There are two factors that need to be considered when deciding which size Solar Panel kit will work best for you.
- Your average daily power consumption; The average daily power consumption can be estimated individually for each device (type of load) and added together to create an overall requirement.
- Capacity of your batteries. ; Like an Inverter, the Solar Panels work in unison with the battery bank. The larger Amperage draw loads, such as a Kettle or Coffee Maker, require the battery power to back up the Amp draw. The Solar Panels keep the batteries charges up. With our MPPT smart solar controllers, the lower the battery voltage drops, the greater the output of the power to charge the batteries.
The average daily power generated by your boat solar panel should be equal or more than the average daily power consumption of your appliances.
Best Solar Panels for Boats
For example, let’s say we got 5 hours of sunshine today. If we have a 50W solar panel on the roof of your motorhome, it will generate approximately 50W*5 = 250W/h (watt-hours) – this is almost in line with the average daily power consumption 210W/h.
There will be some losses of energy due to battery self-discharge, parasitic loads, and long power cable runs to consider as well. These are typically kept within 20% of total output. It is therefore wise to choose a solar panel for your boat or RV that offers a daily power rate of approximately 20% higher than the daily power consumption you require.
Sometimes it is difficult to estimate the daily power consumption – especially when the power rating of individual appliances is not available or have been lost. In this case we recommend the following high-level approach:
- In the case of small loads such as energy saving lighting, a stereo, mobile phone charging and low usage of a computer (2-3 hours a day), we would recommend our 100W solar panel charging kit for your boat or RV
- For larger loads or heavier use including non-energy saving light bulbs, large TVs, frequent use of water pumps or other equipment, we would recommend a larger 200-300W solar panel charging kit.
Suntech Solar Kits are also expandable! You can build the system that suits you today, and expand when your load consumption does to keep your batteries in the green!