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Powerwall 2 and Integrated Solar

powerwall.tesla.com

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Re: Powerwall 2 and Integrated Solar

#301

Post by greglindahl »

illumin8 wrote: post #296
usrusr wrote: post #291

Earlier quoted context omitted.

Actually, that UI is pretty much exactly what I had in mind. All devices that control their own charging should have that "trip" switch. It's a shame that Android does not have an API to customize charge depth like that. I occasionally spend some idle thought on wondering how difficult it would be to overcome this limitation with a bluetooth-controlled charger. Well, I'm not an electrical engineer and "bringing the j…

Most decent smartphones are already doing battery management and avoiding extreme draining or charging of the cells. Think about it this way: If your phone has 8 hours of use, chances are the battery could really give you 9 or 10 hours if it was fully charged, but the manufacturer is software limiting it to prolong the life of the battery.

All things with a LiIon battery do battery management to avoid extreme draining or charging. I've never seen a phone that offered a choice of "more battery cycles vs slightly longer run-time".

For cars, it's not an unusual feature to be able to choose. The Leaf has that feature, and since it cycles its small batter frequently, it's an important consideration for owners. See:

http://livingleaf.info/2012/07/care-and-feeding-of-the-nissa...

Re: Powerwall 2 and Integrated Solar

#302

Post by alanpca »

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…

I used 2400kWh in Canada last month! What are the temperature swings like where you live? We can go from -40F to +100F throughout a year.

Re: Powerwall 2 and Integrated Solar

#303

Post by flushandforget »

throwaway1974 wrote: post #132
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…

Ireland, 4 bed detached, solar water heater which works well for about 4 months of year, oil heating + wood/turf stove for rest of time. No need for air conditioning here but heat recovery thingie is on all time. 5000kWh last year, tho I have computer(s) on 24x7 due to home office, Comes to about 120€/month Half of all the bills are just standing charges, and renewable subsidies charges and taxes, and taxes on taxes.…

We worked out recently that we spent under £20 pcm on gas and electric over the last year. 2 people, washing machine, fridge, 2 x laptop, LED lights, 1 LED TV, and gas heating. Admittedly we only put on heating in the evening for an hour or so. Southern England (UK). Attribute to it not being cold for the last two winters here. Duvets and hot water bottles are used regularly. Yet to turn on heating this year. Not looking forward to the cold. Water bill however is shocking.

Re: Powerwall 2 and Integrated Solar

#304

Post by pmyjavec »

vosper wrote: post #278
dirtyaura wrote: post #263

Earlier quoted context omitted.

But many parts of Europe need heating instead of AC. I think it has more to do with house sizes. More Europeans live in cities compared to US and thus have on average smaller apartments/houses. Also there might be cultural values in the play, at least central and nordic countries are traditionally quite efficiency oriented.

I think you're right about house sizes, but there are a lot of the US that needs both summer AC and winter heating - like the midwest, the north east, and probably the west coast east of the mountains (inland Washington, Oregon).

Do people need air-conditioning or is it just a luxury?

I guess now the globe is heating up there is more need for one, but I've always thought of it as borrowing from the future a little, a viscous cycle. More AC, More emissions, needs more AC.

I'm in Indonesia right now and sure the houses are built for the tropics but with locals, AC is rare and people manage to get plenty of good sleep and have loads of energy.

Re: Powerwall 2 and Integrated Solar

#305

Post by samcheng »

sfblah wrote: post #215
samcheng wrote: post #103

Earlier quoted context omitted.

Tesla automotive batteries have shown pretty strong resilience over the few years they have been running, even on cars that have been driven hard. Cars are at >90% capacity after 50,000 miles. It's not like the batteries need to be replaced frequently. http://i.imgur.com/nWM9ZrS.gif I wonder if these Powerwalls will have the same sophisticated battery thermal management system as the cars?

Houses and roofs last far, far longer than cars. 50k miles is 4 years for many drivers.

Right, but the question was about the batteries, which hang on the wall in the garage. Nobody has the expectation that such an appliance will last the lifetime of the house.

Solar panels also degrade, roughly 1% per year, and commonly have a 20-year warrantee. That is less than the 30 years a good roof will last, but in the same ballpark. I doubt anyone knows the long-term resilience of these solar-panel-tile-roofs, but it's unlikely that they will have the extreme longevity of the clay tile roofs they imitate. In the right climate, those clay roofs can last a hundred years!

Re: Powerwall 2 and Integrated Solar

#306

Post by intrasight »

usrusr wrote: post #183
TheSpiceIsLife wrote: post #159

Earlier quoted context omitted.

Good luck finding someone willing to pay to have squillions of kilometres of above ground power lines buried. Sydney alone has 63,000 kilometres[1] of overhead power lines. One estimate puts the cost at $23.37 billion.[2] 1. http://www.smh.com.au/articles/2002/07/29/1027926858231.html 2. https://www.ipart.nsw.gov.au/files/7b5531d9-cf65-4b1b-ae7b-9...

Some places even managed to get entire sewer systems buried. Granted, that happened on a very different level of urgency (you really want shit to flow, and it only flows downward), but it gives the appropriate perspective on any excuses that are based on the natural scale of infrastructure.

Is not a good analogy since nobody builds a sewer system above ground and then replaces it with one below ground.

Re: Powerwall 2 and Integrated Solar

#307

Post by closeparen »

Retric wrote: post #275
pasiaj wrote: post #199

Earlier quoted context omitted.

To give context: there are about 5,5 million Finns, and about 2-3 million saunas in the country.

Finland has 2.1 people per household so ~2.75 million households. Suggesting they are even more popular.

Suggesting there are also soon to be far less than 5.5 million Finns.

Re: Powerwall 2 and Integrated Solar

#308

Post by closeparen »

dirtyaura wrote: post #263
tghw wrote: post #258

Earlier quoted context omitted.

A lot of it has to do with geography. Europe is quite a bit further north, and doesn't experience some of the heat that the US does. It always helps me to remember that Rome is further north than New York.

But many parts of Europe need heating instead of AC. I think it has more to do with house sizes. More Europeans live in cities compared to US and thus have on average smaller apartments/houses. Also there might be cultural values in the play, at least central and nordic countries are traditionally quite efficiency oriented.

It's much, much better to burn fossil fuels for heat than to burn fossil fuels to spin turbines, transmit the electricity long distances, and then run it "back" through heating elements. Stages one and two are pretty lossy.

Particularly when electricity is from coal and natural gas power plants, using it for heating is a staggeringly bad idea.

Re: Powerwall 2 and Integrated Solar

#309

Post by fulafel »

jacquesm wrote: post #156
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…

The big difference is because of air conditioning and baseboard heating, two things that are relatively rare in Europe.

Baseboard heating, if it's the same thing as radiators, are the norm in central and north Europe IME.

Re: Powerwall 2 and Integrated Solar

#310

Post by awqrre »

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…

Could it be because of the warranty? For example, those batteries in 2 years won't be able to keep half the original charge.
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