The possibly impossible economics of DCFC

[Hydrocarbon302]

The ”capacitor/battery dc charger” is a great ”right now” idea for low traffic areas that are typically kvar limited by the local utility, and face prohibitive demand fees.

A 2-4 stall setup in the middle of nowhere that can bridge the gap between EA/TSLA, etc. would be absolutely wonderful in certain areas. However, the only issue I see is ROI on the long term. If the big boys drop a charging station near yours in the next 10 years your ROI goes bye bye.

Has anyone looked that the difference between 8 gas/diesel pumps with tanks vs a 8 stall DCFC as far as equipment and installation costs?

We need a $15-20k per stall DCFC setup. SETEC 120kw units are $18,000 if anyone is interested. Use at your own risk.

 

[Rocky_H]

However, the only issue I see is ROI on the long term. If the big boys drop a charging station near yours in the next 10 years your ROI goes bye bye.

You seem to be mixing up the manufacturer of a piece of equipment, versus a company that operates a charging network. Those charging network operators already buy equipment from a few different manufacturers. This would be just another slightly different type of equipment they could buy to install into their networks for those use cases in some locations.

 

[nwdiver]

What is your deal? It IS delivering power to vehicles. It doesn't just sit there showing "Out of Order" until the battery refills, as you suggest. It has a minimum power level of about 20-30kW, if there isn't extra battery capacity, or up to 100kW+ if there is.

One needs to choose the right tool for the job, though. If one is going to talk about the paradigm of a "station of chargers", like with a dozen stalls, that's a high traffic site that isn't suited to this infrequent use, buffering type of device. Low use sites, with only one or two stalls, on lesser used routes, is where this is the right tool for the job.

??? It has a 160kWh battery and can deliver 120kW to the cars and uses the battery as buffer to not pull >30kW from the grid... yes? So you have 4 cars that take 40kWh each over a ~2 hour period. Is the 5th car now not limited to 30kW because that's the most it can pull from the grid and the battery is drained? When I said 'I don't think that not delivering power to vehicles that need to charge is a good solution to DCFC...' I was including nerfing a charger to 30kW from 120kW to avoid demand fees...

The main issue I want to highlight with this thread is the absurdity of demand fees that are agnostic to the time of day. What sense does it make to pull energy from an expensive battery at a time when renewables are being curtailed on the grid? What sense does it make to pull 30kW from the grid just because that's under your demand threshold at a time when peaker plants are firing away?

 

[Hydrocarbon302]

You seem to be mixing up the manufacturer of a piece of equipment, versus a company that operates a charging network. Those charging network operators already buy equipment from a few different manufacturers. This would be just another slightly different type of equipment they could buy to install into their networks for those use cases in some locations.

I understand.

I was just talking about the overall cost of installing and running a DCFC station, the big boy operators have the $$ to install large scale stations using whatever brand they want ($250k +) where as smaller franchises and mom and pop locations do not.

Either way the cost of installing and maintaining DCFC is too expensive.

 

[nwdiver]

I found a price for the Freewire charger with the 160kWh battery. Reducing demand fees with a battery comes at a steep price... ~$213,000 US. BUT you can get at 30% tax credit which will lower the cost to ~$150k.

A couple things bother me about this type of setup. For one you lose the ability to value-stack the battery when its sole design purpose is to buffer EV charging. The best solution would be to add a 'grid interactive' battery able to help balance the grid at all times not just when a car happens to be charging. The other issue is that >70% of the energy you're charging your car with will always be discharged by another battery. So you're taking the round trip losses twice.

Maybe spending $150k on a 160kWh battery is better than ~$1800/mo in demand fees?

 

[mociaf9]

The main issue I want to highlight with this thread is the absurdity of demand fees that are agnostic to the time of day. What sense does it make to pull energy from an expensive battery at a time when renewables are being curtailed on the grid? What sense does it make to pull 30kW from the grid just because that's under your demand threshold at a time when peaker plants are firing away?

Demand charges aren't about controlling electric demand though. They are about recovering costs for appropriately sized substations, feeder lines, transformers, and service equipment. Those costs are absolutely insensitive to the costs of energy generation or the state of the supply/demand balance on a grid at any given time. It's really not an easy problem to solve.

 

[miimura]

I found a price for the Freewire charger with the 160kWh battery. Reducing demand fees with a battery comes at a steep price... ~$213,000 US. BUT you can get at 30% tax credit which will lower the cost to ~$150k.

A couple things bother me about this type of setup. For one you lose the ability to value-stack the battery when its sole design purpose is to buffer EV charging. The best solution would be to add a 'grid interactive' battery able to help balance the grid at all times not just when a car happens to be charging. The other issue is that >70% of the energy you're charging your car with will always be discharged by another battery. So you're taking the round trip losses twice.

Maybe spending $150k on a 160kWh battery is better than ~$1800/mo in demand fees?

The Freewire charger is also designed to be used with existing 208V or 240V electrical service. Avoiding installing a new 277Y480V service that would be required for other chargers is also valuable. Clearly this charger is designed for places that need DCFC but are likely to have low frequency of charging sessions for a significant period of time.

 

[nwdiver]

They are about recovering costs for appropriately sized substations, feeder lines, transformers, and service equipment. Those costs are absolutely insensitive to the costs of energy generation or the state of the supply/demand balance on a grid at any given time. It's really not an easy problem to solve.

Those costs are all about ensuring you have the infrastructure to support 'coincident peak' which generally occurs around ~4pm in the summer. My point is that demand fees need to take this into account. Pulling 100kW from the grid at 4pm when demand is 55GW is A LOT more expensive than pulling 100kW from the grid at 4am when demand is 30GW. In fact it's not uncommon now for the price of electricity at 4am to be negative. I'm not opposed to curtailing charge rates if the grid is under stress or using a battery to charge cars to minimize stress on the grid. What's counter-productive is to do either of those things for the sole purpose of minimizing the peak rate at which power is consumed from the grid.

Sometimes it would be good for the grid for you to actually pull as much as you can even if there are no cars charging. Sometimes it would be good to discharge the battery into the grid... even if there are no cars charging.

 

[nwdiver]

The Freewire charger is also designed to be used with existing 208V or 240V electrical service. Avoiding installing a new 277Y480V service that would be required for other chargers is also valuable. Clearly this charger is designed for places that need DCFC but are likely to have low frequency of charging sessions for a significant period of time.

I hope they come out with a slightly more sophisticated version. There are a lot of restaurants that are getting killed by demand fees. I could see something similar to that which is also able to export into the restaurants service and reduce their demand fees as something that would be very attractive. Even if they don't see many EVs using it it's something that could save them money. If I'm gonna invest ~$100k in a battery... I want to use that battery for more than just buffering EV charging.

 

[miimura]

Those costs are all about ensuring you have the infrastructure to support 'coincident peak' which generally occurs around ~4pm in the summer. My point is that demand fees need to take this into account. Pulling 100kW from the grid at 4pm when demand is 55GW is A LOT more expensive than pulling 100kW from the grid at 4am when demand is 30GW. In fact it's not uncommon now for the price of electricity at 4am to be negative. I'm not opposed to curtailing charge rates if the grid is under stress or using a battery to charge cars to minimize stress on the grid. What's counter-productive is to do either of those things for the sole purpose of minimizing the peak rate at which power is consumed from the grid.

Sometimes it would be good for the grid for you to actually pull as much as you can even if there are no cars charging. Sometimes it would be good to discharge the battery into the grid... even if there are no cars charging.

PG&E has another way of addressing grid stress - "PDP". This is Peak Day Pricing. PG&E can declare a certain number of these Peak Days per year. On certain rate plans they get to charge $1.20/kWh between 4-9pm on those days.

We really need a VPP program that allows us to collect $1.20/kWh to export power from our Powerwalls on these Peak Days.

 

[miimura]

I hope they come out with a slightly more sophisticated version. There are a lot of restaurants that are getting killed by demand fees. I could see something similar to that which is also able to export into the restaurants service and reduce their demand fees as something that would be very attractive. Even if they don't see many EVs using it it's something that could save them money. If I'm gonna invest ~$100k in a battery... I want to use that battery for more than just buffering EV charging.

Clearly, if a business has a need for demand reduction of their normal use, then they would be better served by a more general purpose battery system that offsets their demand as well as a charger's demand.

 

[nwdiver]

PG&E has another way of addressing grid stress - "PDP". This is Peak Day Pricing. PG&E can declare a certain number of these Peak Days per year. On certain rate plans they get to charge $1.20/kWh between 4-9pm on those days.

We really need a VPP program that allows us to collect $1.20/kWh to export power from our Powerwalls on these Peak Days.

That's the way it's gonna have to be. I know I plan road trips through major cities to as to not get stuck in rush hour. Maybe in a couple years people will be planning charging stops so as to not pay ~3x more to charge...

 

[Rocky_H]

The main issue I want to highlight with this thread is the absurdity

Yeah, I wanted to avoid absurdity in this thread too, but...

??? It has a 160kWh battery and can deliver 120kW to the cars and uses the battery as buffer to not pull >30kW from the grid... yes? So you have 4 cars that take 40kWh each over a ~2 hour period. Is the 5th car now not limited to 30kW because that's the most it can pull from the grid and the battery is drained? When I said 'I don't think that not delivering power to vehicles that need to charge is a good solution to DCFC...' I was including nerfing a charger to 30kW from 120kW to avoid demand fees...

I just knew you would resort to something like that. You have made up the absurd situation where there is a line 5 cars deep waiting to all use this station at the same time. By definition, that is a high traffic site. And we already established that high traffic sites are not really the appropriate places to use battery buffered stations like this. This is perfect for use in low traffic sites that would have a few cars a day, not piles of cars that stack up 5 at the same time. This is to enable routes that don't have ANY DC fast charging. How many YEARS have we been waiting for coverage for lesser highways that aren't interstates? Even in your ridiculous scenario, the hypothetical 5th car getting 20kW would be happier with that than with having to get 6kW from a J1772 or 14-50 alternative.

 

[sdoorex]

Yeah, I wanted to avoid absurdity in this thread too, but...

I just knew you would resort to something like that. You have made up the absurd situation where there is a line 5 cars deep waiting to all use this station at the same time. By definition, that is a high traffic site. And we already established that high traffic sites are not really the appropriate places to use battery buffered stations like this. This is perfect for use in low traffic sites that would have a few cars a day, not piles of cars that stack up 5 at the same time. This is to enable routes that don't have ANY DC fast charging. How many YEARS have we been waiting for coverage for lesser highways that aren't interstates? Even in your ridiculous scenario, the hypothetical 5th car getting 20kW would be happier with that than with having to get 6kW from a J1772 or 14-50 alternative.

That unit is the worst compromise because you are paying to install a battery that ends up sitting there unused the majority of the time since you can't use it for grid arbitration service without compromising it's availability for EV users. Then on peak travel days when it's most necessary, it provides a subpar charging experience as soon as it's usable capacity is depleted. It's a poor solution to a problem that is better solved by utility pricing and PUC regulation paired with more general battery packs that can take advantage of those regulation to provide arbitrage while not used for charging allowing a far larger pack to be installed since it is earning money continuously.

 

[nwdiver]

By definition, that is a high traffic site. And we already established that high traffic sites are not really the appropriate places to use battery buffered stations like this.

I guess we have different opinions on what qualifies as 'high traffic'. I don't think 3 cars/hr is 'high traffic'. Maybe ~10 or 20 per hour.

Regardless you run into the paradox of usage factor. If you're investing in a $150k DCFC station you're gonna want more than the occasional random car passing through. You'd probably need at least 10 cars per day on average to justify the expense. Most of those would be on the weekend. Traffic is either going to be too sparse to justify the cost or high enough that exhausting the battery will be a common event. It would be interesting to see the numbers for superchargers. I wouldn't be surprised if 90% of the charging sessions occur 10% of the time.

 

[Rocky_H]

I guess we have different opinions on what qualifies as 'high traffic'. I don't think 3 cars/hr is 'high traffic'. Maybe ~10 or 20 per hour.

I think it's more the opposite. You don't seem to have a concept of actual low traffic routes that still need coverage because they are hundreds of miles long. I'm talking about Burns, OR or McDermitt, NV or the 378 mile route from Boise up to Coeur D'Alene, which still doesn't have anything. They are a couple of cars per day, not a couple of cars per hour. We waited years and YEARS for charging companies to put something in. Something that can run from a smaller supply doesn't have to be as big of a construction project with a big transformer being added, so might be more easily installed.

 

[nwdiver]

They are a couple of cars per day, not a couple of cars per hour.

That's the paradox. You need at least an average of ~10 cars/day (which at peak could be >4/hr) for a $150k DCFC to be economically viable unless you're charging >$2/kWh.... in which case I think a lot of people would rather sit on L2 for 4 hours than pay $90 to charge.... or just drive their ICE

 

[Rocky_H]

That's the paradox. You need at least an average of ~10 cars/day (which at peak could be >4/hr) for a $150k DCFC to be economically viable unless you're charging >$2/kWh.... in which case I think a lot of people would rather sit on L2 for 4 hours than pay $90 to charge.... or just drive their ICE

You say that as if it would never happen, and yet slowly, eventually, they have been getting to it. Chargepoint finally put one in Burns and Greenlots finally put one in McDermitt. I'm sure you are correct that they ARE loss leaders at these locations, but they have to do it to promote themselves as actual charging networks with coverage, not just putting up stations only in New York city and Los Angeles. I'm still questioning a bit why the battery size would need to be that big to make it $150,000, though.

Remember that Tesla themselves used to break out specific Supercharger locations in their quarterly financial statements as the ones that were just money losing, which they categorized as "Marketing". But they were necessary for the Supercharger network. Not every site must be always profitable to run the system as a whole.

 

[nwdiver]

You say that as if it would never happen, and yet slowly, eventually, they have been getting to it. Chargepoint finally put one in Burns and Greenlots finally put one in McDermitt. I'm sure you are correct that they ARE loss leaders at these locations, but they have to do it to promote themselves as actual charging networks with coverage, not just putting up stations only in New York city and Los Angeles. I'm still questioning a bit why the battery size would need to be that big to make it $150,000, though.

It's obviously happening. The question is whether it's economically sustainable. It's going to be interesting to see if EA can stand alone once the Diesel-gate money is gone or if they're going to need a bailout.

 

[sdoorex]

You say that as if it would never happen, and yet slowly, eventually, they have been getting to it. Chargepoint finally put one in Burns and Greenlots finally put one in McDermitt. I'm sure you are correct that they ARE loss leaders at these locations, but they have to do it to promote themselves as actual charging networks with coverage, not just putting up stations only in New York city and Los Angeles. I'm still questioning a bit why the battery size would need to be that big to make it $150,000, though.

Remember that Tesla themselves used to break out specific Supercharger locations in their quarterly financial statements as the ones that were just money losing, which they categorized as "Marketing". But they were necessary for the Supercharger network. Not every site must be always profitable to run the system as a whole.

The Burns charger is owned by the electric co-op so it is not subject to demand charges however competing stations like the Tesla Supercharger will be. The co-op servicing McDermitt does not have demand charges for large commercial. Many rural stations that are being built are using a combination of government grants, EV specific negotiated power rate plans, utilities that don't charge demand charges, or straight up utility owned chargers.