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Powerwall 2 and Integrated Solar

powerwall.tesla.com

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Re: Powerwall 2 and Integrated Solar

#331

Post by Yaggo »

espadrine wrote: post #177
Yaggo wrote: post #140

Earlier quoted context omitted.

We use heat pumps as well in Northern Europe, but to transfer heat from outside to inside. You can get even five times more heat for the invested electricity compared to direct (resistive) electric heating. The best winter optimized air-to-air pumps work down to -20 °C (-4 °F) with efficiency ratio over 1. For example, I heat my entire house with a single heat pump through the year. Our average electricity bill is ~1…

I heard great things about heat pumps efficiency-wise, but that their downside were noise. However, that information is dated because I haven't looked into it in a long time. Has that improved? I'd expect the market in Scandinavia to be much more developed than in my country.

Air-to-air pumps will probably always make some noise because air has relatively small thermal capacity, requiring relatively big air flow in order to transfer any meaningful amount of energy.

There also exists heat pumps which transfer heat to water-based central heating system (radiators / floor heating), eliminating the noise issue. The heat source can be either outside air or liquid circulating in soil/well (possibly supported by solar). All these combinations are relatively common in Scandinavia, air-to-air pump being most popular because of quick ROI (small initial investment) and easy retro-fitting, althought practically all new houses are built with water-based central heating (the heat source being either of electricity/solar/wood/air pump or any combination).

Re: Powerwall 2 and Integrated Solar

#332

Post by celticninja »

gaius wrote: post #319
celticninja wrote: post #222

Earlier quoted context omitted.

Crazy US shit, never heard of it anywhere else. Basically a group of your neighbours who say what you can and cant do to your own property.

Here in the UK we have "planning permission" which is basically the same thing. Round our way it's been used recently e.g. to stop people extending their houses over their off-street parking, which would necessitate them parking on the road - if everyone did it the street would be impassable, so it's fair to enforce that no-one does it.

Planning permission is granted or refused by the council though, based on the need and impact on surrounding areas. A HOA can stop you hanging your laundry out to dry on a line, force you to water your lawn x times a week, prevent you painting your house a particular colour, prevent you installing a fence, determine they type of vehicle you are allowed and whether it can be parked on your drive or if it must be in a garage. It is not really comparable to planning permission which is really only required for significant construction work or change of use ie. Shop to residential or vice versa.

Plus if the HOA members don't like you they can make your life difficult. Planning permission affects everyone equally. If a neighbour can extend a property then more than likely you can too, if you are refused it is likely all similar applications would be refused, you don't know the planning officer and they don't know you so no bias can be involved which make the whole process much fairer.

Re: Powerwall 2 and Integrated Solar

#334

Post by Gustomaximus »

A bit late to thread but;

1) I'm wondering why the tiles weren't larger? Wouldn't this make laying them much cheaper in a world where labor is such a significant cost for building. Aside from the shingle look I'm surprised these dont come in 1mx1m type sizes plus some smaller sizes for edges. I cant imaging this want discussed so curious if I'm missing some obvious logic here.

2) If you didn't have a ceiling would these let light through and further reduce electricity usage?

3) The cells seems to be a small proportion of the tile. Is this something they expect to increase so they will increase power generation ability significantly over future releases?

Re: Powerwall 2 and Integrated Solar

#335

Post by perilunar »

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…

> What is your yearly power usage?

Shouldn't that be 'What is your yearly _energy_ usage?' ? Or alternatively: 'What is you average power comsumption?'

2500 kWh/year = 6.85 kWh/day = 285 W, which sounds pretty reasonable

For comparison, an average male requires 8700 kJ/day = 100 W

40 kWh/day for a four bedroom house = 1.67 kW, which is huge. Maybe it includes charging a couple of Tesla cars as well.

Re: Powerwall 2 and Integrated Solar

#336

Post by dirtyaura »

agumonkey wrote: post #293
antisthenes wrote: post #184

Earlier quoted context omitted.

The reason their calculations are so high is because in the US, typical houses are made as cheaply as possible, pretty much with paper, plastic and vastly insufficient insulation. That may have changed in the recent years, but holds true for most residential properties built before 1980.

Seems like Western Europe is getting up to speed with standardized insulation. People are monitoring heat leaks in buildings etc. Two things: 1) I wonder how much energy could be "saved" with proper insulation. Per Country, per planet. 2) Insulation seems like a human sense, by that I mean, whenever I've lived in an old, stone wall house, I enjoyed the delay in temperature. It's still refreshing when the sun hits har…

Partly inspired by this thread, I read a couple of EU reports and realised that 50% of energy consumption in EU goes to heating and cooling. That is huge. Of course it includes industrial heating, but that is 18% in total (~third of 50%).

Clearly, there is lot to win here,with existing insulation techniques. we could do a lot in a short-term with existing technologies, it's mostly policy and financing issue.

Re: Powerwall 2 and Integrated Solar

#337

Post by tincholio »

dabeeeenster wrote: post #162
dirtyaura wrote: post #147

Earlier quoted context omitted.

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 s…

'no sauna inside the apartment' Finnish problems

That is indeed a problem in Finland! :)

Re: Powerwall 2 and Integrated Solar

#338

Post by fdgdasfadsf »

intrasight wrote: post #306
usrusr wrote: post #183

Earlier quoted context omitted.

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.

The point is that for sewers there was no choice so we just swallowed the cost and got on with it. For power there was so we went for the cheaper less reliable option.

Re: Powerwall 2 and Integrated Solar

#339

Post by drakonandor »

zo1 wrote: post #330
whage wrote: post #134

Earlier quoted context omitted.

Thanks! Can someone tell me what kind of architectural style does that house on the landing page represent?

You got 4 different answers. Something just isn't right with that: Modernist Deconstructionist Modern Style Muskhaus Contemporary

Pretty sure the Muskhaus answer was a joke, as Tesla is run by Elon Musk.

Re: Powerwall 2 and Integrated Solar

#340

Post by twothamendment »

slfnflctd wrote: post #264
andrewtbham wrote: post #13

the cool thing is that they look good... they look like a normal roof at the angle you would see from the street in front of the house, but from above... from the angle of the sun they are transparent and you can see the solar cells. I know some rich people that want solar but their neighborhood associations won't allow it, but I don't think they would not have an objection to these roofs. they look really nice.... I…

> they would not have an objection to these roofs Unless the HOA rules have a stipulation about your roof shingles exactly matching the other roofs in the neighborhood, which is common. And boring a shit to look at. I hate HOAs so much. If all they did was protect property values by keeping people from doing outrageous things, I might be okay with them, but they go way beyond that to the point where it diminishes the…

I lived in an HOA that took their rules way too far. Here is an example - paraphrased so your head doesn't explode: "You can't have any wireless devices without written permission, except a garage door opener and TV remote."

Right. Nice try. I joked with neighbors that we should all send one letter to them on the same day. A letter for each cell phone, wifi router, satellite dish, bluetooth speaker, etc.

This was in an area where many people were on wireless ISPs, there were a handful of ham radio antennas, etc. I asked someone on the HOA board why they didn't update or remove the garbage about wireless devices. The answer - it would cost to much to update the documents, so they don't try to enforce it. It is still crazy that they ever put it in there.

This HOA says no solar, but now that it is popular they also ignoring that.

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