Hi from Puerto Rico. Setting up an apartment project to learn solar for a boat.

[BigCharlie]

Hi y'all,

I moved to Puerto Rico to learn to sail. I want a 30-40 foot boat to live aboard and work -- as green as possible removing the diesel engine so no alternator.

Until I get the boat and make it ready, I live in an apartment and think it's a great time to learn about solar and electrical engineering. I don't have access to the roof, but the apartment is south-facing and has a ledge where I can put a couple of solar panels for about 5 hours of direct sunlight a day.

My project is to build a two-panel solar array to power my computers:
A laptop and monitor, a small server, 5+ raspberry pi's, a couple of ethernet switches, and a router -- attaching them directly to the inverter topping off the batteries with a battery charger overnight, if needed. The computers do not run 24/7.

I plan to create a dashboard with home-assistant.io to monitor battery state and appliance usage.
There seem to be some cool options: https://www.home-assistant.io/integrations/#energy

So far I've bought:

• One Renogy Flexible Solar Panel 175 Watt (I plan to buy a second next month). Not knowing the boat I'm buying, I bought the flexible panels because they offer a greater chance of reuse on a boat
• Giandel 2200W with 20A Solar Charge Control
• Two Interstate deep cycle 12v 105AH (I plan to buy two more)
• Outerman Car Battery Charger
• Kill A Watt

 

[sunshine_eggo]

Hi y'all,

I moved to Puerto Rico to learn to sail. I want a 30-40 foot boat to live aboard and work -- as green as possible removing the diesel engine so no alternator.

Until I get the boat and make it ready, I live in an apartment and think it's a great time to learn about solar and electrical engineering. I don't have access to the roof, but the apartment is south-facing and has a ledge where I can put a couple of solar panels for about 5 hours of direct sunlight a day.

Could be worse, but you may find your exposure is very disappointing. hopefully, you're getting 5 hours of unshaded exposure centered on noon for peak power, i.e., full solar from 9:30am to 2:30pm.

My project is to build a two-panel solar array to power my computers:
A laptop and monitor, a small server, 5+ raspberry pi's, a couple of ethernet switches, and a router -- attaching them directly to the inverter topping off the batteries with a battery charger overnight, if needed. The computers do not run 24/7.

You need to estimate what your daily kWh consumption will be.

I plan to create a dashboard with home-assistant.io to monitor battery state and appliance usage.
There seem to be some cool options: https://www.home-assistant.io/integrations/#energy

So far I've bought:

• One Renogy Flexible Solar Panel 175 Watt (I plan to buy a second next month). Not knowing the boat I'm buying, I bought the flexible panels because they offer a greater chance of reuse on a boat

Flexible panels tend to have poor service life. The only ones worth having in a permanent installation are "ETFE" coated, typically have a 5 year manufacturing warranty and a 20+ year performance warranty. Directly affixing them to a surface where they can't shed heat will kill them faster.

Just guessing, but I expect your 175W panel can only capture about 600Wh/day - assuming about 70% of an unshaded day's worth of sun.

• Giandel 2200W with 20A Solar Charge Control

The 2200W is probably overkill for your needs. The only concerns are:
1) operating inverters at a small percentage of their rated continuous output are notably less efficient than their published maximum. Maximum efficiency is around 30% of rated.
2) bigger inverters use more idle power just by being on. I believe the Giandel tend to be pretty good in this area.

• Two Interstate deep cycle 12v 105AH (I plan to buy two more)

That gives you 12V * 105Ah * 2 * 50% = 1260Wh of usable energy (only using 50%).

• Outerman Car Battery Charger

No idea what that is or if it's a good idea. You need to make sure it charges at the appropriate voltage for your batteries.

• Kill A Watt

This is the most important item you have purchased.

 

[12VoltInstalls]

removing the diesel engine so no alternator.

I’d advise against that.
Just don’t use it but know it’s there. I’d even go so far as to put a too-big alternator on it for Justin. Justin Case.

Aux power in a bad situation can save a life. Or perhaps your own barge and butt.

 

[BigCharlie]

BigCharlie said:
Outerman Car Battery Charger

No idea what that is or if it's a good idea. You need to make sure it charges at the appropriate voltage for your batteries.

Thanks for the response, man.

About the battery charger. Inexpensive not name brand. It's a 110-240v 12/24v 10 amp charger.

The purpose is to simulate a larger solar array. The computers will not be plugged into the wall so I don't want to come up short. This 1-2 panel setup is temporary for a few months until I move to a boat.

Are there some considerations when attaching a charger onto batteries other than just clamping them on?

 

[BigCharlie]

I’d advise against that.
Just don’t use it but know it’s there. I’d even go so far as to put a too-big alternator on it for Justin. Justin Case.

Aux power in a bad situation can save a life. Or perhaps your own barge and butt.

The idea is to replace the diesel with an electric motor. That's to be determined, I don't know enough about sailing, electric motors, or electric storage to make that call yet, but it's an ideal I'm shooting for.

But yeah, CYA is near the top of the list.

 

[12VoltInstalls]

don't know enough about sailing, electric motors, or electric storage to make that call yet, but it's an ideal I'm shooting for.

I don’t know either.
Been around a lot of powerboats/fishing boats under 24’ mostly. Freshwater stuff.

At least from big water freshwater lakes I’m sure ditching that diesel being a green sailhand doesn’t even sniff of a good idea. Bluewater when it’s fair ain’t too big of a deal but reefs, anchorages, coastal inlets, and running sounds as a newbie I think it want a good digger twisting the prop in a keel boat. Once you have 15- or 20 thousand nautical behind the transom maybe then electrify.
My thoughts- do as you will but you gotta be smarter than the seafoam