One prediction on electric cars

[Besoeker]

h
and to note, kWh is a oddly normalized rate of energy, 1kW used for 1hr, W is joule/sec, thus its a rate over time = gross energy consumed.

the poco's dont need the "h" in kWh because kJ/sec would suffice and is a more fundamental description of energy rate.

You get charged for energy, nor energy rate.

 

[Besoeker]

Awesome!

I wonder why they don't sell them over here?

An aversion to diesel maybe?

I did at one time. This is just the second diesel I've had. And that's in 50 years of driving.
Despite being a diesel, the engine is quite refined. At normal road speeds you wouldn't know the difference.
Service interval is 12,500 miles.
For sure, it isn't as quick as the 12-pot Jag that I had - 130mph as opposed to 150mph.

But that's a bit academic. Driving above the national speed limit here, 70mph, is to risk a ban. There are speed cameras everywhere.
Three strikes and you're out.
On my drive to and from work, about 50 miles, there are about ten sets each way.
I could get banned on one just trip one way.

 

[GoldDigger]

Awesome!

I wonder why they don't sell them over here?

I can think of several possible problems:
1. The EU diesel engines may meet all of the gaseous emission requirements in the US, but still fail the relatively strict particulate emission limit unless modified.
2. It costs a bunch to get EPA certification, both in engineering time and in money. The manufacturers may not feel that the market justifies it.
3. It is a conspiracy.

 

[mivey]

I wonder why they don't sell them over here?

Because they put the steering wheel on the wrong side!

 

[Besoeker]

Because they put the steering wheel on the wrong side!

It's actually on the right side.
But they do them with the steering wheel on the left side too.....

 

[FionaZuppa]

You get charged for energy, nor energy rate.

yes, agree, but you can only determine energy used by "rate x time". instantaneous look at rate (t=x, delta t=0) is just the flux at that specific time.

kWh = kJ/s * h = kJ, a rate x time, etc. poco normalizes their charges against the rate for 1hr.

 

[Besoeker]

yes, agree, but you can only determine energy used by "rate x time".

Yes - that's exactly kWh gives you.

 

[gadfly56]

yes, agree, but you can only determine energy used by "rate x time". instantaneous look at rate (t=x, delta t=0) is just the flux at that specific time.

kWh = kJ/s * h = kJ, a rate x time, etc. poco normalizes their charges against the rate for 1hr.

Don't they use 15 minutes as the moving window for peak demand?

 

[ggunn]

You get charged for energy, nor energy rate.

Actually, in many places you get charged for both. In addition to the kWh charge for energy used there is a kW surcharge based on your peak demand.

 

[Besoeker]

Actually, in many places you get charged for both. In addition to the kWh charge for energy used there is a kW surcharge based on your peak demand.

I don't know how it is there but here it is usually over a period rather than an instantaneous value.
Such as fault current.

 

[ggunn]

I don't know how it is there but here it is usually over a period rather than an instantaneous value.
Such as fault current.

It varies depending on the utility, but it is kW rather than kWh, though.

 

[GoldDigger]

It varies depending on the utility, but it is kW rather than kWh, though.

Whether it is based on kWh in a 15 minute period or the average kW over that same 15 minutes, the practical effect is identical.
Once you set a time period energy is directly proportional to average power.

 

[ggunn]

Whether it is based on kWh in a 15 minute period or the average kW over that same 15 minutes, the practical effect is identical.
Once you set a time period energy is directly proportional to average power.

Of course, but what some utilities are looking for is that peak rate of current flow. I have read tariffs that explicitly say that. Of course there really is no such thing as an instantaneous measurement of flow rate because any measurement methodology involves some sort of integration over time, but that's cutting it a bit fine for the real world, don't you think?

 

[GoldDigger]

Well, the instantaneous peak power every half cycle will be twice the average power, even for a constant resistive load, so you technically need to specify some time period.
I can also just see a customer billed for 10 or more times their average power when a fault occurs.

 

[ggunn]

Well, the instantaneous peak power every half cycle will be twice the average power, even for a constant resistive load, so you technically need to specify some time period.
I can also just see a customer billed for 10 or more times their average power when a fault occurs.

Of course; see my edit.

 

[Besoeker]

It varies depending on the utility, but it is kW rather than kWh, though.

kW is an instantaneous value.
Time or duration doesn't come into it.

 

[ggunn]

kW is an instantaneous value.
Time or duration doesn't come into it.

I am of course aware of that, but the language in some tariffs refers to kW rather than kWh. Just how many angels can dance on the head of that pin, anyway?

 

[Fulthrotl]

Chickens are birds, right? How many chickens do humans kill every year?

with wind turbines? not more than a handful... the hard part is to throw them high enough
to reach the blades.

 

[Fulthrotl]

there is something like a century's worth of energy available from tar sands and shale oil that is very easy to get and the techniques for getting and refining it are becoming economical. the US has a bunch of coal as well and we have barely begun to exploit it despite several centuries of mining.

natural gas has the potential to replace a bunch of diesel and gasoline, and it is relatively cheap to do so. the payback is often a few months. there are a lot of commercial and industrial entities that are using NG to replace gas and diesel. for some reason despite the cost and other disincentives, propane use is on the rise for transportation as well.

there are other sources of portable liquid energy that you don't have to
dig for, drill for, and deal with all the crap in the middle east for....

http://en.wikipedia.org/wiki/Algae_fuel

the output can be stored without refrigeration as long as tanks have a
carbon dioxide purge. it can replace #2 diesel quite well, it seems.

 

[Besoeker]

I am of course aware of that, but the language in some tariffs refers to kW rather than kWh. Just how many angels can dance on the head of that pin, anyway?

Just as many as the chucks of wood that a woodchuck could if a woodchuck could chuck wood.......