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Powerwall in New England ?
- Thread starter masam
- Start date
yousexy
Member
Except I missed the window to have Solar Panel + battery storage paired installation. To install just the battery, I won't get that 30% tax credit.
Congrats. I had mine installed on 1/31 - but as a heads up it is only now just working. From all of the literature - I had the impression that when the install guy leaves the Powerwall should be working. Mine was an addition to existing solar and the sun was down when they finished the install - some things were misconfigured that you couldn’t really test without the sun. There is also another behind the scenes step where a supervisor reviews detailed pictures of the work that was performed before they try to schedule the inspection. They also do an on-line registration step - but mine failed so I had to call in. Probably because of the initially failed registration - it didn’t show up on my app and I had to call for that too. All of the installers and people I interacted with were great - but they do still seem to have some process issues.
Having said all that - now that it is working correctly - I am very happy.
This is not true, at least on straight National Grid (Northborough, MA).
I get a Credit of $0.20 / kWh when pushing excess Solar onto the Grid and charged $0.25 / kWh when pulling off the grid.
Effectively we have a free, maintenance free, zero vampire loss, no degradation, 80% efficient PowerWall.
Well no degradation, assumes the cost - credit doesn't change, and very well could over time.
The PowerWall is ~90% efficient.
So a PowerWall would gain you ~10% with Net Metering.
I'd love someone to prove my calculations wrong, but I can't see how a PowerWall makes any economic sense with Net Metering on National Grid (Northborough, MA).
My calculation goes, out of 13.5 kWh (usable capacity of PowerWall) you'd save 10% of that by not pushing it to the grid, that comes to 1.35 kWh a day savings (only during over production Solar Season).
That comes to 492 kWh / year, at cost of $0.25 comes to a savings of $123 / year.
Amortize that over 10 years. $1230 savings over 10 years (PowerWall Battery Warranty).
Doesn't a PowerWall cost at least $5000 or more?
That does not factor in that you don't over produce the whole year.
It's in reality half that. And the PowerWall Diminishes in performance.
It also assumes 100% overproduction.
My estimate is break even in about 100 years.
It's an extremely expensive "Generator" and won't last very long, and constantly needs to be topped off in the Winter (sometimes from the Grid). And it can't be your generator and cost savings on Net Metering cost at the same time.
Please tell me how the makes any sense for someone on National Grid (Northborough, MA).
Maybe it does make some sense in other New England States or Towns within MA.
Curious what the numbers look like in other New England towns or States to justify a PowerWall.
robby
Member
I believe all of this is correct, and I say that as someone who bought two Powerwalls with National Grid in Massachusetts. (Note: depending on @EdA's municipality, his economics may be different than ours).
For us, the Powerwall is not an investment; it is a generator with near-instantaneous failover, producing no noise, requiring no maintenance, and having no reliance on any grid service. I live in a town that just had a two-month natural gas outage and which has had multi-day power outages semiannually since I've lived here (~3 years). The peace of mind from knowing our home can now operate independently and within its own means[1] was worth the premium to me (approx 2x cost vs gas generator, after installation and 30% tax credit). Achieving this in a zero-carbon way, enabling solar production during grid outages, supporting a company like Tesla, and not further subsidizing National Grid or Columbia Gas were also contributing factors, though harder ones to quantify.
[1] For us to not be able to run home essentials, we'd need a 2+ day power outage while being unable to replenish solar at 50% rated capacity in December solar conditions. It's not unimaginable, but given how many things need to go wrong, we expect at least as much reliability as we'd have with a gas generator.
Thanks for confirming.
Keep in mind also that the solar panels will often be snow or ice covered after a storm that would have taken out the power in the first place. They can sometimes be cleaned. But not always.
I think I’ve had 2-3 multi-day power outages in 30 years. So my backup need has been fairly low, but certain want something. A $400 genrac generator has covered me. But I plan to get a better Honda super quiet inverter type. Just can’t decide between one big one or the Tandom small ones. For the amount these run over a lifetime the CO2 is pretty insignificant. Nothing has zero footprint. Including solar panels and batteries.
How much is 1 powerwall installed in MA? Assuming no service panel upgrade etc.
yousexy
Member
Powerwall if installed in pair with your solar together, you get to have 30% tax credit on it.
Yes, it is an expensive "generator" and we don't have enough sun in winter in New England. but for folks lives off well water and have frequent power outages in winter, that power wall really helps, especially it is silent. I hate the damn generator noise.
There are folks lives off-grid with, solar panel + powerwall + generator. I know one in Colorado.
Maybe the DOER will come up with some sizable incentive for energy storage device?
Yes, it is an expensive "generator" and we don't have enough sun in winter in New England. but for folks lives off well water and have frequent power outages in winter, that power wall really helps, especially it is silent. I hate the damn generator noise.
There are folks lives off-grid with, solar panel + powerwall + generator. I know one in Colorado.
Maybe the DOER will come up with some sizable incentive for energy storage device?
robby
Member
If a $400 Generac meets your needs, that's pretty compelling. We travel a lot in the winter and our furnace can't run without electricity, so we needed an automatic failover system to ensure our pipes don't freeze. Once we saw the labor costs of that, we decided to put more into the unit itself, so that it could run our central air and do its own self-tests. We were going to be in the hole for no less than $5500, and if we went with a name brand and a warranty half as good as Tesla's, more like $8500.
We are fortunate to have a very efficient home, where two Powerwalls can last 4 days if nobody is home, and 2 days if somebody is home and being judicious (nothing crazy, but e.g. not running the dryer). In the summer it is exceedingly rare not to collect 20kW+ of energy on any given day, so we can even run our central air during outages without concern. Realistically, outside of winter, we'll be charging cars just to dump excess power during outages.
We only got quotes for 2 and 4 Powerwalls. By my math from reverse engineering the quotes, a single unit would have been $9120 (after state taxes and before federal tax credits). The installation costs are mostly fixed, so it works out to about $6466 per additional unit after the first one. There was a pricing change late last year though, and we were locked into the earlier pricing, so I believe it would cost a little more than that for new customers.
A few things missing:
- Exists today - 30% ITC credit (this year) if used along with Solar. I see a lot of posts saying it has to be installed at the same time as Solar, that's not my read, but I believe it does have to regularly cycle, which I believe Tesla complies with in "solar mode"
- Exists today - but only for new solar installs - if you are under SMART instead of SREC (I/II) there is an Energy Storage Adder. Let's call it 5-6c/kWh of Solar produced. There is an Excel sheet on the SMART site to calculate your exact adder, and like the rest of SMART it also decreases as more people sign up for it (its currently in Tranche 3, I assume because some very large storage project got added, I don't think it will move that quickly but maybe I am wrong with the Sunrun news on their ISO-NE bid).
- Doesn't exist yet - the 2019 MA-EEAC 3 Year plan which was just approved by DPU has some programs to incentivize energy storage during peak events (demand reduction) similar to what is done today with thermostats under the ConnectedSolutions program (Nest Rush Hour Rewards under nest branding). In the DPU filing there is a mention that the incentive would be guaranteed for 5 years to justify the costs. The filing does not mention the actual incentive value, but I have heard some crazy numbers that would make this well worth it. My read is Tesla would 1) have to participate 2) change their software to export to the grid upon request from the program and 3) my personal read is that many electrical designs are insufficient for maximizing this because they were done on the assumption that the PowerWall would never be exporting while generating Solar, but in an ideal world for the utilities in the afternoon peak both the Solar and PowerWall would export. But I think 1) is the biggest issue. It does seem like Sunrun (who I believe just uses StorEdge and LG but may have their own SW) and Sonnen may have already done the integration.
If we do see Tesla join whatever the demand response program is, I'll be begging my energy sales rep to put my project through ASAP. They wanted to install me within a few weeks, but I put the whole thing on hold.
Holy smoke, that's good info.
So in a nut shell, there ARE some incentives in place, fairly recently, even in MA, for storage. However, Tesla's excruciating pricing is currently pricing themselves out of the market (around here).
Are there alternatives to Tesla that can create some ROI over 10 years?
robby
Member
Tesla is by far the cheapest option. The second cheapest I found was an LG Chem Resu, quoted $12k (including installation) for 10kWh. That's more than 2x per kWh what we paid for Powerwalls.
yousexy
Member
It's all about how bad you want the second energy source.
Tesla is bar none in terms of consumer energy storage product.
too bad, there is no possible way to use our Tesla vehicle as a secondary energy source during an emergency. It's got a huge battery compared to Tesla wall, lol. I'm dreaming.
Tesla is bar none in terms of consumer energy storage product.
too bad, there is no possible way to use our Tesla vehicle as a secondary energy source during an emergency. It's got a huge battery compared to Tesla wall, lol. I'm dreami
ng.Here is an article that discusses the storage incentive included in the 3-year plan: Massachusetts Is First State To Make Battery Storage Eligible for Energy Efficiency Incentives
So true ! I’m sure many of us here have around 100kWh or even close to 200 kWh of storage that would be great to access during long power outages. Oh well. One can only dreamtoo bad, there is no possible way to use our Tesla vehicle as a secondary energy source during an emergency. It's got a huge battery compared to Tesla wall, lol. I'm dreami
Another battery to consider is The Pika Energy Island™ - Smarter home energy storage - Pika Energy They package Panasonic 18650s in ways that can be stand-alone or added on to existing systems which might be cheaper.
I agree that net meetering, as a seasonal battery, is more helpful than an undersized overpriced battery in a New England garage but some storage is worth a lot when the power goes out.
I agree that net meetering, as a seasonal battery, is more helpful than an undersized overpriced battery in a New England garage but some storage is worth a lot when the power goes out.
