Net Metering with DIY non UL batteries

[Tommytwotone]

Are UL listed batteries required for a Net Metering install?

Net Metering is marginal as we would actually have to pay about 1cent more per KWH for the generation part to use net metering.

We use 4500 to 6200 kwh per month and have a larger than normal daytime load due to being home all day with home office and homeschool use.

As our kwh cost is about $.11 and we would have a $.01 cent increase if we go net metering which is one reason why Net Metering may not make sense. The other is due to our usage we will need a rather large battery bank and if that has to be UL listed, thus the main question, it starts to really erode the Net Metering logic.

The part of net metering that does make sense is we can get some credit for otherwise lost production AND as we have a 400 amp 2 panel (plus a 150amp barn feed off the meter) we can back to, when possible, feed the barn and or heavier loads such as strip heat if they happen to be active when we are feeding upstream.

Any thoughts are appreciated.

 

[chrisski]

I will say yes UL approved batteries are a requirement of net metering.

To get a real answer to that, though you need to get with your Authority Has Jurisdiction (AHJ) either the town or county to find out. IME from my contracted build its between the contractor who designs and build it, the city who approved it, and the fire department that also inspected it. The AHJ can always make acode code stricter.

Also, where I'm at in AZ net metering has been gone for six years and the same is for other states. More rural areas are very, very lax.

As a guy who uses 160 kWh per day max in the summer, which is less than what you do, how big of a battery do you want? Keep in mind a Tesla powerwall holds around 13 kw, about the same as 200 LBS worth of an 16S 280 ah 48 volt batttery.

Could be much cheaper to swap out to an energy efficient appliance, like a inverter air conditioner.

 

[SparkyJJO]

If I were in your position I wouldn't do net metering and just do an "off grid" install with utility backup for when batteries get low, also known as SBU (solar, batteries, utility).

 

[kscessnadriver]

So do you want the batteries to store your own energy, or store the energy to sell back to the grid?

 

[hwy17]

UL batteries are a code requirement and code usually applies whether or not you are doing net metering.

 

[Tommytwotone]

If I were in your position I wouldn't do net metering and just do an "off grid" install with utility backup for when batteries get low, also known as SBU (solar, batteries, utility).

That is the direction I am leaning but trying to flush out before a final design.

 

[Tommytwotone]

So do you want the batteries to store your own energy, or store the energy to sell back to the grid?

To store my own energy. Our power company does offer TOD rates but they are all more expensive compared to the contract our area has with another generator so no point in storing to sell back at another TOD. In an ideal world I would have 200kwh plus of storage.

Many seem to say try to have several days worth of power stored up. The problem is I use power like it is going out of style as 6000kwh per month is, well, 200kwh a day for all intents and purposes.

As such no extra storage for the grid I need it all.lol

 

[Tommytwotone]

I will say yes UL approved batteries are a requirement of net metering.

To get a real answer to that, though you need to get with your Authority Has Jurisdiction (AHJ) either the town or county to find out. IME from my contracted build its between the contractor who designs and build it, the city who approved it, and the fire department that also inspected it. The AHJ can always make acode code stricter.

Also, where I'm at in AZ net metering has been gone for six years and the same is for other states. More rural areas are very, very lax.

As a guy who uses 160 kWh per day max in the summer, which is less than what you do, how big of a battery do you want? Keep in mind a Tesla powerwall holds around 13 kw, about the same as 200 LBS worth of an 16S 280 ah 48 volt batttery.

Could be much cheaper to swap out to an energy efficient appliance, like a inverter air conditioner.

Great points. We are using 16 SEER two stage HP with Variable Speed (DC) air handlers. So not as efficient as min splits but fairly efficient. Our big heating/cooling issue is an old farm house built in 1895. We are working to shore up some HVAC air leaks but that only accounts for a portion of our daily usage. We used AC only overnight the last couple days and we still use 120 to 140kwh per day.

Issues include...Well Pump...Reverse Osmosis system for all water...the biggie is a family of 9/home office/homeschool...robust computer networking equipment (they don't use much but they use it 24/7)....heavy convection oven use...

I am on the same page you are which is to go through and find all the loads, get rid of as many parasitic loads as we can and evaluate the appliances I am suspicious of like the two freezers. There is bound to be some efficiencies that can be had but at our usage and how I know it is used I am hoping to find 10 percent or so. I am going to use more coal to offset winter heating (strip heat) and water heat as it is about 20% to 50% less per btu (and this year or next add a propane boiler as that is less expensive when compared to strip heat or water heating but to a lesser extent).

Anyhow all good thoughts.

How, if I may ask, does it work for you with 160kwh of daily usage at least part of the year? I am hoping to get to where you are at for a high usage mark if I can. How much are you producing, do you use batteries (how much) etc etc.

 

[SparkyJJO]

UL batteries are a code requirement and code usually applies whether or not you are doing net metering.

If you're doing DIY batteries then a UL listed code requirement isn't high on the list.
If it is safe I don't care if it is code or not. I dare say my DIY batteries are going to be at least as well built - if not better - than UL listed batteries.
And if I sell my house they're going with me, so it doesn't matter from that perspective either.
Not dissing those who want the UL listed batteries.

 

[hwy17]

If you're doing DIY batteries then a UL listed code requirement isn't high on the list.
If it is safe I don't care if it is code or not. I dare say my DIY batteries are going to be at least as well built - if not better - than UL listed batteries.
And if I sell my house they're going with me, so it doesn't matter from that perspective either.
Not dissing those who want the UL listed batteries.

Yeah I gave up on code compliance when the permit office told me I wasn't allowed to DIY solar or batteries here. F 'em.

 

[Tommytwotone]

If you're doing DIY batteries then a UL listed code requirement isn't high on the list.
If it is safe I don't care if it is code or not. I dare say my DIY batteries are going to be at least as well built - if not better - than UL listed batteries.
And if I sell my house they're going with me, so it doesn't matter from that perspective either.
Not dissing those who want the UL listed batteries.

Fortunately I am in a township and have no inspection requirement. I just have to meet the rules for sq footage of accessory space, set back etc.

I agree totally I was just trying to make sure I was not wrong about the UL requirement. My wife wants us to ditch the grid but at our use that is a little much.

 

[jpwhit]

Are UL listed batteries required for a Net Metering install?

Net Metering is marginal as we would actually have to pay about 1cent more per KWH for the generation part to use net metering.

We use 4500 to 6200 kwh per month and have a larger than normal daytime load due to being home all day with home office and homeschool use.

As our kwh cost is about $.11 and we would have a $.01 cent increase if we go net metering which is one reason why Net Metering may not make sense. The other is due to our usage we will need a rather large battery bank and if that has to be UL listed, thus the main question, it starts to really erode the Net Metering logic.

The part of net metering that does make sense is we can get some credit for otherwise lost production AND as we have a 400 amp 2 panel (plus a 150amp barn feed off the meter) we can back to, when possible, feed the barn and or heavier loads such as strip heat if they happen to be active when we are feeding upstream.

Any thoughts are appreciated.

To give an answer that makes sense, your post is missing important details about how Net Metering works in your area. Such as what is the reconciliation time period for your Net Metering plan. Each bill cycle? Each calendar year June to June as an example. Does power used offset power consumed during 1 bill period, and then you're credited at x rate for over production, etc....

I know reading these rate plan documents and rider documents can be confusing if you're not use to looking at them. Post a link to your power companies web page, or just the name of the power company, and I'd be happy to look at their rate plans and rider documentations.

 

[dougbert]

If I were in your position I wouldn't do net metering and just do an "off grid" install with utility backup for when batteries get low, also known as SBU (solar, batteries, utility).

YES, reduce your contact with PoCo and gov

I use the grid for when sun is less and battery is low

 

[jpwhit]

YES, reduce your contact with PoCo and gov

I use the grid for when sun is less and battery is low

While that may sound good, I see lots of cases where mis-interpretation of Net Metering riders and Rate Plan's available causes folks to miss out on a lot of financial benefits. And if you live somewhere that has cold winters, going totally off-grid can require a huge investment in equipment that just doesn't have a good rate of return. Or worse IMO, if it causes you to burn stuff in the winter for heat....

And given the original poster lives in an area with very little inspection requirements. They won't have a heavy burden of inspections.

 

[Nobodybusiness]

Many seem to say try to have several days worth of power stored up. The problem is I use power like it is going out of style as 6000kwh per month is, well, 200kwh a day for all intents and purposes

That is a lot of power for sure.

Got all electric home and 30x50 shop and most we used was in December ( prior to solar) 4000kw.

Tough decision.

I would try and reduce usage if possible then circle back to just self consumption.
Unless you are getting a 1-1. Net metering or something close I wouldn’t consider it.

Just my opinion.

 

[Tommytwotone]

To give an answer that makes sense, your post is missing important details about how Net Metering works in your area. Such as what is the reconciliation time period for your Net Metering plan. Each bill cycle? Each calendar year June to June as an example. Does power used offset power consumed during 1 bill period, and then you're credited at x rate for over production, etc....

I know reading these rate plan documents and rider documents can be confusing if you're not use to looking at them. Post a link to your power companies web page, or just the name of the power company, and I'd be happy to look at their rate plans and rider documentations.

To answer your questions let me take a run at it:

Net metering covers just the generator side so you are billed for the delivery part either way. The generator I am contracted with today is at $.067 per khw but they DO NOT offer a net metering credit. I pay $.041 for delivery.

To attain net metering I would need to go with a different generator and that would, at best increase my rate per kwh by $.01 per kwh or a 15% increase in the generator cost per kwh.

The offset rolls forward until the account is canceled so not month to month. There may be a time limit but I do not believe so based on the language around getting nothing from any residual credits when you "move".

So the factors that come into play around whether to go net metering or not look like this to me. First I do not get 1 to 1 credit including deliver per state law. I do get 1 to 1 for generation but still have to pay delivery. That is a negative but could be worthwhile.

I have to go from $.067 to $.077 to get with a generator who offers net metering at all. That really starts to erode the cost benefit.

I have to enter into a net metering agreement and, after reading that agreement, the requirement for insurance at a given level, access to the facilities, the inability to make changes without notifying them and the increased cost of the install to meet their requirements over and above NEC etc makes it even more of a hassle. My wife simply prefers not to allow anyone into our home and an entity that can request entry at any time is not her favorite.

So the biggest issue boiled down to whether or not DIY batteries were kosher on a Net Metering project. Our bill runs $450 to $650 and at the higher end most of the time. We have periodic power outages that last about 2 to 6 hours. I run my own business and home office so my goals are 1) lower my electric bill in the most cost effective manner possible 2) Provide the ability to support the house in a power out situation 3) In the event we have a longer term grid issue maximize the effectiveness of both solar and generator power to live and limp through that circumstance. With DIY batteries appearing to be at $150 per KWH and UL listed at $250 per KWH DIY batteries are a plus.

 

[Tommytwotone]

That is a lot of power for sure.

Got all electric home and 30x50 shop and most we used was in December ( prior to solar) 4000kw.

Tough decision.

I would try and reduce usage if possible then circle back to just self consumption.
Unless you are getting a 1-1. Net metering or something close I wouldn’t consider it.

Just my opinion.

I agree. We are hunting for where the energy goes but realize HVAC is a huge consumer. That is the most likely area we can tighten up in this old house. I agree on the net metering makes sense at 1 to 1 but not so much below that.

 

[kscessnadriver]

I agree. We are hunting for where the energy goes but realize HVAC is a huge consumer. That is the most likely area we can tighten up in this old house. I agree on the net metering makes sense at 1 to 1 but not so much below that.

How old is your well pump, how old is your well pressure tank?

 

[Tommytwotone]

How old is your well pump, how old is your well pressure tank?

Great question. Our well pump is under 2 years old with a newer pressure tank as well. The issue here for water is it is in the mid 70s for hardness, iron bacteria and high iron. I looked at the monitor and it shows we use about 30 to 35kwh a week so say 120 to 140kwh a month with the water pump. Not sure how that compares to others. I believe it is a 1.5hp 20GPM non VFD/constant pressure pump. Cleaning up the water's hardness via our "water plant" in the basement has a lot of wasted water. I am temped to pull it at some point and put in a 3phase with a VFD but then again the Solar Inverters are not going to tolerate a VFD from what I gather.

 

[kscessnadriver]

Great question. Our well pump is under 2 years old with a newer pressure tank as well. The issue here for water is it is in the mid 70s for hardness, iron bacteria and high iron. I looked at the monitor and it shows we use about 30 to 35kwh a week so say 120 to 140kwh a month with the water pump. Not sure how that compares to others. I believe it is a 1.5hp 20GPM non VFD/constant pressure pump. Cleaning up the water's hardness via our "water plant" in the basement has a lot of wasted water. I am temped to pull it at some point and put in a 3phase with a VFD but then again the Solar Inverters are not going to tolerate a VFD from what I gather.

Well, at least that eliminates the well pump, typically that's a place with a lot of wasted energy with a bad pump and/or a bad pressure tank. I'm very familiar with the water quality, it's similar in Indiana. That's a big pump, you must use a lot of water. I've never directly measured what kind of power usage my well uses, but it's a big chunk, as I'm running geothermal openloop HVAC. So heat or AC on, and the well is running.