Search results

Wow. Only 100A current capacity compared to the 200A capacity on the current unit. I have a 400A feed and a generator, so was really hoping the next rev of gateway would support 400A, or at least support controlling a real transfer switch that can handle arbitrary current. Not being able to...

miimura, thanks for the note. The houses are near each other, but not adjacent or in the same city, but are in the same county. I gather you are saying the answer is no? :) thx mike

Guys, may I ask a PG&E question thats slightly off topic? We're building a new house not far from the house we live in now. That new house is bigger, but has some issues with solar generation because of trees and style of the roof. Our existing house has just about optimum conditions for...

Well, with a hybrid car, you could still get the EV-A rates correct, even if you didn't charge it that much? We have a Pacifica Hybrid, and charging it at night would be only a modest cost impact, but could still provide access to EV-A rates. Too bad the car can't push power to the grid off...

Am I reading this right that the EV-A rates have no banding based on usage? As someone who gets hosed regularly for band 4 and band 5 pricing, it would seem to be a big deal to get out of that curve. Also, does that mean that if I push power to the grid in the peak hour I'd get paid $0.48/kWH...

I think Tesla is focused on being able to make money on electric cars. I don't think it's an accident that while they are cutting jobs here to the bone, they are investing in China. Lower wage workers and much less aggressive environmental laws there should enable them to make more cars faster...

Most of the big name US systems need a lot of amps to start up, but still run at full speed. These multisplit systems, like the Fujistsu in the pic in the thread can start off as low as 5A and then gradually scale up to full speed as needed, and are much more efficient too. If you want to...

The larger new APC UPS's go from 47-65 Hz, so that's good, at least for me. Though all these gotchas (generator interfacing, only 200A gateways, no availability and uncertain timeframe for installs, etc...) are starting to make think I should just give up on trying to use powerwalls and just...

ai4px, are you a ham? If so, you need to be very careful about inverter choices. Many of these units, esp solaredge have terrible RFI from the DC-DC converters that are in the optimizers. At least the older optimizers destroy everything between 40 meters and 15 meters. Older enphase...

+1 Even better is that generators run a low efficiency at low loads and can get soot build up if running at less than 10% of capacity, but if you want to back up the whole house, you need a big generator in order to handle the peak demands. Coupling a generator to a set of powerwalls allows...

I suspect the google.com fetch is a Internet connectivity test. Google is almost never down, so if it cant be reached, it means there is an issue with Internet connectivity. Yes, there are more sophisticated ways of doing this, but clearly they did a hack. It's good to know though, as with...

I did get a call from TE about the Solar Roof as I had requested info on it fairly early after the announcement since we are building a new home here in the Bay Area. The timeframe sounded like early 2019, but that was beyond my window so declined further involvement. thx mike

Maybe there is a space designed in underneath the tiles so the roof is elevated a bit over the roof underlayment? That might also result in some airflow to cool the tiles as well and improve efficiency.

Meh. No details on specific costs, wiring diagrams, inverter configuration etc... What kind of story is this?

Well, if you connected it the way I outlined in my note, you never have the generator on at the same time the solar inverters are connected. You don't actually want that to happen, because the solar could generate enough power to backfeed the generator and fry it. In my scheme, the generator...

The problem with this approach is the house load ends up having to be supported by the residual PW2 reserve, which may or may not be adequate for lasting enough until the solar kicks in. Even then, it could be a cloudy day and not enough power being generated to support the house load. This is...

Welcome and thank you for doing this!!! A few questions: 1) When is a bigger gateway unit coming? The current unit handles a max of 200 Amps, and I am building a new house with a 400A feed, so a 400A unit coming out in the next few months would be great! 2) The current approach for...

Your idea might work, but I think the efficiency of those conversions will be terrible, and the warranty for your solar inverters will almost certainly be voided by feeding it DC from a generator. I would also worry about how you deal with grounding, as those small generators are really not...

This is an interesting. My main problem with the way Tesla engineered the powerwall setup is that when the PW reaches 0 charge, the solar can't charge the battery anymore, because the inverter needs line power for the inverters to turn on. Even if you were feeding DC power from a generator to...

Interesting. is this via adding a 3 phase inverter, or making a DC version that can be more easily integrated? thx mike

If Tesla had followed through on their original plan to have a DC version of the PW 2, then it would have worked fine with Pika and all the other hybrid inverters. In fact, we'd have full support right now for generators, offgrid use, TOU shifting and a whole host of other applications, as all...

I think this is maybe a bait and switch. People are all excited about powerwalls, but since they aren't available, how about we sell you basic solar, and add the PW later? Trying to bring back some SolarCity sales volume maybe? Maybe they are trying to prevent others from getting in there...

If they are are really doing this, how come supply of PW's seems so poor? Or is this just another vehicle for selling SC solar installs with conventional gear?

Higher end gensets don't do that. I am looking at used gensets from cellsites that are available at a fraction of list price and generally very well maintained. These are all most 1800 RPM and locked to that speed, and the engine power adjusts based on demand to spin the generator end at a...

Kohler has a whole set of NG/LP generators starting at 8KW. There are a of industrial generators in the 20-30KW range. If the PW was DC, it could be integrated with some hybrid inverters that have generator inputs, and this would all be much easier. But Tesla likes building things all by...

yes, thats what I think was described, but I am having trouble understanding how the automatic transfer switch avoid turning the genset on when the PW kicks in. It's just looking at voltage from the grid, and would have no way of knowing if the TEG has disconnected the loads. So in this...

Dhu1 does - he talked about it in this thread...

DHU1 and others, I realized I am missing something significant in my understanding of how this all works. In the normal situation without a powerwall, when the grid goes down, the transfer switch will detect that, initiate a generator start, and when the genset's voltage hits the required...

Well, first off, I travel quite a bit, and I don't want my wife having to try and figure this out if I am not home. Secondly, I am a software engineer, and have a rack of servers that burn about 2kw's on a more or less continuous basis. Some of that will power down in an extended outage, but...

I think you still need a transfer switch. The TEG seems to just break the circuit, not switch it to something else.

This is always about statistics. If you have an outage during really rainy weather with little sun, or someone in house does something that burns a lot of power without realizing what's going on, you are going to still have situations where you will run out of power. More PW's reduce the odds...

Interesting, so you have to do it manually? No way to set a timer or take input from a signal of some sort? Can you program in a reserve so it would shut off at 15% or 10% instead running almost all the way down? Can you power cycle the powerwall from the app if the network connections are...

Hi everyone. I'm still trying to understand the behavior of the system as I try and see if getting a set of powerwalls makes sense for me, esp if I use them instead of a generator for backup. In the normal self use optimization mode and backup modes, what happens if the powerwall runs out of...

Makes sense and that load is easy to demonstrate in my case. This would be in the SGIP large storage claiming ITC category, coprrect? Any other differences in how SGIP works there from the normal residential? How do I calculate the value of the rebate? Is there an online calculator I can...

Again, super helpful - Thanks! How exactly is peak demand calculated? Peak in terms of 5 min, or an hour or a day? The house is big (9000+ sq ft), plus a pool (gas heater on that though) and will have a 400A PG&E feed. No Teslas, but we do have a hybrid minivan that is good for 50A itself...

This is super helpful. Sounds like I need to decide on the powerwall option now and apply rather than wait for everything to get built and do it then. Is there a limit on batteries? Could I have 3 or even 4 if I wanted to (it's a big house) and still qualify under the SGIP program? Audi...

So for SGIP, how long do you have to after applying for the credit to actually install all the hardware and pass inspection? I'm building a house but it won't be done for another 9 months or so... We're in the process of designing all the solar etc... now, and I am wondering if we could apply...

You have a fair point in being able to turn down demand. My worry is my wife being able to do that if I am away on a work trip, etc... Heating is not so much a problem because the house is new and will be very well insulated and tight, plus we have Mitsubishi heatpump system in it that can...

This is a good question. Yes, we'll have solar, and plenty of it - that's why I am thinking about powerwalls instead of a generator alone. I don't think powerwalls alone are reliable enough given variations in weather to be counted on to provide power as a alternative to generator service in an...

I am in the process of building a house with genset, and making electrical system choices soon (type of panel, transfer switch etc...) . If I call Tesla, would they help me design this properly, or want to wait until the house was done? thx mike

Any updates on generator support?

Well, you know the times when the inverters won't be generating any power - the times of the day when it's dark outside. As long as you know the time and date, you can tell if it's daytime. You can also tell if the the grid is active from the automatic transfer switch. When it comes back you...

I bet they are going to include a transfer switch to isolate the home from the Grid, just like Tesla does. Maybe they'll even give it a misleading name like Tesla does. :)

I think what you want is something where the PW's or a "gateway" tells the transfer switch what to do, not the other way around. I guess you could have some 3rd party device that is self powered command the PW's and the transfer switch all over the local network. Can the API tell the PW to...

I think the way to support this and deal with the off grid case is pretty straightforward. You have a transfer switch that connects the house load on one side to either a genset (and/or Grid), or the solar inverters AND the PW's on the other pole. By separating the loads from the inverters...

On most of the solar forums, Solar City had a very poor reputation for installs - sloppy wiring, too quick to say they were done, etc... Maybe with the Tesla acquisition that has changed.

It depends. For a conventional air conditioner, you are right, starting current is 100A and then runs all out at 40A. But a VRF unit or a Greenspeed unit with a variable inverter based compressor can start out at 5 amps, and then grows as demand grows. It's not all on or all off. These...

Aren't these the Solar city folks that everyone hated?

Which option is that? And which POCO offers that?

This has me intrigued. What exactly do you mean by more refined control? You mean through home automation? I know the old separate panels don't seem to be very common anymore - whole home backup makes sense if you can afford it. The house does have gas piped to it, so even a larger genset is...