The International Simutrans Forum

 

Author Topic: Feature suggestion: electricity supply  (Read 4747 times)

0 Members and 1 Guest are viewing this topic.

Offline AvG

  • *
  • Posts: 308
Feature suggestion: electricity supply
« on: April 19, 2014, 02:53:15 PM »
Electric locs also have kind of a range.
They need a catenary with enough energy.
Suggestion:
Powerstation connected with transformer connected with electric locdepot.
Add the powervalues of all locs in use together.
They can only run if enough power is available.


A very good motivation for a reliable coal-transport.
AvG



Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #1 on: April 19, 2014, 05:11:56 PM »
I have split this from the discussion of range, as this seems to be a suggestion of a quite different feature.

I have previously considered adding a requirement for an electrical supply, but this could become extremely complicated: actually computing at every step the distance from a substation, the power consumption of each unit and what to do about any given convoy if there is not enough electricity (so as to avoid deadlocks) can become astonishingly complicated if one were to try to implement it, and it would add very great complexity for players, too.

Whilst not necessarily ruling it out for the far future, it is difficult to see how this could be made to work in a practical way.

Offline ӔO

  • Devotees (Inactive)
  • *
  • Posts: 2345
  • Hopefully helpful
  • Languages: en, jp
Re: Feature suggestion: electricity supply
« Reply #2 on: April 19, 2014, 05:51:18 PM »
the easiest way would be to buy x amount of power that is always available, even if it is not connected to the network.
then the electrics will use up whatever is within that limit.

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #3 on: April 19, 2014, 05:54:19 PM »
The complexity comes when one goes slightly over that limit...

Edit: And, also, at that level of simplicity, that does not really add anything to just paying for electricity by the standing cost for the electrification infrastructure and the per kilometre cost of electric vehicles.

Offline sdog

  • Devotee
  • *
  • Posts: 2039
Re: Feature suggestion: electricity supply
« Reply #4 on: April 19, 2014, 11:39:55 PM »
Simulating the electrical network of electric railways would be a game itself, on the scale of simutrans complexity. The suggested is just not feasible, any implementation would be either completely out of place or so much simplified it would not matter at all.

When you go one step further you have huge economic implications: Tram lines were the first to electrify cities in many parts of the world. Trams require a lot of power when they accelerate. This required generators to be planned for peak load. They were oversized for average loads however. The tram companies therefor connected private consumers. Since mostly lighting and very simple motors (refrigerators) were connected, it didn't matter very much that the phase drifted everytime a tram accelerated.

But if this was done the player would directly influence the economic development of the map, not just indirectly by providing efficient transport. Players would be consumers and a different kind of business at the same time.


Third argument against this: There are alredy enough deadlock situations. Having the whole network collapse because somewhere a convoy got stuck on the way to a plant just asks for game-breaking frustration. Just imagine you have to kick-start the system with lorries again, but all the coal you deliver doesn't suffice to generate enough power to move anything...

Offline ӔO

  • Devotees (Inactive)
  • *
  • Posts: 2345
  • Hopefully helpful
  • Languages: en, jp
Re: Feature suggestion: electricity supply
« Reply #5 on: April 20, 2014, 02:31:06 AM »
There should also be plenty of motivation to ship coal, since it's supposed to be a highly lucrative business.

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #6 on: April 20, 2014, 10:29:16 AM »
One highly simplified system that could be used is only to allow placing of electric depots (for any type of transport), that is, a depot that allows building powered electric or battery operated vehicles (and possibly hydrogen fuel cell vehicles, which need recharging with electricity), in electrified towns.

Even this has some complexity, as the question then arises as what counts as an electrified town: what if a player were to connect a substation but send only one load of coal to the power station? What proportion of the town's electricity demand would have to be fulfilled and over what period of time? What electrical consumption would these depots have themselves? Should they be able to support a limited number of electric vehicles?
« Last Edit: April 20, 2014, 10:36:40 AM by jamespetts »

Offline AvG

  • *
  • Posts: 308
Re: Feature suggestion: electricity supply
« Reply #7 on: April 20, 2014, 01:36:09 PM »
Amazing, the amount of people that seem to think in problems i.s.o. solutions.


The range thread is a start for letting steam and petrol vehicles  NOT run forever without refuelling.
Before that can work a lot of things have to be done.


This electric supply idea can be easily implemented ( I think), because all the necessary data are available.
All you do is add the power of the locs in use together, and compare it to the available power.


No extra details, extra power when accelerating, economic influences, power-use in depots, etc.


Like many other features this idea must be disconnectible.(Uncheck via settings.)


Compare the idea to the situation as is : 100% compared to nothing. If realy wanted it can be implemented in a month.
It is a priority matter.


Compare the idea to all the suggested and  to solve problems, it is still not worthless. Let's say 25 to 100%.
The main problem is that the latter 100% will take years of development time.


If you want to play a more easy Simutrans then play Standard. Experimental should be more difficult because you have
extra possibilities.


If you make at present a GOOD network it can work for hours without a problem. Chances for a system-hangup (PC) are larger
than problem in your network. (when you let it run for a day)


The lucrative coal transport is probably due to an unrealictic fee or vehicle-running cost.
AvG

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #8 on: April 20, 2014, 03:24:22 PM »
The real complexity comes in deciding: (1) precisely what the available power is at any given moment; (2) precisely what power is being consumed at any given moment; and (3) what should happen if there is not enough power available at any given moment.

As to (1), one must ask - available where? A power station connected to, say, a depot to power a small tram network in a town in the far East of the map could not sensibly power an electric railway in the far West, so there would have to be a concept of the network being connected to something. We already have power networks (which are, incidentally, extremely complicated, and still not quite right when more than one separate network is trying to supply a city), so it would be theoretically possible to use the same code for connecting electrically powered vehicles, except the question would then be: for any given tile of electrified track, to what network is it connected? This is far from trivial, and would get exceedingly complicated if one were, for example, to connect one depot to one network and another depot to another, hitherto separate, network.

As to (2), the power output of vehicles is quite different to the power input, as there can be considerable variations in efficiency between vehicles, so we would have to have a new parameter determining how much power is consumed by each vehicle. It would make little sense to have them consuming full power when stationery, so we would have to implement a whole system of determining power use from activity, which again, is enormously complicated in itself.

On (3), this is where it gets beyond complicated. Suppose there is a power network consisting of three cities, twelve industries, two trolleybus networks, a tram network and an electric rail network, supplied by two coal fired power stations. If one of the two power stations is short of coal such that only, say, 70% of the power demand is fulfilled throughout the network, what exactly should happen to each vehicle on each of the four networks; and what should then happen to the amount of power that is left for the cities and industries to consume after accounting for whatever effect is being had on the rail/tram/trolleybus networks? As far as I can see, there is no clear answer to this, and it is very difficult to conceive of anything other than a gargantuanly complicated answer to this question that does not break the simulation.

Offline isidoro

  • Devotee
  • *
  • Posts: 1129
Re: Feature suggestion: electricity supply
« Reply #9 on: April 21, 2014, 12:01:17 AM »
To give a possible answer to (3), the electric vehicles reduce their speed to half, a quarter, or whatever other factor when short/lack of supply.  From the game perspective (not a realistic one), the player would observe that things slow down if he is not able to supply enough power to the network.

As a possible simplified system for power management, a transformer could be attached to stations, stations will consume electricity each time a convoy passes by, the electric convoys will also have "range" and if not reach another electric station within its range or if that station is short or has no power, then the vehicle is severely slowed down.

Not physically realistic, but can make the trick...

A good point to include electricity in this, is that ST has a complete infrastructure programmed to deal with electricity, but it is hardly used for transportation purposes, isn't it?


Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #10 on: April 21, 2014, 12:30:49 AM »
So, if there is enough power for 99% of everything, every tram, trolleybus and electric train goes at half speed; and players can get electric vehicles running at half sped with only 1% of the necessary power? And how much power would be available for cities/factories; would these half-speed electric vehicles consume half the power (leading to a circularity)? The exploitability of edge cases always makes the question of what happens if there is insufficient electricity a complicated one to answer.

As to the range, that is interesting, but I am afraid also introduces great complexity, not least the necessary route-finding between every point on the electrified network and the nearest connected substation, which I fear would greatly add to computational load.

Offline ӔO

  • Devotees (Inactive)
  • *
  • Posts: 2345
  • Hopefully helpful
  • Languages: en, jp
Re: Feature suggestion: electricity supply
« Reply #11 on: April 21, 2014, 01:43:04 AM »
For the transformers, it would make more sense if they had their own coverage area and anything outside of it will run slower or not be powered.

Each transformer could have its own maximum capacity and if more power is desired, expanding it with more transformers, like stations, could work.

Offline Junna

  • Devotee
  • *
  • Posts: 1081
Re: Feature suggestion: electricity supply
« Reply #12 on: April 21, 2014, 11:22:33 AM »
Really, this is just undesirable complexity. I'd rather have the ability to shunt wagons from one locomotive to another than this needlessly complex system for so little reward.

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #13 on: April 21, 2014, 11:33:43 AM »
Really, this is just undesirable complexity. I'd rather have the ability to shunt wagons from one locomotive to another than this needlessly complex system for so little reward.

Shunting will be very complicated to implement, too, but I agree that this is more desirable than explicit simulation of the electricity supply to electrified lines.

Offline prissi

  • Developer
  • Administrator
  • *
  • Posts: 9472
  • Languages: De,EN,JP
Re: Feature suggestion: electricity supply
« Reply #14 on: April 21, 2014, 11:38:44 PM »
Just a short remark: You know how much power is there (theoretically) and how much is available. One could run all convois as now, but when buying a new convoi, and there is not enough electric power (by just adding all electric engines kw together), then you cannot buy an electric engine. If you take the current production, then one has to take only the sum of all running convois.

This would just give an error message when starting (and one can still run a diesel instead) and would not break existing games.

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #15 on: April 21, 2014, 11:53:52 PM »
That is an interesting idea - but would this not be exploitable and/or give unpredictable results if a player connected a depot to a substation, bought lots of electric vehicles, and then disconnected the depot from the substation (having bought all desired vehicles), and then used the remaining power to connect more factories/cities? Indeed, a player might temporarily disconnect some factories and/or cities just to buy new vehicles, and reconnect them after they are purchased.

Offline ӔO

  • Devotees (Inactive)
  • *
  • Posts: 2345
  • Hopefully helpful
  • Languages: en, jp
Re: Feature suggestion: electricity supply
« Reply #16 on: April 22, 2014, 12:00:36 AM »
If substations had a coverage area instead of only powering things directly adjacent to it, might that work better against such an exploit?

Offline sdog

  • Devotee
  • *
  • Posts: 2039
Re: Feature suggestion: electricity supply
« Reply #17 on: April 22, 2014, 01:00:58 AM »
One could have more electric vehicles running at once than what would be permitted if the sum of their peak power would not be allowed to exceed the network power. They do not accelerate all at the same time. Especially with rail, where signaling and the inability to overtake can safeguard that only a very limited number of vehicles draw peak power at once.

Offline ӔO

  • Devotees (Inactive)
  • *
  • Posts: 2345
  • Hopefully helpful
  • Languages: en, jp
Re: Feature suggestion: electricity supply
« Reply #18 on: April 22, 2014, 01:34:49 AM »
Speaking of exceeding network power, has the city electricity consumption been fixed?

In the last game, that map was consuming more than two times the amount of power available and the total power generation was more than three times the peak load of UK.

Offline jamespetts gb

  • Simutrans-Extended project coordinator
  • Moderator
  • *
  • Posts: 18619
  • Cake baker
    • Bridgewater-Brunel
  • Languages: EN
Re: Feature suggestion: electricity supply
« Reply #19 on: April 22, 2014, 10:46:49 AM »
The idea of coverage areas would introduce further complexity in and of itself, and may produce undesirable side effects (people might want to connect one factory, but end up connecting two other factories and a city, for instance).

As to fixing bugs: I do not now remember in detail exactly what has been fixed, but I think that at least some electricity bugs have been fixed since the time of the second Bridgewater-Brunel game.