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If you are planning on living aboard your houseboat or are just looking to save money on fuel by not running your generator as often or at all then solar is a great way to produce the power that you need for your houseboat.
Choosing a houseboat solar system comes down to how much power you will need at a time and how flexible you can be on that power usage. For example, if you have a solar panel that produces 300 watts but it is partly cloudy the amount of electricity that is being produced will be significantly reduced. According to this study 87% cloud cover will reduce the amount of power produced by 50%.
To fit one 300 watt panel, you will need a location that is approximately 5ft x 3 ½ ft. 300 watts isn’t very much power so most people would want three or four panels. Assuming you aren’t going to try and run an AC unit you will want approximately 1,000 watts to power all of the appliances and electronics on board your boat.
Houseboat Solar System
Unless you have set up a solar system before you might not realize that there are four main things that you need for your system to operate properly. You will need
- Solar panels
- Solar batteries
- An inverter
- A charge controller
All four of these things are required for your solar system to work properly. If you have panels and an inverter but no batteries you will only have power during the daytime. If you have panels and batteries but no inverter then your power will only be in DC and won’t be able to power most of the things on board your boat.
Having all four things is a must to setup your houseboat’s system properly. Solar systems are quite an endeavor so don’t think that you can just order any solar panel online and be set up in a couple of minutes. It requires some planning ahead as well as making sure you have the right products for your system.
Boat Solar Panels
When you are going to set up solar the first thing to look at is which panels you like and how many panels you need to provide enough power. From the people I have surveyed the average houseboat owner will want 1,000 to 1,500 watts of electricity produced. Of course that can vary greatly depending on how “off grid” you are wanting to live or if having a TV, computer, cell phone, air conditioner, etc. are all requirements for you. Remember the more things you have plugged in the more panels you will need.
Assuming that you purchase 300w panels the average houseboat owner will need 4-5 panels to cover their usage and have a little extra electricity stored to cover their overnight needs. If you have room for larger panels or more panels it isn’t a bad idea to have extra. Each 300w panel will run you $300-$400 so an extra panel isn’t too much extra cost if you have the space available to mount it.
Boat Solar Batteries
The next thing that you will need is that now that you have solar panels producing electricity you need to have power at night as well. Obviously you won’t be producing solar overnight so you will either need to use a fuel powered generator or have batteries that you can use to store power during the day.
There are a two main battery types that are commonly used with solar. They are lead acid and lithium. Both types of batteries have their pros and cons so ultimately you will have to decide which works best with your budget and for the way you intend to use your houseboat.
Lead acid are the most inexpensive option but they also have a far shorter lifespan than their lithium counterpart. Lithium solar batteries are quite expensive but have a much longer life cycle and can often last 10-15 years before they need replacing.
When you think of solar batteries many people think they can just go out and buy some car batteries and they will be good to go. Unfortunately that really isn’t the case. There are quite a few differences between a normal car battery and a battery designed for solar.
A car battery is designed to supply a large amount of power for a short period of time to allow your car to start. Once your car is started the battery is then recharged to become ready for the next use.
A solar battery is a “deep cycle” battery which is designed to provide a lower current for a much longer period of time (such as overnight). A deep cycle battery is also made so you can run it almost entirely dead over and over again without the battery becoming damaged.
Now that you know which battery you need to purchase the question becomes how many do you need? Unfortunately the answer isn’t black and white. Knowing how many batteries or how big of a battery you need requires you to know how much power you will use overnight.
If I assume that you will need 300 watts an hour overnight and you have 10 hours of darkness then you will need battery capacity for 3,000 watts. If you use less or more than that you will will have to adjust accordingly.
Now there is a problem, most batteries have a volt and amp hours listed not watts. How do you know how many watts each battery will hold? You simply multiply the volts by the amp hours and that is how many watts the battery can hold. If you find a battery that is 12v and 100ah then you know you have 1,200 watts from that battery. If you need 3,000 watts overnight then you will need to have 3 of those batteries to run your boat off of while it is dark.
The other way to know how many batteries you need is simply trial and error. Perhaps you are ok with all of the electronics being off overnight and since no one is opening and closing the fridge you assume that it won’t take much power. You could purchase one battery and hope that it is fine for your overnight needs.
If it is… GREAT, if not then you just buy another one. Some people choose this route to try to save a little money and that works fine as well. As long as you are ok with some hassle you can certainly go this route if you choose.
Boat Solar Inverter
The last thing that you need to take your houseboat solar is an inverter. An inverter is what takes the current from your solar panels (DC) and changes it into usable electricity for your normal devices (AC). There are some items on board a boat that can run off of DC current but most everything that you encounter uses AC current.
The computer I’m using to write this article uses AC current to charge it. The ceiling fan that is turning above my head uses AC current. Everything inside my house uses AC current to work as well. Since most of the items on board your boat will be traditional products they will all require AC current to operate.
That is why you need an inverter!
Inverters are all rated with the load that they can handle putting out. If you have 3,000 watts coming in from your solar but have an inverter that can only handle putting out 1,000 watts your system won’t work very well. As with anything, it is better to have an inverter that is a little too big than to have one that isn’t big enough.
Solar Charge Controller
The last main thing you will need for your solar system is the charge controller. This device is designed to make sure the current coming from your panels is regulated and doesn’t overcharge your batteries. Most solar panels will put out 15-20 volts which can harm your batteries if the charge isn’t controlled. The controller will only allow enough charge to go through to your batteries to charge them as much as possible without damaging them.
The charge controller also blocks reverse current to keep the batteries from losing some of their charge back to the solar panels during nighttime hours.
The charge controller is an important part of your solar setup that many people don’t even realize that they need until their batteries explode or become damaged due to overcharging.
If all of this sounds like a lot of work to get solar set up that’s because it is! Setting up a solar system on your houseboat is a far cry from something that can be done in a few minutes before hitting the water.
If you don’t want to worry about finding all of the correct items, wires, etc. then you can just buy a solar kit. There are many places where you can buy kits that include everything you need to get your solar on your boat up and running in one easy purchase.
If you choose to go the kit route make sure you know what is included as some kits don’t come with the batteries that you need to store the power and other kits do. Just be sure that you are comparing apples to apples when you make your decision.
Installing solar on houseboat can be a great investment and can pay off in a big way as long as you do your research and plan ahead. This is especially true if you are planning on living on board your houseboat for a few weeks or even full time. Only needing to use fuel when you move your houseboat is a nice way to save some serious money in the long run