6 ms·

you would be able to deploy and consume energy in the most efficient and sustainable way possible, lowering your costs and minimizing your dependence on fossil

by abalone 10y ago

you would be able to deploy and consume energy in the most efficient and sustainable way possible, lowering your costs and minimizing your dependence on fossil fuels and the grid Naive question: Why is minimizing dependency on the grid more sustainable? Doesn't connecting with the grid allow you to distribute excess power more evenly?

netinstructions 10y ago
Well, when the zombie apocalypse happens relying on the grid is unsustainable. But in reality, there are also transmission losses (which I think are actually quite small when you have high voltage) when you produce energy away from where you use it.
- abalone 10y ago
  There are also losses from battery charging. I haven't researched thoroughly but some Tesla fan discussion thread puts it at 20-30%[1], which would be vastly higher than transmission losses. Especially since the electricity typically wouldn't have to travel very far at all before it's used. [1] https://forums.teslamotors.com/forum/forums/battery-charging-and-discharging-losses https://forums.teslamotors.com/forum/forums/battery-charging...
  - sowbug 10y ago
    That's the Roadster from 2011. The Model S is more than 90% efficient (https://www.teslamotors.com/support/model-s-specifications https://www.teslamotors.com/support/model-s-specifications).
- dvdkhlng 10y ago
  I think most of the losses are due to the cost of building and maintaining transmission lines. These have to be paid for by users of the power grid. In Germany these transmission costs constitute about 20% of the total end-user price per kWH (i.e. about 5 cent/kWh).
devindotcom 10y ago
I would say the idea is, you're not dependent on the grid. You can use it, you can contribute to it, and the grid is still a necessary part of the energy ecosystem (along with fossil fuels), but renewables mean a sub-ecosystem is tolerant to interruptions at the grid level and may even be able to operate completely independently.
marshray 10y ago
Literal grid operators are sometimes quite hostile to residential solar installations feeding energy back into the grid. So "the grid" is equivalent to buying 3rd party energy rather than generating it renewably yourself and the term refers to whatever mix of energy generation plants happen to be supplying it at the time.
ageofwant 10y ago
Its used here as a marketing and branding term, not "efficient distribution mechanism" as you interpreted it. So they are playing on people's (correct) perception that "the grid" is the man with a death grip on your wallet, while you, as a techie, just appreciate the obvious benefits a power distribution system. You need to put your bullshit hat on when you read these things.
gpm 10y ago
I read those as separate benefits. It's more sustainable because of transmission losses, reusing the real-estate of your roof, and I believe doubling as partial shading and insulation. Minimizing dependence on the grid is a benefit because power outages exist, and sometimes they can really suck.
- bbcbasic 10y ago
  My solar system will shut off if the grid shuts off. The reason is to guarantee no voltage on the lines when the technician is looking to repair. Having said that I have no battery, but if I did then probably it could just isolate the grid and stop feeding back when the grid shuts down and run the house off the battery.
- abalone 10y ago
  Even if those are separate phrases they still claim it's "the most efficient way possible" to consume energy. But there are energy losses when going through a battery instead of redistributing the energy in realtime -- much greater than transmission losses. So unless I am missing something, that appears to be a false claim.
  - dvdkhlng 10y ago
    I think you need to factor in the costs incurred by building and maintaining high voltage power transmission lines. These have to be payed for by users of the power grid. If you go off grid, then you not only reduce transmission losses, you also eliminate costs for use of the power distribution infrastructure.
- imtringued 10y ago
  I guess I'm lucky because all power outages I've experienced (1 to be precise) were during the day and were resolved within a few hours.
  - majewsky 10y ago
    It depends on the quality of your grid. For example, here in Germany, the grid quality is higher than the average US grid. I don't recall any power outage that lasted more than a few minutes.
IkmoIkmo 10y ago
Yes and no. I'm an amateur here, but here's what I understand. 1) Yes, any storage capacity connected to the grid could, if run by a benevolent dictator, help the grid a lot. The basic idea of load shifting I'm sure you're familiar with, is to store energy when the load is low (and energy is cheap), and redistribute it when the load is high (and energy is expensive). By doing this, you smooth over supply and demand, reduce volatility, reduce market imperfections, reduce difficulties in planning generating capacity that is subject to wildly fluctuating demand etc. Further, this makes more renewables viable (which increase volatility/intermittency/imbalance issues, but are inevitably necessary on large scale for the future of humanity). 2) There's no such benevolent dictator. In reality there's tons of economic actors, and they have to deal with the economic reality of batteries, which are not at the moment economical (i.e. zero or positively profitable) to load shift. i.e. a battery has limited lifetime. e.g. the Tesla Powerwall has 6.4kwh capacity, 5k cycles and costs $3k. That means you can charge and decharge a total of 32k kwh, for $3k, or in other words $9.35 cents per kwh just to store the energy. And that's before figuring in cost of installation, or the $2k inverter or the roundtrip efficiency of 92%. Now note that this is roughly the cost of electricity retail in most US states. So participating in load shifting will usually mean you're buying energy at 6 cents at a nightly rate, storing it for 9 cents, and then selling it for 10 cents at a daily rate, or something to that effect, it's a money losing proposition at the moment. 3) If you can't (or won't) aid the grid then, then it becomes a question of: do your presence on the grid help it, or vice versa. And the answer is probably that the grid would be less burdened if we didn't all pile up on it as much. Going off-grid then may be better. 4) Further, in some areas storage is renewable-empowering. e.g. in off-grid locations, or in areas where the grid price is so expensive (e.g. Hawaii), that generating your own energy and storing the excess for later when the sun's down, instead of consuming energy from the grid when the sun doesn't shine, is cheaper. (although again, even here if you'd have sold that excess energy instead of storing it, and then bought the cheap nightly rate later on, it'd probably have been even more economical.) tl;dr, it's mostly bs. Batteries don't make economic sense in most states and connecting to the grid where possible tends to make sense in terms of economics and sustainability. And there's no surprise there, i.e. connecting to a bigger (grid) rather than an isolated (off grid) market tends to improve efficiency and allows a better distribution of scarce resources, which happens to be sustainable in this market, too.

by abalone 10y ago

netinstructions 10y ago

Well, when the zombie apocalypse happens relying on the grid is unsustainable. But in reality, there are also transmission losses (which I think are actually quite small when you have high voltage) when you produce energy away from where you use it.

abalone 10y ago
There are also losses from battery charging. I haven't researched thoroughly but some Tesla fan discussion thread puts it at 20-30%[1], which would be vastly higher than transmission losses. Especially since the electricity typically wouldn't have to travel very far at all before it's used. [1] https://forums.teslamotors.com/forum/forums/battery-charging-and-discharging-losses https://forums.teslamotors.com/forum/forums/battery-charging...
- sowbug 10y ago
  That's the Roadster from 2011. The Model S is more than 90% efficient (https://www.teslamotors.com/support/model-s-specifications https://www.teslamotors.com/support/model-s-specifications).
dvdkhlng 10y ago
I think most of the losses are due to the cost of building and maintaining transmission lines. These have to be paid for by users of the power grid. In Germany these transmission costs constitute about 20% of the total end-user price per kWH (i.e. about 5 cent/kWh).

devindotcom 10y ago

I would say the idea is, you're not dependent on the grid. You can use it, you can contribute to it, and the grid is still a necessary part of the energy ecosystem (along with fossil fuels), but renewables mean a sub-ecosystem is tolerant to interruptions at the grid level and may even be able to operate completely independently.

marshray 10y ago

Literal grid operators are sometimes quite hostile to residential solar installations feeding energy back into the grid. So "the grid" is equivalent to buying 3rd party energy rather than generating it renewably yourself and the term refers to whatever mix of energy generation plants happen to be supplying it at the time.

ageofwant 10y ago

Its used here as a marketing and branding term, not "efficient distribution mechanism" as you interpreted it. So they are playing on people's (correct) perception that "the grid" is the man with a death grip on your wallet, while you, as a techie, just appreciate the obvious benefits a power distribution system. You need to put your bullshit hat on when you read these things.

gpm 10y ago

I read those as separate benefits. It's more sustainable because of transmission losses, reusing the real-estate of your roof, and I believe doubling as partial shading and insulation. Minimizing dependence on the grid is a benefit because power outages exist, and sometimes they can really suck.

bbcbasic 10y ago
My solar system will shut off if the grid shuts off. The reason is to guarantee no voltage on the lines when the technician is looking to repair. Having said that I have no battery, but if I did then probably it could just isolate the grid and stop feeding back when the grid shuts down and run the house off the battery.
abalone 10y ago
Even if those are separate phrases they still claim it's "the most efficient way possible" to consume energy. But there are energy losses when going through a battery instead of redistributing the energy in realtime -- much greater than transmission losses. So unless I am missing something, that appears to be a false claim.
- dvdkhlng 10y ago
  I think you need to factor in the costs incurred by building and maintaining high voltage power transmission lines. These have to be payed for by users of the power grid. If you go off grid, then you not only reduce transmission losses, you also eliminate costs for use of the power distribution infrastructure.
imtringued 10y ago
I guess I'm lucky because all power outages I've experienced (1 to be precise) were during the day and were resolved within a few hours.
- majewsky 10y ago
  It depends on the quality of your grid. For example, here in Germany, the grid quality is higher than the average US grid. I don't recall any power outage that lasted more than a few minutes.

IkmoIkmo 10y ago

Yes and no. I'm an amateur here, but here's what I understand. 1) Yes, any storage capacity connected to the grid could, if run by a benevolent dictator, help the grid a lot. The basic idea of load shifting I'm sure you're familiar with, is to store energy when the load is low (and energy is cheap), and redistribute it when the load is high (and energy is expensive). By doing this, you smooth over supply and demand, reduce volatility, reduce market imperfections, reduce difficulties in planning generating capacity that is subject to wildly fluctuating demand etc. Further, this makes more renewables viable (which increase volatility/intermittency/imbalance issues, but are inevitably necessary on large scale for the future of humanity). 2) There's no such benevolent dictator. In reality there's tons of economic actors, and they have to deal with the economic reality of batteries, which are not at the moment economical (i.e. zero or positively profitable) to load shift. i.e. a battery has limited lifetime. e.g. the Tesla Powerwall has 6.4kwh capacity, 5k cycles and costs $3k. That means you can charge and decharge a total of 32k kwh, for $3k, or in other words $9.35 cents per kwh just to store the energy. And that's before figuring in cost of installation, or the $2k inverter or the roundtrip efficiency of 92%. Now note that this is roughly the cost of electricity retail in most US states. So participating in load shifting will usually mean you're buying energy at 6 cents at a nightly rate, storing it for 9 cents, and then selling it for 10 cents at a daily rate, or something to that effect, it's a money losing proposition at the moment. 3) If you can't (or won't) aid the grid then, then it becomes a question of: do your presence on the grid help it, or vice versa. And the answer is probably that the grid would be less burdened if we didn't all pile up on it as much. Going off-grid then may be better. 4) Further, in some areas storage is renewable-empowering. e.g. in off-grid locations, or in areas where the grid price is so expensive (e.g. Hawaii), that generating your own energy and storing the excess for later when the sun's down, instead of consuming energy from the grid when the sun doesn't shine, is cheaper. (although again, even here if you'd have sold that excess energy instead of storing it, and then bought the cheap nightly rate later on, it'd probably have been even more economical.) tl;dr, it's mostly bs. Batteries don't make economic sense in most states and connecting to the grid where possible tends to make sense in terms of economics and sustainability. And there's no surprise there, i.e. connecting to a bigger (grid) rather than an isolated (off grid) market tends to improve efficiency and allows a better distribution of scarce resources, which happens to be sustainable in this market, too.