We know that we need a lot of power to have a comfortable vacation. Electricity consumption varies greatly if we are at rest, under sail with instruments, heater and autopilot in use. It also varies whether we have one or two refrigerators, are in hot climates or on a long voyage.

When the batteries start to run out, how do we charge them as quickly as possible?

Here we consider two well-known charging sources, solar panels and dynamos

Are you on a long trip where the sun is stable, solar panels are a great solution. In the banner on our website you can see a picture of a Dufor 430, 43 foot sailboat. This boat was anchored for weeks during the corona period without being able to move. With a solid solar cell system (400 watts), the boat was self-propelled. The fridge and watermaker were powered by electricity from the solar panels. It was never necessary to charge the Makspower lithium batteries with the alternator. Shore power was not available either.

On holiday in the Nordic countries
It can charge well with a good solar cell system here in the north. We got more than 100 Ah on a good day with 2 x Makspower 80 watt Semirigid solar panels placed on the deck and angled towards the sun. We have moved the solar panels after the sun throughout the day for optimal angle and charging. In the evening, we set the solar panels towards the sunrise to charge in the morning sun.
If you have larger panels, it charges more. Remember that these were optimal conditions. If there is a veil of clouds, charging is significantly reduced.
If there's no sun, there's no charging either. As we know from experience, the weather is unpredictable and so is charging.

Regardless of whether the solar panels are shade-optimized or not, they are very vulnerable to shadows. On the deck of a sailboat, shadows are everywhere and they move during sailing, when the boat turns at anchor and when the sun moves in the sky.

Installing the solar panels on the cabin roof or hatch garage, you get very little out of the panels. Solar panels are also prone to damage when they are stepped on. Although the manufacturer of the solar panels claims that they can be stepped on, it's only a matter of time before they break. Thin and flexible panels are particularly vulnerable.

Glue the panels to the deck, you won't get Sikafleks or other adhesives when the panels need to be replaced.
If you screw down the panels, there will always be marks and holes.

Consider Velcro tape instead. It sits well and the glue can be washed away later. The galecoat will be slightly discolored under the glue, but it can be bleached with galecoat cleaner.

Targa bar on the hedge is an efficient way to mount solar panels. There is little shade and you can utilize the solar panel during sailing, for the engine and when the boat is at rest.