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0% for now because of 110+ temps in AZ and 2-8pm peak period - trying to avoid a peak demand charge. I may bump it back up when the temps come down but the system generally retains whatever was left on the table after the peak since it is set to cost savings mode. The remaining charge after the...

Here is our plot from yesterday (car charging at 9:30p)

Sorry for the late reply - I haven’t logged on for a while. Here in the Phoenix area during summer, with 2 Powerwalls I can usually run the house through our entire peak period of 2-8pm without using any grid. It does eat through most of the battery though by end of peak.

My wife and have basically those same two cars (2017 S 75 - wife’s and 2018 3 Perf - mine). As others have said, different use cases. My wife does wish we would have gotten the 75D instead of the 75 because of the increased regen, but even then she’d prefer the 3 as a driver’s car as I do...

CleanTechnica asked the question too at Tesla Autostopping — 7 Notes On New Autopilot Feature | CleanTechnica - what does TMC think?

Or even in the Tesla world.

Can you help me understand why a single shoulder period works better than a shoulder at 5a and a peak at 5p? I haven’t tried a single shoulder so you may be correct, but intuitively I would think the Powerwall would prioritize peak over shoulder. In my case, if the battery ever gets into a...

It generally does what I want - typically not much from the grid in the morning peak and when I charge the Tesla at night it usually uses grid unless there is a surplus of battery. Having two “real” peak periods might be slightly better in some cases.

I do 5pm-9pm peak, 5am-5pm shoulder, 9pm-5am off peak. I figure this makes it so it will try not to use the battery during the morning peak, but try harder during the evening peak. Since there is usually plenty of solar in the middle of the day, the shoulder there doesn’t really seem to matter.

We have 8.2kW DC like you in the Phoenix area and today got 6.7kW peak around noon. If you didn’t have clouds around that time I’d expect you to get similar. What facing are your panels? Ours are all south facing and the roof angle is probably close to ideal. I’ve 7kW or more this fall, although...

We have two peak periods during winter, 5a-9a and 5p-9p. As a workaround, I set up my peak hours from 5p-9p and a partial peak period (everything not peak or off peak) that starts at 5a. We don’t need as much power from 5a-9a, those hours get a little solar, and Powerwall avoids grid usage...

Probably about when I got it too. I wish they wouldn’t go into standby to do an update during peak hours. This update cost me about 10 bucks in demand charge.

I’m in Arizona with a relatively new install (PTO 10/18) and got 1.41.2 on 10/31. So far my self-powered scores seem to be much higher and the system seems smarter about when to discharge the Powerwalls on Time-Based Control. Lots of variables though so not sure if it’s the software update or...

Thanks - I didn’t mean to sound like I was bragging about our units. What you did at $5k is impressive and I have to hand it to you there and I’m glad it worked out. I was just using our units as a data point about effectiveness of high SEER units here in AZ. Far as I can tell the efficiency...

All things being equal, I imagine if the best single stage A/C unit (~16 SEER) were pitted against the best variable speed unit (~26 SEER) and both were set to full blast all the time, they would roughly match efficiency. Variable speed units gain efficiency over single stage units because they...

We actually replaced two four-ton 13 SEER units with 20 SEER units here in AZ. First full month in September showed about a 30% decrease in overall energy usage YOY, implying greater than 30% of A/C energy decrease as advertised. I’m not sure the high temperatures bothered them. Will they ever...

Here’s hoping! Thanks for your help.

I think maybe the missing meters (yet to be installed by the utility) are in series with the breakers. I actually asked one of the installers if it was possible to disconnect from the grid and use the system prior to PTO but he said it wouldn’t work because the meters needed to be installed.

I’m not sure this will work yet unfortunately. When they tested the system they had some bus bars installed in lieu of the missing power meters, but they pulled those before they left. So I imagine it might be an open circuit even if I flip the breakers to turn on the system?

Tesla installed our solar and Powerwalls on Tuesday and we are now waiting for SRP interconnect. They tested the system briefly but left the Powerwalls basically at 0%. Anyone else with a new installation have their Powerwalls left completely discharged? I know there is a buffer but I worry that...

Too bad arbitrage isn't feasible. We could buy power from SRP off peak and sell it to APS on peak.

If you pay cash, simple payback should be close to 10 not considering time value of money. Net cash outlay on 8 kW and 2 PW after federal tax credit and SRP battery rebate should be a little over $21k. If you can drop to $32 per month on average and save $182 per month, you would save $2100 per...

I get where you’re coming from. 4 kW and 1 PW might be cutting it close for our house when it comes to demand mitigation on cloudy days. 8 kW and 2 PW might be overkill in cooler months since we have gas heating/dryer, so it would be nice to drop below $32. Simple payback on 8 kW and 2 PW could...

Interesting - that’s good news. My interpretation of page 5 of https://www.srpnet.com/prices/pdfx/April2015/E-27.pdf was that the floor was the service charge so good to hear an actual experience.

I don’t know if they have intent to soak people here, but one other thing that’s a bummer is not being able to drive your bill below the minimum service charge of $32.44 per month even if you sell back lots of energy during peak. At least that’s the way I read it.

That’s awesome. I’ll bet SRP won’t give you a negative demand charge for negative peak demand, though. ;)

I’d also guess a bit of cloud cover passed over about 1 pm. You can see the power output dip and then jump above the rest of the curve. Presumably the array cooled off a little and temporarily gained efficiency until it warmed up again.

Sounds like healthy skepticism. Tesla battery chemistry and thermal management is pretty impressive on their vehicles that have been out there a while though, so I’m cautiously optimistic. When the batteries die I guess we should still have pretty decent PV arrays.

Thanks for the info. Looks like the trade off is in the temperature coefficient: the Hanwha panels lose 0.37% per degree C whereas the Panasonic lose 0.258%. But since we’re playing the demand game here maybe it doesn’t make much difference. Link to the “discontinued” Panasonic 315W is: N315K...

Our A/C units were pretty old so we replaced them with two Lennox XC20. They have a startup current of only 20 amps each. Tesla checked the specs and they said they could be backed up.

Exactly what I signed on for as well recently - SRP just approved the design today. I agree that 4 kW and 1 PW might have been a better ROI but like you said it depends on whether your house can make it through peak. Anyway, with 2 PW I can back up our A/C that we just replaced with more...

When I was in talks with Tesla about backing up our new Lennox system with only 20 LRA per unit they implied there was even more to it than LRA. Still not sure what - maybe power factor? In any case I sent them the spec sheet and it worked out, but it would be nice if they published all the...

Our air conditioning units were pretty old and inefficient, so I proactively replaced them with Lennox XC20 variable speed units so the Powerwall system we are installing could back them up. LRA is only 20A. They are more expensive units that won’t ever fully pay back even with the higher...

Cool - what does your energy usage look like during those hours?

@JayClark, how much electricity do you use during the SRP 2-8pm peak period? I’m also planning to try to mitigate peak demand via Powerwall here in AZ but figure it should be possible for me to get through peak with 8 KW and 2 PW on ~3200 square feet, even on most cloudy days. For example on...

I will probably end up with a setup like yours with A/C and 14-50 plug backed up by 2 Powerwalls. But with every load in the house turned on, the Powerwalls alone couldn’t keep up. Without solar, or if solar cuts out due to cloud cover, will a breaker trip to protect the house from brownout?

Tesla has a quick rule-of-thumb calculation here that may help provide some intuition: Solar Panels Monitoring | Tesla Support

I'm with SRP in AZ. In my case it's selling back to the utility that is poor. I would get anywhere from 3.6 (off-peak summer) to 6.2 (on-peak summer) cents per kWh. And that's on a plan that makes the most money selling electricity. Another plan pays only 2.81 cents. So I'm probably not going to...

I’m planning to get an 8kW Tesla system with 2 Powerwalls. We don’t have many outages either but in our area selling energy back to the utility is almost worthless, but reducing on-peak demand can be very worthwhile. So the Powerwalls should end up helping quite a bit in our case. Our utility...

I haven’t been down this road yet but in practice it seems like Tesla may be correct. SRP pays $300 per kWh of DC capacity and the Powerwall specs indicate they have 13.5 kWh usable.13.5 * 300 > 3600 so I think one PW would hit the limit.

And he mentions the McLaren 600 in almost the same breath. Interesting juxtaposition.

Maybe you have me confused with someone else - I don’t think my post requested a 360 view. Regardless I see what you mean and stand corrected. For some reason I was thinking there were rearward facing cameras closer to the back of the car. Unfortunate.

What I’d considered a crazy fast Mustang. The Model 3 would wipe the floor with it, though.

I’m not sure. Have you seen the Autopilot camera views stitched together at ? I’m just asking for a way to tell if cars are coming laterally when pulling out. The cameras look like they have enough field of view to see vehicles at those angles. Granted, it’s a harder software problem without...

This. Or at least cross-traffic alerts when reversing. I’m surprised Tesla hasn’t done this yet - even the weak sauce ICE loaner I had once was able to do this. I mean Cuphead looks fun and all, but...

And that’s gotta be worth something, right?

Right, put PS4s on your wife’s AWD and I’ll bet she stops just as fast when the brakes are relatively cool, all things being equal.

I’m a Performance 3 owner in the Phoenix area. 1. Can’t get 18s or 19s from Tesla but aftermarket options are available. I wanted 19s but since Tesla didn’t offer I just stuck with the 20s. No problems yet and I’ve averaged 281Wh/mile vs 250Wh/mile rated since last September. I tend to like the...

A team of German engineers painstakingly redesign the crankshaft. After months of combined effort, they achieve a 40hp increase and congratulate each other. Meanwhile at Tesla, Elon gives a lone software engineer the nod... After a few keystrokes to change a line of software code, Tesla Model 3...

Surprise! Are you delighted? :rolleyes: