arnis
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Re: 2017 Leaf to offer V2G: Thoughts?

Sat May 20, 2017 7:59 am

Again, since the ROUND TRIP distance from the renewable generators to the BEV plus from the BEV to the home loads is MUCH shorter than the typical distance from a power plant to a home, the overall losses in the V2G configuration is likely to be LOWER than the losses in the current situation.


Just based on this, I can conclude, that you are not fully aware how inefficiency happens. It's not measured in "miles from power station to consumer".

There is a lot online about grid efficiency if you want to learn for more.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

Aussie
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Re: 2017 Leaf to offer V2G: Thoughts?

Thu Jun 01, 2017 7:34 pm

arnis wrote:Just based on this, I can conclude, that you are not fully aware how inefficiency happens. It's not measured in "miles from power station to consumer".

There is a lot online about grid efficiency if you want to learn for more.


What's the difference in heat rate of a CCGT power station at 50% load vs 100% load? What's the difference in heat rate of a OCGT at 50% load vs a CCGT at 100% load? What's the difference in heat rate between a inefficient peaking liquid fuel turbine or reciprocating engine to a CCGT at 100% load? To answer these questions, heat rate at least efficient operation will be more than double that at most efficient. These are where the real benefits of V2G come into play - removing peaks and troughs and allowing generation to operate in an efficient way. 50% reduction in fuel required for the same generation certainly makes the few percent conversion losses pale into significance. And this is before even getting into the mitigation of generating capacity (capital investment), which means power charge per kWh reduces.

To your point on grid efficiency. What's the difference in copper losses in a transformer (indicative of the transmission network) between 50% load and 100% load? Transmission and distribution efficiency is not linear but rather follows a curve. Iron losses will dominate at very low loadings, and copper losses (which vary proportional to the square of the current) will dominate at periods of high loadings. The grid is most efficient somewhere between the two. Using V2G to avoid pushing the grid into higher peak loadings on a summer day will make it slightly more efficient on average.

You mentioned that your neighbor would not be using the power you push out from V2G and that your power will need to go through 2 transformers at minimum. That is likely an incorrect statement. If you are on a shared transformer (which all urban customers and a lot of rural customers are) then your V2G 'generation' will almost certainly be consumed downstream of the distribution transformer and therefore have almost no network losses. A lot of it may even be consumed in your own house. Keep in mind that V2G will be likely occurring far after the solar peak, so you'll be offsetting the PV generation that has reduced as the sun went down.

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Marktm
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Re: 2017 Leaf to offer V2G: Thoughts?

Fri Jun 02, 2017 7:14 am

Aussie wrote:
What's the difference in heat rate of a CCGT power station at 50% load vs 100% load? What's the difference in heat rate of a OCGT at 50% load vs a CCGT at 100% load? What's the difference in heat rate between a inefficient peaking liquid fuel turbine or reciprocating engine to a CCGT at 100% load? To answer these questions, heat rate at least efficient operation will be more than double that at most efficient. These are where the real benefits of V2G come into play - removing peaks and troughs and allowing generation to operate in an efficient way. 50% reduction in fuel required for the same generation certainly makes the few percent conversion losses pale into significance. And this is before even getting into the mitigation of generating capacity (capital investment), which means power charge per kWh reduces.

To your point on grid efficiency. What's the difference in copper losses in a transformer (indicative of the transmission network) between 50% load and 100% load? Transmission and distribution efficiency is not linear but rather follows a curve. Iron losses will dominate at very low loadings, and copper losses (which vary proportional to the square of the current) will dominate at periods of high loadings. The grid is most efficient somewhere between the two. Using V2G to avoid pushing the grid into higher peak loadings on a summer day will make it slightly more efficient on average.

You mentioned that your neighbor would not be using the power you push out from V2G and that your power will need to go through 2 transformers at minimum. That is likely an incorrect statement. If you are on a shared transformer (which all urban customers and a lot of rural customers are) then your V2G 'generation' will almost certainly be consumed downstream of the distribution transformer and therefore have almost no network losses. A lot of it may even be consumed in your own house. Keep in mind that V2G will be likely occurring far after the solar peak, so you'll be offsetting the PV generation that has reduced as the sun went down.


Thanks for the knowledge-based recap.

Another possibility (IF the "disruption" of EVs can occur timely enough) is continuing the use of our existing energy facilities (production and distribution) and use the (massive amount of) money required for new facilities to build renewable energy facilities (that are "peak producers") rather than the traditional carbon based plants. I'll bet there will be a vigorous debate about the alternative of nuclear as base loads!

However, the politics (costs to us) of our energy supply may not promote V2G, V2H, (V2X), as an economical alternative for most of us - even if home solar (including V2G, V2H, V2X) becomes much more affordable from a capital cost perspective. IMHO, this could be the biggest barrier to "autonomous" energy generation/storage that the combination of solar, V2G, V2H, (V2X) can provide - good luck Elon!!

** I've included V2X as it seems there will be a smorgasbord of V2's in our future V2I, V2L, PV2V?, etc, etc).
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.
Rural cabin with 6750 watts Grid tied PV. Off-grid solar Leaf charging capable (level II).

arnis
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Re: 2017 Leaf to offer V2G: Thoughts?

Thu Jun 08, 2017 3:26 pm

So we develop V2G infrastructure (which takes some decades) assuming fossil based grid..
for how long? 100 years? 200 years? Or we develop a system for few decades?

I would not consider that as an awesome planning.

Again. Which is more efficient: two neighbors both having PoD* tech everywhere at home
or two neighbors and only one has V2G, other one has nothing.
Both are under the same transformer.
So first scenario: grid is peaking, EVERYBODY reduces their load as much as requested.
Nobody discharges, nobody recharges later on.
Second scenario: grid is peaking, some give back energy they already consumed, others
continue their nominal peaking load. After peak those who gave back take it in again.

*PoD - Pause on Demand. Smart Delay. Whatever means "less consumption if requested".
Works with cars, AC, washing machine, water heater, PowerPacks.

You said PoD is first step, V2X is next step. And the reason for that next step is...?
How do you fix a problem that doesn't exist?
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

Aussie
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Re: 2017 Leaf to offer V2G: Thoughts?

Wed Jun 21, 2017 10:02 pm

arnis wrote:*PoD - Pause on Demand. Smart Delay. Whatever means "less consumption if requested".
Works with cars, AC, washing machine, water heater, PowerPacks.


The correct terminology is demand response. It tends to be used only in critical periods when supply shortages are imminent. Typically it curtails interruptible municipal loads (ie. multi MW water pipeline transfer pumps) and industrial loads. These loads are compensated for being interruptible. A lot of the balancing authorities have tariffs which incentivize customers to have an interruptible load.

In an ideal world DR would be implemented on a mass scale. But alas, people don't want to have power prices that fluctuate like the stock market, which would be what is required to provide the economic signal to support this. And people don't want someone else turning off their AC, dishwasher, washing machine etc during the time they want to use it. Hence why we all pay for so much generation, transmission and distribution capacity that is only used a few hours a year. Access to services when and where we want them is a hallmark of a modern capitalist society. We're not quite trusting enough of our utilities and governments to allow them the political scope to implement freely floating energy prices (+ billing mechanisms would become a nightmare) or centralized control of our appliances.

In it's absence of someone managing to convince a city to stop using power during summer afternoon/evening, a mechanism to pay owners of energy storage devices (ie. EVs) to provide the storage would provide a great solution for all. It would need to be optional (ie. opt in). EV owners would need to be adequately compensated for the services they provide. Everyone wins.

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Marktm
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Re: 2017 Leaf to offer V2G: Thoughts?

Thu Jun 22, 2017 6:11 am

Aussie wrote:In it's absence of someone managing to convince a city to stop using power during summer afternoon/evening, a mechanism to pay owners of energy storage devices (ie. EVs) to provide the storage would provide a great solution for all. It would need to be optional (ie. opt in). EV owners would need to be adequately compensated for the services they provide. Everyone wins.


The issue for me is that "free" nights (no power bill from 9:00 to 6:00) is simply not enough incentive to make up for the cheaper 24 hour rates. I don't use enough energy to break even until I can shift over 60% of my energy to night time, let alone pay for added equipment/battery degradation.

HOWEVER, if V2H/V2G/S2V becomes a reality, solar becomes even cheaper, EV batteries get large enough (and durable against constant cycling), inductive charging/discharging a reality, smart app controls of battery storage/major energy consumers, AND the energy producers incentivize the needed load shifting to stabilize the grid (not likely), it seems possible that "adequate compensation" could be in our future. This could be for both home owners and businesses smart enough to use employees batteries :mrgreen:. Sure like to see a "carbon footprint" analysis of this future - ICE vrs EV, new solar/wind vrs new conventional power plants, production of auxiliary EV charge/discharge equipment, additional grid stabilization equipment, etc, etc .

Will the energy industry allow this???
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.
Rural cabin with 6750 watts Grid tied PV. Off-grid solar Leaf charging capable (level II).

arnis
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Re: 2017 Leaf to offer V2G: Thoughts?

Fri Jun 23, 2017 8:55 am

Aussie wrote:In an ideal world DR would be implemented on a mass scale. But alas, people don't want to have power prices that fluctuate like the stock market, which would be what is required to provide the economic signal to support this. And people don't want someone else turning off their AC, dishwasher, washing machine etc during the time they want to use it.


Thanks for Demand Response thing. I didn't know that terminology but I suspected it exists.

In EU our electricity prices fluctuate at hourly. And there is only forecast for tomorrow.
http://www.nordpoolspot.com/Market-data ... view=table

Sometimes prices fluctuate multiple times. So 20€/MWh and next hour it's 75€/MWh.
Some like this way more, some like day/night tariff, some like stable tariff for the whole year (with profit margin integrated into the price so choosing stable tariff usually costs more). I like unbound fluctuating market price. So I can manually skip power-hungry activities when juice costs skyrocket for few hours.
Our power meters report consumption hourly. And central server adds all up. Then you get the bill. You never know what you get :lol:
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

edatoakrun
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Re: 2017 Leaf to offer V2G: Thoughts?

Fri Jun 23, 2017 9:26 am

Marktm wrote:
Aussie wrote:In it's absence of someone managing to convince a city to stop using power during summer afternoon/evening, a mechanism to pay owners of energy storage devices (ie. EVs) to provide the storage would provide a great solution for all. It would need to be optional (ie. opt in). EV owners would need to be adequately compensated for the services they provide. Everyone wins.


... AND the energy producers incentivize the needed load shifting to stabilize the grid (not likely)...

For some of us, this incentive is already reality.

My PG&E E-6 s rate plan will charge me ~$0.94 per kWh this afternoon (from 2 to 7 pm, on up to 15 high-demand days each Summer).

I would really like to run my Home's AC this afternoon using the ~$0.14 kWh that I loaded into my LEAF battery last night, rather than from an inefficient and highly-polluting grid peaker plant.

Today's California ISO data:

Get an at-a-glance view of supply and demand, renewable energy production, emergency notifications and requests for energy conservation. These displays are provided for information only and do not represent real-time system operating conditions. Click here for more information...

http://www.caiso.com/outlook/SystemStatus.html
no condition is permanent

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Marktm
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Re: 2017 Leaf to offer V2G: Thoughts?

Fri Jun 23, 2017 10:28 am

edatoakrun wrote:My PG&E E-6 s rate plan will charge me ~$0.94 per kWh this afternoon (from 2 to 7 pm, on up to 15 high-demand days each Summer).

I would really like to run my Home's AC this afternoon using the ~$0.14 kWh that I loaded into my LEAF battery last night, rather than from an inefficient and highly-polluting grid peaker plant.


I had no idea rates could be so outlandish! The provider in Texas offers "free" electricity (and deducts both generation and distribution) during night and $0.15 per KWH during day. Does this high-demand happen often? Is there a plan available that has a rather substantial differential "day and night". I would believe with high differential rates, one could afford to spend some substantial $$'s to shift to night EV charging (and V2G).
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.
Rural cabin with 6750 watts Grid tied PV. Off-grid solar Leaf charging capable (level II).

montreid
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Re: 2017 Leaf to offer V2G: Thoughts?

Mon Sep 11, 2017 10:36 pm

Bumping this -- I'm new to Leaf community, but have been PV Solar array since 2005 and EV owner (nonLeaf) since 2014 -- looking for a V2H solution.

The simple solution is Tesla's Powerwall 2.0. I am hoping that we shouldn't have to buy another entire battery and leverage the one already sitting in the garage and driveway that's 3x larger than the Powerwall.

Anyone see a V2H solution at all? Only seen a few case studies of V2G applications like Nuvve's, but nothing at the house level where Tesla is dominating the conversation and don't see why these V2G solutions aren't micronized to deliver V2H solutions like Powerwall..... and by scaling all those V2H solutions, will essentially become V2G solutions if they push back into the grid like any NetMetering PV Solar system does

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