kWh to kW

[kwired]

Another is a transmission line from a wind farm.

That is a little different, now the wind maybe makes some difference of what can be generated but otherwise why wouldn't they size things for near full capacity? Maybe I'm missing something but seems to me that the goal would be to maximize production as much as possible or else you have idle equipment that is maybe costing you instead of generating profit. And as far as wind goes, the wind farms around here spent months or years doing wind studies before they ever built anything, sure would think they selected places where they will get better wind conditions for their needs.

 

[gar]

131206-0749 EST

You can make some useful estimates on short time peak power requirements from known energy use over a known time with some additional information.

Consider kwired's example of a church. Suppose the monthly energy consumption is 2000 kwh, the church has heavy usage of 8 hours per week, and and there is a base load of 1 kW. Next assume a 31 day month and 4 weekends per month. Base load is 1*24*31 = 744 kWh. This may be a good guess for a refrigerator and gas fired furnace plus some incidentals. Subtract this from the 2000 total and the result is 1256 kWh. There are 32 hours that produce this 1256 load or 39 kW is the added load. Thus, over some short time periods we can expect about 40 kW loads.

With a few measurements at some specific times you should be able to get some reasonable estimates. Summer, winter, and spring-fall will all have different values. You need to use some intelligent techniques plus some fudge factors and the results can be quite good.

.

 

[ggunn]

That is a little different, now the wind maybe makes some difference of what can be generated but otherwise why wouldn't they size things for near full capacity? Maybe I'm missing something but seems to me that the goal would be to maximize production as much as possible or else you have idle equipment that is maybe costing you instead of generating profit. And as far as wind goes, the wind farms around here spent months or years doing wind studies before they ever built anything, sure would think they selected places where they will get better wind conditions for their needs.

Well, of course there are differences, but with a wind farm you still must design the transmission lines to carry the peak power, not the average power, because there will always be variability in production and storing/levelizing output is not yet a viable option.

 

[Besoeker]

Well, of course there are differences, but with a wind farm you still must design the transmission lines to carry the peak power, not the average power, because there will always be variability in production and storing/levelizing output is not yet a viable option.

Yes, quite.
No point in installing a 3MW turbine if you can never use it above 2MW because of limitations imposed by transmission line capacity. If/when storage on that sort of scale it could be looked at differently.
For on-shore wind turbines, the typical capacity factor claimed is 25%-30%. Taking the lower of the two, the average output of the 3MW unit is 750kW. You could use that for estimating the energy contribution it would make over a year. But not for sizing the transmission system.