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My beef with standard temperature triggered fans is that they turn on at a preset temperature. What I want for my garage is for it to only turn on when the air outside is colder than the inside, thereby cooling the garage. I don't need a fan set for 85F on if it is 95 outside and 85F inside the...

You might look into an exhaust fan controlled by a dual temperature controller (like the ones used for solar water heating). You can set the fan to exhaust warm air from the garage space whenever it is warmer inside than out. You can then leverage any overnight cool down to precool the garage...

I would wonder how insulated your office floor is, especially if the garage doesn't have an insulated door. I had an office over an area exposed to the outdoors, and the floor only got warm-ish after I blew in 24" of insulation. Obviously, the reverse case for you. I think that mini-splits...

Welcome to TMC! Are you adding two more powerwalls, or staying with just the one? All the best, BG

For PG&E, you can tell them that you plan a second EV and more electrical appliances. On that note, you may want to wire in the power for those appliances before Tesla arrives. Altering your electrical panels after solar/Powerwall installation becomes complicated. Based on your numbers above...

@tuomo @Redhill_qik I pulled the heat pump data from energy.gov Thanks for posting real world data. All the best, BG

Once you have solar, you will probably want to change your car charging to the daytime on days that you aren't out, as there is no point in taking the 10% energy loss of taking solar energy, putting the energy into the Powerwalls and then taking it back out. A second EV will cost you...

@wwhitney Sorry! I missed that the URL was the same. But yes, worth repeating.

FWIW: I have seen HDPE (high pressure lines), black iron pipe, galvanized pipe, aluminum, stainless pipe, and copper tubing used in gas service. Everything in the photo looks good from a distance. As galvanized is prone to flaking, I have never been a fan, but I have never seen a problem either...

Get the bigger system. The marginal cost isn't much, and you are likely to use the additional production one way or another. e.g. more electrical appliances or more cooling/heating, or more miles driven. If your system lasts for 15 years, that additional $5k will be generating power at a locked...

I agree that the loss is really happening as energy, but since the transaction ends up getting priced by the utility, I decided to do the math as dollars and cents rather than kWh. From the energy perspective, what gets put in gets shaved, as does what is in the battery, as does what comes out...

For EV2A, here are the values that I used; Summer: For peak: buy $0.60, sell $0.56 mid-peak: buy $0.30, sell $0.27 off-peak: buy $0.17, sell $0.14 Winter: For peak: buy $0.45, sell $0.41 mid-peak: buy $0.33, sell $0.30 off-peak: buy $0.16, sell $0.13 I am not saying that these are "right"...

I took a page out of @Redhill_qik's work, and made the sell price lower than the buy price by both the Powerwall efficiency loss and the NBC, and it seems to function reliably to use the solar for the house first and grid second during the peak period, until the solar production tapers away and...

I'm curious how many of you have been approved? My request still shows "pending". All the best, BG

In going back over your wiring diagram, I realized that I did make a mistake reading your power diagrams. Your string data only shows four strings, and string A shows voltage but connected=false, which isn't right. If there is nothing on string A, there should be no voltage, and since there is...

I would call Tesla as you don't have the option in your app, and point out them that part of your array seems to be unconnected, (MP2&5) and that your output power appears to be low, finally that the head installer said told you it wasn't performing and never returned to fix it. Keep calling...

And to make it worse Schneider has two different lists themselves.

I think @wwhitney's point is that just because the wire goes to the breaker, it doesn't necessarily mean that the other end goes to the the AC, and vice versa. My bottom line: I suspect that it is time for a professional to dig in to what is ailing this panel. All the best, BG

Maybe. The enclosures can still corrode, and since the materials exposed within the enclosure are different alloys, there is the probability of corrosion. My point is why run the risk? I would adjust the irrigation to get the water to the plants that need it and not to things that don't need it...

@RKCRLR what is wrong with your Enphase system?

(I am not an electrician. IIf the pink and purple wire share a neutral, then that would make them a multi wire branch circuit, and I believe that the newer codes require that the poles be connected. Nevertheless, if it is 12ga, and the wire goes only to the microwave (I.e. the microwave circuit...

I think that your concerns are valid. However, deviating from your permit may cause issues with your AHJ, and you run the risk that the installers may not have the conduits, concrete anchors, and fittings for what you are proposing on the installation day. Others here have put up solar shields...

@komrade that purple wire looks to be 12 ga; is it? Second, is there a neutral wire associated with it? In the photo, there doesn't look to be one. All the best, BG

@komrade Can you post a photo of the breaker? If it is a multi wire branch circuit, the latest electrical code requires that both poles to be connected, I.e. looking like a 240V breaker. All the best, BG

It is not just earthquakes for us. Fire, old IOU equipment and wires routinely giving out, and of course the next big solar flare... I think we had more than five fires within twenty miles of us this week. Car crash, poorly maintained IOU equipment, lightning, are amongst the suspected causes...

If you have truly sensitive equipment, you may want/need a double conversion UPS that does AC to DC to AC, constantly running your loads off of batteries that are always being charged. Like others, our experience with outages is that while there have been a couple of times with a short, three...

Just in case you were sleeping well; we are entering what is forecast to be an exceptionally strong solar cycle. If you thought the current supply chain problems were problematic, this article works through how much worse a Carrington event could be. Aka, "why you might want Powerwalls and...

Why would you buy a durable item that you will have for decades if it isn't what you want? Go through the redesign. Yes, it is a process, yes, it takes time, yes,y our have to be diligent about calling to ensure the process is on track. All of that goes with the low price. All the best, BG

And now fire blankets to limit the spread of fire; https://www.allhandsfire.com/Bridgehill-Lithium-Battery-Fire-Blanket available for vehicles as well...

Interesting; I have never seen a surge suppressor like that. Do you have links to surge suppressors that shutdown their loads? Thanks! BG

Having lived other places with arguably fewer natural disaster risks that had better power/communications quality, I just find it odd that places like the Pacific coast and Florida don't have more resiliency built into their grid and telecommunications systems. Locally, I find it even stranger...

Surge suppressors just keep voltage spikes from harming your electronics. They have no power backup function. There are any number of outage scenarios where it can take the Powerwalls a fraction of a second to seconds to respond and take over power delivery. If you are curious, there are a...

Given earthquakes and fires, you would think that cell towers would be required to have days of back up power, but that's not the case in most places, and certainly not in California. It is worth thinking about what your backup communication will be. Email can be a good option because it can...

My bad; I missed that it was an outage. No worries. All the best, BG

Sorry to hear it. Given your location, I am curious what sort of lightning protection/surge protection you have. Care to share? All the best, BG

I would call installer. Now. Something is not right in the gateway, or connection to the Powerwalls. What I find interesting is that it looks almost as if your solar connection is loose and it makes contact, heats up, breaks open, cools, and then makes contact again. Has your system always done...

Or just one ethernet cable and put a POE switch there if you have to... Like @jjrandorin, I would be inclined to just run one and go from there. All the best, BG

Oops! What does your Gateway say its current settings are? What is your layout, e.g. similar to what @GWord posted above? All the best, BG

You are welcome! There is a small chance that in an off grid situation if the house loads are low, and the solar is running that there will be too much current for the Powerwalls to charge. Given the size of your house loads, it is probably unlikely, but it has happened to other folks here. (If...

@holeydonut just a warm up exercise for next week's heatwave. ;)

@miimura answered #1. You are good. #2, if Tesla uses that main service panel, you will have a large load and a small load section. As you will have three arrays, that seems about right, and gives you the option of a second gateway (covered in my prior post) and fully backing up all your...

One gateway can only switch 200A of load. If your remaining load can be shutdown during outages, one gateway will be sufficient. If you want all of your loads backed up, you will need two Gateways to switch the total load. Having two Gateways means that you would then have to partition the solar...

Not that it is relevant to what the Oakland Fire is enforcing, but Tesla has a well defined protocol for fires. https://www.tesla.com/sites/default/files/downloads/Lithium-Ion_Battery_Emergency_Response_Guide_en.pdf

@holeydonut Thanks for the PSA! FWIW: there is a slightly different list of affected panels on the Schneider Electric website; https://www.se.com/us/en/work/products/local/safety-notices/2022/qo-pon-loadcenters/ and yet a different list here...

I think @wwhitney and @Vines are the experts on this. Some jurisdictions have requirements around the type of smoke (heat) alarm installed in a garage to go with ESS with requirements that it be connected to the main house alarm, but I have no idea about the City of Oakland. Have you called the...

I never thought of dividing the MDC by the NBC. That is a great way to look at it. Thanks! All the best, BG

MCI: Mid-Circuit Interruptor rather like a safety switch to keep your panels out of trouble. per Tesla; "The Mid-Circuit Interrupter functions as a Rapid Shutdown Device and is installed to be within in compliance with NEC 2017 and NEC 2020 where conductors are within 1’ of the PV array. When...

If you and your family are absolutely creatures of habit, the "zero brain" version would be great.👍👍 It does however neglect your usage in peak TOU, but it could just use yesterday's peak TOU usage. The algorithm would wake up at the start of peak period every day, do one calculation, set the...

I have no knowledge of Tesla's algorithm. I have however written a few algorithms. I don't know if this helps, but here is how I look at the discharge behavior. If you discharged the solar directly to the grid, you would get credit for 1kWh at off peak, or mid-peak rates. If instead, you put...

Lithium battery chemistry really constrains the allowable temperature range, and at some point the battery makers would have to bite the bullet and add refrigeration, which is energetically expensive... The thing that kills many batteries is dendritic growth, and their growth is enhanced by...