Wikidata:Property proposal/solar irradiance

solar irradiance edit

Originally proposed at Wikidata:Property proposal/Natural science

Representssolar irradiance (Q7556707)
Data typeQuantity
Template parameter"solar_site_resource" in en:template:infobox power station
Domainall types of solar power stations worldwide, sample: Solnova Solar Power Station
Allowed valuessingle numerical value, or a numerical range
Allowed units(kWh/m2/day) or (kWh/m2/year)
Example 1Solnova Solar Power Station (Q2944639) → 2,012 kWh/m2/year
Example 2Rewa Ultra Mega Solar (Q24929801) → 5.0-5.5 kWh/m2/day
Example 3Mohammed bin Rashid Al Maktoum Solar Park (Q30588403) → 2,150 kWh/m2/year
SourceSolar irradiance

Motivation edit

Solar irradiance is the rate measured at any given point on earth (usually power stations) for the power per unit area received from the Sun in the form of electromagnetic radiation. Rehman 11:33, 10 March 2019 (UTC)[reply]

Discussion edit

GPSLeo, true. But would that mean we need separate properties for "per day" and "per month" or any other period? Rehman 11:22, 14 March 2019 (UTC)[reply]
I think per day dose not make sense for power stations because it is always just a mean of many days of many years. --GPSLeo (talk) 11:51, 14 March 2019 (UTC)[reply]
You're right. I'm ok with your label suggestion (i.e. annual solar irradiance). Rehman 14:37, 14 March 2019 (UTC)[reply]
@Katjos: This does sound like what we want, and is well defined. We should have a Wikidata item for it then? And I don't think "annual" makes sense as part of the label, it's defined as a power level so energy per unit time, the time unit on which it's measured is not part of the meaning (but could be attached via a qualifier if that seemed important). So I would advocate labeling this "global horizontal irradiance" with GHI as an alias. ArthurPSmith (talk) 19:13, 15 March 2019 (UTC)[reply]
@ArthurPSmith: I do agree with you. I followed the suggestion from GPSLeo above to specify the time frame. However, I agree that we should add the time as a qualifier. I added items for total solar irradiance (Q62071458), direct normal irradiance (Q62071452), global horizontal irradiance (Q62071435) and diffuse horizontal irradiance (Q62071441) as subclasses of solar irradiance (Q7556707). --Katjos (talk) 20:24, 15 March 2019 (UTC)[reply]
I'm fine with this. But does that mean we would need four separate properties, instead of one? See also: Solar irradiance#Units. Rehman 01:19, 16 March 2019 (UTC)[reply]
Thank you for looking into this, Lymantria. Looking at the supported data types, it seems like quantity is the way to go. By needing units, did you mean Q item(s) such as "kWh per square metre"? I can create that, if so. (The standard SI unit is "Wh per square metre", so both may need to be created)
Time limit must always be stated, so it should ideally be a mandatory qualifier. Per year, and per day, are the most common scales.
We could also support another qualifier for the method of measurement; any one of the four types mentioned above by Katjos. This IMO, cannot be made a mandatory qualifier, as the information is not often provided together with the solar irradiance figure.
As for the name, because unit and time scale are included in the value or as qualifiers, maybe we could simply name the property "solar irradiance". Please do let me know if I misunderstand any question. Appreciate any thoughts from others as well. Kind regards, Rehman 10:59, 20 June 2019 (UTC)[reply]
Yes, the items for "kWh per square metre" and "Wh per square metre" should be created. For the time qualifier, would you think of duration (P2047)? Lymantria (talk) 13:42, 20 June 2019 (UTC)[reply]
Lymantria, watt hour per square metre (Q64748817) and kilowatt hour per square metre (Q64748823) are created. As for the time period, I believe valid in period (P1264) is more relevant. What do you think? Rehman 02:10, 21 June 2019 (UTC)[reply]
I can live with the way User:ArthurPSmith treated the time the examples > by seperate items. Lymantria (talk) 05:17, 21 June 2019 (UTC)[reply]
Thank you for pointing that out, Lymantria. I hadn't noticed kilowatt hour per square metre per day (Q64740314) and kilowatt hour per square metre per year (Q64740041). I cannot think of an issue with that as well.
That being said, what are your thoughts with regards to the points by Katjos? Do we have a way of setting something like a "recommended qualifier" in the form of determination method (P459), for one of the four methods of measurement? Rehman 06:03, 21 June 2019 (UTC)[reply]
You might think of making determination method (P459) a mandatory qualifier. Lymantria (talk) 09:06, 21 June 2019 (UTC)[reply]
Lymantria, I just tried, but I think I didn't do it the right way. Would you mind reviewing my changes please? Rehman 14:54, 21 June 2019 (UTC)[reply]
ArthurPSmith, would you be able to help recheck this please? I'm not sure if I did it right, as it currently shows errors. Rehman 13:50, 29 June 2019 (UTC)[reply]
@Rehman: I fixed the constraint. ArthurPSmith (talk) 13:41, 1 July 2019 (UTC)[reply]
Thank you, ArthurPSmith. Much appreciated. Do we have a way of further setting the constraint to one of the 4 options? Or is that currently not possible? Rehman 14:13, 1 July 2019 (UTC)[reply]
Sorry, I don't know of a way to do that, but it is probably possible with complex constraints (which I have not really used myself). ArthurPSmith (talk) 14:41, 1 July 2019 (UTC)[reply]
No worries, ArthurPSmith. Thank you for all the help. I will casually look around for a solution; maybe ask at project chat or something. Cheers, Rehman 14:54, 1 July 2019 (UTC)[reply]
Thank you, ArthurPSmith. Continuing discussion above. Rehman 02:10, 21 June 2019 (UTC)[reply]