New Here - Audacious Plans Afoot - 8000kWh System Coming Soon

Hello everyone! I am new here!

A friend of mine has been doing some solar on a piece of property he owns and has been sharing his journey. He shared a few of @Will Prowse videos a couple months ago and I have been super interested. So much so that I got in touch with the company that installed a small amount of solar on the house I bought 5 years ago (before I bought it) and had them come out. I took that quote, with their blessing, and shopped for cheaper equipment options, them expecting I would still pay them to help me install all or most of it.

With the advice of my friend I checked out Signature Solar and contacted them to help me design something as well. They suggest EG4 18K's and outdoor batteries (more details later). It is a fraction of the cost of what the local guy quoted and he said he has no problem installing it for me which is cool.

In my highest months I use just short of 8000kWh of power and if I can pull it off (which it looks like I can), I want to find a path to be completely off grid (still grid tie, but not reliant on it). Using used panels and the huge southern facing area I have below a retaining wall I can get more than enough production for my total usage no problem. I have 3 200 Amp Panels in the home and each one will get 1 x 18K to start. The idea then is to use Bus Bars to connect at least 3 of the EG4 PowerPro outdoor batteries and do a master/slave config on the 18K's so they can share all the batteries. This seems to be supported from what I am being told.

Then, over time I can work to 1. Reduce energy consumption where it makes sense and 2. Add batteries over time. Doing both I can "meet in the middle" to achive my goal.

I will likely do more than 3 batteries to begin with, but that is just the general idea - to be setup for expansion and have the ability to keep adding.

A few things I know I need to do:

Get a small roof built off the stone wall where all this will be mounted to keep the sun and rain off of it.

Install Emporia energy monitors in all panels to make sure I am not DRAWING more than 100amp per any panel (If so, I need to add a second 18K to that panel to allow for over 100 amp solar/battery draw)

A few things I want to do / questions:

I would like to figure out how to suggest the local guy builds the frame system for the panels so that I can adjust it up and down per season/month to be at the ideal angle. I have an idea in my head of how this could work but I don't know enough about how they are built to explain it very well. I will try here now in case anyone has any ideas. They hand build it all so I suppose anything is possible.

• Build the main frame that includes the concrete and all base members as they normally would. Build this at the lowest angle needed for my area.
• Build another rectangle made from the same material that the panels will mount to.
• Place that on top of what they built in step 1.
• Hinge it at the bottom.
• If it just lays there, it is at the lowest angle, but if I began to "lift it" from the rear, I could achieve other angles.
• From there, I could either have fixed angle iron piece to keep it at those levels, or I could use some sort of actuator to raise it up or down
• I am big into home automation so it would be simple for me to cause the actuators to move up and down as I wanted them to. I could even move them daily - whatever made the most sense. I didn't think of this till now but if there was a storm or a lot of wind I could even have it auto put them to their lowest setting.
• I imagine having horizontal 5 panels high (about 20') and 6' wide. I will have about 110 panels so I would have to do this 22 times.

Does anyone have any experience doing something like this?

1. This is not REQUIRED, just seems nice to have.
2. Even if I just had the ability to raise them up and down I could either add the actuators later, or not. I am thinking more about the ability to do.

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Do you have any experience with connecting tons of the batteries together with bus bars? Does that make sense? With the master/slave setup I suppose the one 18K will control all the charging (even though that will be coming through all 3 of them). This is the part I would love to hear people's experiences with, if it has been done.

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Since the 18K's have generator support I am also thinking of getting at least one generator as a backup in the event it's stormy AND grid power is down (which I suppose is likley to happen at the same time if the grid is down). Any advice on that part? I will have to use propane and can bury a 1000 gallon tank nearby.

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Any questions, comments, concerns, advice, etc?

Thanks!!

Craig

8000kWh per month? Is there a way you can reduce your consumption?

Welcome to the forum!

Bkord said:

8000kWh per month? Is there a way you can reduce your consumption?

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Maybe a little but not by half or anything. It is a 7000sq ft home with 3 floors, 4 AC's, pool pumps, home theater, etc etc. I am aiming for convenience as much as self reliance and resilience - I would like to keep living my life whether the grid power is there or not.

However, I have already been noticing things that I have began to change, even before having the energy monitors in place and taking action on them. I realized my pool pump was running 8 hours a day and changed it to 5 (which is about what it needs to run), I had a ton of florescent under counter lights and just ordered all new LED ones, and other stuff like that. But, I will only be able to get things so low without making life less enjoyable or creating a pain to manage it.

Another thought I have had is that even if I do not have enough battery to last through a night in the event of a grid outage (until I get more batteries) I COULD flip off breakers to extend the batteries. (Critical Load panels are not interesting to me for a lot of reasons)

PotusGobbleBottom said:

Welcome to the forum!

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Thanks!

8000 kWh/day in a summer month, or winter?
Daytime, or night?

Summer is doable with a moderate to big budget, winter probably not.
PV panels are a fraction the cost of batteries, so daytime A/C and water pumping are more economical than night time loads.

Forget actuators. They hardly made sense 20 years ago when PV panels cost $5.00/W, but now can be bought for $0.14/W.
Just orient some strings toward morning sun, some toward afternoon.

Pool pump may use more kWh per turnover at high speed vs. slow, so consider variable speed or two pumps with check valves.

There is nothing super unusual about your build. 8000kwh/month is less than 300kwh/day.

My suggestions:
Build a climate controlled enclosure for your electronics.
Don’t waste money on movable panels, just work with orientation to cover loads (usually panels biased toward early mornings and late afternoons).
Consider separate systems entirely for non-critical loads (eg: pool pump, secondary aircon, irrigation etc)

Consider using fuel generator power as a planned part of your energy generation. (ie rather than size your bank for three days of no sun, plan on two days of no sun and then generator - that battery bank saving will likely pay for the generator and a lifetime’s supply of fuel for it)

I’ve designed a few farm systems that have similar energy requirements. Every time it has been simpler to have seperate systems for separate areas of consumption. Keep in mind you can run a pool pump battery to minimum SOC and turn it off until it sees a charge, you can’t do this with your primary battery that powers things like refrigeration.

My initial comment/question/concern was the part about building a roof to keep the sun and rain off it.
I realize the 18kpv is ip65 rated but with that much invested in a build my brain simply does not compute the notion of 10s of thousands of dollars of electric equipment outdoors.

Climate controlled room is by far my preference. And a system this size, cost shouldn’t be a deterrent

Be super interested to follow the plan as it comes into play! Sounds awesome

Hedges said:

8000 kWh/day in a summer month, or winter?
Daytime, or night?

Summer is doable with a moderate to big budget, winter probably not.
PV panels are a fraction the cost of batteries, so daytime A/C and water pumping are more economical than night time loads.

Forget actuators. They hardly made sense 20 years ago when PV panels cost $5.00/W, but now can be bought for $0.14/W.
Just orient some strings toward morning sun, some toward afternoon.

Pool pump may use more kWh per turnover at high speed vs. slow, so consider variable speed or two pumps with check valves.

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Usage - Here you go!








I did wonder if it make more sense to just add more panels than to mess with changing their angle. One issue I would have is producing more power than the inverter can handle in the summer to get what I need in the winter. I could add another inverter to handle that I suppose. It is prob overall cheaper and easier to do that than it is to spend the money trying to move the panels up and down. I would be interested in further opinions about this subject for sure.

Pump - yea a friend said he switched to a variable pump and there was a huge difference. I have the pump set to run only in the daytime so it may be a non issue with as much solar as I could produce. We could potentially even do some extra cooling in the house so less is needed at night. I am big into home automation so there are certainly some things I could do to keep lights and stuff off at night, etc too.

toms said:

There is nothing super unusual about your build. 8000kwh/month is less than 300kwh/day.

My suggestions:
Build a climate controlled enclosure for your electronics.
Don’t waste money on movable panels, just work with orientation to cover loads (usually panels biased toward early mornings and late afternoons).
Consider separate systems entirely for non-critical loads (eg: pool pump, secondary aircon, irrigation etc)

Consider using fuel generator power as a planned part of your energy generation. (ie rather than size your bank for three days of no sun, plan on two days of no sun and then generator - that battery bank saving will likely pay for the generator and a lifetime’s supply of fuel for it)

I’ve designed a few farm systems that have similar energy requirements. Every time it has been simpler to have seperate systems for separate areas of consumption. Keep in mind you can run a pool pump battery to minimum SOC and turn it off until it sees a charge, you can’t do this with your primary battery that powers things like refrigeration.

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Climate controlled - hmm.

Position of panels .... So I have a couple considerations. One, I want this to look as symetrical as possible to this retaining wall. It will be all along this wall and the current pool solar you see is going away. I think I am going to want to keep them all against that wall. I would rather have more of them if needed. For reference that pool solar is about 12' deep and about 60' wide. That whole wall is way over 100' long.



LOVE what you are saying about the generator and reasons for it. DONE - that will be part of the plan!

Separate systems - I really don't want to do this. But, for things like the pool I have a control system and can easily setup something in Home Assistant to turn the pumps off if XYZ happened. I did also think about smart breakers that I could also control but I have not successfully found then to fit in my panel. Generally I find like Shelly relays which would requite another box somewhere near the panel. I really prefer not to get into all that if I can help it.

G00SE said:

My initial comment/question/concern was the part about building a roof to keep the sun and rain off it.
I realize the 18kpv is ip65 rated but with that much invested in a build my brain simply does not compute the notion of 10s of thousands of dollars of electric equipment outdoors.

Climate controlled room is by far my preference. And a system this size, cost shouldn’t be a deterrent

Be super interested to follow the plan as it comes into play! Sounds awesome

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Ok ... interesting thought. I guess I need to look into the cost of just closing in the area I am talking about and maybe getting a mini split in there or something. I don't love the idea of adding that cost, but it is worth looking into. I have room in the mechanical room of the house to put all this stuff but God forbid something catches on fire. Where this wall is (around the corner in the image I attached above), there is nothing to hurt - burn all you want.

If you are completely off grid, write down a list of all your components - then write down a plan for what you will do if each one of them fails. That will help guide your system layout.

A well put together system will last for a long time, but you need to consider how you will transition to a replacement system as batteries approach end of life.

Dang, your base load is like 6kW!
My house is like 300-400 watts.
I guess luxury uses lots of energy

How cold does it get there in the winter? I doubt fully enclosing the inverters is needed, but if you put them in with the batteries, at 6kW base load, the inverters may produce enough heat to keep the batteries warm. The flip side is getting rid that heat in the summer.
I'd probably build something insulated for the batteries and hang the inverters on the outside, north (shady) side if possible. If you put the inverters inside, you'll need that mini spilt to get rid of the heat the inverters put out.

400bird said:

Dang, your base load is like 6kW!
My house is like 300-400 watts.
I guess luxury uses lots of energy

How cold does it get there in the winter? I doubt fully enclosing the inverters is needed, but if you put them in with the batteries, at 6kW base load, the inverters may produce enough heat to keep the batteries warm. The flip side is getting rid that heat in the summer.
I'd probably build something insulated for the batteries and hang the inverters on the outside, north (shady) side if possible. If you put the inverters inside, you'll need that mini spilt to get rid of the heat the inverters put out.

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Haha yea I guess you are right about the luxury part.

It can get below freezing but usually only a couple times in the winter.

I am still thinking about how to do the enclosed space like y'all are talking about. At first I was just going to do the shed roof over it all, then saw comments about enclosing it, now you are talking about heat vs cool. It is turning into a project of it's own haha.

Hedges said:

SOK 12-Slot Outdoor Insulated Battery Rack

Why wouldn’t we use one of two of these instead of a power shed out by a ground mount and then we can run AC to loads in the house etc. https://www.currentconnected.com/product/sok-12-slot-outdoor-battery-rack/?gad_source=1&gclid=EAIaIQobChMImozA8s6EhgMVRG1_AB2LLQiMEAQYASABEgI-g_D_BwE

diysolarforum.com

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That’s interesting. I haven’t run the math yet but I wonder if it would make more sense to do something like that so you get the integrated bus bars vs the external ones when using the wall mount batteries. And it’s perhaps a little more protected from the elements this way.

Your pulling 8kwh not 8000 KWH a day I thought I was reading that wrong you could say 8000 Watt hours. I'm in Phoenix Last year Jul-Aug we went 117F-119F for 30 straight days. The peak power load in one day was on July 22 168KWH. My 4 ton roof top heat pump unit ran for hours non-stop I was worried it was going to give out but it got through it. My monthly load in July was 3704 KWH. You should be able to do something with only 8kwh a day build a 20-25kw system more then enough.

k490 said:

Your pulling 8kwh not 8000 KWH a day I thought I was reading that wrong you could say 8000 Watt hours. I'm in Phoenix Last year Jul-Aug we went 117F-119F for 30 straight days. The peak power load in one day was on July 22 168KWH. My 4 ton roof top heat pump unit ran for hours non-stop I was worried it was going to give out but it got through it. My monthly load in July was 3704 KWH. You should be able to do something with only 8kwh a day build a 20-25kw system more then enough.

View attachment 217270

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No, i'd said in my original post that I have used as high as 8000 kWh per month. Then after I got the charts and posted them it is around 5000 - 7000 kWh per month depending on the month.

AutoMater said:

Install Emporia energy monitors in all panels to make sure I am not DRAWING more than 100amp per any panel (If so, I need to add a second 18K to that panel to allow for over 100 amp solar/battery draw)

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Definitely start with an energy survey. Know the difference between KW and KWHR.

18Kpv is good for 50 amps (with 2 PowerPro batteries)

Maybe keep some of your bigger loads on the grid to begin with, or load-shed them on grid failure? If the grid is down for a few days you may not care that your pool pump doesn’t run.

wpns said:

Definitely start with an energy survey. Know the difference between KW and KWHR.

18Kpv is good for 50 amps (with 2 PowerPro batteries)

Maybe keep some of your bigger loads on the grid to begin with, or load-shed them on grid failure? If the grid is down for a few days you may not care that your pool pump doesn’t run.

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That 50 amp is at 240v. I think what the lady at Signature Solar was telling me is 100amps at 120v. I remember her saying to get 200 i’d need two inverters for that panel.

Definitely need to get the monitors on there and see what I’m pulling! The emporia measures amps at 120v (measures per leg). Here’s an example of my barn that I’m measuring that has an RV connected and how it’s measuring per leg.

AutoMater said:

No, i'd said in my original post that I have used as high as 8000 kWh per month. Then after I got the charts and posted them it is around 5000 - 7000 kWh per month depending on the month.

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That's lot of power probably going to need at least 100 450W panels and multiple inverters in parallel. Look up in your area see how large of a battery system your AHJ allows on the property. I noticed mine only allows 81kw max for residential which is about 5 EG4 power pros. Although I only glanced at it. How many panels did the local solar contractor quote you for? Trying to go completely off grid might not be worth it, but you can easily have a good battery backup system reducing non critical loads. You don't really need a pool pump if there is a power outage, or every AC unit running. Don't buy anything until you have a plan approved by your AHJ and power utility. Were you planning on using Greenlancer for the solar permit design plans?

If you connect a 50 amp inverter to a 200 amp panel have to reduce your grid main breaker so the max bussbar does not exceed 120%. 200 amp main bussbar max current allowed for that panel is 240 amps. You have to reduce the main to 190 amps to connect the 50amp EG4 18kpv. Not sure you can find a 190 main breaker. You would have to reduce the breaker down whatever you can get another method is conencting in the supply side before the main using a tap. You want to hire a electrican to do all this if you can find one who will work with you. You could upgrade the panels to 225 solar ready main service panels that gives you enough bussbar overhead. That's what lot of new homes coming with solar ready 225 amp panels.

AutoMater said:

That’s interesting. I haven’t run the math yet but I wonder if it would make more sense to do something like that so you get the integrated bus bars vs the external ones when using the wall mount batteries. And it’s perhaps a little more protected from the elements this way.

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That enclosure is made to hold rack batteries, 100 Ah each. There are larger 280 Ah rack mount (I think). The PowerPro is an attractive package, 280 Ah available in an outdoor enclosure, with heating (but no insulation). Also wall mount indoor.

280 Ah with fewer strings in parallel is the way to go for now. 560A cells have been announced.

k490 said:

I noticed mine only allows 81kw max for residential which is about 5 EG4 power pros.

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Some batteries have BMS that talk to each other, aggregate their requirements and tell inverter what voltage and current to charge with. Other systems run open loop, inverter/charger pre-set with values. So long as each battery string has separate BMS to disconnect, that avoids the (catastrophic) failure where others dump into battery with failed cells.

Ideally each battery string would be independently connected, like each with its own inverter. Tesla PowerWall for instance. This requires good coordination to form and support grid. When HV (like 400V) strings are used it can be pretty high capacity. BYD sells a 32kWh battery; would be much higher if made with 280 Ah cells.

I gotta admit, I saw the thread title of 8000kWh and assumed you meant 8000kWh of Battery Storage I thought @timselectric was finally going to get a run for his money!!

Very interested in seeing this project come to fruition as my parents are in a similar situation.

Good Luck! Welcome to the Forum!

AutoMater said:

Maybe a little but not by half or anything. It is a 7000sq ft home with 3 floors, 4 AC's, pool pumps, home theater, etc etc. I am aiming for convenience as much as self reliance and resilience - I would like to keep living my life whether the grid power is there or not.

However, I have already been noticing things that I have began to change, even before having the energy monitors in place and taking action on them. I realized my pool pump was running 8 hours a day and changed it to 5 (which is about what it needs to run), I had a ton of florescent under counter lights and just ordered all new LED ones, and other stuff like that. But, I will only be able to get things so low without making life less enjoyable or creating a pain to manage it.

Another thought I have had is that even if I do not have enough battery to last through a night in the event of a grid outage (until I get more batteries) I COULD flip off breakers to extend the batteries. (Critical Load panels are not interesting to me for a lot of reasons)

Click to expand...

I'm not sure you're correct about investing money to reduce you load. One of my houses is a similar size and I don't use anywhere close to the amount of power that you're using. Looking at your usage graphs, it makes me think a lot of your usage is on HVAC. Can you post the model numbers of your 4 HVAC units?

About 5 years ago, I installed three 4-Ton Trane XR20 Heat Pumps along with natural gas air handlers for dual fuel heating. That cut my heating and cooling costs in about half. I also have 3 super high efficiency mini-split systems to more efficiently heating and cooling of selected spaces.

Investing in more efficient HVAC systems will probably save you money on the size/cost of the solar / ESS system, that along with energy savings will probably cover a good bit of the HVAC upgrade costs. Especially if the HVAC systems you have now have any age on them and will need to be replaced anyway in the next 5-8 years.

Are you heating your pool? If so, is it a heat pump based unit and what is the efficiency rating on that unit?

The cost to reduce energy consumption, and increase efficiency of all your appliances, is ALWAYS cheaper than more Solar/Battery/Inverters.

Before designing a system, I always try to look at where you can cut consumption first, especially when it's a situation like a 10 year old, 6 SEER, 4 ton AC unit that you don't know how long it's going to last anyways. Or the 15 year old electric water heater that could be replaced with a heat pump model. If you think it's going to have to be replaced soon anyways, might as well do it before it goes bad, and get a highly efficient unit to replace it with.