Powerwall 2: SGIP/Incentives

[jandesailorman]

Hey, my first post, been reading for many moons though.

I am signed up for 2 PWs with one of those expensive outfits (Swell), got into Tier 1 so as someone said given the 0.50/W incentive it still makes sense. Though I don't believe Swell's claims that you can count 30% of the full cost towards ITC (i.e. without deducting the SGIP payment) unless you declare the SGIP payment as income. But now that it's 2018 I guess my marginal tax rate went down so may actually work out better. Note however that I am no tax lawyer...

I'm looking forward to seeing how TOU Arbitrage works when it finally comes out. I have 2.4kW PV pointing SW, on PG&E's EVA rate (with Ford Focus EV, I know don't laugh) so don't really need a PW for economics (yet), but hoping to eventually use them for more like Demand Response with somebody like OhmConnect or eMotorWerks. And whole house backup of course, though my circuit seems to be pretty reliable so far. But man those units are taking a long time to get to me, Tesla must be sending a lot to Puerto Rico and Australia

 

[miimura]

I am also with Swell Energy in SGIP Step 1 for two PowerWalls. They are supposedly going to install this week.

 

[fresnoboy]

You have a year to complete the project once you receive confirmation. But you will need to know battery manufacturer, installer if different, and technical stats of the battery you want to install in order to reach the confirmation stage. You will need to know if you are installing one or two batteries. You may also need to know the specs of your PV system. So in your case it may not make sense since you haven't determined your battery situation and designed your system yet. Plus who knows, in 9 months something bigger, better and cheaper might come along. I heard Audi motors is coming up with their version of the Powerwall.

This is super helpful. Sounds like I need to decide on the powerwall option now and apply rather than wait for everything to get built and do it then. Is there a limit on batteries? Could I have 3 or even 4 if I wanted to (it's a big house) and still qualify under the SGIP program?

Audi? I have an Audi. It is a great car, but they test and trial everything in Europe first and new tech sometimes takes a long time before it reaches here. I would not hold my breath waiting on a battery solution from them.

There will be plenty of solar (20+ KW of panels) to charge the system with. The only problem is it looks like I have to deal with Tesla directly for the powerwall's, but not necessarily for solar system. Do folks here have positive experiences with Tesla on the panel an inverter side? I have heard horror stories re: SolarCity and in general their reputation seems crap in almost every solar forum I can find. Would Tesla engage on a project where the house hasn't been built yet?

But requiring a separate contractor to work with Telsa on the powerwalls make that option seem painful as well.

thx
mike

 

[wwhitney]

Is there a limit on batteries? Could I have 3 or even 4 if I wanted to (it's a big house) and still qualify under the SGIP program?

Yes, but once you exceed 2 Powerwalls, your system size (in kW, at 5 kW per Powerwall) is capped at your peak demand during the past 12 months, for existing customers. For new construction, you need to estimate your peak demand when applying for the rebate, and then before you can receive the rebate you have submit proof that sufficient demand has actually occurred.

4 Powerwalls would be 20 kW, which wouldn't be hard to achieve if you have 2 Teslas or a Tesla with twin chargers and the proper wall connector to support it (I'm not very familiar with Tesla's automotive offerings).

Cheers, Wayne

 

[fresnoboy]

Yes, but once you exceed 2 Powerwalls, your system size (in kW, at 5 kW per Powerwall) is capped at your peak demand during the past 12 months, for existing customers. For new construction, you need to estimate your peak demand when applying for the rebate, and then before you can receive the rebate you have submit proof that sufficient demand has actually occurred.

4 Powerwalls would be 20 kW, which wouldn't be hard to achieve if you have 2 Teslas or a Tesla with twin chargers and the proper wall connector to support it (I'm not very familiar with Tesla's automotive offerings).

Cheers, Wayne

Again, super helpful - Thanks!

How exactly is peak demand calculated? Peak in terms of 5 min, or an hour or a day?

The house is big (9000+ sq ft), plus a pool (gas heater on that though) and will have a 400A PG&E feed. No Teslas, but we do have a hybrid minivan that is good for 50A itself. If we turned all sorts of gear on, it would be easy to hit 20-30 KW, though it would be rare to see that on a frequent basis. Maybe when it's hot and the HVAC is on full, pool equipment running, minivan charging and all the kitchen appliances cooking with all the AV and coomputer hardware on.

thx
mike

 

[miimura]

3 or more PowerWalls go into the Commercial segment of the SGIP program. Residential is capped at 2 PowerWalls.

 

[Kren]

Audi? I have an Audi. It is a great car, but they test and trial everything in Europe first and new tech sometimes takes a long time before it reaches here. I would not hold my breath waiting on a battery solution from them.

Yes, you are right. I forgot about that. We had a super efficient A8 diesel in Germany. Couldn't even import it into California. No guarantee Audi's version of Powerwall would even get the okay to operate in the U.S., Audi smart home battery grid creates a 'virtual power plant'

 

[wwhitney]

How exactly is peak demand calculated? Peak in terms of 5 min, or an hour or a day?

Pretty sure it's peak average demand over one metering interval, which I believe is 60 minutes for residential.

Cheers, Wayne

 

[fresnoboy]

Pretty sure it's peak average demand over one metering interval, which I believe is 60 minutes for residential.

Cheers, Wayne

Makes sense and that load is easy to demonstrate in my case.

This would be in the SGIP large storage claiming ITC category, coprrect? Any other differences in how SGIP works there from the normal residential?

How do I calculate the value of the rebate? Is there an online calculator I can find? The handbook is hard to read. Are they really meaning kW of inverter power and not kWH when they say kW?

thx
mike

 

[wwhitney]

This would be in the SGIP large storage claiming ITC category, coprrect?

More than 2 Powerwalls puts you in the large storage category. Whether or not you take the ITC is a separate issue; the large storage category has the feature that the SGIP rebate is reduced if you take the ITC.

So in the large storage category, if your project is cheap enough, you don't want to take the ITC, since the ITC is calculated on your cost after rebate. That is, when your cost after rebate is low enough, the ITC is low enough that it is below the amount of the rebate reduction on the SGIP, and you would lose money taking the ITC. Just something to check once you have a quote.

Any other differences in how SGIP works there from the normal residential?

Not that I'm aware of for the rebate recipient, although I haven't closely read the handbook for large storage.

How do I calculate the value of the rebate? Is there an online calculator I can find?

At the $0.40 per Watt rebate level, the rebate per Powerwall is $4,640. That's based on the labeled inverter size of 5 kW continuous, and the nameplate capacity of 13.2 kWh (which differs from the spec sheet of 13.5 kWh). The first 2 hours of capacity is rebated at $0.40 per Wh, or $4,000 for 10 kWh. The next 2 hours is rebated at half that rate, so $0.20 per watt hour for 3.2 kWh, or $640.

If you are in a different step with a lower rate, or taking the ITC for a lower rate, then just multiply $4,640 by the ratio of rates. For example, the Large Storage with ITC rate is $0.29 per Watt, so the the rebate on a Powerwall would be $3,364. Which means that the breakeven point for taking the ITC under Large Storage Step 2 (if charging 100% from solar) is $7,617 per Powerwall; at a project cost below that, you lose money taking the ITC.

Are they really meaning kW of inverter power and not kWH when they say kW?

Yes, they are very careful with the use of kW versus kWh. Remember that one of the goals of the SGIP is to reduce peak demand load on the grid, so the size of the inverter in kW is entirely relevant.

Cheers, Wayne

 

[SoundDaTrumpet]

Hey, my first post, been reading for many moons though.

I am signed up for 2 PWs with one of those expensive outfits (Swell), got into Tier 1 so as someone said given the 0.50/W incentive it still makes sense. Though I don't believe Swell's claims that you can count 30% of the full cost towards ITC (i.e. without deducting the SGIP payment) unless you declare the SGIP payment as income. But now that it's 2018 I guess my marginal tax rate went down so may actually work out better. Note however that I am no tax lawyer...

With 2018 tax reform, it appears that if the household income is under $157,500 (single) or $315,000 (married/joint), it is even better to declare the SGIP payment as income. This improves with the reduced 2018 tax rates. This upside came with a downside also. I just realized home equity loans interest is not deductible in 2018.

 

[markb1]

Am I correct in thinking that Tesla has not reached their developer cap for large scale storage, and that 3 powerwalls would qualify? And San Diego is still in step 2 for that category?

 

[wwhitney]

Yes, 3 Powerwalls, if you can demonstrate that your demand was high enough in the last 12 months, would be under the Large Scale Storage category.

You can answer the rest of your questions at https://www.selfgenca.com/home/program_metrics/ Choose Large Scale Storage under Budget Category: SCE is now Step 3, SCG has almost run out of Step 2, and CSE and PG&E are not as close to finishing Step 2. As for the Developer Cap, scroll down to that section again choose the proper Budget Category. Tesla is at $17.6M of $20.7M for its Step 2 Developer Cap in Large Scale Storage.

Cheers, Wayne

 

[markb1]

Yes, 3 Powerwalls, if you can demonstrate that your demand was high enough in the last 12 months, would be under the Large Scale Storage category.

You can answer the rest of your questions at https://www.selfgenca.com/home/program_metrics/ Choose Large Scale Storage under Budget Category: SCE is now Step 3, SCG has almost run out of Step 2, and CSE and PG&E are not as close to finishing Step 2. As for the Developer Cap, scroll down to that section again choose the proper Budget Category. Tesla is at $17.6M of $20.7M for its Step 2 Developer Cap in Large Scale Storage.

Cheers, Wayne

Ok, so by my reading of the handbook, for 3 powerwalls, I would need peak demand of 15kW. I'm not quite there. But the handbook says:

For new construction or projects with future load growth, projects can be sized up to future peak demand, but the load must be substantiated before the incentive can be paid.

I could just say that I plan to install a Tesla Wall Connector and charge my car at 20kW, which is the truth. (I already have the wall connector and my car has dual chargers.)

Does that sound right?

 

[wwhitney]

Does that sound right?

Yes. The handbook also says that at the final stage of the rebate process (ICF), before you can claim the rebate you need to provide proof that the expected load has materialized. So they'll check your peak demand again at that time.

Cheers, Wayne

 

[miimura]

That's kind of funny. Intentionally increasing load to qualify for a subsidy that encourages reducing load.

 

[Frankman60]

How did Tesla plan to do the installation without any new panels (other than the Gateway)?

I have been comparing Tesla estimates with other contractor estimates and as others have mentioned, Tesla is much lower in cost. However, because I am not able to get a SGIP rebate through Tesla, even though the other contractor bids are much higher, the net cost to me is lower than Tesla. For example, if I use the $2200 installation you mentioned plus the cost of two PWs and a gateway ($11,700), that cost is still more than what I would pay another contractor with a bid almost twice as high after considering SGIP and ITC.

They quoted me $2000+$200, for an install that I don't think could be simpler. The backup gateway is an extra $700 (separate line item), and there are no new panels. Their website says "typical installation cost ranges from $800 to $2,000."

 

[Frankman60]

Do you have to demonstrate more than peak demand of 15 kWs? What I mean is there another metric that must be met such as X average daily kWh consumption? I think I could show 15 kWs being used by charging my Tesla at 40 amps (9.6 kW), two 110V plug-in hybrids charging (3 kWs), and my AC and spa running which would put it over 15 kWs. This scenario doesn’t happen every day but could happen and would that qualify for a large installation?

Yes. The handbook also says that at the final stage of the rebate process (ICF), before you can claim the rebate you need to provide proof that the expected load has materialized. So they'll check your peak demand again at that time.

Cheers, Wayne

 

[dailo]

I downloaded all my PGE data, which breaks it down into 15 minute intervals. I found there was a few instances in the summer where I consumed 5 kWh in 15 minutes, which means I was averaging roughly 20 kW during that period. Based on the wording from the handbook, that should qualify. The other thing for the large scale systems is that the system needs to be fully discharged 130 times a year. Debating if I would want to hook up the car charger to the system to help meet this requirement, although I should be able to do that without charging (roughly 5500 kWh)

4.2.5 System Sizing for Projects without Peak Demand Information
Sites with 12-months of previous energy usage data (kWh) but without peak demand (kW) information
available (e.g., customers on rate schedules without a demand component) will have an equivalent peak
demand calculated using the highest amount of energy consumed (kWh) in a given interval in the previous
12 months of consumption at the project site divided by the duration of that interval, in hours. The most
granular interval for which there is 12 months of available data should be used.
For example, if a residential customer’s meter collected hourly interval data for a 12-month period, and this
data revealed that the greatest hourly consumption data was 5.5kWh during the previous 12 months, then
the peak demand estimate would be 5.5 kW. If the data revealed that the greatest consumption within a
15-minute interval was 5.5kWh during the previous 12 months, then the peak demand estimate would be
22 kW.
For customers with less than 12 months of history with the utility or customers that have meters incapable
of recording interval usage data, methodology from Section 220 of the National Electric Code (NEC) may
be used to determine instantaneous peak demand.

 

[Frankman60]

Thanks. I did some digging into the SGIP handbook and below is the section that covers what you mentioned. I haven’t tried downloading my energy usage data from SDG&E but maybe that is worth doing to see if it meets the requirements.

4.2.5 System Sizing for Projects without Peak Demand Information
Sites with 12-months of previous energy usage data (kWh) but without peak demand (kW) information available (e.g., customers on rate schedules without a demand component) will have an equivalent peak demand calculated using the highest amount of energy consumed (kWh) in a given interval in the previous 12 months of consumption at the project site divided by the duration of that interval, in hours. The most granular interval for which there is 12 months of available data should be used.
For example, if a residential customer’s meter collected hourly interval data for a 12-month period, and this data revealed that the greatest hourly consumption data was 5.5kWh during the previous 12 months, then the peak demand estimate would be 5.5 kW. If the data revealed that the greatest consumption within a 15-minute interval was 5.5kWh during the previous 12 months, then the peak demand estimate would be 22 kW.

I downloaded all my PGE data, which breaks it down into 15 minute intervals. I found there was a few instances in the summer where I consumed 5 kWh in 15 minutes, which means I was averaging roughly 20 kW during that period. Based on the wording from the handbook, that should qualify. The other thing for the large scale systems is that the system needs to be fully discharged 130 times a year. Debating if I would want to hook up the car charger to the system to help meet this requirement, although I should be able to do that without charging (roughly 5500 kWh)