Solar panels are an excellent way to generate power on a boat, especially in Thailand, where you get high solar exposure year-round. With the right setup, you can comfortably run a refrigerator and other essential systems without relying too much on the engine or shore power.
How Much Solar Power Can You Expect in Thailand?
Thailand is in the tropics (6°–20° latitude), meaning it gets strong, consistent sunlight year-round. The average solar irradiance is around 5.5 to 6.5 kWh/m² per day, meaning well-positioned solar panels can produce excellent power output.
A well-installed 100W solar panel in Thailand will generate around 400–500Wh per day, assuming minimal shading and good panel orientation.
Solar Panel Size | Daily Power Output in Thailand (Estimate) |
100W | 400–500 Wh |
200W | 800–1,000 Wh |
300W | 1,200–1,500 Wh |
400W | 1,600–2,000 Wh |
600W | 2,400–3,000 Wh |
A typical cruising yacht (30–60 feet) can fit between 300W and 800W of solar, depending on available deck space and solar arch installations.
Running a Fridge on Solar Power
Marine fridges draw 30–50Ah per day (12V system), depending on insulation, ambient temperature, and compressor efficiency.
A small 12V fridge (~40L): ~30Ah/day (~360Wh)
A mid-sized 12V fridge (~80L): ~50Ah/day (~600Wh)
A large 12V fridge (~130L): ~70Ah/day (~850Wh)
How Much Solar Do You Need?
To run a fridge solely on solar, you need at least:
300W of solar for a small fridge (with some extra power for lights, charging, etc.).
400–600W of solar for a mid-sized fridge and other loads.
600–800W of solar if you have a fridge + freezer + other electrical loads.
Other Factors to Consider
Battery Bank Size:
Since solar is inconsistent at night, you'll need enough lithium or AGM batteries to store energy for the fridge and other essentials.
A 200Ah lithium battery (~2,400Wh) is a good starting point for running a fridge overnight.
MPPT Solar Charge Controller:
Always use an MPPT (Maximum Power Point Tracking) controller (e.g., Victron, Renogy) to maximize solar efficiency.
Shading & Panel Placement:
On a small yacht, panels should be mounted on an arch, hardtop, or deck with minimal shading from the boom or rigging.
Hybrid Charging (Engine & Shore Power):
If you have cloudy days, you may still need engine alternator charging or shore power to top up the batteries.
Final Thoughts
In Thailand, a well-designed 400W–600W solar setup can reliably run a marine fridge, charge small electronics, and power lights and navigation equipment. If you're running more loads (freezer, inverter, watermaker, etc.), you'll need a larger array and battery bank.
Would you like recommendations on specific panels, controllers, or installation tips for your boat? Give us a call or drop in to our Ocean Marina Jomtien store.
Powering the Modern Yacht: Electrical Systems for the 21st Century
At Buzzcats Electrical, we specialize in bringing cutting-edge technology to small yachts and pleasure boats, ensuring owners get the most efficient, reliable, and future-proof electrical systems. The marine industry is rapidly evolving, and traditional setups are being replaced by smart energy solutions, lithium power banks, high-efficiency charging, and integrated digital monitoring.
In this series, we’ll share our expertise on how modern electrical advancements are transforming boating. Whether you're looking to upgrade your power system, improve energy efficiency, or integrate the latest tech, we’ll guide you through the essential innovations that make boating smarter and more sustainable.
Stay tuned each month as Buzzcats Electrical explores the latest trends, practical upgrades, and expert insights to help you navigate the future of marine power with confidence.
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