Zardoz2525
New Member
- Joined
- Dec 1, 2021
- Messages
- 17
I am having trouble finding an all-in-one that I am confident will run the way I want.
Basics are I have an off-grid system that needs to have a must-work 24/7 side and a works-only-with-surplus side. My thought is to implement a DC side that runs off battery backup and and AC side that runs only when surplus power is available.
Specifics:
12 panels in series running 445.2 V(oc) 8.53 A(sc)
8 12V 90Ah AGM batteries in two 48V strings
A remote start AC generator in event of extended bad weather.
If power needs later require, the panels will be changed to two 12-panel banks in parallel, one SW and one SE
No comments on the battery choice please. This is a temporary setup intended to run a couple of years while the site is built out. It is more than enough power for now as my needs are not likely to be over 100 W when occupied for 1-2 days a week and more like 15 W otherwise. Once the build-out is further along and I can make a reliable prediction of what my power needs will be, which right now is way up in the air, I will switch to a Li battery system.
The location will be mostly used by me, carefully monitoring energy use, but will occasionally be used by guests who will consume electricity with wild abandon. I also have a few AC systems that only need to run during peak daylight hours (plus some power tools for building).
My thought is to have a 48 DC system that runs off the batteries, which have priority on any power usage (with a DC-DC converter for a few items that will run on 12V DC). Other than a few USB charger ports, all DC demands will be hardwired in and have very predictable power requirements.
Once batteries are fully charged the inverter will be switched on and unrestricted AC power available via standard wall outlets.
I am OK with the batteries being used to maintain AC power levels against a dropoff from a passing cloud, but if they are drained more than a few minutes or a few percent, the AC should be shut off until the batteries are fully charged again. The generator should only be used to charge up the DC system. If someone wants to overuse the AC system, they just don't have power.
An alternative would be to have two battery banks, one which is charged first and then kept isolated to run DC and one which is charged second which is tied to the inverter to smooth out AC power. AC should be disabled when battery charge is below a minimum.
I can see good ways to do this using separate components but I prefer an all-in-one for better monitoring as this is also a bit of an experiment to define needs for the next system and I like the consolidated monitoring & reporting capabilities. I find some systems that look like they might be able to isolated the DC system from the AC like I want, but nothing I am 100% sure would work. Can anyone provide a suggestion for a system they are certain will work the way I want?
Basics are I have an off-grid system that needs to have a must-work 24/7 side and a works-only-with-surplus side. My thought is to implement a DC side that runs off battery backup and and AC side that runs only when surplus power is available.
Specifics:
12 panels in series running 445.2 V(oc) 8.53 A(sc)
8 12V 90Ah AGM batteries in two 48V strings
A remote start AC generator in event of extended bad weather.
If power needs later require, the panels will be changed to two 12-panel banks in parallel, one SW and one SE
No comments on the battery choice please. This is a temporary setup intended to run a couple of years while the site is built out. It is more than enough power for now as my needs are not likely to be over 100 W when occupied for 1-2 days a week and more like 15 W otherwise. Once the build-out is further along and I can make a reliable prediction of what my power needs will be, which right now is way up in the air, I will switch to a Li battery system.
The location will be mostly used by me, carefully monitoring energy use, but will occasionally be used by guests who will consume electricity with wild abandon. I also have a few AC systems that only need to run during peak daylight hours (plus some power tools for building).
My thought is to have a 48 DC system that runs off the batteries, which have priority on any power usage (with a DC-DC converter for a few items that will run on 12V DC). Other than a few USB charger ports, all DC demands will be hardwired in and have very predictable power requirements.
Once batteries are fully charged the inverter will be switched on and unrestricted AC power available via standard wall outlets.
I am OK with the batteries being used to maintain AC power levels against a dropoff from a passing cloud, but if they are drained more than a few minutes or a few percent, the AC should be shut off until the batteries are fully charged again. The generator should only be used to charge up the DC system. If someone wants to overuse the AC system, they just don't have power.
An alternative would be to have two battery banks, one which is charged first and then kept isolated to run DC and one which is charged second which is tied to the inverter to smooth out AC power. AC should be disabled when battery charge is below a minimum.
I can see good ways to do this using separate components but I prefer an all-in-one for better monitoring as this is also a bit of an experiment to define needs for the next system and I like the consolidated monitoring & reporting capabilities. I find some systems that look like they might be able to isolated the DC system from the AC like I want, but nothing I am 100% sure would work. Can anyone provide a suggestion for a system they are certain will work the way I want?
