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Powerwall 2 and Integrated Solar

powerwall.tesla.com

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Re: Powerwall 2 and Integrated Solar

#141

Post by anantzoid »

andreyk wrote: post #116

His argument about the solar roof starts by equating the situation to how Tesla started out - electric cars were slow and ugly and needed to be sexy and cool to be attractive, and the same is true for solar. Except I highly doubt this is true here - do people really mind the look of typical roof-mount solar? My impression is that the upfront cost is just too high and cost recoup is just too slow. The argument for the…

> Unrelated: gosh, I like the content of the video presentation but it would be nice if Musk was a slightly better presenter.

Same goes for the audience. I heard one shouting "Save us Elon!". Where do they get these people from?

Re: Powerwall 2 and Integrated Solar

#143

Post by makomk »

swampthinker wrote: post #4

Solar panel roofing tiles have been around for a long time. I wonder what this will do different? Pricing? Or perhaps they are relying on brand strength alone. Edit: I understand the urge to downvote because I'm not singing praise, but I promise I'm not trying to be overly pessimistic or critical of what Tesla is doing. Fact of the matter is, solar tiles have been done before, and failed miserably.

Marketing and business model, primarily. Previous solar tiles were more expensive than conventional solar and so are these. The difference here is that Tesla and SolarCity are marketing it as no more expensive upfront than a conventional roof replacement by keeping ownership of the roof and having buyers sign a contract committing them to buying power from it at ever-increasing prices.

There also seems to be some efficiency and aesthetic improvements over previous tiles, but those alone wouldn't be enough to make it viable.

Re: Powerwall 2 and Integrated Solar

#144

Post by extrapickles »

TheSpiceIsLife wrote: post #62
onesun wrote: post #56

Any idea why the solar cells aren't packed more densely? It looks like there's a lot of wasted space on due to a square cell centered on a rectangular tile.

From when I was reading more about solar cells I recall there being something about the distance from the conductor (the two stripes visible equidistant from the midline of the cell) being a problem especially with monocrystalline cells, which these appear to be. I think this was more a problem for cells that had the conductor fixed to the back of the cell. Google image search for monocrystalline solar cell and you'l…

I'm not sure you can even make a mono crystalline ingot eliptical. The process heavily relies on spinning the ingot while pulling it out of a silicon puddle which results in the round shape.

Re: Powerwall 2 and Integrated Solar

#145

Post by extrapickles »

JoeAltmaier wrote: post #69
toomuchtodo wrote: post #60

Earlier quoted context omitted.

That Powerwall was of a different chemistry, and has been discontinued. EDIT: This is a baller feature: "Always Connected: Monitor your solar energy use in real-time and receive alerts when Powerwall is preparing for cloudy or severe weather. " They're performing weather forecasting, and then ensuring the Powerwall has charged up for a possible outage event. Brilliant.

I cannot imagine what preparation they could be making. Surely the default process is to charge the powerwall at all times if feasible. What extra operation could it do in the event of a bad weather forecast? Other than tell you about it.

To get better lifetime out of the cells, you don't fully charge them. I bet when bad weather is occurring soon, it charges to maximum storage capacity, not to max cycle level.

This lets you have best of both worlds, with a minor tradeoff in unpredictable outages you have slightly reduced runtimes.

Re: Powerwall 2 and Integrated Solar

#147

Post by dirtyaura »

Loic wrote: post #118

Quick question for the people living in the US (Target customers of the Powerwall). What is your yearly power usage? On the website[0] they put for sizing 10kWh/day/BR. Which means 14600kWh/year for a 4 bedroom house. Here in Germany, working from home with a 4BR+office house, we are using 2550kWh/year. So, I suppose the Tesla sizing is to support a "peak day" usage, but still, I am surprised by the calculations. Thi…

Interesting to compare different countries.

Helsinki, Finland here. Roughly 2100kWh/year. 2 people, a flat with 2 rooms + kitchen. We have district heating. Several laptops in the house, frequent home cooking, most lights are LED based, no sauna inside the apartment. We don't pay any attention to manually saving electricity, i.e. turning off lights etc. Our electric company provides a comparison report on their web site, according to it we are well below the average for similar household.

Re: Powerwall 2 and Integrated Solar

#148

Post by Roritharr »

martin_bech wrote: post #127
manav wrote: post #75

I haven't looked into it yet, but I'm curious about using utilizing my Teslas in case of emergency for power. With 75kwh+ each (leased so no concern about cycles) I don't think I'd need a powerwall at home.

They would have more than enough power, but you cant pull power out of a Tesla. That would make supercharging to good of a deal.

Never thought of a Tesla as a driving bucket of electricity.

Re: Powerwall 2 and Integrated Solar

#149

Post by Annatar »

So I used the calculator on Tesla's web site, in my case, I'd want 3 powerwalls and I'd want a solar installation to complement it: $18,000 USD.

That's still way too high: $1,800 - $2,500 would have been acceptable. That is how much I'm willing to pay for some solar panels, three batteries, and a little bit of electronics (processed sand) to control the lot.

As far as I'm concerned, this is all still hype. Prices need to go down, waaayyy down, and the profit margin and the engineering needs to be recuperated through volume. The days of fat profit margins and the early adopters amortizing the research and development have come and gone. The computer industry learned that lesson the hard way; it would be a shame if Mr. Musk repeated the same mistake, instead of learning from history.

Re: Powerwall 2 and Integrated Solar

#150

Post by antmldr »

manav wrote: post #75

I haven't looked into it yet, but I'm curious about using utilizing my Teslas in case of emergency for power. With 75kwh+ each (leased so no concern about cycles) I don't think I'd need a powerwall at home.

Musk and JB got asked about this (I think at the 2016 AGM?). Their response was basically "yeah we get asked this a lot; No, because of the make up of the cells makes them inappropriate for the number of cycles."
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