Hi, folks.
First post, as I am new to the forum and the world of residential backup power systems. I have been watching videos, reading posts, and working to formulate a plan to meet my needs. However, before starting to purchase components, I wanted to document what I am thinking of at a high level, and hopefully tap into the expertise of the group in order to minimize dumb mistakes. First of all, I'd like to acknowledge what a great resource this forum is, and thank everyone in advance for any assistance you can provide. A quick bit of background:
I live on a rural property fairly close to town, but without water, sewer or natural gas services. Obviously, this means that we have a well pump (1hp), and we also have a 1hp sewage grinder, plus two 1/3hp sump pumps. Until recently, we had a functioning Generac 7kW standby generator, which had been fairly trouble free for the 6 years it has been in service. However, on December 26th, it grenaded, leaving us operating on our backup portable generator and extension cords (until we get a better solution in place). Unfortunately, Generac has no parts available for the unit, so repair is impractical, and we need to come up with a better solution. While the current emergency power setup is not ideal, it is workable for the short term, so I am taking this opportunity to carefully consider our needs, and build a cohesive plan for a more resilient standby power system.
After a fair amount of research and careful consideration, I believe that the best solution for us is to install a 48v all-in-one system of sufficient capacity to support the critical loads, plus a few additional comforts (a few lights and a couple of outlets). Fortunately, our climate tends to be relatively moderate (at both extremes), so we don't need to be overly concerned about either heat or AC, and we're less concerned about comforts than just keeping the basics running. In addition to this, I'm planning on having an auto start generator that we can use for recharging batteries during extended power outages. Most outages in our area are <4 hours, but they can sometimes extend (Christmas Eve was more than 14 hours). As a further layer of redundancy, I am planning to maintain the existing transfer switch to allow the generator to be manually redirected to support the critical loads directly if the inverter ever fails. We're not immediately planning on solar, but like having the option, and will probably explore that further in the near future. For now, the priority is to get a reliable, automated, backup power solution in place, with normal replenishment through the grid, and generator backup as needed. Minimizing cost is important, but simplicity and reliability are the primary objective.
In the current setup, only the sump pumps, grinder, a few lights, and a couple of plugs have emergency power, but we would like to add refrigerator, freezer and well pump, at minimum. So, our emergency power needs look like something this:
With the assumption that not everything will running at the same time, and based upon the surge capacity of the unit, I'm leaning towards the following components, and would appreciate any feedback on my thinking:
- Growatt 6000T.
- Fortune LiFePO4 100AH cells. I'd be interested in hearing about recommended capacity and configuration.
- Overkill BMS (model appropriate for final battery configuration)
- Standalone charger to be powered by generator on demand from the 6000T.
The reason I am planning for a separate charger is that the generator is an 8000w (10,000w surge) unit that doesn't have the capacity to support the various loads (especially with startup) and the recharging load. Also, this is not an inverter generator, so the power isn't clean, and it probably isn't fantastic for the pumps over time. Configured this way, everything operates on inverter, taking advantage of clean power and 18,000w surge capacity, and the generator will just kick in as necessary to charge the batteries independently of the power situation. I'm also suspecting that a consistent charging load on the generator might be healthier for it over a constantly-changing load, not to mention that it will have to run much less than if it were supporting the loads directly.
Hoping to get input on a few questions:
1. Am I understanding things correctly? I'm still very much in learning mode, so please feel free to poke holes in my logic, or fill on obvious gaps.
2. Am I sizing the all-in-one unit correctly? I have read that it should be sized at about 70% of the anticipated combined run load, and I have gone larger than that, but should I go larger?
3. Based upon my obectives (reliability first, but minimizing costs where it make sense), are these components recommended, or should I be looking at others?
4. Does anyone know if the Growatt unit will immediately turn off the generator dry contact if grid power returns?
5. If the answer is no, are there any issues with running a separate charger in tandem with the inverter charger when grid power returns?
6. Based upon generator capacity, what standalone chargers might be recommended to recharge batteries during an extended outage?
7. If I understand correctly, the Growatt 6000T is an off-grid unit, so it should not be capable of feeding power back to the grid, correct?
Apologies for the long first post, but I wanted to try to provide as much info as possible up front. Looking forward to any input.
Cheers,
Shaun
First post, as I am new to the forum and the world of residential backup power systems. I have been watching videos, reading posts, and working to formulate a plan to meet my needs. However, before starting to purchase components, I wanted to document what I am thinking of at a high level, and hopefully tap into the expertise of the group in order to minimize dumb mistakes. First of all, I'd like to acknowledge what a great resource this forum is, and thank everyone in advance for any assistance you can provide. A quick bit of background:
I live on a rural property fairly close to town, but without water, sewer or natural gas services. Obviously, this means that we have a well pump (1hp), and we also have a 1hp sewage grinder, plus two 1/3hp sump pumps. Until recently, we had a functioning Generac 7kW standby generator, which had been fairly trouble free for the 6 years it has been in service. However, on December 26th, it grenaded, leaving us operating on our backup portable generator and extension cords (until we get a better solution in place). Unfortunately, Generac has no parts available for the unit, so repair is impractical, and we need to come up with a better solution. While the current emergency power setup is not ideal, it is workable for the short term, so I am taking this opportunity to carefully consider our needs, and build a cohesive plan for a more resilient standby power system.
After a fair amount of research and careful consideration, I believe that the best solution for us is to install a 48v all-in-one system of sufficient capacity to support the critical loads, plus a few additional comforts (a few lights and a couple of outlets). Fortunately, our climate tends to be relatively moderate (at both extremes), so we don't need to be overly concerned about either heat or AC, and we're less concerned about comforts than just keeping the basics running. In addition to this, I'm planning on having an auto start generator that we can use for recharging batteries during extended power outages. Most outages in our area are <4 hours, but they can sometimes extend (Christmas Eve was more than 14 hours). As a further layer of redundancy, I am planning to maintain the existing transfer switch to allow the generator to be manually redirected to support the critical loads directly if the inverter ever fails. We're not immediately planning on solar, but like having the option, and will probably explore that further in the near future. For now, the priority is to get a reliable, automated, backup power solution in place, with normal replenishment through the grid, and generator backup as needed. Minimizing cost is important, but simplicity and reliability are the primary objective.
In the current setup, only the sump pumps, grinder, a few lights, and a couple of plugs have emergency power, but we would like to add refrigerator, freezer and well pump, at minimum. So, our emergency power needs look like something this:
With the assumption that not everything will running at the same time, and based upon the surge capacity of the unit, I'm leaning towards the following components, and would appreciate any feedback on my thinking:
- Growatt 6000T.
- Fortune LiFePO4 100AH cells. I'd be interested in hearing about recommended capacity and configuration.
- Overkill BMS (model appropriate for final battery configuration)
- Standalone charger to be powered by generator on demand from the 6000T.
The reason I am planning for a separate charger is that the generator is an 8000w (10,000w surge) unit that doesn't have the capacity to support the various loads (especially with startup) and the recharging load. Also, this is not an inverter generator, so the power isn't clean, and it probably isn't fantastic for the pumps over time. Configured this way, everything operates on inverter, taking advantage of clean power and 18,000w surge capacity, and the generator will just kick in as necessary to charge the batteries independently of the power situation. I'm also suspecting that a consistent charging load on the generator might be healthier for it over a constantly-changing load, not to mention that it will have to run much less than if it were supporting the loads directly.
Hoping to get input on a few questions:
1. Am I understanding things correctly? I'm still very much in learning mode, so please feel free to poke holes in my logic, or fill on obvious gaps.
2. Am I sizing the all-in-one unit correctly? I have read that it should be sized at about 70% of the anticipated combined run load, and I have gone larger than that, but should I go larger?
3. Based upon my obectives (reliability first, but minimizing costs where it make sense), are these components recommended, or should I be looking at others?
4. Does anyone know if the Growatt unit will immediately turn off the generator dry contact if grid power returns?
5. If the answer is no, are there any issues with running a separate charger in tandem with the inverter charger when grid power returns?
6. Based upon generator capacity, what standalone chargers might be recommended to recharge batteries during an extended outage?
7. If I understand correctly, the Growatt 6000T is an off-grid unit, so it should not be capable of feeding power back to the grid, correct?
Apologies for the long first post, but I wanted to try to provide as much info as possible up front. Looking forward to any input.
Cheers,
Shaun
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