I have 200 watts, 1000 inverter, 2 100ah batteries, pwm charge controller all 12v. I am looking to upgrade the system. I am not good with numbers, math, engineering and am seeking help. All I power right now is lights. This is off grid. I want to be able to power a fridge/freezer, lights, washer, dryer, well pump, fireplace heater, fan and dishwasher in addition to lights. It wouldnt need to be all at the same time except the fridge/freezer would be constant. I read reviews and saw that 1000watts of solar panels, 40amp charge controller, 3000 watt inverter and 4 100ah batteries would be sufficient. I dont know where I saw the review now and am unsure of what I am doing. I have 10 12v 100 watt solar panels. How do I connect them? Will that require additional connection wires? I have 4 12v 100ah lithium batteries. I have a 40amp mppt charge controller which now I am doubting thinking I might need double that. And I am stumped when it comes to the inverter. Why are some so expensive and others not? Is 3000 watts what I need? Should it be more or less than that? And the most important thing is connections between all of these for performance and safety. What size wire? Are all battery cables the same or should those be sized too? How do I connect 10 solar panels down to one cable? Should I connect in series and in parallel to make a 24v system because 12v will be inadequate? I am unsure of so many things and would appreciate some type of guidance or advice please.
Solar upgrade question, I am new to this
- Thread starter Tbleppy
- Start date
if you want to learn - people here can help.
First things first - STOP - don’t buy anything else until you know what you need. This will be a process - not a quick answer.
The system you say you are wanting is a complex but doable system. It will have a couple of different parts; You will have the Loads. How much power will you use at once and for how long. You will have the Battery size, and you will need to refill that battery.
Let’s start with the first step. The Loads. In order to buy the right sized inverter we need to know the largest amount of power (in watts) that it will power. Also, how long i(in hours) each load will run in a day.
The best method for finding out how many watts are used is to use a “kill-a-watt”. This will measure the watts while you use something. If that’s not available- you need to look at each item’s nameplate or owners manual and find out how many watts or amps it uses.
To convert amps to watts you multiply the amps times the voltage. For example, a hairdryer might say it is 1500watts or it might say 12.5 amps. 12.5 amps *120volts = 1500 watts. You use the hairdryer for 6 minutes a day - which is 1/10th of an hour- so report it as:
Hairdryer 120v - 1500 watts - 1/10th of hour per day.
Do that for all the items on your list. When on batteries, power capacity is very expensive- so if you don’t need something - cut it off the list.
Good Luck
First things first - STOP - don’t buy anything else until you know what you need. This will be a process - not a quick answer.
The system you say you are wanting is a complex but doable system. It will have a couple of different parts; You will have the Loads. How much power will you use at once and for how long. You will have the Battery size, and you will need to refill that battery.
Let’s start with the first step. The Loads. In order to buy the right sized inverter we need to know the largest amount of power (in watts) that it will power. Also, how long i(in hours) each load will run in a day.
The best method for finding out how many watts are used is to use a “kill-a-watt”. This will measure the watts while you use something. If that’s not available- you need to look at each item’s nameplate or owners manual and find out how many watts or amps it uses.
To convert amps to watts you multiply the amps times the voltage. For example, a hairdryer might say it is 1500watts or it might say 12.5 amps. 12.5 amps *120volts = 1500 watts. You use the hairdryer for 6 minutes a day - which is 1/10th of an hour- so report it as:
Hairdryer 120v - 1500 watts - 1/10th of hour per day.
Do that for all the items on your list. When on batteries, power capacity is very expensive- so if you don’t need something - cut it off the list.
Good Luck
Thanks for your help with this. I am having a difficult time with evaluating my loads because none of the appliances have been purchased yet. I took your advice on eliminating what I can as well. If I just focus on a freezer, that is my main need. I found a chest freezer that says this: powered via AC (1A) or DC (5.5A/2.75A) power. I took the 1A AC because I dont know how to do DC. 1 x 120v= 120watts x 1000 is 1200watts per hour. Is that calculation correct?
pollenface
Solar Addict
If you look at the annual energy ratings on the manufacturers website of the appliances you're interested in running it will give you a starting point.
(Eg. My TV is rated to use 270kwh a year based on 10hrs of use a day = 74w/hr)
(Eg. My TV is rated to use 270kwh a year based on 10hrs of use a day = 74w/hr)
That freezer at 5.5ah @12v dc - will not use a lot of power. That’s only 66 watts. 132 ah for 24 hours. Your current system can probably handle it and some lights - especially if you turn off the freezer at night and let it coast. I would definitely get a battery monitor so you know what’s happening with the battery.
Well Pump, dishwasher, washer/dryer, fireplace heater - these are your large draws and will take much more power than a 1000w inverter can supply. How much more - I don’t know - that’s why we need to figure out the power information.
It also depends on how you want to live in this off grid place. If you are ok living large when the sun shines and little power when no sun - then you want a larger solar array, with a good inverter, but a smaller battery. That is the most cost effective.
Well Pump, dishwasher, washer/dryer, fireplace heater - these are your large draws and will take much more power than a 1000w inverter can supply. How much more - I don’t know - that’s why we need to figure out the power information.
It also depends on how you want to live in this off grid place. If you are ok living large when the sun shines and little power when no sun - then you want a larger solar array, with a good inverter, but a smaller battery. That is the most cost effective.
