powerwall2 behavior when paired with solar

[J.P.M.]

Is there any place in the US where such system can be economically justified based on hard cost factors? It's certainly not in California with NEM but not sure about places without NEM.

As for going completely off grid with alternate energy and batteries as normally construed and for common residential applications where grid power is available and mostly reliable, probably not many places in the developed world at this time.

As for emergency duty applications where uninterruptable power is deemed essential, cost becomes less important than reliability.

As for the economic viability of battery systems to avoid peak power costs, that'll be at least partially contingent on the price differential between the cost of power to charge the battery and the cost of the peak power that the battery offsets.

Simple answer: Take a SWAG at how much money you'll have saved in electric bills over "X" years by acquiring and servicing a battery system, and subtract that from the cost of the system. If the result is negative, it might make sense.

In doing so however, use life cycle costing methods such as LOCE analysis or other means to bring all expenses and revenues to present values.

[scrambler]

Thanks, this is interesting, and below is the Tier map

https://ia.cpuc.ca.gov/firemap/

Unfortunately I am not in either Tier 2 or Tier 3, close but no cigar

[Ampster]

I have not found anything so far about a planned new round of funding. let us know if you do.
......

This is old news, before the recent fire. I haven't figured out the definition of Tier 1 or Tier 2 but it is a start:

https://www.greentechmedia.com/articles/read/california-approves-100m-in-energy-storage-incentives-for-wildfire-resilien

[solardreamer]

...

For the application of non emergency load shifting, or more correctly grid usage avoidance during peak pricing times of grid power, while battery cost effectiveness is still a ways off for most applications at this time, ...

Is there any place in the US where such system can be economically justified based on hard cost factors? It's certainly not in California with NEM but not sure about places without NEM.

[ButchDeal]

independence from uncontrollable irradiance (the PV fuel) availability

Thought you were talking about extreme solar flares at first

the other thing to consider is the lower maintenance with some battery systems vs an ICE. ICE maintenance isn't that hard but not everyone is as familiar with any more.

[J.P.M.]

Is it really a question of generator vs Powerwall (or any other solar battery system) with respect to backup power? To me a generator is necessary even if you have a solar battery system for backup power purpose. Relying exclusively on solar battery system for backup power seems risky. Solar is great when it's available but there is little control over its availability.

To me, If the duty is for backup to the grid only - as an emergency power source, then two backups, a generator and a battery is redundancy.

For that application - the highest priority would seem to be reliability when/if the grid is down.

I'd think that the ICE, fossil fuel fired generator with it's known track record and systems, as well as its independence from uncontrollable irradiance (the PV fuel) availability, would tip the scales in favor of a generator.

For the application of non emergency load shifting, or more correctly grid usage avoidance during peak pricing times of grid power, while battery cost effectiveness is still a ways off for most applications at this time, it may be a better choice for that application than a generator, both in terms of noise and cost - but that's not to say its a great way to meet that duty at this time.

In the end, there are two separate applications here. One requires high reliability to meet the duty. The other requires cost effectiveness. Either one meets some of the application requirements of the other, but neither meets all the requirements of both - at least not at this time.

[solardreamer]

If you have natural gas, a stationary generator is by far the best solution for prolonged outages. But a good one (~20kW, 1800 rpm, water cooled) fully installed will be $~15K. A pair of PowerWalls (closer to $20K fully installed) might work if you get enough sun to charge them -- provided it's not raining, snowing, foggy, or too smoky. The benefit of the PowerWalls is there is no operating cost -- unlike a generator -- the natural gas gets expensive after a day or two.

Is it really a question of generator vs Powerwall (or any other solar battery system) with respect to backup power? To me a generator is necessary even if you have a solar battery system for backup power purpose. Relying exclusively on solar battery system for backup power seems risky. Solar is great when it's available but there is little control over its availability.

[scrambler]

Is SGIP really over or just waiting for the next round of funding? I have seen conflicting reports, some as recent as this month, about the CPUC adding more incentives for the small residential side.

I just got a quote from a local certified installer of the Tesla Powerwall and for one unit installed they want $16-17K...ouch.

I have not found anything so far about a planned new round of funding. let us know if you do.

I also asked Tesla a quote for a single Powerwall (basic partial backup no extra work, everything close by the house panel), and their quote is 11k plus sales tax on the &7600 of equipment, so basically under $12k. FYI, the $1k rebate only applies to Solar plus PWW not PWW standalone.

I asked a PWW certified installer for the same quote and got $18k (50% more) !!

These certified installers are just out skimming the market.

[Ampster]

Is SGIP really over or just waiting for the next round of funding? I have seen conflicting reports, some as recent as this month, about the CPUC adding more incentives for the small residential side.

I just got a quote from a local certified installer of the Tesla Powerwall and for one unit installed they want $16-17K...ouch.

Politically in California almost anything related to renewable energy is possible. I would not be surprised to see another phase of SGIP funding.
Regarding Tesla Powerwalls, Elon Musk tweeted that he is dropping the price of a Powerwall for people affected by the wildfire outages. If you dont need SGIP money that could be a good deal direct from Tesla.

[Ampster]

If you have natural gas, a stationary generator is by far the best solution for prolonged outages. But a good one (~20kW, 1800 rpm, water cooled) fully installed will be $~15K. A pair of PowerWalls (closer to $20K fully installed) might work if you get enough sun to charge them -- provided it's not raining, snowing, foggy, or too smoky. The benefit of the PowerWalls is there is no operating cost -- unlike a generator -- the natural gas gets expensive after a day or two.

And I might add that a generator doesn't offer any way to leverage TOU rates or leverage solar when the grid is down on a clear fall day like we have been having in Northern California during these PSPS outages. It all depends on where you are standing. I am intrigued with what Generac might be doing with their purchase of Pika. A scaled down battery combined with a generator could provide a better value that what is currently on the market.

[w00dy]

The Powerwall is by far the cheapest Lithium battery you can get right (when you can get it).
At $7600 for the Powerwall and supporting HW for 13.5kW usable, nothing else come even close (LG Resu, Humless, NeoVolta, Sonen (the most expensive)…)

Although SGIP is over, I read there was a Waiting list in case some reservation fall though, not sure if that waiting list would also be used in case of new funding (I would hope so)

Is SGIP really over or just waiting for the next round of funding? I have seen conflicting reports, some as recent as this month, about the CPUC adding more incentives for the small residential side.

I just got a quote from a local certified installer of the Tesla Powerwall and for one unit installed they want $16-17K...ouch.

[JSchnee21]

If you have natural gas, a stationary generator is by far the best solution for prolonged outages. But a good one (~20kW, 1800 rpm, water cooled) fully installed will be $~15K. A pair of PowerWalls (closer to $20K fully installed) might work if you get enough sun to charge them -- provided it's not raining, snowing, foggy, or too smoky. The benefit of the PowerWalls is there is no operating cost -- unlike a generator -- the natural gas gets expensive after a day or two.

[scrambler]

The Powerwall is by far the cheapest Lithium battery you can get right (when you can get it).
At $7600 for the Powerwall and supporting HW for 13.5kW usable, nothing else come even close (LG Resu, Humless, NeoVolta, Sonen (the most expensive)…)

Although SGIP is over, I read there was a Waiting list in case some reservation fall though, not sure if that waiting list would also be used in case of new funding (I would hope so)

[w00dy]

Due to the current PG&E shutdowns I am also researching things like the Powerwall and other options. I have an interest in 1 Powerwall 2 as it would just meet our basic needs daily, but I don't like the price or the wait. I am thinking I might see what happens in July 2020 regarding the SGIP funding - since I have read that there may be more money allocated towards Tesla...

However, I am also looking at other options including the Enphase AC Battery setup and the Sonnen Eco or really anything else I can find that will work for us.

So far at a minimum I am going to hook up my 24kW LEAF to a 1000w pure sine wave inverter to at least power stuff in our detached garage - this will include the beer fridge, which will become the backup fridge, a LED TV, some LED lights, various charging stuff, and a Wi-Fi router with an internet connection! We could honestly live in our garage - I am sure my wife thinks I do sometimes!

Here is what I wish I had - a small battery/inverter on the wall that allowed my solar to run while the power was out and the grid was down - a Vehicle To Home connection from my current LEAF (looking soon at a larger battery LEAF soon) to power the home during the night until the solar kicks back in. It would be really to cool to also use the LEAF to load shift during peak power times while I am at it - Why add a big battery when the LEAF is sitting there parked doing nothing and could do the same things...

Back to emergency back up plans - we have our main electric panel in the garage, so I could hook up a transfer switch or an interlock panel there - I wish all of our circuits were powered from this main panel, but we have a sub panel in our laundry room that has circuits for things like our fridge and freezer, lights, computers etc...so I think I would have to have a transfer switch with lifeline circuits there for things to work properly for our home.

If we had one panel I could hook things up a little easier. This stuff gets complicated. Hopefully we are done with fires and power shut offs for this year.

[SunEagle]

5 full days, and the power is back in town. I never lost it, being off grid. did have to scramble a bit with the milk situation. with nightime temps in the upper 20's and no power, lots of folks with no heat, or hot water

I am glad you made it through the power outages along with being safe from the fire.