You should definitely contact SRP and present your evidence. It could be that the false peak demand values result from peak export instead. The trouble with go-off-grid is unrelated; that would be a Tesla question.
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SRP demand (kW) number is huge different with Powerwall app
- Thread starter SuperCarrot
- Start date
Thanks for the advice. In summary, there are 2 issues on meter reading: 1. battery consumption (usage and demand) is treated as grid consumption. 2. solar export power is treated as grid demand.
I just made a call with SRP, their representative guaranteed their meter is capable for net metering. He said since I'm a new user of the plan, my SRP's generation data graph is not showing up yet, so it is unable to analyze the data for now. He let me wait for the generation data. And he also mentioned for the first few days of a new plan, the data may not display correctly, it will get corrected at the end of billing cycle. I don't know if this is true or just an excuse.
I also contacted Tesla, their representative let me send them SRP hourly data and may respond me in 7~10 business days. So it looks like what I can do for now is nothing but waiting.
I just got my first SRP bill, although I can’t see the PDF yet. I switched to Average Demand in February and am noticing similar behavior. SRP is saying I have grid demand while my Powerwalls are discharging. When solar kicks in, my demand is 0 so I know everything is wired “after” Solar. SRP doesn’t appear to recognize the Powerwalls discharging.
When you say “resolved”, did SRP go back and see all of the Powerwalls discharge and change the bill amount?
When you say “resolved”, did SRP go back and see all of the Powerwalls discharge and change the bill amount?
Hi Bailey, we are on the TOU E-13 plan, where SRP charges us a $32 "maintenance fee". I have our system set on self-consumption and have seena steady decline in our SRP bill. February was $36.38 and March was $26.29. So we have produced enough to offset the $32.
We run off the panels in the day and then the PWs at night. (9.45kW panels and 2 PWs).
You didn't say the plan number. As I said earlier, we are on the E-13 plan. also, it will take SRP like 3 months to send you paper bills.
I am installing a solar system with PW with Tesla under SRP. I am interested in knowing more details about how your issue were resolved, and any strategy to lower the demand charge will be greatly appreciated. I feel there is another possibility to your issue: if your whole house is backed up by the PW. If there is an A/C or appliance not backed up by the PW, then you will see charges outside of the Tesla system.
Make sure you are on the E-13 plan. There is absolutely NO demand charges under this plan. There is a mandatory $32 "service fee", which can be lowered by excess production, (my April bill was $25.76). We have a 9.45kW system with 2 PWs. We run off the panels in the day, and the PWs at night. I am looking forward, (tongue in cheek), to summer to see if the system will still perform well with the a/c running at night.
Thanks for your reply! The $32 meter fee is the same for all solar plans. The reason for me or others considering the E-27 plan is because its much lower cost per kWh (~ $0.04-0.06) and higher credit (same as your usage rate, i.e. $0.04-0.06/kWh) for export back to the grid. As long as you can fully shift your peak usages by PW, you can save much more. I am not sure if you ever considered it, but I see you have two PWs that could fully shift your usage with zero demand charge (depending on your house), which will save you more, but it can take some practice. SRP mentioned that you could install a "Demand management device" to avoid surprising demand charge. I checked but found it is hard to find good info and company for that. Anyway, I may start with E-13 to see my demand usage, then consider E-27 based on my usage.
I did look at the E-27, but seeing the Demand Charge costs, I figured you could wind up with $50-100 added on to the bill during summer if you exceeded power input from the PVs or PWs. Just don't want to chance it. I'm pretty happy with the way things are going on the E-13. FYI, SRP says you have to stay on the plan for a year cuz they don't want to change the meter so often and be able to equalize out the billing.
I would seriously look at the E-27 and probably the slightly better E-15 (the latter averages the daily peaks so soothes out the occasional cloudy / very hot day). To your point these plans given you access to net metering and a very low rate as long as you can load balance. I'm on the E-15 plan now (was on the E-27 for the first year and it was annoying that 1 day skewed bills so I switched) and with 3K sqft efficient home with 2 heatpumps (5T & 2.5T), 8.4Kw Solar a 1 Powerwall 2 I can generally ride out summer with minimal demand charges (this winter I've had $0 of demand charges but the averaging heled a couple of months). With 2 Powerwalls 2's this would be easy to manage.
I am planning to install solar and 1pw for my home too. It's in design phase now. I just installed a smart energy monitor from Amazon with 8cts. So, I am monitoring all the usage of all high power equipments( 2 AC, EV, dryer,hot tub, oven ). I looked into demand management device and it's noting but a smart monitor with relays to operate breakers in panel(open when demand goes high). Instead you can write a IFFT and configure your ACs or devices to turn off if other devices are ON. That will eliminate your demand charges. This is my plan and I will try it in a few days. Is anyone already doing this?
Maybe this has been hashed to death. Does anyone have a good understanding for Tesla's PW specs?
Tesla defines the max operating temp of 122deg but recommends a max temp of 86deg. It sounds like Tesla de-rates PW load for temps above 86deg. If so I gotta wonder how PWs hold up in environments like Phoenix where it can be 100deg at 10p.
Tesla defines the max operating temp of 122deg but recommends a max temp of 86deg. It sounds like Tesla de-rates PW load for temps above 86deg. If so I gotta wonder how PWs hold up in environments like Phoenix where it can be 100deg at 10p.
Nothing electronic benefits from added heat in my opinion, and times some large integer for chemistry.
If I were planning a battery installation in, say, Phoenix, I would do it indoors, in an air conditioned area. Sure you could install it outside, but what is the upside?
I think the tip-off in the specification sheet is the maximum storage temperature, 30C/86F. That would be my target.
All the best,
BG
If I were planning a battery installation in, say, Phoenix, I would do it indoors, in an air conditioned area. Sure you could install it outside, but what is the upside?
I think the tip-off in the specification sheet is the maximum storage temperature, 30C/86F. That would be my target.
All the best,
BG
I highly recommend you get at least 2 PWs, we have found out that our PWs only make it to 9-9:30pm with the A/C going more now. We moved the temp up to 76 degrees.
Sorry BG, but if you read the sheet, the max operating temp is 122 degrees. Not 86 degrees.
There are three ranges that Tesla and most vendors publish
- Storage which is -20C to 30C or -4F to 86F and is for the unused/uninstalled condition
- Recommended which is 0C to 30C or 32F to 86F and this is the preferred environmental conditions
- Operating which is -20C to 50C or -4F to 122F and is the range that Tesla guarantees that the device will operate and meet the specifications
Looking at the operating range, I am shocked that equipment that is mostly installed outside has a low end range of only -20C/-4F this should really be -40C/-40F unless the number is something other than ambient temperature. The same for high end as 50C ambient is usually a data center number and for equipment that is outdoors this should be 70C/158F or higher. I'm glad that I'm in a relatively temperate section of California and mine are mounted in the garage.
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 elevated temperature. That is why I was pointing to the allowable storage range, as it is a pointer to where the battery pack/chemistry is most stable. (nice catch @Redhill_qik, I probably should have emphasized it in my prior post)
High temperatures and high states of charge also bring the battery closer to thermal runaway temperatures, which is a different type of failure.
All the best,
BG
