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Offline jamespetts gb

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Calibrating electricity demand
« on: September 29, 2013, 12:07:03 PM »
AEO has spotted that, in the current Bridgewater-Brunel online game, electricity demand appears to be out of proportion to the population. According to the National Grid's website, peak electricity demand in the UK is currently about 60gW. We have in the region of 60 million citizens, giving a peak electricity demand of something in the region of 1kW per person. This is not just household demand, but includes all industry, public lighting, transportation, etc.. Current demand (as in demand right this minute) is less than half that.

In the current Bridgewater-Brunel game, the town of Dulmead has a reported population of 30,994 and a reported power demand of 644mW, which gives a per person electricity demand of 21.42kW. This would on the face of it suggest that a reduction in electricity consumption by a factor of around 20 is warranted.

However, things are rather more complicated than that. The passenger-generation branch, which is to be the next major version, has a different way of counting population than the current version, resulting in much lower numbers (as only residential buildings are counted towards population). Making the comparison more complicated, I have not yet modified in the passenger-generation branch the system for computing population per city, although I have done it globally. The global population reported in 11.11 is 15,282,328. In the passenger-generation branch, by contrast, it is 896,452 - a difference of a factor of 0.05865938749646. If we multiply the city population of Dulmead by that figure, we get 1,818, or an electricity demand of just over 354kW per person, which is insane.

However, the population levels in the passenger-generation branch are not calibrated yet: that code permits the population level to be set directly in the buildings' .dat files, which has not yet been done, and the fallback computation from the "level" uses default values which are probably too low.

The net result of all of this is that there is no point in calibrating the electricity demand now because the thing against which it needs to be calibrated is set to undergo major change in the next version (the passenger-generation branch), and I shall not have a sensible idea of how to calibrate electricity per person in the passenger-generation branch until I have done more work on that code, which means that the calibration of electricity consumption had probably better wait for the next major version.

Offline greenling

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Re: Calibrating electricity demand
« Reply #1 on: September 29, 2013, 05:14:20 PM »
Hello Jamespetts
I come in Moment not to play with Pak128.britain ex 0.9.0 and new Simutrans ex 11.11.
I think that the Calibrating electricity demand make in the game the Playability better, but that it inderect a part of this:
http://forum.simutrans.com/index.php?topic=12625.msg125172#msg125172

Offline jamespetts gb

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Re: Calibrating electricity demand
« Reply #2 on: September 29, 2013, 05:41:03 PM »
Yes, indeed, the two are linked.

Offline Sarlock

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Re: Calibrating electricity demand
« Reply #3 on: September 29, 2013, 05:43:20 PM »
Agreed - get the passenger generation and population working and then target electricity demand.

You could shortcut and do a population x kW demand per citizen to calculate electrical demand.  This wouldn't take in to account industrial and commercial demand but it would probably approximate a city's electrical demand well enough to not matter or be noticed.  More discussion regarding population computation in the other thread.

Offline jamespetts gb

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Re: Calibrating electricity demand
« Reply #4 on: October 16, 2013, 12:12:19 AM »
I have now recalibrated the electricity demand on the passenger-generation branch; for every (1 citizen + 1 job + 4 units of visitor demand), there will be a demand of 1kW at 100% in electricity.tab, which is a considerably lower electricity demand (by a factor of something not far off 10) than at present.

Offline Sarlock

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Re: Calibrating electricity demand
« Reply #5 on: October 16, 2013, 12:22:57 AM »
Fabulous!  Nice clean method of calculation.