Germany and Tesla’s PowerWall | Hacker News Reader

Germany and Tesla’s PowerWall

catalyticengineering.com

33 pointsiamjdg13 comments

Just an observation that this analysis doesn't include the powerwall's benefit of also providing backup power when the grid is down. It's hard to know how much this would be worth and certainly would vary from home to home.

On the other hand, since Tesla is also selling a battery specifically for grid backup I would assume that they've done some market research into it and this value might be higher than one would think.

> When the grid is down

Historically in Germany (and most of western and northern Europe AFAIK) a blackout is something that happens every ten years and lasts for two hours. It's rare and inconsequential enough that no-one bothers hedging against them.

Wind and solar are increasing the probability of large blackouts, but the proper solution to that is building more nuclear power, eventually transitioning to fusion.

> Wind and solar are increasing the probability of large blackouts, but the proper solution to that is building more nuclear power, eventually transitioning to fusion.

Can we stop betting on pipe dreams? Fusion isn't proven, and while I'll advocate for continuing research into it, solar, wind, and geothermal is here today.

We should be advocating for the installation of solar on every roof, on every brownfield that can't be used for housing or agriculture, wind where ever possible, and geothermal where it makes sense.

It is silly that we continue this nonsense that nuclear (fission today and fusion tomorrow) are our saviors. We have proven, as a species, incapable of properly managing the small risks that nuclear presents.

It takes 10-20 years and over $1 billion US to bring a new nuclear plant online, and this does not take into account the government limiting their liability in the event of an accident. Wind turbine parks and solar fields can be developed in under a year, with fewer (if any!) cost overruns.

No reason we can't do both.

Fusion is the ultimate energy generation technology. It will be real soon enough.

Your comment reminded me of Interstellar :-)

As an European an unscheduled blackout is unheard of. We had the first loss of power( a few hours ) this year in a span of ten years due to maintenance.

Where I live we have a lot of large trees and during the Winter it's quite common that storms will topple the trees and cause power outages of a couple of hours to up to about 24 hours max. And for those who live in areas prone to ice storms I gather it can be quite a bit worse.

The proper solution isn't nuclear, it's distributed storage like the tesla powerwall.

Nuclear reactors can be build in a safe way, it's the storage of spend fuel that makes them uneconomical because of the high cost to do it properly.

A few points:

1 - Assuming that the power-wall acquisition costs are already "sunk," I wonder if it could ever make financial sense anywhere to do "power arbitrage." IE buy electricity at cheap off-peak rates and sell it back at peak times.

2 - The existence of those kludgy sell-to-the-grid solar setups is a gift for Tesla. There are so many of them installed and they're pretty much just waiting for a powerwall to come along.

3 - I hope those setups don't crowd out other applications. The obvious one is necessarily off grid installations. There are a lot of off grid setups in the world. They mostly run on generators that smell, make noise and get turned off at night (melting all your ice-cream). Remote homes, hotels, mobile homes, boats... lots. Yachts alone...

This really is a bottleneck product.

I'm looking at a powerwall specifically for powering a sailboat, with solar providing the bulk of my power needs with the remainder provided by a diesel generator while underway.

EDIT: After a quick shower, I wanted to come back to expound on this a bit.

I've also wanted to lead a bit more of an independent life on a sailboat, traveling within my home. As an engineer at heart, I've always thought about how to best manage energy to have the top quality of life on a boat with minimal sacrifice. Solar is almost always the way to go, as the sun is usually shining where ever you're at (some folks do go with a wind turbine, but they're unreliable at sailboat scales).

Tesla's PowerWall product enables this. No longer do I have to consider running a generator full time, or having a dangerous amount of lead acid batteries onboard to store enough power to meet my first world standard of living. The more energy I can safely store, the longer I can be aware from a port, not run a generator, or in short, spend money. The less money I spend, the less I have to work a job I don't enjoy or want to (disclaimer: I love technology, I'll always work in it, I just want to be able to always be picky about the jobs I take)

Dense, cheap energy storage enables everyone to better manage their energy use, and energy is what (mostly) drives the world now. Thanks Tesla!

I have good news and bad news.

Bad news: the battery chemistry used in the Tesla PowerWall (Li-ion NCA or NMC) is not safe for marine applications. Only Lithium-iron-phosphate batteries, with lower energy density, are safe for this purpose. Putting a PowerWall on your boat would not only void your insurance, it would carry a real risk of setting your boat on fire.

Good news: there are already several manufacturers that sell lithium battery packs that have been safety tested and approved for marine use. GIYF.

I had spoken to my prospective insurance company, and they had assured me a lithium ion chemistry was acceptable for onboard use, even if I choose to use it as part of the power train in a series hybrid setup (this is going in a multi-hull catamaran). I'll have to call them back and get something in writing. Thanks!

No problem. Remember when the entire Boeing 787 fleet was grounded due to li-ion fires - you really really don't want that in your boat. If possible, buy something that's been certified for marine use by an independent safety auditor like Bureau Veritas or similar.

1 - Currently (I believe) only grid operators can make profit on grid arbitrage, since in all cases I know you are either paid a lower tariff (i.e. the maximum you pay is lower than the minimum you're sold for), or nothing at all. The only arbitrage you can make is as described here, by storing to avoid buying from the grid, that is, "self-arbitrage", for the back of a better term. Perhaps you could even sell your neighbor some energy, I don't know if regulations anywhere would allow that.

That said, this is obviously the way to go in the future, but it needs a good system-wide regulatory design first (from both an economic and technical perspective) to avoid things like grid instability (from the technical side) and compromising utilities and grid maintenance financially (from the economical side).

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