[Matsu]

For emergency weather event back-up, a natural gas whole home generator (or even better a dual/tri fuel) is probably the best. This can be done really pretty cheap, especially if you go with a manual transfer switch and generator.

[Yontsey]

I got everything for under $10k. Had the electricians install the transfer switch which is automatic and I ordered the generator and my cousin and I are installing it. They are very simple and straight forward to install. For my new network Unifi setup, I have a UPS in my rack to bridge that split second from electric to the generator so there's no hiccup.

[turtle]

Originally Posted by Yontsey I got everything for under $10k. Had the electricians install the transfer switch which is automatic and I ordered the generator and my cousin and I are installing it. They are very simple and straight forward to install. For my new network Unifi setup, I have a UPS in my rack to bridge that split second from electric to the generator so there's no hiccup.

That is good planning!

In Va Beach I ended up doing the manual route because as many tropical storms as we had, I just couldn't justify the additional cost. For me, we didn't have gas to begin with and adding it to the home would have just been one more bill. If I were to go new and had gas available I would have done it that way.

Once solar gets installed in my home now I'll have solar, batteries and propane central heat. This will allow me to run the propane heat off the batteries in the event of a "dark sky and grid down" situation. Otherwise, my panels will be able to generate enough to power the heat on their own.

[turtle]

Install started Thursday and Friday. The install is not completed. My existing electrical system is... absurd. The panels are on the roof and wired into the basement to the inverters. The Powerwalls are in and the Tesla Gateway is wired to it.

The most frustrating part is that we knew a storm was coming through the south Thursday and the installers insisted we start. The bulk of the storm passed after the outside work was done but the problem for me is it left me without power for the whole day until 0309 in the morning. It sucked so bad. It was cold and windy outside.

I have a big family, that means we have lots of food storage. Five fridge/freezers total in my house. Very little of it sits in those for long. Those things tend to want to maintain power to keep working. I had to go outside and figure out how to get my generator running in the storm and run extension cords everywhere because of this.

[drewprops]

Ugh. Passage from "broken" to "fixed" can be painful and being at the mercy of installers is frustrating, especially in poor weather conditions. I want to redo several fundamental things about my home; dad passed along several stories about how inept the builders of this home were. I don't relish trying to find someone with the knowledge and skills.


...

[turtle]

I have solar, finally. Today I was given permission to operate and it was fantastic... accept that it is dreary and already late afternoon so I didn't get much from the panels. Thankfully the batteries had charge to 91% during testing last week so I'm actually running off of battery right now.

In fact, at this very moment I'm 100% powered by the batteries. At my current rate that is good for another 17 hours. I should have sun in the morning and I am still grid tied if I end up with less solar power than we consume tomorrow.

[kieran]

Well that's awesome. Glad it finally came together for you.

We've been looking into it at our house in CT and it's been such a hassle. We got rid of our gas furnace and hot water heater and swapped it for a tankless hot water heater and electric heat pumps, but that has obviously put a huge increase in our electric bill.

We look online for all of these solar programs that are promising the world, but they end up just selling that information and we never actually get anyone to give us an estimate.

We had one person scheduled to come out, but before he got here, the company called and said due to them looking at Google Earth, we have too much shade from the trees and they're not coming out. 20 mins later, the tech shows up and says we would be able to do it, but at that point, I just wanted to move on from them.

[Matsu]

That's great. I'm about to upgrade my service to 200amp and leave space for a transfer switch. It's not strictly needed at the moment but, the wall perpendicular to the panel is open now and it leaves a path for an easy run to a sub panel in the garage for my workshop and the master suite above. This way there's enough amps and breakers for solar/battery and car charger if/when, and a laundry closet, radiant heat and/or mini split for the master suite above the garage.

[turtle]

I think I'm finally willing to share more details about my build. I struggle between sharing something I'm really excited about and maintaining my privacy. So rather than post the prints used for permitting about my solar build I built a basic diagram that will cover it.


I have a solar array that is rated for 23kW that feeds the two inverters. We are using SolarEdge with panel based optimizers. These help the strings maintain voltage in the event of partial shading and such. Those inverters feed the Tesla Gateway. This Gateway serves as the primary disconnect from the utility as well as the traffic cop for where I get and send electricity. Our build also uses two Powerwalls to provide power to critical loads in dark sky and grid down situations. During daylight we will continue living like there is no grid down. Since we only have two Powerwalls we are limited to ~60A continuous AC out. This would quickly fill if high current appliances all turned on at once. To prevent overcurrent you would normally use a dedicated critical loads panel to host those items you wanted backed up by the batteries. I want it all so I went a different route and am trusting relatively new technology.

Enter the Span Panel. It replaces the main load center/breaker panel in your home and allows for custom software based rules. So rather than have only the critical loads backed up, all my loads are. To prevent overcurrent the Span will shed loads when running on battery. This will mean all my high current loads will be shed immediately but programmatically. The breaker isn't turned off, but backend control of the breaker is. The Span Panel allows you to designate Must have circuits, Nice to have circuits and non-essential circuits. Non-essential circuits are shed immediately. Nice to have circuits shed at 50% battery capacity. Must haves shed when the batteries are dead. The downfall of the Span (beyond cost) is that is only has 32 breaker slots. We have to have a number of circuits in sub-panels. Those sub-panels are shed first with the true critical loads on individual circuits in the Panel.

I have been operating for almost two weeks now and have already gone positive for the month with net metering. So I'm sending more electricity to the grid than I'm using from them. We currently use the grid for overnights and dark days (cloudy, rain etc..). Net though, we are still positive. I have three apps to monitor everything though I typically only look at the Tesla and Span app since they provide everything I really need and have the controls for my system.

Here you can see the yellow line showing I'm powering my home electrical loads as well as charging the batteries AND feeding the grid.

So far I know I would like more energy storage for longer periods overnight as well as dark days. Other than that I really am genuinely thrilled with this system. It is a horrible shame it took us almost 18 months from start to finish. I'm actually in communications with upper management about the build and challenges we have faced along the way. The install process has been one wrong thing after another. So many challenges along the way. In the end I do believe it will be worked out.

[Kickaha]

Verra nice. Curious, did you have the Tesla Powerwalls already in place, or were they a deliberate purchase choice? Looking at something similar, but no Tesla in the driveway so options are open.

[turtle]

The Powerwalls were not present before this install and were the choice I made at the time. I'm not certain they would be my choice now though. I love the polish and general function, but I'm paying for that at the expense of real capacity in my Energy Storage System.

At this point I would be looking for something that can utilize server rack batteries I think. This would allow for easier expansion and replacement if a cell were to fail. With the Powerwalls it is all Tesla and their hand. Again, I don't regret it, but I can't say I would undoubtedly get them again if I were to start over.

Oh, I have no Tesla vehicle either. Heck, I don't even have an electric vehicle right now. I do have a Hybrid, but it isn't a plugin.

[Kickaha]

I hear you, it's honestly still hard to beat good old lead acid batteries for density and longevity at the moment. Which is kind of galling. XD

"Wow, amazing smart home! What does it run on?"

"1859 technology."

[turtle]

Well, I'm more thinking Lithium Iron Phosphate like these. For the price and density it stomps what you get from Tesla. The thing you really lose though is that polish and such from the app like Tesla.

If I even knew these existed before I signed the contracts for my current system I would likely have looked down this road instead. Adding another rack of batteries is expensive, but a full rack of six with the rack is less than one Powerwall.

[Kickaha]

Ok, I'm now getting intrigued. Have an electrician coming next week for an all-house overview, possible panel upgrade, etc, etc.

Not looking to pull the trigger ASAP on the whole enchilada, but thinking:

Phase 1:
SNAP Panel (or similar) - get clear idea of load requirements
Single battery bank – LiP bank, agree on modularity being key, can add capacity later as needed, fill from grid for the moment

That gives me short-term power backup, smart control over the distribution during outages (often enough we have a generator, rare enough we don't have a built-in auto-on generator), and needed Information for the phase 2...

Phase 2:
Solar panels / wind vertical turbine
Add to battery bank

The latter is actually useful here, winds are variable but for about 4 months of the year in winter, they tend to blow more often than not, and up to 50mph for sustained periods. A small unit may be worth it, and hell, fun to play with if nothing else.

Those silly online estimators keep coming back to about a 26kW solar install, which seems excessive, but at least gives me a ballpark before getting better info from a smart panel.

Pros: Modular, incremental, spreads out costs
Cons: Any confidence that today's tech setups will be compatible with a future solar install? I mean, spark is spark, but...

[turtle]

If your first goal is to monitor and gauge your actual usage then I would (and I actually did) get an Emporia Energy Monitor for my electrical main panels. Once this was installed and running for a little over a month I knew what my actual usage was. I didn’t get any of the 50A leads, just the main 200A lugs were enough for me. This is a minimal investment to see what you actually do peak up to. Of course, you have to be “careful” not to adjust your usage knowing that you are looking now. So don’t tell your family you put it in. Then you will know for certain actual usage.

I don’t think the Span Panel will work with anything other than a Tesla Gateway. That is one limitation to it that seems relevant since I wouldn’t recommend the Tesla system in favor of server rack batteries. While the Span Panel would still give great insight and allow you to manage your electrical system, if it doesn’t work with anything other than a Tesla Gateway then it isn’t a direction I would point you.

The Tesla system also doesn’t allow for another source of power that isn’t solar. So you might need to get creative with adding wind to the mix. I would think it would have its own inverter that can feed the battery bank though so that might be the best option for integrating it in. As long as it feed the same voltage the batteries you use are rated for.

Of course, in all of this, grid approval is going to be a big deal. So some things you might electrically be able to do won’t be allowed by code. I faced that with my system and some of my proposals.

Also, there is a new all-in-one inverter on the market that looks good for most 200A service homes. It is the Signature Solar 18k. It looks good on paper and the one review I have seen on it looks really good.

[turtle]

Now with pictures!

This is how my panel looks with the Emporia installed in it a few months ago before I cleaned it up and corrected some things:

The primary CTs clamp on the main feeds to the top of the breaker panel. The two hots go to breakers that are fed from different phases. Typically this is a double pole breaker like mine is at the bottom right. The others go to the neutral bar. Then there is a WIFI antenna you pop out of the side of the box which you can see in this image.

In my region, code requires a physical disconnect within 6' (lug to lug) for service main from the meter. So I had to have my meter moved from the area on the right to the wall it sits on now. 400A service in the middle that feeds the two disconnects on either side. My Tesla Gateway is the primary disconnect on the right with the "standard" 200A disconnect on the left. Far right in the image you can see the required PV disconnect as well.


Based on load calculations and the fact that I had four breaker panels they determined I required 400A service. Because I ran the Emporia for a few months (total) I knew that wasn't true. I was certain it wasn't true but how can I argue with master electricians and load calculations? Well, since I had the data I took matters into my own hands and resolved the problem myself.

This is my panel setup before the solar/Powerwall install:

200A main panel on the left fed the two middle sub panels plus other high current items.

Here are my breakers panels now:

Far left is the Span Panel that is fed from the Tesla Gateway. The middle two sub panels are fed from the Span Panel as 90A and 70A feeds (Span Panel has a 90A breaker limit). The far right is the original 200A main panel fed from the left hand disconnect in the earlier picture above. Notice the physical interlock on the far right panel? Well, I couldn't get the electrician to direct wire the one panel to the other because load calculations... but I could get him to install a NEMA 14-50 outlet off of the Span Panel. So I installed a generator inlet, the interlock and a 50A breaker on the main panel (far right). This allowed me to be able to feed the main panel on the right from a generator. What electrician is going to fight that?


Well, my generator ended up being the Span Panel thanks to the NEMA 14-50 outlet installed that matched my generator cable. So my service main on the far right panel is off and the 50A inlet is on meaning my far right panel is being powered by the inlet. That panel is lights and outlets now. All the major loads were moved to the middle left sub panel or Span Panel. Like, right at this very moment that far right panel is pulling 238w total.

If you notice in the image of my panels, that outlet is gone and I've spliced the wires directly so no more generator cable laying on the basement floor:


So the generator inlet is gone and the NEMA 14-50 outlet is now just a splice.

[drewprops]

I have read this twice and it still hurts my brain. I am absolutely impressed by all of this.


...

[turtle]

Originally Posted by drewprops I have read this twice and it still hurts my brain. I am absolutely impressed by all of this.

It wasn't until I was discussing my plan with the master electrician that I finally got someone who was actually following me and what I did (or planned to do at the time). I stayed at a random express hotel once... must be why.

To make it better, I added another image to the earlier post and more details so you can see the before and after. Now you can look at it two more times!

Kickaha, if you are going to add batteries you will require an inverter to manage the energy storage. Might as well make sure that inverter can handle batteries AND solar so you don't have to change it out but once.

[Kickaha]

Fabulous insights, thanks! The Emporia sensors are indeed a more flexible (and cheaper!) approach, and I don't need automation at this stage, just information.

Noted on the solar/battery requirement, I hadn't gotten that far in my research. XD

I think we're truly going to do this as a battery bank + inverter first, with the expectation of adding in solar / other later.

Mad jelly of the IT rack there too... trying to find a space in the garage for same, but my wife suggested using the top of the linen closet in the central hub of the house, which logistically makes good sense (with venting) and who am I to argue? Will make cable runs simpler.

[turtle]

There are a ton of angles to consider especially if you plan to add wind into the mix. Batteries will be a huge help for any outage, but if you charge from the grid they will not be eligible for the tax credit. They have to be 100% renewable charged for the credit. Not a big deal if you aren't planning on the tax credit, but something else to consider.

For the rack, your closet isn't a horrible idea if you can swing it. The temp would likely be more stable and the worst thing you might have to do is skim a little off the bottom of the closet door to allow air in for an exhaust fan lowing heat out.

Here is a more current version of my rack as of just a few weeks ago:

I had to put the UPS in there because while that circuit is under critical loads of the Powerwalls, the minor power drop during the switchover is enough to power cycle some of the systems. I found that out the hard way.

[turtle]

Today I decided to unplug from the grid. Just plain turn off the power. It has been a very good eye opener. I was sent a link to a video on YouTube for an off grid challenge. This guy has a similar setup as me so I decided I wanted to try it too. We did not build our system to be off grid, but want the ability to go off grid and handle long duration outages. What better time to try it than when there is no issue. I saw things in his video that I wanted to understand for myself with my setup and usage.

So I turned off the power at my main disconnects at around 2:45 this afternoon. We were at 100% charge on the Powerwalls and plenty of sunlight. I told my family to live life normally during sunup so we could see what happened with the grid down. So we lived life normally so far. When I turned off the grid the solar production stopped. I kinda knew this was going to happen but didn't really know why until later when I had to look it up, about 15 minutes later as a matter of fact. Why you might ask? Because the UPS connected to my network rack died and my network stack dropped. Why did this happen? Well I assumed it had to do with the power being clean but wasn't sure. Checking the outlets I still had 120VAC on them so the UPS had power to it but it refused to be powered from the outlet. I moved my power strips to the outlets directly (off of the UPS) and they all powered on normally.

Turns out the Gateway turns off the solar inverters by messing up the power with frequency shifting. This article talks about it in better detail than I'm going to but it even mentions that some UPS won't accept power from the Gateway when it shifts the power frequency from 60Hz to 66Hz. I don't have a meter handy to check the frequency so I'm going to have to assume this is right. At least my assumption of clean power was right, but it was controlled "dirty" power. We did notice the microwave sounded funny as well as a few other things also mentioned in the article. One thing that wasn't was some of the cheaper LED bulbs wouldn't light properly with the shifted frequency.

So the solar production stayed off until we reached 85% charge on the Powerwalls. At that point it finally started production and we ran off of solar and the batteries as needed while the batteries charged to 98% (not 100%):


Here you can see a little while later we stopped solar production and were using the batteries again.


Now this was a little bit ago as we were settling in for the night.


We still have more than 50% charge right now though I did move my two A/C systems to non-essential to turn them off. This prolonged the batteries given they pull around 7kW combine when running. Tonight when we made dinner we actually over pulled from the Powerwalls (10kW max continuous) and lost all power briefly. Both A/C units were running as well as the microwave and other general circuits. So we moved one unit to non-essential (turning it off) and then later moved the second since we didn't really need it overnight. I've also learned at least two more circuits that I need to move to a different sub panel.

At this point we are 11 hours in and I've learned a ton about my system and even the technical aspects of some portion of it. I'm still thrilled!

[drewprops]

I am astonished that you are able to run air conditioning, microwave, etc from the system. Clearly, my understanding of your setup's capabilities was set too low.


...

[turtle]

Originally Posted by drewprops I am astonished that you are able to run air conditioning, microwave, etc from the system. Clearly, my understanding of your setup's capabilities was set too low.

Let me blow your mind then.... I'm intentionally using electricity AND turned off one of my inverters today just so I can fully charge my Powerwalls. Why might you ask? Well I'm glad you did so I can explain.

The Powerwalls are capable of 5kW in or out continuous. So just like last night when we over pulled and the Powerwalls reset because I pulled more than 10kW, today I realized it won't charge if we actually try to send 15.7kW to the batteries and the grid isn't present to offload the extra to!

Why aren't my batteries charging?


OH! To much power!


While I was at church I checked on the batteries and was really perplexed that they weren't charging. So I happened to catch the inverters sending power and even with the A/C running and other items we just weren't pulling more than 5700w of power to keep the two inverters from over powering the Powerwalls! The only option the Gateway has to prevent over powering is to turn off the inverters. The way they are wired that is an all or nothing thing. So both inverters get turned off an no solar production at all until it can handle the input power from them.

So what was my solution? When I got home I intentionally started heavy loads and turned off one of the inverters.

[Kickaha]

"when it shifts the power frequency from 60Hz to 66Hz."

Giggling at the idea of old analog clocks running 10% faster.

[turtle]

Originally Posted by Kickaha "when it shifts the power frequency from 60Hz to 66Hz." Giggling at the idea of old analog clocks running 10% faster.

Yes, you get it. Isn't it kinda funny when you think about that? I have one of those but I don't know if it is impacted because it runs on a wall wart. If the frequency shifting impacts the DC to the clock it would, but I haven't stopped to check it out yet.

[turtle]

We tripped the system again when the main A/C condenser fired up. This time it reset the Gateway and not just the Powerwalls. This wouldn't be a problem normally but I changed the password for the Gateway customer login so I could get in there and pull from the API. This means when it resets it reverts back to the default password and I have to manually set it again.

I was watching earlier and saw the system spike to over 16kW when the condenser kicked on again. We had solar supplementing so it didn't trip the house offline but it did register. We also had low usage overall at the time so it didn't impact us at all, but at least I know why we have tripped a few times. Spike to 16kW while running other loads AND no solar as well and it makes a ton of sense.

Anyway, since Span Panel can't communicate with the Gateway it isn't going to be able to shed loads properly through the night once we hit 50% capacity in the batteries. So tonight before we go to sleep I'm going to turn off the A/C so it doesn't end up burning up the battery and causing all power to be depleted dropping my network rack and other things again.

[turtle]

Yesterday afternoon when I discovered the broken connection of Span Panel and Tesla Gateway I submitted a ticket to have it repaired. They got it working again this morning and everything worked as expected again.

This afternoon was also 48 hours off the grid... as in a little over 4 hours ago. We are still off the grid.


It is really cloudy out there today so I'm more inclined to keep going with the test while we have less than perfect weather. I was talking with Mrs T about it and we might actually take our house off the grid during overnights and reconnect during daylight when we can send surplus energy to the grid. This would have us really independent while gaining ground with Duke. Not sure how practical that is right now though. We do have a real limitation of 10kW continuous when the grid is down. Both A/C units and one other high current pull and we trip. We aren't certain how we will be able to work that... though we are certainly going to try to figure it out! The less dependent we are on Duke the better it is for us!

[turtle]

We are now into our third full day off the grid and I'm getting the swing of this. Today I turned off one of my inverters to slow the battery charging. This is keeping to solar running on the one inverter providing steady power to the home and charging the batteries.


I also told my family to start using electricity. With a 10kW limit on the batteries we can't go over that without the solar being on. If solar is producing then we can do solar + 10kW from the Powerwalls. This gives us around 17kW with one inverter. If full solar production happens then we max out the input to the Powerwalls (10kW) and production stops. Then we are back to just batteries and limited to 10kW. So I've got a hotplate running to distill water, oven going baking things, dishwasher running.... you know... Freaking my kids out because I'm always running around telling them to turn things off and here I am saying "hurry up and get something using electricity so we don't go battery only!"

This silly dance wouldn't be a problem if my batteries could output 20kW. So my next real goal is to get another couple of Powerwalls to bring my input/output capacity to 20kW. Then I can have full sun charging (15.7kW full production) and not worry if I'm only on battery.

I will say that I notice the lights flickering more now that I'm off the grid. Not horrible, but it does stand out as a thing so I have to wonder if it is damaging any of the electronics. Something I'm keeping an eye on and figured I'd at least mention it.

Edit: This is working and I'm pushing the line too!

I got REALLY close to tripping it all. Had the dryer, oven, stovetop, both A/C systems, a hotplate and dehumidifier all running. I had the dryer stopped. We are good.