 ## Introduction Before taking advantages of using the sun-based energy to run your boat, it is essential to see how solar panels work.

It sounds great when you learn that the function of the solar panel is to generate electrical power and subsequently charge the batteries.

However, that knowledge alone is not enough; several factors must be put into consideration before deciding to go to a marine store and risking losing your hard earned cash on either a solar panel or a wind generator.

Going for any of the top 3 solar generators for sailboats requires that you have the basics understanding of your boat first; you need to know the amount of current consumed by your boat on a daily basis while still anchored.

### Determining The Number Of Solar Panels Required

Take a list of the essential items on board the boat and find out the power in watts based on their current ratings. To calculate the power, find the product of the rated current and the system voltage, for example, most marine boats with a single fridge or freezer can use about 120A to 180A of current every day.

Assuming a moving average of 150A and 12-volt system, we can easily find the power demand which is given by 150A x 12V= 1800W. Dividing this figure by five which represents an average of 5 hours of rated power produced by solar panels when well placed, we get 1800W / 5= 360W.

Now 360W is the power that will be required to power the boat with solar panels. This computation is based on the premise that the solar panels are placed flat but if your panels can orientate for optimal sunshine, then divide the power required by 8 i.e. 1800W/8=225W assuming the day was 80% clear.

Now supposing we have a combo of both solar panel and a wind generator, we take the wind generator power and multiply by 1.5 after that subtract the result from the boats required power.

For example, if the wind power is 400W then 400Wx1.5=600W, subtracting the result from the required energy gives 1800W-600W=1200W dividing this result by 5 gives the power needed to be generated by the panels i.e. 1200W/5=240W. From the examples, you can determine the number of solar panels required based on their power ratings.

### Charge Controllers

Photovoltaic (PV) modules usually generate currents with higher voltages as compared to the batteries they are meant to charge. These high voltages cannot be tolerated by the reservoir cells for long periods as they can cause damage to them.

For this reason, the charge controller’s primary purpose is to keep the battery fully charged without causing an overcharge as well as from excessive discharge. Maximum power point tracking (MPPT) controller can sense the batteries maximum power voltage by seeking the solar panel’s maximum power point to transfer its energy.

There are other additional functions added to solar charge controllers, and this includes the protection of a battery against excessive discharge. When the lead-acid battery is deeply discharged, it will rapidly develop a Sulfate deposits on its inside electrodes services hence compromising on its capacity as well as reducing its life expectancy.