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New to the forum and new to solar with some electrical and solar knowledge but many folks out there with way more smarts that me. So, thank you for the wisdom and advice in advance. Apologies if the questions I have don’t even make sense due to my lack of knowledge.
I currently have two main panels fed in parallel from the meter with 150A main breakers each and 150A bus ratings. I am looking to add solar panels to achieve 105% of my current electricity use. I have an all-electric house with two heat pump HAVC systems, an 80 gallon hot water heater, a freezer, and the rest of the standard appliances. I use, on average, approximately 2300kWh a month and have been quoted systems with 58 to 60 solar panels to meet my needs. That seems like the easy part.
I am planning to install a ground mount, grid-tied, whole home battery backup system. The catch is whole home battery backup is not really that practical for my amount of usage. So, I am looking at the Span.io panel(s) to allow for automated (and manual) control over the circuits receiving power from the solar array and or batteries during a grid down condition. The battery connections are not that much of an issue, one battery per panel however, the solar connection is the question. I know I could go with a critical loads panel but that’s not really the type of system I’m looking for.
My first question, does anyone here have any experience with the Span panels? I would love to hear your thoughts and experiences, good or bad. They are a relatively new company and new product so there’s not a lot out there that I can find about it at this point.
Second, and the technical question. As I understand it, the Span panels have a 200A bus bar rating. Unfortunately, they have no current transformer so I would not be able to monitor the solar power in a supply side application within their system therefore, needing to use a backfeed breaker configuration. While I don’t mind that, the solar array will produce approximately 87A and the panel would be limited to a 40A backfeed breaker unless I down rated the main breaker to 150A. Probably never an issue but could be. The problem I see with this is that in a grid down condition, the only panel that will see solar power is the one with the backfeed breaker as the grid cutoff is in each panel by design, which would isolate the panels from each other. So, is there a solution that will feed both panels with solar power when the grid is down? I believe I could split the solar array, half to each panel, but I’d rather not. Can the solar array be feed to both panels in parallel with a backfeed breaker in each panel? I have seen that configuration with generators. Would it work with a solar panel array? Is that a bad idea?
Thank you again!
I currently have two main panels fed in parallel from the meter with 150A main breakers each and 150A bus ratings. I am looking to add solar panels to achieve 105% of my current electricity use. I have an all-electric house with two heat pump HAVC systems, an 80 gallon hot water heater, a freezer, and the rest of the standard appliances. I use, on average, approximately 2300kWh a month and have been quoted systems with 58 to 60 solar panels to meet my needs. That seems like the easy part.
I am planning to install a ground mount, grid-tied, whole home battery backup system. The catch is whole home battery backup is not really that practical for my amount of usage. So, I am looking at the Span.io panel(s) to allow for automated (and manual) control over the circuits receiving power from the solar array and or batteries during a grid down condition. The battery connections are not that much of an issue, one battery per panel however, the solar connection is the question. I know I could go with a critical loads panel but that’s not really the type of system I’m looking for.
My first question, does anyone here have any experience with the Span panels? I would love to hear your thoughts and experiences, good or bad. They are a relatively new company and new product so there’s not a lot out there that I can find about it at this point.
Second, and the technical question. As I understand it, the Span panels have a 200A bus bar rating. Unfortunately, they have no current transformer so I would not be able to monitor the solar power in a supply side application within their system therefore, needing to use a backfeed breaker configuration. While I don’t mind that, the solar array will produce approximately 87A and the panel would be limited to a 40A backfeed breaker unless I down rated the main breaker to 150A. Probably never an issue but could be. The problem I see with this is that in a grid down condition, the only panel that will see solar power is the one with the backfeed breaker as the grid cutoff is in each panel by design, which would isolate the panels from each other. So, is there a solution that will feed both panels with solar power when the grid is down? I believe I could split the solar array, half to each panel, but I’d rather not. Can the solar array be feed to both panels in parallel with a backfeed breaker in each panel? I have seen that configuration with generators. Would it work with a solar panel array? Is that a bad idea?
Thank you again!
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