Tesla POWERwall

Musk dreams big. The Gigafactory is a huge gamble.

I was curious about the possibility of competing technologies beating Li-x at the energy storage game in small scales, and so far have only found carbon nanotubes as a possible candidate. They can be built to act as a spring that I gather wears *very* slowly, has very little waste energy, and has 10x the energy density of Li-x when produced without manufacturing defect.

I wondered about magnetic springs but am still grappling with the mechanics.

 

Regardless of all bad comments, TESLA sold out all merchandise until mid 2016

 

@Zythryn

If you don’t mind me asking, did your Tesla Powerwalls qualify for the Federal Investment Tax Credit (ITC)?

I understand they should qualify if installed at the same time as solar. But we already have an amount of solar capacity installed we desire and the Powerwalls appear to qualify if adding onto our existing solar system, if I understand the terms correctly.

Was that your experience?

The Tesla website supports this and says:
Powerwall 2 is designed to qualify for the Federal Investment Tax Credit (ITC) when it is installed on an existing or new solar system and is charged 100% with solar energy. It does not qualify when installed without solar or if solar is installed after the Powerwall.

 

They were installed this year, so I only know what you do at this point.
When we do our taxes next spring I can say for sure.

 

We probable won't pull the trigger at this time, but quite tempting as CA has some killer incentives taking thousands off the cost of Powerwall and other battery storage solutions. This can be taken with the Federal ITC.

To encourage more residential storage deployments in California, the California Public Utilities Commission (CPUC) established the Self-Generation Incentive Program (SGIP). The program provides incentives to help reduce the costs of storage to consumers. Residential storage batteries, like Powerwall, reduce strain on the utility power grid and in turn help reduce the need to build expensive fossil fuel-fired power plants.​

California Self-Generation Incentive Program (SGIP) | Tesla
https://www.selfgenca.com/home/program_metrics/

 

That is why people are going solar during the day. Hopefully you generate enough power to supply home, charge powerwall and maybe put some back on the grid at higher rates

 

Batteries for the powerwall are a secondary priority compared to supplying the Model 3 sales.

 

I've long suspected the PowerWall is the first recycling step for used batteries. Just there aren't enough.

There is an outfit in Tennessee that did a YouTube documentation of the Tesla Model 3 battery. My understanding is they want the battery from a salvage Tesla as a battery buffer for their solar roof business.

Bob Wilson

 

Tesla website quotes $11,800 for 2 Powerwalls and $1,100 for supporting hardware for a "$12,900 total equipment cost".

The first quote I got today from a certified Powerwall installer was for $21,500 "gross system price". After Federal ITC and the CA SGIP they quote net cost to customer of $8,090. I asked the rep to explain how they came to such a high install price and he didn't have an answer. Although not overtly saying so, he suggested the Tesla website was not correct.

The Tesla website notes "typical installation cost ranges from $1,000 to $3,000. This does not include solar installation, electrical upgrades (if necessary), taxes, permit fees, or any retailer / connection charges that may apply."

Based on tax in my area we are talking about $1k and there are no upgrades needed. So the install costs are still way out of line with the Tesla website.

Waiting to hear back from another company.

 

My install for three was about $26k. This did not include any tax rebates or such, if there are any.
Ours was also an unusual installation. I'd keep looking.

 

Is this just for PWs or solar to?

 

No solar in the price. We already have a solar system that produces 16+ MWh/yr.

Our install for Powerwalls would be quite straightforward as it would be just inside the garage from the circuit panel (which is on the same wall external to the garage). So very short run and no upgrades needed.

 

They seem to be assigning a lot of cost to the transportation of the batteries. There's certainly something to pay attention to, but it looks like they are trying to amplify its effect as a differentiator.

They also seem to have a very low cycle limit for the lead acid cells.

I installed an 11kWh lead acid battery in an off-grid power setup at the family vacation cottage. Based on previous experience with the exact cells used, we are anticipating that the cells will last about 8 years before needing replacement, and the overall system is getting roughly 150 cycles per year. The oldest cells were installed in 2013 and are aging right in line with everything we've seen in the past.

 

What volts are the PWs at? Additional electronics needed for the tie in to panel or gid??

 

The Powerwall uses "2170" format lithium NMC (Nickel-Manganese-Cobalt) battery cells such as used in Tesla's Model 3.

Internal battery is 50 V DC. The unit outputs 120/240 V AC. No additional electronics needed except for an external gateway that is included in the "$12,900 total equipment cost" for 2 Powerwalls above.

 

Yes, that's not what I'm referring to. In the linked comparison, they've assigned lifecycle count values to both types of battery. I can't speak for the Powerwall values, but I think the values they used to represent the lead acid cells are a bit off.

 

Still hoping to go Powerwall(s) in the future, but will probably hold off for now. It is tough to pass up California's very generous SGIP rebate which continues to phase out. Maybe they will do something like this again in the future.

For some folks like Zythryn, the Powerwall(s) have several potential important benefits that are less important to us that involve having back-up power. We have had several years experience with our utility PG&E, but so far the longest blackout was 3 hours, others only seconds to 30 minutes and we average no more than 1 blackout a year AFAIK. Our weather is also much more mild in the winter, so even if power were out for days the house and its occupants would not freeze and neither would the pipes. Historically, natural disasters are also very uncommon here. No hurricanes, tornadoes, very low flooding risk, and despite living in California we are on one of California's rare geological quite spots.

We also already practice load shifting/time-of-use at our house, so help smooth out the duck curve already. More solar PV next year would be in order if we are not still net zero with house + vehicles after this winter.

Our new central air sourced heat pump completed its first summer duty and performed above expectations; we used only 1258 kWh this year to cool a 2555 sqft house with 4 full time occupants to 77F (11 days 100F+ this summer). We don't think we will have to run cooling more this year based on weather forecasts and the ability of the whole house fan able to cold soak the house when needed on unexpected warm days.

The heat pump will have to go through its paces for warming for the first time this winter, so I am excited to see how energy hungry this thing is. Did calculations at its rated 13.0 HSPF and everything looks to pan out well.