Powerwall Home Battery - Hawaii

Papafox said:

Solar City just announced that Hawaii customers will be the first to get Tesla batteries in systems that take them completely off the grid:
Don't expect to go off grid with new Tesla home battery just yet

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I read somewhere that it's a package deal for new customers (PV + battery system)..battery system won't be available to those with existing solar until later...at least from Solar City.

nanimac said:

I read somewhere that it's a package deal for new customers (PV + battery system)..battery system won't be available to those with existing solar until later...at least from Solar City.

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Until later is better than never. I've signed up (Reserved) for the Powerwall. I fully intend to get completely off the grid. I plan on adding a few more panels at that time too.

I reserved, but not sure if it's right for my particular situation yet.

StephenM said:

I reserved, but not sure if it's right for my particular situation yet.

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Certainly no harm in "getting in line now". They will visit you, advise you, let you decide to proceed or cancel. But you won't have to wait until everyone's done before you know if it might work.

Like all things, later it will be cheaper and better. This may be one thing that I lease versus buy outright. But we are the early adopters, aren't we?

I am going to wait and see. I am curious how long the 10kw pack will last in a blackout and if you can have a special outlet come from that to power the refrigerator only.

drtko147 said:

I am going to wait and see. I am curious how long the 10kw pack will last in a blackout and if you can have a special outlet come from that to power the refrigerator only.

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Got to keep the beer cold

Papafox said:

Of course you could accomplish this by turning off the other stuff. The real advantage of the battery is for people with PV panels. The battery becomes a buffer and you can use lots of power during the day. Just be sure to leave the battery mostly full as the sun sets so you have enough juice for the night hours.

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Of course, I have PV and it does cover all my energy needs. I am wondering how many batteries I will need. Not sure how long 10kW covers. Does anyone know?

drtko147 said:

Of course, I have PV and it does cover all my energy needs. I am wondering how many batteries I will need. Not sure how long 10kW covers. Does anyone know?

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The most recent info discussed about the Powerwall is that the 10 Kw version is designed primarily as a back up system. That the 10 Kw pack should only be charged 50 times a year - or weekly. Its more like a UPS versus a primary battery.

And the 7 Kw pack is a daily charge battery. Until I hear different from Solar City, Tesla, or someone else, my day time use needs to come directly from my PV. And my Powerwall pack(s) would charge during the day and should be as near 100% as the sun sets, so the packs supply my night time needs. I guess I need to monitor my meter to determine how much juice I use from sunset to sunrise to learn what my pack requirements are. I will also need to shift my Model S charging to daytime versus draining the packs at night. I believe I am going to need to add more PV too in order to have ample for recharging the packs, charging the Model S, and day time house use.

Maybe this will change in the coming months as we learn more or Tesla adds additional pack configurations to the product line. And we know they will, since they are routinely adjusting pricing and product availability.

When the state created the tax credit for PV installation in Hawaii, helping the consumer was not the primary motive. The tax credit was done to jumpstart the fledgling solar panel industry and start down the path to reduced fossil fuel use. Growth of PV installation has slowed with HECO's help. Will battery packs such as Powerwall help stimulate the PV installation industry? Will it happen with or without state support such as the expansion of the solar tax credit? If we rush into Powerwall installations will we miss the chance to qualify for tax credit? I believe if we each contact our individual PV installation company and encourage them through their industry lobbying organization, The Alliance for Solar Choice to get the legislature to expand tax credit to cover battery packs, we might save some dollars as early adopters.

Akikiki said:

Growth of PV installation has slowed with HECO's help. Will battery packs such as Powerwall help stimulate the PV installation industry? Will it happen with or without state support such as the expansion of the solar tax credit? If we rush into Powerwall installations will we miss the chance to qualify for tax credit? I believe if we each contact our individual PV installation company and encourage them through their industry lobbying organization, The Alliance for Solar Choice to get the legislature to expand tax credit to cover battery packs, we might save some dollars as early adopters.

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Just a note: yesterday I was looking at a huge roof filled with solar panels. my friend said that it was the Aiea public library and that those solar panels were not hooked up to anything because HECO wont allow it. thank you HECO for making taxpayer money go to waste. Maybe the state can recoup that wasted money by installing a Tesla Powerwall and take the public library off grid.

Papafox said:

Here are two ways to tell. First, you can look at your electrical meter reading after the sun goes down and then compare to the reading just before the sky gets very light. The difference would be your typical overnight usage. The second approach would be to do a test of minimal electrical use by being careful about what you use during this period and then checking using the previous method. This would give you your "when using the battery" overnight usage. I'm going to do these tests over the next month or so while deciding if I need one or two batteries.

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Excellent points. Don't forget, we need peak winter and peak summer, and maybe spring/fall. In the winter, we produce less during rainy season. In the summer we produce more but likely our usage is higher with A/C turned on.

Considering the massive numbers of people that signed up for Powerwall on the first week, our chances of being in Powerwall line for this fall or winter are slim. So, we probably have time over the next 8-9+ months to check our own usage during different seasons to learn how much we need.

Akikiki said:

Excellent points. Don't forget, we need peak winter and peak summer, and maybe spring/fall. In the winter, we produce less during rainy season. In the summer we produce more but likely our usage is higher with A/C turned on.

Considering the massive numbers of people that signed up for Powerwall on the first week, our chances of being in Powerwall line for this fall or winter are slim. So, we probably have time over the next 8-9+ months to check our own usage during different seasons to learn how much we need.

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Let's all go to a "powerwall party" at Akikiki's house and see what his max usage would be.

Haven't quite figured out what I would use the Powerwall for yet. I'm still zeroing out on my bill (besides the minimum interconnect fee) and I think the 10 kWh battery pack would be too small to last any decent length of time during a blackout for my place. I already have essential circuits isolated on a subpanel connected to a transfer switch designed for a generator, I'm probably going to wait a little longer before getting in line to see how things play out and whether pricing will come down once the Gigafactory comes on line.

Good news! Our application to add more panels (which would exceed 10kw) was approved by HECO last week after two years! But we're not allowed to energize them yet and the wait could be 18 months before we can!! Screw HECO...I want off the grid :cursing:

I am thinking that the 7kw battery may be the way to go for night use. I may need to consider the 10kw for backup.

I placed a reservation for a Powerwall unit. :biggrin:

WeazL said:

I placed a reservation for a Powerwall unit. :biggrin:

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welcome to the club.

The race is on for who will be the FIRST to get the Powerwall call!