If ones peak vs non peak is not any big deal, what is the value of even using batteries when the grid is up? One loses 10% with the batteries.
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What hours should I run my Powerwalls
- Thread starter Merrill
- Start date
I am on TOU-C. set peak for 3pm to 1am. Reserve 10%. Without AC so far much, 99% off grid. Batteries recharge around noon.
I am also on TOU-B, 3 Powerwalls and 15% reserve.
M-F
Peak: 4-9 PM
Off Peak: everything else
Shoulder / Partial Peak: Not used
Sat / Sunday
"All day off peak"
skepticcyclist
Member
My billing has peak rates from 4-9 at $0.41 and off peak at $0.17. So I set mine to Balanced with peak from 4-9 during the winter. I run off the battery during peak and impermanently during the night until it reaches my reserved settings.
During the summer I set my peak to 7-9 and shoulder from 4-7. This way I still use much of the solar during the 4-7 hours with the battery providing the balance that solar may not provide
During the summer I set my peak to 7-9 and shoulder from 4-7. This way I still use much of the solar during the 4-7 hours with the battery providing the balance that solar may not provide
I don't set any hours other than the peak. 4-9 PM. The Powerwall Gateway makes all the other decisions, and at 97+% self-powered seems to be doing a good job. From what I read, the advanced modes use a Machine Learning model that gets tweaked with your usage pattern.
Unless the battery is low or our load is very high, during the peak we are powered by the batteries. After that time, we usually have sufficient charge to cover us until the next day when solar takes over.
Because I need to send as much power back to PGE for credit so it can be used during winter. For folks who have gas heat, one never has to worry about it. But for folks like me that have electric heat, it actually takes more than AC. So, without NEM2, and 99% electric, solar would not make any sense from an ROI.
Ok, I really appreciate everyone’s input but now I’m very confused it seems like hardly anyone is doing the same thing with their Powerwalls. My main goal would be to use the least amount of grid power but also get as many credits during the summer to help offset the winter usage without as much solar.
RKCRLR
Active Member
As others have mentioned, it depends on your goal.
My goal is to have a $0 true-up while minimizing the use of the Powerwalls.
I use Cost Savings mode, set the Peak to correspond with PG&E's peak , and set shoulder to start the same time as Peak and end at midnight.
Right now my reserve is set at 60%, I'll tailor that to hone in on the $0 true-up.
But my system is sized such that my total solar production is about equal to my annual usage in kWh.
My goal is to have a $0 true-up while minimizing the use of the Powerwalls.
I use Cost Savings mode, set the Peak to correspond with PG&E's peak , and set shoulder to start the same time as Peak and end at midnight.
Right now my reserve is set at 60%, I'll tailor that to hone in on the $0 true-up.
But my system is sized such that my total solar production is about equal to my annual usage in kWh.
This is what I believe I am trying to do. I use 99% from battery and solar. Ship back all my solar when batteries are full, and minus house use. Then at 3pm, ship all my solar back at peak rates. So, your goal, and my goal are the same.
My first goal is to keep the wife happy!!!!! So going for 74 temp in the summer, and next winter, will set heat at like 66 or 68. After that, a zero ENERGY true up is my goal, plus a little propane. I could case less how much the PW's get used, that is what the warranty is for
RKCRLR
Active Member
I keep my thermostat set for comfort also.My first goal is to keep the wife happy!!!!! So going for 74 temp in the summer, and next winter, will set heat at like 66 or 68. After that, a zero ENERGY true up is my goal, plus a little propane. I could case less how much the PW's get used, that is what the warranty is for
Personally, I believe the Powerwalls can last beyond the warranty period and that how long they last beyond that is proportional to how much they are used.
Yes, age is a factor but I believe it is second order compared to usage.
No one has any real idea how long they will last vs use, storage level, etc. Just one thing I am willing to ignore and live with whatever happens. We can compare our two different use approaches as the years go by and see if it makes any difference.
RKCRLR
Active Member
I agree, but from everything I've seen, in general the driving factor on how long rechargeable batteries last is cyclic usage, not age.
This is hardly surprising, since we all live in different houses, with different electricity usage patterns and different goals.
My advice - try different settings and see what it does. If you don't like something, try it a different way. The reason people do things differently is that everyone's situation is different.
Here are the big gotchas in my mind.
1. Don't charge an EV from Powerwall energy. It's a waste of battery cycles. Use TBC and define an Off-Peak period to charge your car. This should prevent Powerwall discharge while the EV is charging. If you really want to optimize for self-consumption and you're home during the day, set the car to charge slowly while you're generating the most solar. Tesla does not provide an automatic way to charge from surplus solar. They really should implement that feature.
2. If you have TOU utility rates, align the Peak hours in the Powerwall schedule to the utility schedule. You can fudge the Off-Peak and Shoulder to adjust how the system works at other hours.
3. If you want TBC to act the most like Self Powered, set your solar generating hours to Shoulder, even if the utility considers it Off-Peak.