Norcal heat wave

[SMAlset]

We charged last night at a SC after 10p (when Flex Alert ended). There were a few Teslas charging at that hour. This SC has a rate of .47/kWh all day presently. One SC further south I checked was same all day rate but at .45/kWh. There use to be a tiered charge, where if you charged from like 9pm to 11a it was at a discounted rate (.24/kWh commonly). Thought when I went last night that’s what I would see, although the map location did show one rate. I added 127mi for $15.36 at .47 rate. Matched what was posted to my car’s charging history.

If not for the current extremely continuous high 100+ temps, I typically charge for free off our Solar/PWs when needed. Even with our 3PW system (24 panels) these temps and our desire for AC (set to 78 degrees upstairs and down) just can’t sustain us through out night without going out to grid. Last night grid triggered at 9:55p (PWs at 20% reserve in case of outage—which clearly couldn’t handle AC usage at that point—reset today to 25%). Temp at 11p when car charging completed was 89F. We’re suppose to have another 3 days at 100+ (live somewhat inland). I don’t understand why some SC locations still have off-peak pricing while others don’t.

BTW 101 south of Gilroy buckled in the heat yesterday across a number of lanes. Repairs being made for Highway 101 near Hollister for raised asphalt – KION546

Last night maybe around 9 we decided to get takeout from TacoBell. Had just driven up and in line when all of the lights in shopping center and buildings there a bit north (McDonalds and hotels too) went dark and from PG&E map a wide swath of area past San Martin was out. I spoke to a guy charging at the SC at 11p and he said his mother’s house in Gilroy lost power and she just called to say it was restored.

 

[getakey]

curious as to why you guys charge at Charging Stations instead of home?

 

[dailo]

Looks like the peak record is going to be broken soon, a few hours before peak is supposed to hit!

 

[SMAlset]

Current Caios chart:

 

[cwied]

Current Caios chart:

Previous record was 50,270 MW on July 24, 2006: https://www.caiso.com/documents/californiaisopeakloadhistory.pdf

 

[roblab]

curious as to why you guys charge at Charging Stations instead of home?

Yeah, me too. My car charges more slowly in my garage, which is better for the battery, lets it stay cooler, and I don't have to head over to a charging site in the middle of the night and sit there playing games on my phone. Is it cheaper at the supercharger? Doesn't make sense using superchargers unless you live right next to one. I always thought Tesla charged about what the electricity rate was. No, I've got it. You don't like your spouse, and this gives you an excuse to bug out and sit in your car while you call your girlfriend.

 

[roblab]

Just came back from St' Helena, where the temp was 117. I can't imagine what people did without AC back in the good old days. Oh, wait. I remember those days. We 3 boys lay on the floor with the fan blowing from the screen door over us. It was too hot to fight or argue, and I don't remember how hot it was, but it wasn't this hot. Used to have to pull into a service station for a few minutes hooked up to a swamp cooler. Raised the humidity to near 100%. Yeah, that worked. Then we drove off with all the windows down, sweat running off of everywhere. Where did those good old days go?!

 

[cwied]

By the way, if you want to see the current grid status from CAISO in system-readable (json) format, you can get that here - updated every five minutes: https://www.caiso.com/outlook/SP/stats.txt

{
"CurrentNetDemandWithoutPumpTS": "20220906151411",
"slotDate": "09/06/2022 15:15",
"renewablesPercentwoBatteries": 29,
"histDemand": "50,270 MW",
"CurrentSystemDemandWithoutPumpTS": "20220906151411",
"Unloaded_capacity_derated_max": 15058,
"histDemandDate": "Jul 24, 2006",
"Required_reserve": 2915,
"CurrentSystemDemandTS": "20220906151456",
"TodaysPeakDemandTS": "20220906151456",
"Unloaded_capacity_4H": 7291,
"Unloaded_capacity_10M": 4444,
"currentRenewables": 12967,
"Limitation": "2990.98",
"PS_VERSION": "1.26b",
"AvailableCapacity": 61522,
"renewablesPercent": 26,
"CurrentAdjustedUnloadedGenerationCapacityTS": "20220906151457",
"todayForecastPeakDemandTS": "20220906164500",
"currentCo2intensity": 0.2859800897458747,
"todayForecastPeakDemand": 52240,
"currentSolar": 12140,
"CurrentSystemDemand": 50610,
"currentCo2": 14474,
"CurrentAdjustedUnloadedGenerationCapacity": 10912,
"OutageDTS": "07/17/2019 23:30:00 (PPT)",
"HistoryFirstDate": "20180410",
"Available_capacity": 55054,
"CurrentNetDemandWithoutPump": 37713,
"CurrentSystemDemandPlusUnloaded4h": 57901,
"Shutdown": "2501.37",
"Unloaded_capacity_1H": 4708,
"TodaysPeakDemand": 50610,
"currentWind": 684,
"tomorrowsForecastPeakDemand": 49868,
"CurrentNetDemandTS": "20220906151411",
"CurrentNetDemand": 37891,
"currentRenewableswoBatteries": 14439,
"gridstatus": [
"Restricted Maintenance Operations",
"Transmission Emergency"
],
"Current_reserve": 3760,
"CurrentSystemDemandWithoutPump": 50446
}

 

[SMAlset]

curious as to why you guys charge at Charging Stations instead of home?

As I mentioned I usually do most of my charging at home free from the sun when PWs are full, usually late morning or at noon during summer. Harder to do with these 100F+ temps and have sufficient battery back up in case if outage and have AC throughout night. More panels and PWs back in 2020 would have been great but restricted by roof design and PG&E. We were able to stack two of our 3 PWs but now wish we added a 4th stacked. Dollars and Limited useable wall space inside garage played into our decision to stop at 3. There’s still a real possibility we could have outage here, have backup for lights and refrig/freezer, but not enough for AC in these high 80s-90F overnight temps. That reality sucks.

 

[SMAlset]

Just came back from St' Helena, where the temp was 117. I can't imagine what people did without AC back in the good old days. Oh, wait. I remember those days. We 3 boys lay on the floor with the fan blowing from the screen door over us. It was too hot to fight or argue, and I don't remember how hot it was, but it wasn't this hot. Used to have to pull into a service station for a few minutes hooked up to a swamp cooler. Raised the humidity to near 100%. Yeah, that worked. Then we drove off with all the windows down, sweat running off of everywhere. Where did those good old days go?!

Your forgetting to mention the vinyl car seats and no AC in the car either!

 

[jboy210]

curious as to why you guys charge at Charging Stations instead of home?

If I am out and about, I will just stop by a Supercharger. We have a lot here in Norcal so it is very convenient, 8 within in 10 miles.

Also, I prefer to save my solar production in the Powerwalls for ensuring my house has power in our all to frequent power outages. We work from home and no power means a hit to productivity/income.

 

[getakey]

If I am out and about, I will just stop by a Supercharger. We have a lot here in Norcal so it is very convenient, 8 within in 10 miles.

Also, I prefer to save my solar production in the Powerwalls for ensuring my house has power in our all to frequent power outages. We work from home and no power means a hit to productivity/income.

I prefer to save my PWs for backup too, but wouldn't charging at Off Peak rates be the preferred method no matter what? Or are you concerned about NBCs?

 

[HardHitter]

Pretty annoyed at the install process. Install date was scheduled August 30 and 31. On August 31, installers installed all 30 panels on the roof and 2 powerwall batteries, but say they won't be able to complete the install because they didn't have all the parts. They schedule September 7 as date for them to come back to complete the install.

I get a call an hour ago from the installers (contractors) saying that they are going to need to reschedule the install to next Tuesday because temperatures are too hot. I call the company I'm contracted with and they claim OSHA regulations and stating that if they made their installers install in heat and they were to get sick, OSHA would get involved etc.

So what should have been done August 31 is now scheduled to be done September 13...

 

[Redhill_qik]

curious as to why you guys charge at Charging Stations instead of home?

In my case I was using a ChargePoint at 6.6kW because Tesla delivered my Model 3 without also delivering the mobile charger that I order at the same time. A neighbor had installed a wall charger and has let me use their mobile charger, but that was at 120V/12A/1.4kw so I went with a faster and free option to get my 50% SOC at delivery up to 85% and then I did use solar on a slow 1.4kW trickle to get to 100% (LFP battery). I now have a 14-30 adapter and can get 240V/22A/5.3kW at home from solar.

I want to try out the SuperCharger at least once, so that I can know what to expect on a longer trip and to make sure that nothing is wrong with that part of the car sooner rather than later.

 

[cwied]

I get a call an hour ago from the installers (contractors) saying that they are going to need to reschedule the install to next Tuesday because temperatures are too hot. I call the company I'm contracted with and they claim OSHA regulations and stating that if they made their installers install in heat and they were to get sick, OSHA would get involved etc.

Having just done the research to see whether or not to cancel an AYSO soccer practice today, I can say that I think this is a legitimate concern. If you want a quantitative view of how bad it got today, see here: Heat - OSHA Outdoor WBGT Calculator | Occupational Safety and Health Administration and see this table:

Workload	Limit for Unacclimatized Workers (Action Limit)	Limit for Acclimatized Workers (Threshold Limit Value)
Effective WBGT
Light	28°C (82.4°F)	30°C (86°F)
Moderate	25°C (77°F)	28°C (82.4°F)
Heavy	23°C (73.4°F)	26°C (78.8°F)
Very heavy	21°C (69.8°F)	25°C (77°F)

According to my estimate, WBGT could have been over 90F at its peak today (103F, 18% humidity, direct sun).

 

[jboy210]

I prefer to save my PWs for backup too, but wouldn't charging at Off Peak rates be the preferred method no matter what? Or are you concerned about NBCs?

Home charging rate is slow. So, when I need more than 10 kWh or so I go to a Supercharger and combine it with other activities like shopping, going for a walk at a nearby park, grabbing coffee, buying the latest gadget and Home Depot, etc. The price delta does not concern me. Well, not too much.

 

[getakey]

Home charging rate is slow. So, when I need more than 10 kWh or so I go to a Supercharger and combine it with other activities like shopping, going for a walk at a nearby park, grabbing coffee, etc. The price delta does not concern me. Well, not too much.

Got it
sounds like a variety of good reasons

 

[dailo]

Already seeing red on the outage map, looks like parts of San Jose are down hard.

 

[charlesj]

I was looking back at my logged data and the first two events on 8/17 and 8/31 charging continue from 4:00-6:00pm, but on 9/1 and the later events Powerwall charging stopped at 4:00pm. There was some very small numbers on 9/1 from 4:00-4:20pm with up to 10 kW showing up which may be a system glitch in the fleet data or maybe a few Powerwalls didn't get the command to stop charging and continued to charge from solar.

Somebody changed the behavior here, but why that was changed I don't know. Maybe someone decided the buy/sell behavior for Peak should be given a higher priority over continued Powerwall charging from solar.

Edit: Looking at the CAISO demand forecast for today the Peak demand is expected to be from 3:35-5:30pm with demand above 52,000 MW. It is probably better for the system to be using the solar for mitigating the house load and exporting to the grid during this period than to keep charging Powerwalls at below 1MW until 6:00pm when the VPP event will start. It also helps to reduce the amount of Peak imports for anyone that didn't get to 100% on solar.

Same today but now I have pictures battery at 91%, zero charging, excess to grid Even and the VPP page is 0 for all, 3519 fleet homes, no activity.

When all this VPP started several days ago, I believe the charging went to time of need and house from grid.

 

[holeydonut]

Wow, big outage in Santa Clara and South San Jose already...