Im not in Hawaii, but I seem to remember reading somewhere that new solar installs might not even be able to get Net metering at all, meaning they cant export any solar to the utility at all. Again, I dont live there so I am not sure on this, but if one is not allowed to export any energy at all to the utility, a large amount of battery storage would make sense.
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Should I upgrade to 6 Powerwalls?
- Thread starter Gu$ G
- Start date
Jeremy3292
Active Member
Totally agree with your premise but the OP stated in the first post he is looking to get more solar and powerwalls, not just powerwalls themselves. Also with currently 17 kW solar and only 2 powerwalls, he is likely either sending a lot of energy back to the grid or it is being "wasted" already.
In a perfect world where you’re able to charge during the day that would be great. The problem we have is working all day and not getting home until the sun is setting. We don’t fully drain the PW’s every day. I stop charging the car when my PW’s drop to 38%. That leaves plenty of power to cover our house until the next day. The only time we can charge during the day is on the weekend. There is absolutely zero possibility to ever work remotely, so for now the only option is PW charging for an hour or two every day, and topping off on the weekend.
HECO is planning to charge everyone TOU by the end of next year, which will be triple the cost from 5-9pm and double the cost from 9pm-9am. For those EV owners who can’t charge during the day their bills will be insanely high unless they have PW’s.
Certainly it won't work if you drive too much, but the average person drives something less than 30 miles per day. At 300W/mi and 85% charging efficiency that is 10-11 kWh per day which is certainly doable. It might not make financial sense though.
Personally I am operating in self powered mode most of the year and my car takes whatever remains in the battery to the reserve level when it charges early morning. This time of year through the summer it can almost completely make up for what I use during the day. I can't charge during the day as I am at work.
We haven’t had true net metering since early 2015. They have a new program called CGS+ that charges us full price for what we use from the grid, and pays back less than 20% for what we send back to the grid. That makes it pretty pointless to have solar if you’re paying full price when the sun isn’t out. Where I live on the island it’s cloudy and raining most of the time so PW usage is a must.
I'm guessing there is little/any ROI then. OP wasn't Wahiawahi, but most folks don't drive much in Hawaii since folks sit in traffic and it's short distances (generalizing I know). If you can swing only charging during the weekends perhaps, try that, but as much as I love more batteries, I probably wouldn't depend on charging my EV with them at all.
I assume your solar install is large already?
One factor is you have to front $15k-$20k to Tesla or some other installer and that's even if have space on your roof since your install was in 2022. Tesla may not do additonal batteries without panels and you now have 2 different installs now. (should have maxed out in 2022?).
I don't know about the HECO credits, but I suppose, if the numbers work for you, then they work for you and don't let me/anyone talk you out of it.
I assume your solar install is large already?
One factor is you have to front $15k-$20k to Tesla or some other installer and that's even if have space on your roof since your install was in 2022. Tesla may not do additonal batteries without panels and you now have 2 different installs now. (should have maxed out in 2022?).
I don't know about the HECO credits, but I suppose, if the numbers work for you, then they work for you and don't let me/anyone talk you out of it.
CrazyRabbit
Active Member
Can you get over the range anxiety and only charge during the weekend? It is what I do. I don’t need to as I got 1:1 net metering, but I like driving on solar!
definitely get get more PW since you are in Hawaii…
There’s definitely a little range anxiety going on because we’ve only owned the M3 for a month. We’ve put 1,392 miles on it during that time, but it’s mainly driving to and from work during rush hour traffic.
I guess I just don’t want to pay the electric company a single penny now that we have solar panels and PW’s. I would rather get more panels and PW’s to avoid paying them.
There’s definitely a little range anxiety going on because we’ve only owned the M3 for a month. We’ve put 1,392 miles on it during that time, but it’s mainly driving to and from work during rush hour traffic.
I guess I just don’t want to pay the electric company a single penny now that we have solar panels and PW’s. I would rather get more panels and PW’s to avoid paying them.
I would think less and do it then. I've always stated there was 0 ROI on batteries, but nothing wrong with paying $15k to save $5k on enery for however many years that is if that's someone desire (to not pay HECO).
(more) Batteries are an easier decision when one simply doesn't factor any ROI and don't convince oneself of it.
Oh boy. This is not my intent. I am frustrated by HECO's rising prices but I'm not going to waste my money away to spite them. I realize electricity pricing is largely market fundamentals way out of my control. Frankly, a lot of the Florida and California numbers presented here have made me feel much more at ease with the prices we pay.
Back on topic:
So far, my biggest takeaway has been solar generation is more important than storage. Generation is cheaper than storage. There are smart home alternatives that might help me consume energy during the day a bit more than I do presently. Still going to need a bit more storage, but probably not 6 total PW...
As I mentioned earlier, I calculated out an impressive 4.5 year break even on our first 17 kW / 2 PW system installed in 2021. That is over twice as good as I was expecting, in large part from us switching to driving two (sometimes three) Teslas.
I'll need to really put some brain bytes into the math for ROI of this second addition. There have been some really great points presented here.
@yblaser you mentioned that in the AM you will recharge your EV with any remaining energy in your PW above 38%. Is this automated in a way that pulls from the PW but not the grid? I've started using the app ChargeEV and have had mixed results.
@dareed1 you said I should take a look at our energy flows. As later discussion has highlighted, its not so much seasonality for me here in Hawaii. I am trying to maximize energy captured from my solar. This can be difficult to do during the day if we don't have an EV parked in the driveway. At the rate my wife and I are driving, I'm looking at a ~$3000 electric bill for 2023 despite my current solar/PW setup.
As @Wahiawahi pointed out, Hawaii is planning to transition everyone to TOU in a year-ish. I'm not currently on a TOU plan. The TOU they've proposed (peak costs is 3x evenings and 2x overnight) seems very, very unfavorable if you're not home during the day. That further justifies the cost of storage.
I’m still waiting for PTO so I’m capped once our PW’s hit 100%. I contacted our Tesla Energy advisor in Mililani, and they informed me that they won’t fill out the paperwork for the Battery Bonus plan because they think it might void my warranty and they don’t think it’s beneficial for their customers. To me that’s a complete load of garbage because I’m already having to use my PW’s every single day when the sun isn’t shining. The cost of additional panels and PW’s is definitely worth it if I can get enrolled in the Battery Bonus program. I’m getting frustrated that HECO is so slow to give us PTO because we can’t enroll in the Battery program until we are officially in CGS+.
Tesla needs to switch their policy on this issue and stop telling their customers that it will void our warranty.
I just spoke to my next door neighbor who had his solar system installed a couple of months before me. He’s still waiting for PTO, and said he’s still paying HECO hundreds of dollars every month despite having one PW, and he doesn’t have an EV. One PW isn’t enough in Hawaii. As I’m discovering…two PW’s isn’t enough if you have an EV. If you have multiple EV’s and you work during the day you need 4 PW’s.
Second data point that Tesla as a contractor is trying to avoid participation in BB here in Oahu. Maybe we spoke to the same employee. Definitely frustrating. Some HECO employees suggested these programs are counter to Tesla's bigger plan of networking solar energy as a utility.
I also learned that the HECO application for a new solar install goes to the same team your BB enrollment application goes to. Since I had both applications in at the same time, only one could be approved. Right now I'm proceeding with increasing the size of my ESS. Once the upgrade is complete, I'll try to resume my saved battery bonus application and see what happens. I'll probably have to go it alone since Tesla doesn't seem to want to help their customers in this area.
We were dealing with Shaun from the Mililani office, but the response I got yesterday was from Elaine, who is also in the Mililani office. This is the first time I’ve corresponded with her.
With the high rates HECO is charging us there’s a record number of people getting solar installed. I’m guessing that’s what’s causing the long wait times for PTO… unless they’re working on Island time.
I would like to add more solar panels and PW’s to get in the Battery Bonus program before the June 2023 cutoff, but at this point I can’t move forward with anything until they give the official PTO. If their goal is to use our PW’s to lighten the load on the grid that’s probably not what’s going to happen. Most of their customers will just use our PW’s to charge our cars during that 2 hour nightly period to get the $8,500 for 10kw per night and the $50 monthly bill credit.
I just got off the phone with Elaine, the new Tesla Energy project advisor in Mililani. I asked her about the Battery Bonus program from HECO, and specifically why it wouldn’t benefit us. She said in the fine print of the agreement you authorize HECO to take all of the power from your PW’s if they need it. They will also have the ability to drain all 10kw that you agree to use almost instantly. I asked if we could just use the 10kw to charge our car, and she said HECO can take it during that 6-8:30pm timeframe if they need it because that’s what you’re agreeing to. Even if you set your PW’s not to go below a certain level HECO can still drain it if they feel there’s a need for more power in the grid.
If this is true, this has always been my concerns with VPP or these battery export programs. Once they have access or an agreement to take your energy, sometimes it might be hard to control or someone working there just turns it on to drain consumer's storage for the "great good" of the grid.
It all boils down what's in the fine print, but if it's there, then it's probably because the Battery Bonus program is so generous that it's almost like it's HECO's battery and you're just along for the ride and they're using your solar/home to help stabilize themselves. That's not particularly a bad thing with how great some of the Hawaii incentives are, but one needs to know what they are getting into.
bkp_duke
Well-Known Member
I would need to go back and look up screenshots, but IIRC the VPP participants in California could set reserve levels that they would not let the VPP drain their systems below. So you do have some control over how much gets pulled out of your batteries. And IIRC Tesla gave you the right to drop out of the program at any time.
During the peak demands, however, the payments were spectacular.
True in CA, but in HECO land, I think they have ESS credits like SGIP so if you can get your batteries for 85% off, I think it's actually fair for HECO to have near total control since they sorta paid for the cost of the battery. I don't follow their credits so someone else can chime in, but it looked pretty generous when I read about it earlier.
I still personally wouldn't want the IOU to have any contact/access to my stuff personally for a few hundred bucks, but that's just me.
bkp_duke
Well-Known Member
I did SGIP in CA, 5 years they can prevent you per the contract from exporting from batteries. That period ends for me next month. I wonder if there is a similar time limitation in HECO land.
OCJeff
Active Member
New to Powerwall here, but not new to solar. I have a system that just received PTO for the Powerwall today, and my next question was with regards to the SGIP rebate. I was curious about exporting to grid during peak, and the only reference I found is that they actually REQUIRE you to export to grid 52 full cycles per year (essentially once per week). I could find any "limitations". I'm also still trying to figure out if the SGIP rebate will exclude me from VPP participation.
Any guidance in this area would be appreciated,
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