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Using Tesla car as free storage for renewables — feature suggestion

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Hello,


I have a suggestion for a new Model S feature that can help with the renewable energy storage problem and improve the green imago of long range electric vehicles. This would be especially practical in Spain, Denmark, Germany and Sweden, where the share of wind and solar power production is high, but highly fluctuating. And when renewables and long range electric cars becomes more commonplace, feature becomes more important also elsewhere.


Lithium batteries do not like to be neither fully charged nor fully discharged. Optimally they would like to be always at 40–60 % range. But if we include practicality, then 80 % standard charge is perhaps the best for the longevity of battery. This feature of lithium batteries that they like to have charge level around 60 %, could be used as almost free renewable energy storage.


In normal circumstances (excluding longer road-trips) charge level is kept at 40 %. But when wind power production exceeds about 40 % of nameplate capacity, Model S battery is charged into 90 %. This kind of smart charging generates almost free 40 kWh storage capacity for renewables.


Tesla could enable this kind of feature directly with software update without any needs for "smart grids" or other expensive smart charging or v2g hardware investments. Model S can fetch the real time wind power production data from the Internet.


Here is a real world example of wind power generation in Denmark in August/September 2013. Bolded days are when Model S is charged into 90 %. All the rest of the days charge level is kept above 40 % that should be good enough level for everyday driving and the battery longevity. The cutoff wind power generation is at 1800 MW, when Model S starts charging above 40 %. In Denmark there is about 4500 MW wind power capacity installed and daily peak consumption is around 5000 MW.


Date ≀ wind power generation in 2:00 PM in Denmark
8/22 ≀ 18 MW
8/23 ≀ 509 MW
8/24 ≀ 1839 MW ≀ 90 % charge
8/25 ≀ 1402 MW
8/26 ≀ 645 MW
8/27 ≀ 145 MW
8/28 ≀ 245 MW
8/29 ≀ 888 MW
8/30 ≀ 575 MW
8/31 ≀ 2926 MW ≀ 90 % charge
9/1 ≀ 2811 MW ≀ 90 % charge
9/2 ≀ 3340 MW ≀ 90 % charge
9/3 ≀ 581 MW
9/4 ≀ 44 MW
9/5 ≀ 1307 MW
9/6 ≀ 2606 MW ≀ 90 % charge
9/7 ≀ 1187 MW
9/8 ≀ 2585 MW ≀ 90 % charge
9/9 ≀ 985 MW


Real time Danish wind power production data can be fetched e.g. from here:
Nord Pool Spot


This is of course simplest possible method. With advanced power market modeling, it is naturally possible to optimize Model S charging so that it is the best for the grid stability and renewable energy generation.
 
Good idea. Tesla is working on this:
Smarter Charging | Blog | Tesla Motors

However, as an owner I want to participate in the financial benefit when Tesla remotely controls my car charging. I suggest that Tesla offers a special EV tariff to all model S owners. Without further meter installations, the kWh that went into my car get dropped from my utility bill. Tesla negotiates a kWh wholesale price with the utility, for helping to level demand with generation capacity.

Let me take things a bit further. Look at this:
attachment.php?attachmentid=38849&d=1387679817.jpg


We know how much energy is delivered to cars via the supercharger network: 2GWh since inception of the SC network. We know that storage batteries are deployed to more and more supercharger stations to level peak demand charges.
Within several years, Tesla will be a big player in the electricity market.
- Tesla has access to lots of used automotive cells
- Tesla will define global cell price point with the Mega battery factory
- Tesla has severe purchasing power for renewable energy, e.g. at times when there is surplus generation
- Tesla can sell ancillary services like reserve generation capacity, black start, frequency regulation

Power purchase for supercharger network will go from 2GWh per year to .1TWh at full North America deployment around 2015. This is only limited by the number of electric miles driven.
Power purchase for home charging via EV tariffs will exceed this by factors.

Edit: the longer I think of it, the more it boggles my mind...
Edit2: Wrong conversion of units pointed out to me. Oops. :redface:
 
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What's interesting is for a bulk buyer like Tesla, power is probably $0.05/kWh. This means the total electricity cost is under $150,000. This is a tiny amount compared to how many car purchases it must have encouraged, and how insignificant it is in comparison to building cost (~$100,000/station.)
 
What's interesting is for a bulk buyer like Tesla, power is probably $0.05/kWh. This means the total electricity cost is under $150,000. This is a tiny amount compared to how many car purchases it must have encouraged, and how insignificant it is in comparison to building cost (~$100,000/station.)

Not in most places.

First, in many places it's likely that the landlord is buying the power.

Second, when the SC is metered, it will be served under a commercial rate tariff. It's power cost might be $0.05/kWh, but Tesla will also pay transmission and distribution charges, though as a commercial customer, most of these will be linked to the peak kW draw, rather than kWh.

In California, the effective rate will be close to $0.20/kWh, once all the extra charges are figured in.
 
So you propose that Tesla control charging to benefit the grid, V2G? I tried to convince them to do that at Teslive, they said it's a great idea but they have other concerns. I wouldn't expect to see this from Tesla anytime soon, but I would expect to see a private company offering it by the end of next year if I have any say in the matter...

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If Tesla can accomplish all of this, it may very well be Capitalism's finest hour.

They can, but they're not interested. Believe me, I've tried.
 
I'm not convinced that this is the way to go, for a number of reasons. Building in the capability to use the car to power an external source is going to increase the cost of the car. Second, you want your car to be mostly charged whenever you want to leave, so if after storing the energy from the grid, they need to take the energy back, it is going to drain your battery, leaving you stuck. On the same note, you don't want your grid to suddenly lose its power storage facility when everyone gets on the road at the same time, say, rush hour.

It is true that the time your car spends sitting in the garage is wasted, but the solution to that is car sharing programs, not using it for an unrelated task that conflicts significantly with the function of being a vehicle.
 
So you propose that Tesla control charging to benefit the grid, V2G?

No it is not V2G (Vehicle To Grid). Power is not fed back to the grid. The idea behind V2G is somewhat silly. It degrades unnecessarily the battery and required infrastructure is expensive compared to benefit. It is always cheaper to have specialized grid storage batteries than to use EV batteries.

The point is only have timing for charging when the demand for electricity is at lowest. Many Tesla drivers already have this feature in use as Model S is scheduled to start charging at midnight. As renewable generation capacity is mostly low in United State, midnight charging mostly sufficient for the grid stability, because off-peak is at midnight.

But when the share of wind power is high, then this timing for charging is not that simple anymore.
 
I spoke with JB Straubel at the battery swap event in June and asked him about using the car for grid buffer or V2I.

He pointed me to the future packs being built with Solar City.

He didn't seem interested. Not sure why 20K cars x 75kWh (average) packs wouldn't be useful in reducing energy costs for owners.

Nissan just did a proof of concept with 6 Leafs and one office building.

Seems like all those batteries in our cars are going to waste 22 hours a day.
 
He didn't seem interested. Not sure why 20K cars x 75kWh (average) packs wouldn't be useful in reducing energy costs for owners.

EV battery power is more expensive than grid power. EV battery power costs something like 30–60 cents per kWh. Using EV battery for providing grid supplement power reduces the range of EV, this is especially relevant with LEAF battery that starts significantly degrade after 100 000 km driving. Hence Straubel is correct, that it makes always more sense to use specialized grid storage batteries for grid back up. With specialized grid batteries, battery power costs only about 20 cents per kWh and this could already make some sense in some locations.

If people would use Tesla batteries for Grid back up batteries could be easily driven out of juice before eight year warranty limit and hence Tesla certainly does not like the idea!
 
No it is not V2G (Vehicle To Grid). Power is not fed back to the grid. The idea behind V2G is somewhat silly. It degrades unnecessarily the battery and required infrastructure is expensive compared to benefit. It is always cheaper to have specialized grid storage batteries than to use EV batteries.

The point is only have timing for charging when the demand for electricity is at lowest. Many Tesla drivers already have this feature in use as Model S is scheduled to start charging at midnight. As renewable generation capacity is mostly low in United State, midnight charging mostly sufficient for the grid stability, because off-peak is at midnight.
@rolosrevenge discussed exactly this concept at TESLIVE 2013. As his very detailed analysis demonstrated, there's a big upside to allowing the system operator to manage the charging rate. As you say, this value doesn't require power to be drawn from the car, only that the utility can manage the charging rate (with some bounds, to assure that you have the charge you need).
 
@rolosrevenge discussed exactly this concept at TESLIVE 2013. As his very detailed analysis demonstrated, there's a big upside to allowing the system operator to manage the charging rate. As you say, this value doesn't require power to be drawn from the car, only that the utility can manage the charging rate (with some bounds, to assure that you have the charge you need).

Hmm. Mr Srevenge, do you have that presentation somewhere? The concept seems like a no-brainer to me since it's part of what a lot of utilities already do, but I'd like to read/hear/see more detailed analysis on it.

(And V2G will never happen).
 
No it is not V2G (Vehicle To Grid). Power is not fed back to the grid. The idea behind V2G is somewhat silly. It degrades unnecessarily the battery and required infrastructure is expensive compared to benefit. It is always cheaper to have specialized grid storage batteries than to use EV batteries.

V2G is the provision of energy and services from an electric vehicle to the grid. What you describe is Vehicle-to-Grid, and Tesla isn't interested in doing it.

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(And V2G will never happen).

Bidirectional power flow will totally happen, but on commercial fleet vehicles and not your average consumer car.
 
Bidirectional power flow will totally happen, but on commercial fleet vehicles and not your average consumer car.

I just don't see it: it's not the technical possibility, it's that to me I don't see the vehicle owner, vehicle manufacturer and utility all being interested at the same time. Expensive batteries means vehicle manufacturers leery of battery use and warranty claims; cheap batteries (realistically needed for electric vehicles to be successful) reduce the value of customer's storage to the utility.
 
And quite likely anyone who is interested in their battery life isn't interested either.
Yep.

I just don't see it: it's not the technical possibility, it's that to me I don't see the vehicle owner, vehicle manufacturer and utility all being interested at the same time. Expensive batteries means vehicle manufacturers leery of battery use and warranty claims; cheap batteries (realistically needed for electric vehicles to be successful) reduce the value of customer's storage to the utility.
Yep.

Besides all of the above, we'll probably have the opposition from ALEC. I posted about the crazy garbage I learned about over at Garage Wiring Fire - Page 14.

From EV drivers beware, ALEC is coming for your solar power, specifically the crazy garbage mentioned at ALEC calls for penalties on solar-panel owners | Grist
Eick dismissed the suggestion that individuals who buy and install home-based solar panels had made such investments. “How are they going to get that electricity from their solar panel to somebody else’s house?” he said. “They should be paying to distribute the surplus electricity.”

In November, Arizona became the first state to charge utility customers for installing solar panels. The fee, which works out to about $5 a month for the average homeowner, was far lower than that sought by the main electricity company, which was seeking to add up to $100 a month to customers’ bills.
From ABG:
ALEC, a group of about 800 people that includes such notables as ex-vice presidential candidate Paul Ryan and Texas Senator Ted Cruz, appears to be going after any and all things related to renewable energy, and that includes people who install their own home solar panels and sell their excess power back to the grid. In fact, ALEC not only is saying these people shouldn't be paid for the energy, but believes they should pay for the privilege of sending energy back to the grid because they don't have to pay for the grid's infrastructure.

Ridiculous! Somehow I'm not surprised about who the players are for the above crap.

Sorry to go somewhat OT...
 
And quite likely anyone who is interested in their battery life isn't interested either.

Yes that is correct. Vehicle-to-Grid is just silly. However my model is opposite to V2G and it basically optimizes the longevity of battery compared to 90 % standard charging. It is better to keep daily charge level around 60 % rather than around 90 %.

Today this kind of charging pattern is of course for the Green Imago enhancement while optimizing the battery longevity. But around 2020's if it is turned into real time pricing of electricity, then this kind of charging is no brainer. Utilities however are not very happy with Smart Grids, because this means inevitable reduction in profitability, because highly profitable peak consumption flattens and average retail prices of electricity plummets. Therefore is not very probable that utilities will push this kind of change in the system. The change must come from the Tesla and Tesla drivers.

Also other car companies are unwilling to introduce long range EVs so this another reason, why Tesla alone must push this kind of change.
 
Yes that is correct. Vehicle-to-Grid is just silly. However my model is opposite to V2G and it basically optimizes the longevity of battery compared to 90 % standard charging. It is better to keep daily charge level around 60 % rather than around 90 %.

I hear you, and you're right in principle. But the problem is that you don't know which day you're going to need the difference between 60% and 80 or 90%. I had one of those a couple of months back when Denise had a flat. It just wouldn't have done to say "I'll be there in three hours because I have charge the car for two to be able to make it". The idea with the additional range of the Tesla is that you'll seldom have alter your plans to accommodate your electric vehicle.
 
Back to the OP's original scheme: He is saying that during those periods when renewable energy is in excess of normal margins, that there be some battery network available to quickly DUMP this excess, rather than losing it by either 1. feathering turbine blades or 2. moving shades over solar panels. Just examples.

One such battery network would be the Tesla MS owners in the 'neighborhood' who by prior arrangement allow 'extra' charging to be done on their cars whenever these special circumstances occur. The wind/solar farm operator could call each MS owner and suggest they run out to the car and jack up the CHARGE LIMIT slider from 40% to 90% thereby enjoying 'almost free' energy for the ensuing xx kW hours. Or this could be done over the internet or WiFi. There would be no need for Tesla Motors, Inc to be involved.

Now if on the following day it happens that the renewable energy source returns to normal or less, then the MS owner will not be offered the 'almost free' charging so she simply drives that 90% down to 40% and things return to normal.

This is a G2V scheme only, NOT the other direction. Unless I haven't a clue in which case: "Never mind".

I'm told wind farms in the Rocky Mt area have to feather their blades @35 mph (knots?) which to me seemed surprisingly slow. FWIW.
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