at once. In this article, we'll show you how we planned, expanded, and optimized the power supply on board the SY Joline step by step: from the solar system and batteries to the Victron integration.
You will also learn how our requirements have changed over time, how we have adjusted them, what has proven successful and what has not.
We'll show you pitfalls and solutions for electricity and energy, and how we can now use solar power to cook, wash, and even power the air conditioning on board.
How much electricity is enough and how can it be generated effectively?
First of all: In my experience, the question of how much power you need on a long-distance cruise isn't easy to answer. The correct answer is, it depends. Here are the most important factors that influence the power requirements of a long-distance or blue-water yacht:
- on the type and size of the boat
- the comfort requirements and the size of the crew
- the sailing area
We've met several crews who are happy with a solar panel and have even completed an Atlantic crossing, including a watermaker, with it. At the other end of the spectrum, there are boats whose energy needs, at 6 to 8 kWh per day, are equivalent to the energy needs of a two-person household in Germany, and others that require over 2 kWh per day.
Joline’s energy requirement is now 6 to 8 kWh per day.
These include
- Cooking & Baking Electric
- Fully automatic coffee machine and kettle
- Watermaker 12 V – Schenker Zen 50
- Washing machine 8 kg capacity
- Starlink Standard Operation 24/7
- 3 refrigerators including freezer compartment (at least 2 refrigerators run continuously)
- Small consumers – pumps, lighting, chargers for notebooks, mobile phones, cameras
- Air conditioning in owner's cabin if required
- At sea additional chart plotter, radar, radio, autopilot
With our LiFePO₄ battery bank and solar cells, we are 100% self-sufficient and do not require shore power.
☀️ Our solar system
Our Lagoon 421 is equipped with over 2000 watts of solar power. The modules deliver up to 10 kWh per day in the Caribbean. Important to us:
✅ Reliable alignment and operation (rigid modules, mounting on equipment carrier and cabin roof)
✅ Optimization of power generation when shaded by mast, boom, sail
✅ Good combination with MPPT controllers, redundancy
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🔋 AGM or LiFePO₄?
We took the detour via AGM – and later converted to LiFePO₄. Why it was worth it: Spoiler alert: "The conversion to LiFePO₄ was a real game changer.
✅ Significantly higher usable capacity
✅ Faster charging
✅ Integrated BMS with balancer
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🔌 Victron configuration & energy management
We rely on Victron: MPPT, shunt, inverter, chargers. These factors were crucial:
✅ Separation of 12V and 24V systems
✅ Inverter size vs. actual consumption (e.g. air conditioner, washing machine)
✅ Energy flow monitoring via Bluetooth & app
✅ Redundancy and reliability
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