Talk:Key:plant:storage
Substances and generation means
Storage capacity can be more complex than output power counts, mainly because capacity doesn't mean actual availability.
A pumped water storage plant stores water while you expect electricity to comes out of it when needed. Problem is the energy you'll obtain from water depends on generator you use in the plant. You may find plants with several generators with different ratings or different design figures. Example in 3107019
3107019 (La Coche, France). For the same amount of consumed water from the upper reservoir, you'll get different amount of electricity because of used generator efficiency.
Battery storage is the same : you store chemical energy and you want electricity when needed, but I'm pretty sure the amount of electricity you'll get depends on temperature and operating status of batteries.
So, if we want to document such capacities, some questions have to be solved :
- Should we indicate amount of output energy or the actual amount of stored substance in the plant? (i.e electricity in GWh or cube-meters of water?)
- Third possibility : should we store required energy to restore the storage at its full availability?
- In case we choose output energies, what context description should we use to make this value understandable and valuable for other consumers?
It would be nice to make these points clear before this key will be widely used Fanfouer (talk) 22:00, 8 December 2019 (UTC)
- I think you could make a very similar argument about output power. Plants may not be able to attain their rated output power for any number of reasons: cooling water temperature, maintenance, type of fuel in use, river flow (in case of hydro), etc. My intention with this tag is to record the nominal rated storage capacity, equivalent to the rated output we use for plant:output. This is frequently published in case of battery storage, and it's sometimes published in the case of pure pumped-storage hydro.
- I don't think we can reasonably model anything more complex in OSM, and I also don't think that we'll be able to get more comprehensive data for most plants.
- I primarily added this tag for the case of battery storage (and partly because some people are already using the plant:capacity tag which is ambiguous) - in this case it's simple: the tag should be the nominal storage capacity published by the operator. In quite a few cases there is a similar capacity published for pumped storage as well.
- In terms of amount of water stored for hydro plants - I wonder if that should be a property of the dam object, rather than the plant itself.
- Russss (talk) 22:41, 8 December 2019 (UTC)
- My point is it should be clearly stated on the key page. Any mapper comming there will ask how would he fill this field. It's ok to store published figure if available. Wiki should explain mappers have to avoid anual productibility values for pumped hydro storage (often published as well) which doesn't reflet storage capacity.
- The water volume should be included on the water=* feature, not on the dam because a single lake could be contained by several dams. Fanfouer (talk) 23:11, 8 December 2019 (UTC)