Solar generator or solar power humidifier

I have a cabin on the gulf coast on a river …. It’s quite humid here ….. I want to install a dehumidifier anyone have any experience with doing this and what’s the best option…. My cabin is 24 x24 high ceilings …..

My suggestion would be to go with a 24, or 48V AC cabin system.  The single cheapest components right now are solar panels.  Don't buy little 12V panels you see online.  You get far more bang for your buck going with large residential panels in the 250-350W range.  With a good MPPT controller, a series string of several large panels will be transformed down to battery charging voltage, making extra charging amps out of the extra volts.

Some may recommend a 12V RV style system, but I'd say that's a mistake.  12V is just too limiting.  As you scale up to higher system voltages, you gain a LOT of capacity.  My 48V cabin system can run my 240VAC well pump.  It's a 1hp Grunfos.

Where you need to start is with an itemized list of everything you want to power.  Start with the dehumidifier, but also include lights, TV, the computer, a refrigerator, an air-conditioner.  Add up the Watts per day you think you might need, and then plan from there.

Just keeping the lights and TV on, with a refrigerator running in the background, I'd suggest you'd need about 3kWh of power per day.  Remember that the inverter being on consumes power even if nothing is turned on.  Some of the cheaper AllinOne inverters (AiO) can consume more than 100W per hour, which works out to be >2.4kWh of power per day, just leaving the inverter on.

Here is a quick list of things to make a whole-cabin system that will power what I'm mentioning.

Four 6V golf-cart batteries, wired in series for 24V  CostCo has a 210Ah battery for 110$ now.
Four 250W 30V residential panels.  About 50$ each on Craigslist right now, more or less depending on your location.  Don't buy online panels.  Buy locally with cash and carry purchase.
40A MPPT charge controller.  Epever makes a budget model called the Tracer 4210AN for 125$.  For a bit more money, you could get the 5415AN, or Triron4215N, which have significantly higher voltage limits.
Sine-Wave inverter.  Don't be tempted by cheap MSW models.  They will shortly burn out anything running an electric motor.  The Samlex PST2000 is UL listed.  Cheaper inverters are not.  I have a Conext SW4024.  It can make both 120V and 240VAC.

The system I'm describing might be a bit large for only a dehumidifier, but is far more scaleable than a simple 12V system.  Being a component system, it can grow by adding/replacing individual parts one by one.

Wow, Michael has given you some really good advice.

My solution would be to use a product sold at most hardware stores called Damp Rid:

https://permies.com/t/62494/Passive-dehumidification-control-mold-grid

https://permies.com/t/162929/Humid-Pantry-problems

https://permies.com/t/150487/Desiccant-Compressor-dehumidifiers

Ben,

I would love to add in my own input on this topic as I am currently working on my own project that parallels your project.  However, I would find it hard to say anything better than what Michael has already stated.  Take special note about the solar panels being the cheap point of the system right now--in the past, solar panels were the most expensive component.  Also, a true, MPPT controller is a good investment.  Just make certain it is actually a true MPPT controller as there exist brands out there whose name is "MPPT" and sell a cheap controller but it is not a functional MPPT controller.  Buyer beware.

Good luck,

Eric

That is very true.  Fake MPPT controllers are out there, and a previous Permies poster was one victim.  There are a couple of ways to spot the fakes.  First, if it gives max voltages that are different for 12V batteries, and 24V ones, that's one clue.  Another clue is a max voltage <100V.  I believe no-one is marketing a real MPPT controller with a max voltage less than 100V.  Another clue for one maker is the presence of USB ports on the front of the controller.  Lastly, is shipping weight.  MPPT controllers have big toroid rings of thick copper wire for the voltage transformation, that add considerable weight to the total.  So, if a controller has a shipping weight of just 8oz, it's fake.  If it weighs 5-10lbs, then it's likely to be a real MPPT.

Michael Qulek wrote:  So, if a controller has a shipping weight of just 8oz, it's fake.  If it weighs 5-10lbs, then it's likely to be a real MPPT.

That is a fantastic point, I never considered looking at the weight. I'm going to have to keep that in mind for the future.

One option to consider that hasn’t been suggested yet is a direct DC mini split air conditioner. These are relatively new and getting affordable. They can run 4-8modern 360-400w solar panels straight into the unit depending on voltages and AC size. They always dehumidify, and can keep a stable temp and humidity as long as the sun shines. Many have remote app control if that’s something you care about.

If your primary goal is to keep humidity down, and you don’t care about a versatile system that also makes home electricity I wouldn’t hesitate to get one of these newer Dc solar mini splits. They’re quite good. I’ve installed quite a few and the customers are happy with them.