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Tesla Wins Contract to Help Power the California Grid

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Re: Tesla Wins Contract to Help Power the California Grid

#201

Post by JoeAltmaier »

nraynaud wrote: post #200
JoeAltmaier wrote: post #175

Earlier quoted context omitted.

DC sucks for transmission over more than a few meters. I'm thinking, even in a house, you still want AC in the walls.

can you explain a bit more?

Heat in wire is ~ current squared times resistance. If you use low-voltage DC, and you're supplying any significant power, then the current is high and the losses to wire heating are high. Inefficient and dangerous (fires).

AC at high voltage can be low current, you can use much smaller wires for a given power.

Re: Tesla Wins Contract to Help Power the California Grid

#202

Post by _ea1k »

semi-extrinsic wrote: post #99
manicdee wrote: post #94

Earlier quoted context omitted.

The batteries used for cars are different to the batteries used for power banks. Tesla is selling internally to themselves, and already has production set up for batteries for stationary power. The best outcome is for demand to ramp up, keeping prices high long enough to fund the rest of the construction of the gigafactory. No praying required.

Musk has stated publically that they're betting the company on the battery price coming down for the Model 3 to be profitable. That's why they're building the Gigafactory, to reach $100/kWh. If suddenly power companies start buying lots of batteries, and prices stabilise at or above today's levels, it would mean (by implication) that the Model 3 won't be profitable (at least initially). Sure car batteries and power b…

18650 is a packaging size. The internals can vary.

Re: Tesla Wins Contract to Help Power the California Grid

#203

Post by davedx »

zaroth wrote: post #166
nl wrote: post #155

Earlier quoted context omitted.

To be clear, in Aus we don't have 99% reliability. It's about 45 min every 2 years (whatever that works out to). That number was to explain the cost savings. In much of the world those cost saving are directly applicable. Most of the world's population doesn't have 99% reliable electricity, and so they build reliability at the edges with everything from batteries in phone towers, to batteries in lighting. It isn't at…

Rooftop solar is on average a $25,000 - $35,000 investment, and that's not even counting energy storage required to actually be off-grid. I don't think that only the rich should have reliable energy, and the poor should suffer brownouts to theoretically save some infrastructure costs. For countries who don't yet have a reliable electric grid, I think investing in providing quality / reliable electricity to their popu…

If you need your solar to generate your AC in California or another southern state of the US, sure.

Here in the Netherlands, our complete solar system with installation cost us EUR 4,500, and we do run some AC in the hottest summer months. We are currently generating more than we use, with a household of 2 adults and 4 kids.

Re: Tesla Wins Contract to Help Power the California Grid

#205

Post by paulmd »

WalterBright wrote: post #194
paulmd wrote: post #165

Earlier quoted context omitted.

Once the smart-device interface is properly defined and the software is written, the hardware cost should not be a problem. You will end up with some kind of "smart device" router that connects to your internet/home network to talk to the power company, and uses a commodity wifi interface to talk to your smart devices. The cost of an ESP8266 is already sub-$7 at hobbyist volumes, you can expect the additional hardwar…

It is completely unnecessary for appliances to talk to the power company. They only need to talk to the internet. The power company just posts the spot price on a web site.

The appliances won't talk to the power company, they'll talk to the appliance hub. The appliance hub will be the one with the logic to handle temporarily raising the thermostat or whatever, and will handle the internet connection.

Also, using a website or other resource run by the power company is still talking to the power company. Not sure ho else you could have parsed that, but you clearly had some crossed wires there.

Re: Tesla Wins Contract to Help Power the California Grid

#206

Post by hx87 »

JoeAltmaier wrote: post #201
nraynaud wrote: post #200

Earlier quoted context omitted.

can you explain a bit more?

Heat in wire is ~ current squared times resistance. If you use low-voltage DC, and you're supplying any significant power, then the current is high and the losses to wire heating are high. Inefficient and dangerous (fires). AC at high voltage can be low current, you can use much smaller wires for a given power.

DC doesn't have to be low voltage though. Before high power solid state electronics became reliable, it was difficult to do DC-DC voltage conversion without going through AC first, but that isn't true today. Plenty of power is delivered across different grids using HVDC.

Re: Tesla Wins Contract to Help Power the California Grid

#207

Post by hx87 »

allendoerfer wrote: post #49
oldmanjay wrote: post #45

Earlier quoted context omitted.

If the future is predictable to you, use that ability to make trillions of dollars and then use the resulting power to impact the future. Whining about it on the internet just makes you seem dismissive.

I predict that solar will be used in the future. How do I make trillions with that wisdom? You can only make money with predictions you are right on but others are not. > Whining about it on the internet just makes you seem dismissive. That was not my intention at all. It was more the child in me that wanted to see flying cars and jetpacks instead of massive adoption of stuff, which has been here for 150 years. I sti…

We've had flying cars and jetpacks for a while now. They're just not economical to implement on a large scale.

Re: Tesla Wins Contract to Help Power the California Grid

#208

Post by hx87 »

wallace_f wrote: post #198
forgetsusername wrote: post #130

Earlier quoted context omitted.

> certain types of people -- politicians, lawyers, business executives I forgot how altruistic software engineers, web developers and IT consultants were.

In a general sense is it not better for all people to be in he business of creating value than to quarrel over transferring it from one to another? I believe that if you care about human welfare, then it is obvious that it is.

Because distribution of value is important, and people believe that distribution of value is important. After all, there are limits to how much I can feel your well-being, and vice versa.

Re: Tesla Wins Contract to Help Power the California Grid

#209

Post by hx87 »

klakier wrote: post #109

What a bullshit. I'd call this Russian way of doing business, where you benefit from unhealthy connections with state. 2500 houses? Go find out how many houses are there in California.

> I'd call this Russian way of doing business

That's a funny call, since no one has been tax raided yet.

Re: Tesla Wins Contract to Help Power the California Grid

#210

Post by samatman »

JoeAltmaier wrote: post #175
zymhan wrote: post #174

Earlier quoted context omitted.

This was brought up in a Fresh Air interview I listened to recently. Nowadays most of our devices use DC, and our grid is also on the verge of becoming much less centralized. You could reap some easy efficiency gains by omitting the DC-AC-DC conversion of a solar panel powering a house that charges a laptop.

DC sucks for transmission over more than a few meters. I'm thinking, even in a house, you still want AC in the walls.

This is true of low-voltage DC (V), but very much untrue of high-voltage (MV).

Irrelevant to the use case under discussion, of course, but someone reading this thread might find HVDC long-range power transmission interesting.

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