So confused! Batteries/generators

[CamWrenRoo]

Hey folks!
So, we want to set up a fantastic solar set up, but were are considering waiting until next year so we can "do it right," aka wait until we've saved up more money.
We will be living at a marina most of the time, but we want the option to live on anchor/mooring if we want to. So we'll take advantage of shore power, but want to be fully able to meet our electrical needs if we change the plan. That is, after all, one of the best things about having a home that moves!
Our boat came with a brand new, not yet installed Webasto 12000 btu fcf air con/heat pump system, ready to install with all needed equipment on board. It also has a barber alder fridge/freezer. Clearly, we can't run those things on solar unless if we cover our boat in solar panels (Imagine a floating version of the space station...). So, I'm thinking a generator/inverter might be a good option. There are several out there on the market, and the ones I'm considering are in the 1500-2000 running watt range. The ac pulls 8.5 amps. If I'm understanding it right, the ac needs to be directly wired into the boat's ac power system. This, too baffles me.

So, here's what I'm trying to understand:
A- Do I need a "house battery bank" like one I would use for solar? If so, how many amps worth of battery do I need?
B- Is a 1500 watt generator enough to run the ac plus other things on board? Our other power consumption is pretty light. We'll be on the Chesapeake, so having heat in the winter is important to us, and I'd like to use the ac to do this.
C - Do I need just a generator, or a generator inverter? Do I use the generator to fill up my batteries, and then run off that? Or would I need to run the generator all the time to have ac or heat going?

I honestly am a novice at this kind of thing, so any help you could provide with these naive questions would be so awesome.
Thanks!

[billknny]

Your questions are very difficult to answer with any authority since I have no idea what kind or size of boat you have.

Originally Posted by CamWrenRoo

A- Do I need a "house battery bank" like one I would use for solar? If so, how many amps worth of battery do I need? !

You do not need a separate "house bank" to run an AC unit.

Originally Posted by CamWrenRoo

B- Is a 1500 watt generator enough to run the ac plus other things on board? Our other power consumption is pretty light. We'll be on the Chesapeake, so having heat in the winter is important to us, and I'd like to use the ac to do this.

Almost certainly NOT. AC units draw 2 to 4 times the amps they need to run when the compressor starts. Unlike shore power, generators and inverters can not deliver power above what is on the spec sheet for even a few seconds.

Originally Posted by CamWrenRoo

C - Do I need just a generator, or a generator inverter? Do I use the generator to fill up my batteries, and then run off that? Or would I need to run the generator all the time to have ac or heat going?

It would be very difficult to have a battery bank big enough to run a 12,000BTU AC unit for more than a couple hours. Unless you are going to get pretty exotic, you'll be running the generator when ever the AC is being used.

You might also be disappointed with the performance of the heat pump in a cold winter, like 2 years ago. Most of the ones I am familiar need the surrounding water temperature to be at least 40F to generate heat. Having seen the Chesapeake pretty well frozen, I am betting it gets colder than that.

Finally, if the idea of wiring an AC unit into the boat's power system baffles you, get a knowledgable marine electrician to install things for you. This is NOT a place to learn by trial and error.

On the bright side, a fridge freezer should be able to be powered by solar without a problem. Typically, a 400 watt solar panel system would be enough for one fridge, although maybe not in the depths of winter at your latitude.

[Stu Jackson]

None of us was born an electrician. That's why most of us, who ALL started out where you now are, bought books and studied the subject. You really should buy a few boating electrical books. Start with Charlie Wing's:
https://www.amazon.com/Boatowners-Il...s%2C432&sr=8-3