pdx_m3s
Active Member
There’s no way an 11kW system with 3-4 PWs will be as cheap as a competitor’s solar-only system.
Looking forward to more details from Tesla.
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Elon tweets: Solar Roof and solar panels will only be sold integrated with Powerwall
- Thread starter willow_hiller
- Start date
Looking forward to more details from Tesla.
As to the cited article, its worth a few minutes of anyone's time who either has solar or is thinking about it to look up, say in California, CAISO, to see the wholesale price of actual electricity, which varies throughout the day but is about 3 cents per kwh.
Well, how come then the consumer is charged 17 cents and up? Well, its some combination of costs to maintain the grid and "profits" depending on how you view them.
But regardless of what it is, as long as, post solar, or even post solar and PW, a customer needs to remain hooked up to the grid, there is a structural problem for utilities where they need to keep the grid in shape and the entire administrative process, but a certain, growing percentage of customers only pay a fraction of the costs of maintaining the grid they are connected to.
Is just a function of the cost of the electricity as compared to the cost of delivering the electricity.
The solution is obviously that instead of utilities being essentially private companies, that delivery of electricity be done on a governmental level, like roads. Roads have the advantage of a built in tax, on gasoline, which funds construction and upkeep to some extent. But although some people use public transport and some use EVs and some ride bikes or whatever, everyone uses roads, so the funding is fair.
Its not the case with elecricity.
But I'm not holding my breath on massive restructuring of utilities. Its both great and frustrating at the same time. My own house is proof we don't have to burn the planet to a crisp. Yet, there is a lot of talk and very little action on expanding this.
Its basically one company trying to push against all sorts of forces who talk the talk but are hugely invested in the status quo. Good thing, I suppose, that the one company is run by a guy with a huge ego and billions of dollars. Although that comes with its downsides.
Well, how come then the consumer is charged 17 cents and up? Well, its some combination of costs to maintain the grid and "profits" depending on how you view them.
But regardless of what it is, as long as, post solar, or even post solar and PW, a customer needs to remain hooked up to the grid, there is a structural problem for utilities where they need to keep the grid in shape and the entire administrative process, but a certain, growing percentage of customers only pay a fraction of the costs of maintaining the grid they are connected to.
Is just a function of the cost of the electricity as compared to the cost of delivering the electricity.
The solution is obviously that instead of utilities being essentially private companies, that delivery of electricity be done on a governmental level, like roads. Roads have the advantage of a built in tax, on gasoline, which funds construction and upkeep to some extent. But although some people use public transport and some use EVs and some ride bikes or whatever, everyone uses roads, so the funding is fair.
Its not the case with elecricity.
But I'm not holding my breath on massive restructuring of utilities. Its both great and frustrating at the same time. My own house is proof we don't have to burn the planet to a crisp. Yet, there is a lot of talk and very little action on expanding this.
Its basically one company trying to push against all sorts of forces who talk the talk but are hugely invested in the status quo. Good thing, I suppose, that the one company is run by a guy with a huge ego and billions of dollars. Although that comes with its downsides.
And why would Tesla not want it that way? They have more business than they can handle. They offer a highly sought out product. If you owned the company, what would you do? Just like ticket prices at Disneyland, one keeps raising until some balance is achieved.
The one issue with this that was pointed out earlier is that, unless there is a change, there is a solar install warrantied for 25 years and a PW warrantied for only 10. Of course, that does not mean the PW will fail at 10 years + 1 day, but it does suggest you might need to replace the PWs once during the expected lifespan of the solar (which also won't suddenly be useless at 25 years.) And, depending on the specifics of the new design, it is not clear how different types of PW failures could affect the system as a whole.
So, for those whose situations suggest little value from a PW, I could still see it as being a net negative. But I do agree that this might be their goal in pricing. And for many, PW will add some value (both for backup and some ability to arbitrage TOU rates, even if the amount wouldn't have paid for the PWs as an add-on.) This might be enough to continue attracting most of their prospective customers, even if cost is no longer a big differentiator.
I am very unsure that it has a negative impact and the warranty on a PW is 10 years regardless of the number of cycles.
The reason why I am unsure about having using the battery to cover the high rate period is a negative impact is looking at the vehicle batteries. Operationally one of the things we have been told not to do with the vehicle is keeping the battery at a high state of charge day after day. Tesla dropped the default charge max to 90% on vehicles years ago. Using a battery for only backup will hold the battery at a high state of charge day after day after day. If the charge bleeds off a bit, the system will send it power from solar to get it back up to the max. Some say this is a non-issue because there is a buffer, but is the buffer 10% or more of the battery's capacity?
As far as the impact on your electrical costs, we have seen our power bills drop over $300/mo in the summer months. We never pull from the grid during the 4-9 PM peak rate period and often don't pull from the grid the entire day.
I wonder how far Tesla can push the vertical integration to avoid unnecessary parts. Is it even possible for a new Tesla Charger to connect on the DC side of say the inverter/gateway to then DC charge Tesla vehicle batteries directly. So the same inverter that allows Powerwall to power the home or send solar to the grid is reused to allow grid AC to DC charge if Solar + Powerwall are insufficient? Here's a crude diagram of what I'm thinking of:
Code:
Ideal?
Solar <-dc-> Powerwall <-dc-> Inverter/Gateway <-ac-> Utility Meter
Vehicle Battery <-dc-> Charger <-dc-^ ^-ac-> Main Panel <-ac-> House
Current
Solar <-dc-> Solar Inverter <-ac-> Main Panel <-ac-> Gateway <-ac-> Utility Meter
Powerwall <-dc-> Powerwall Inverter <-ac-^ ^-ac-> Wall Charger <-ac-> Vehicle Inverter <-dc-> Vehicle BatteryWhere potentially this DC charger could make it easier for Tesla Vehicle Batteries to just "plug in" to appear as a Powerwall-on-wheels?
FurryOne
Member
Really? I got a quote from a well established installer for a 10.5K system with 2 PW's that was $34,800 for the Solar, and an additional $21,700 for the Powerwalls. I have my quote from Tesla for an 8.16K system with 2 PW's for $31,400. That's $3,400 less for 2.3KW less.
(I realize that their web page shows an 8.16K system goes for $33,400, but they knocked off $2K on the contract.)
Electrph
Member
you were actually SOL over a month ago .. i tried to add a powerwall to my 2 powerwall / solar system all tesla .. no go .. they would not even add 1 powerwall with any less panels than adding a "small system"
but as many have said just wait a bit tesla changes policy fairly frequently
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Electrph
Member
there were people that knew ted bundy and went on record saying he was a wonderful person .. warm and caring ... just sayingI may not like PGE, but they are no where near as bad as you keep saying. You just have a "special" relationship with them
dhanson865
Well-Known Member
I only have a 3 ton HVAC and if I replace it someday I'll downsize it. I'd be fine with a single powerwall if it can start my 3 ton. I don't need multiple days of capability, 24 hours of backup is plenty for my use.
I wonder how building codes would handle 350-400V DC wiring running 50 feet from my panel/gateway outside through my walls to my garage - do such building and electrical codes exist for high voltage DC in homes?
I disagree that solar+powerall solution is revolutionary. Our grid is very stable and powerall solution is too expensive for the rare times that it would be needed.
What we really need is the ability to use that huge car battery to power our homes in an emergency. With cars going the EV route, it wouldn't be surprising to see a car maker offering this solution at some point to differentiate themselves. Hopefully it will be Tesla but if not, someone else can come up with a solution.
Let me charge my car battery from solar even if the power is out and use car battery to power my home in an emergency. Now that's revolutionary
What we really need is the ability to use that huge car battery to power our homes in an emergency. With cars going the EV route, it wouldn't be surprising to see a car maker offering this solution at some point to differentiate themselves. Hopefully it will be Tesla but if not, someone else can come up with a solution.
Let me charge my car battery from solar even if the power is out and use car battery to power my home in an emergency. Now that's revolutionary
I thought the first tesla could do that, but I had no one had interest so they took out the feature?
Every time someone says some variation of this, I post a bunch of reasons why there is no reason or incentive for tesla to ever offer this, both safety related and business related. The only people that this MIGHT happen for, are people with powerwalls (and the appropriate permits and such) already.
People thinking they are going to roll up with their Tesla vehicle, with no permits, no additional safety, etc and plug into their home to use the car as a power source will be waiting a very long time for this from tesla, because it wont happen.
I sure thought I heard him say it worked, but no one used. But, maybe I miss heard him
pdx_m3s
Active Member
Agreed. We have this wonderful innovation called the grid, and it feels like we're re-creating the wheel here. I don't want to be my own utility... it feels like we're going backwards.
I totally agree. PW doesn't make finance sense to a lot of people due to the reason of 10 years warranty. If you have to pay 10k to replace the PW or gateway after 10 years. Then Tesla option become very expensive. Also one of the biggest advantage of having a PW is during power outage. If that cannot use the solar during day of outage, it will be bad deal to many of us.
If not Tesla, someone else will implement. And I don't think it will be that long. Do a search for Mitsubishi.
Sunny boy allows it's inverter to have a power outlet during power outage. Sure, maybe you'll have to disconnect from the grid during the outage but there's no technical reason why it can't happen.
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