Trying to use my ford station pro to charge a cycbertruck

[bmwhitetx]

Funny, I could charge the truck for $.18 and sell it for $275, can't do that at a bank! Of course it's cycling the battery so there's also that "cost".

No, no. That was my point, you are mixing up units. The $0.18 is what you pay per kWh (kilo-watt hour). That is a unit of Energy. The $275 is per kW (kilo-watt, no hour at the end). That is a unit of Power. Energy is Power x Time. They are completely different "things".

Sponsored

 

[Danface]

No, no. That was my point, you are mixing up units. The $0.18 is what you pay per kWh (kilo-watt hour). That is a unit of Energy. The $275 is per kW (kilo-watt, no hour at the end). That is a unit of Power. Energy is Power x Time. They are completely different "things".

I understand, KWH is rate of transfer and KW is amount of charge. Please correct me if I'm wrong!

I have 20KW in the battery and start my charging session at $.15/KWH (I typoed .18). This charger generally runs at 70KWH and I charge for an hour adding 70 KW to the battery, spend 70*$15=$10.50 and the battery now has 90KW in it. I drive home, the battery has 88KW and hook it to the charger inverter.

Later that day National Grid taps my battery and draws down 1KW over the course of the next 5 hrs (so a xfer rate of .2KWH) and then pays me $275 for the 1KW, yes or am I off by a factor of 10 or 100?

Thanks!!
Dan

 

[bmwhitetx]

Ok, I'll correct you

I understand, KWH is rate of transfer and KW is amount of charge.

The opposite. kW is power or the rate you use/transfer/store energy. If you use/transfer/store power at the rate of 10 kW then after an hour you would have used/stored/transferred 10 kWh (kilowatt-hour) of energy.
10 kW times 1 hour = 10 kWh.
It's that "h" at the end which stands for 'hour' that can be your key to knowing your talking about energy amount.

I have 20KW in the battery and start my charging session at $.15/KWH (I typoed .18). This charger generally runs at 70KWH and I charge for an hour adding 70 KW to the battery, spend 70*$15=$10.50 and the battery now has 90KW in it. I drive home, the battery has 88KW and hook it to the charger inverter.

Later that day National Grid taps my battery and draws down 1KW over the course of the next 5 hrs (so a xfer rate of .2KWH) and then pays me $275 for the 1KW, yes or am I off by a factor of 10 or 100?

I have 20KW 20 kWh in the battery and start my charging session at $.15/KWH (I typoed .18). This charger generally runs at 70KWH 70 kW [note, no home charger charges at 70 kW. Probably 7-19 kW, but maybe you're doing cheap DCFC] and I charge for an hour adding 70 KW 70 kWh to the battery, spend 70*$15=$10.50 [Yes!] and the battery now has 90KW 90 kWh in it. I drive home, the battery has 88KW 88 kWh [took 2 kWh to drive home, at 2 mi/kWh, that's a 4-mile drive so good] and hook it to the charger inverter.

Later that day National Grid taps my battery and draws down 1KW over the course of the next 5 hrs (so a xfer rate of .2KWH) and then pays me $275 for the 1KW, yes or am I off by a factor of 10 or 100? I haven't read their TOS but let's say they take power from you at a 1 kW rate for the entire 5 hours, your average delivery rate is 1 kW (but you delivered 5 kWh). Your .2 KWH is not the right math unless you meant they draw at 0.2 kW rate for 5 hours causing you to use 1 kWh. Then your payment is based on the average 0.2 kW delivery rate.

However, typically these programs are for an entire year (or maybe a summer) and they average over the entire year/summer. There can be many events where they will need to draw power and they will average that 1 kW delivery rate over all event hours.

It could be they call for power only for 5 hours the whole year/summer or maybe they call for it 200 hours. Either way you get the one demand payment of $275. If it was 5 hours (e.g. 5 kWh energy used), that cost you 5*$.15= 75 cents. If it was for 200 hours (200 kWh used), that cost you 200* $0.15 = $30.

If they call for your power for 200 hours and you are only available half the time then your average delivery is only 0.5 kW and your payment is half of $275.

 

[Danface]

Ok, I'll correct you

The opposite. kW is power or the rate you use/transfer/store energy. If you use/transfer/store power at the rate of 10 kW than after an hour you would have used/stored/transferred 10 kWh (kilowatt-hour) of energy.
10 kW times 1 hour = 10 kWh.
It's that "h" at the end which stands for 'hour' that can be your key to knowing your talking about energy amount.


I have 20KW 20 kWh in the battery and start my charging session at $.15/KWH (I typoed .18). This charger generally runs at 70KWH 70 kW [note, no home charger charges at 70 kW. Probably 7-19 kW, but maybe you're doing cheap DCFC] and I charge for an hour adding 70 KW 70 kWh to the battery, spend 70*$15=$10.50 [Yes!] and the battery now has 90KW 90 kWh in it. I drive home, the battery has 88KW 88 kWh [took 2 kWh to drive home, at 2 mi/kWh, that's a 4-mile drive so good] and hook it to the charger inverter.

Later that day National Grid taps my battery and draws down 1KW over the course of the next 5 hrs (so a xfer rate of .2KWH) and then pays me $275 for the 1KW, yes or am I off by a factor of 10 or 100? I haven't read their TOS but let's say they take power from you at a 1 kW rate for the entire 5 hours, your average delivery rate is 1 kW (but you delivered 5 kWh). Your .2 KWH is not the right math unless you meant they draw at 0.2 kW rate for 5 hours causing you to use 1 kWh. Then your payment is based on the average 0.2 kW delivery rate.

However, typically these programs are for an entire year (or maybe a summer) and they average over the entire year/summer. There can be many events where they will need to draw power and they will average that 1 kW delivery rate over all event hours.

It could be they call for power only for 5 hours the whole year/summer or maybe they call for it 200 hours. Either way you get the one demand payment of $275. If it was 5 hours (e.g. 5 kWh energy used), that cost you 5*$.15= 75 cents. If it was for 200 hours (200 kWh used), that cost you 200* $0.15 = $30.

If they call for your power for 200 hours and you are only available half the time then your average delivery is only 0.5 kW and your payment is half of $275.

It is a DC fast charger in West Boylston, MA put in by the municipal light company so it's $.15 which is 1/2 the $.30 I pay at home. I put in a commerical charger at home that I got off eBay that draws 80 Amps but I have an SR so it only can pull 48 amps but that's fine. Between the two, I figure my blended cost is about $.20.

One thing I do know about the demand power is the inverter can be set to only allow for a certain level battery depletion.

Thank you professor, much appreciated!
Dan

 

[chl]

The Mass program is interesting.

The utility sell us all energy in kWh.

Their program pays folks for their energy producing ability during times of high demand.
Power is a measure of energy producing capability, that is, how much energy a system can produce.

1 kWatt = 1 kjoule per second (rate of energy transfer/production).

So they say there could be 30 to 60 events lasting from 2 to 3 hours.
So take the longest most frequent period, 1kw x 3hrs x 60 events = 180kWh. If you pay 30 cent per kWh, then that would be $54 worth of energy if you bought it.

Or if it was the shortest and fewest, 1kw x 2 hrs x 30 events = 60kWh. At 30 cents per that would be $18 worth of energy if you bought it.

But they are going to pay $275 for that 60kWh to 180kWh (1kw of power x hours used).

I wondered why? Then it dawned on me, it's because it is a lot cheaper than building a large utility power plant.

2021 numbers:
nuclear power plant costs about $5,000-$8,000 per kW,
wind is around $1400/kW,
solar photovoltaic is around $1500/kW

See https://www.eia.gov/electricity/generatorcosts/ which didn't include nuclear, I guess because they are prohibitively expensive now (are you listening Bill Gates) and f-ing dangerous too.

Sponsored