Very unsatisfying Tesla app for powerwall, especially for Australia

[ZTrekus]

The Tesla app for powerwall is quite deficient in that it doesn't even allow you to schedule very basic operations of the powerwalll such as charge and discharge.

Especially with the time-of-use that we have in Australia and the feed-in tarrifs that AGL provides, the app ends up costing you money unless you ride it every day and night.

I mean it's just obvious isn't if? Charge at 10pm every night and discharge every day at 7am. Duh! Who writes this crap? Instead it wants to guess what it thinks is best for us without even knowing our prices and feed-in tarrifs. Go figure.

 

[paulp]

The Tesla app for powerwall is quite deficient in that it doesn't even allow you to schedule very basic operations of the powerwalll such as charge and discharge.

Especially with the time-of-use that we have in Australia and the feed-in tarrifs that AGL provides, the app ends up costing you money unless you ride it every day and night.

I mean it's just obvious isn't if? Charge at 10pm every night and discharge every day at 7am. Duh! Who writes this crap? Instead it wants to guess what it thinks is best for us without even knowing our prices and feed-in tarrifs. Go figure.

Why would you charge at 10pm if you know you have enough battery to last til morning?

 

[Nobody Famous]

Why would you charge at 10pm if you know you have enough battery to last til morning?

Arbitrage - Buy Low, Sell High. ECOnomics vs. ECO friendly

 

[Nobody Famous]

Tesla app for powerwall is quite deficient

It is very likely intentional on Tesla's part. Otherwise they'd never be able to sell you a domestic version of Autobidder.

Autobidder | Tesla Support

Autobidder is a real-time trading and control platform that performs market bidding and dispatch control for value maximization against business goals.

www.tesla.com

 

[ZTrekus]

Off peak charging from 10pm is literally cheaper than solar charging the battery the following day. In lieu of solar charging, you sell that excess solar to the grid for 17c feed-in tariff whereas off-peak charging from grid is only 15c.

Particularly on rainy days during peak times, you want to start the battery off with a full charge. I mean 100% as opposed to 54%. That can get you through the whole day to the start of the next off-peak time ready to charge to 100% again at el-cheapo rates.

 

[ZTrekus]

It is very likely intentional on Tesla's part. Otherwise they'd never be able to sell you a domestic version of Autobidder.

Autobidder | Tesla Support

Autobidder is a real-time trading and control platform that performs market bidding and dispatch control for value maximization against business goals.

www.tesla.com

Unbelievable

 

[ZTrekus]

Is there a "domestic version' available?

 

[Nobody Famous]

17c feed-in tariff whereas off-peak charging from grid is only 15c.

I'd think there'd need to bigger margins to make that game worth while.
What's the round trip efficiency of the battery and what is the lifecycle cost per warranted kWh stored and released?

Is there a "domestic version' available?

Not known of, but sure to be a thing eventually

 

[ZTrekus]

I'd think there'd need to bigger margins to make that game worth while.
What's the round trip efficiency of the battery and what is the lifecycle cost per warranted kWh stored and released?

Ahh but you see, having bought the battery, we are pretty much lumped with the 'round trip efficacy' and 'lifecycle cost' already.

As Holmes would say, "the game's afoot".

Either it charges from off-peak-grid or it charges from solar. I prefer the cheaper option. The app prefers the latter.

But the point is we only get a say if we ride the app like a monkey instead of hacking the gateway like a...armm... Gorilla??

 

[Vostok]

Why would you charge at 10pm if you know you have enough battery to last til morning?

Because not everyone has a 30kW solar array like you do.

If it wasn’t for Tesla TBC in winter, my battery would often not be full at 2pm when peak rates start, and my battery is often empty by 8pm when peak rates end (sometimes I manage to stretch it to 10pm when offpeak starts). A house using 13 kWh in 6-8 hours in winter is not unusual.

So, yeah, the ability to charge the battery from the grid when grid rates are cheap is pretty important for some of us.

 

[Vostok]

Off peak charging from 10pm is literally cheaper than solar charging the battery the following day. In lieu of solar charging, you sell that excess solar to the grid for 17c feed-in tariff whereas off-peak charging from grid is only 15c.

Particularly on rainy days during peak times, you want to start the battery off with a full charge. I mean 100% as opposed to 54%. That can get you through the whole day to the start of the next off-peak time ready to charge to 100% again at el-cheapo rates.

Exactly.

While the Tesla “Time Based Control - Cost Saving” mode for PW2 does a reasonable job of optimising battery charging and discharging, my modelling of how it works when you have a small solar array like mine shows it could be improved. I have sent into Tesla a suggestion of a new mode called “Simple cost optimisation”. This would have just two toggles:

• Do not discharge the battery during off-peak times
• Fully charge the battery before off-peak time ends

Turning the first on would mean during off-peak times the battery charge state would be maintained, and you’d only use grid power. If the battery was 30% when off-peak started, it would be at 30% when it ends. This would be great for those of us with EVs, for example, that we want to charge overnight solely from the grid at cheap rates and keep the battery power for when shoulder grid rates start in the morning.

Turning on the second is going a step further. Not only do you not draw from the battery, it is fully charged at off-peak rates. TBC “Cost Saving” mode uses this concept but instead charges the battery to 100% at shoulder rates before peak starts. With this toggle on, if the battery was 30% when off-peak started, it would be at 100% when it ends.

Modelling this idea on my power usage profile shows it works even better than TBC “Cost Saving” mode, meaning grid usage charges are even lower. Not by a huge amount, but enough to make it worthwhile.

 

[Vostok]

What's the round trip efficiency of the battery and what is the lifecycle cost per warranted kWh stored and released?

Based on my 2 years of 5-minute PW2 data, the roundtrip efficiency is 93.7%.

 

[GrimRe]

There is a huge war going on right now between traditional electricity generators (coal, gas hydro etc) and the new upcoming energy retailers that have real time wholesale pricing (Powerclub, Amber) according to some whirlpool threads.

what's happening is that the traditional energy retailers and electricity generators are colluding to make the wholesale price very high. The retailers often hedge pricing with insurance or by owning some portion of the supply side also, so they don't really mind that wholesale price is high but they do very much care if a new power retailer doesn't form part of their cartel to fix retail pricing. This being exacerbated by unusually high gas prices.

AutoBidder would break this collusion as it will just arbitrage demand and supply to whatever corrupt mechanics are happening on the AEMO network at any given time. With 5min settlement happening this October (after having been fought tooth and nail by the energy retailers and generators) this is the perfect opportunity to have an AutoBidding system across many residential batteries buy low and sell high. Unless the AEMO provides some sort of privileged access to power generators beyond AutoBidder, Tesla have the software skills to make this system better than any other legacy forecasting software that exists today.

The philosophy from Tesla as seen in other jurisdictions is to partner with existing energy retailer and create a virtual electricity generation which is an aggregation of many power walls. The autobidding component is then controlled by the retailer and not the consumer. There are very, very few people that would be bothered to optimise AutoBidder for maximum returns. It's therefore in everyone's best interests to put AutoBidder in the hands of the professional energy retailers. This however brings with it benefits to the consumer as the upfront cost of a power wall can be subsidised and lower electricity rates provided.

I suspect Tesla will have a partnership with someone like Amber in the future or create an entirely new energy retailer in the future.

 

[paulp]

Off peak charging from 10pm is literally cheaper than solar charging the battery the following day. In lieu of solar charging, you sell that excess solar to the grid for 17c feed-in tariff whereas off-peak charging from grid is only 15c.

Particularly on rainy days during peak times, you want to start the battery off with a full charge. I mean 100% as opposed to 54%. That can get you through the whole day to the start of the next off-peak time ready to charge to 100% again at el-cheapo rates.

You wont get those rates in SA. 8.5c FIT is rapidly becoming the norm. Tesla’s preferred supplier offer 17c off peak and 8.5c fit, or if on a flat rate 25c all day/night. Hence there is no circumstance in SA that the night rate is cheaper than the FIT (Unless you have a legacy 53c FIT). I would be substantially worse off on either flat or tou plans if I filled my battery ‘just in case’

 

[paulp]

Because not everyone has a 30kW solar array like you do.

If it wasn’t for Tesla TBC in winter, my battery would often not be full at 2pm when peak rates start, and my battery is often empty by 8pm when peak rates end (sometimes I manage to stretch it to 10pm when offpeak starts). A house using 13 kWh in 6-8 hours in winter is not unusual.

So, yeah, the ability to charge the battery from the grid when grid rates are cheap is pretty important for some of us.

I agree with your comment. I was trying to make the point that not all users of powerwall have the same needs or circumstances, and not all rates are equal across Australia so its not always financially desirable to fill the battery using grid power.
As with all things power related there is no universal one size fits all soltion. Everyone has to do their own calculations. That seems incredibly difficult to achieve in an app.
Although the cost of power in SA is now falling, going back 5 years a solar array with the cost of power and the decent FIT (and good sun levels) would have a payback of 2 years. Maximising that investment made a lot of sense, which is 30kw.

 

[Vostok]

You wont get those rates in SA. 8.5c FIT is rapidly becoming the norm. Tesla’s preferred supplier offer 17c off peak and 8.5c fit, or if on a flat rate 25c all day/night. Hence there is no circumstance in SA that the night rate is cheaper than the FIT (Unless you have a legacy 53c FIT). I would be substantially worse off on either flat or tou plans if I filled my battery ‘just in case’

Last year I was on a plan with 21c FIT and offpeak of 15c (although with 4.5c 100% GreenPower on top). So you could actually make money via arbitrage - fill the battery up with offpeak, then sell excess solar to the grid at a higher price.

However after washing my actual power flows against various rateplans to check how things were tracking, I was substantially better off moving to a more "conventional" plan with much lower FIT of 7c (since reduced to 5c) and 100% GreenPower charge of 2.8c.

Seems counterintuitive, but the key factors that drove this result were the daily connection fee and offpeak tariff. Because I have a small array that cannot fully power my house, but have a battery, I am much better off minimising the daily connection fee (82c) and offpeak tariff (11c) than maximising the FIT with higher daily connection fee and offpeak rate.

 

[atj777]

While I have only been on TOU charging with my retailer (Powershop) for a little over a month, I find TBC - Cost Saving works very well for me. Sure, it would be nice to have a little more control, but so far it has saved me a few hundred dollars already (in just 6 weeks!)

My cheapest rates are 00:00-04:00. My rate from 04:00-07:00 is pretty good (a little over half what I was paying as a flat rate before I switched). My rate for 07:00-13:00 the rate is a little more than what the flat rate was and between 13:00 and 20:00 the rate is around 50% higher than the flat rate. Then 20:00-22:00 it drops back to the same rate at 07:00-13:00 and 22:00-00:00 is the same rate as from 04:00-07:00.

So, i have the app set up with 00:00-04:00 as Off-peak, 04:00-07:00 as Shoulder and 07:00-00:00 as Peak.

The Powerwall charges from the grid from 0:00 and is at 100% by 04:00. Between 04:00 and 07:00 the Powerwall is mostly in standby with the house being powered from the grid. From 7:00 the house is being powered from the Powerwall and/or solar until the Powerwall gets to 5% or 0:00 whichever come first.

I think only once so far the Powerwall has got to 5% before 20:00 - this was on a particularly cold cloudy day. There's been a few days where it's got to 5% before 22:00 (but only just and partly because one of our HWS is on the main supply not controlled load - that's a story in itself). Most days it gets to 00:00 with still more than 5%.

FIT for me is a joke (5c/kWh) so I will avoid at all costs putting anything back to the grid. This may mean adjusting my settings as it gets warmer and the days get longer but I think that will just be a matter of moving the start of Peak earlier so that I'm powering from the Powerwall longer before the solar kicks in.

 

[Vostok]

While I have only been on TOU charging with my retailer (Powershop) for a little over a month, I find TBC - Cost Saving works very well for me. Sure, it would be nice to have a little more control, but so far it has saved me a few hundred dollars already (in just 6 weeks!)

That’s a good idea to tweak the offpeak/shoulder/peak rate time periods to “force” PW2 to fully charge at off peak rates. I’ll try that.

Whenever I have washed my actual consumption patterns against PowerShop’s tariffs, though, they have always been in the middle or bottom half of the pack.

 

[atj777]

I mean it's just obvious isn't if? Charge at 10pm every night and discharge every day at 7am. Duh! Who writes this crap? Instead it wants to guess what it thinks is best for us without even knowing our prices and feed-in tarrifs. Go figure.

Set Off-peak from 22:00-07:00 and peak from 07:00-22:00 and it will do just that.

 

[ZTrekus]

Set Off-peak from 22:00-07:00 and peak from 07:00-22:00 and it will do just that.

You know, that's what I thought! BUT instead it wants to start the day with 54% battery charge and for some dumb reason it starts discharging well in the off-peak period... Crazy algorithm man. Next time i send screen shots...