Convert Watts to Watt-hours - Marianne

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Discussion Overview

The discussion revolves around converting electricity consumption data from Watts to Watt-hours, particularly in the context of a household survey in Kenya. Participants explore the implications of the data collection method and the accuracy of the reported figures.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that if the Watts figures represent an average over a month, then Watt-hours can be calculated by multiplying Watts by the number of hours in a month.
  • Another participant proposes that if the data consists of periodic recordings of instantaneous wattage, then each reading should be multiplied by the time interval between recordings, and the results summed to obtain total monthly consumption.
  • Marianne mentions that the survey question asks for total watts used over the last month, but multiplying this by 24*365 yields a figure that exceeds the national electricity company's sales statistics.
  • One participant expresses skepticism about the survey's clarity, suggesting that respondents might report total wattage of appliances rather than actual usage, which varies over time.
  • Another participant argues that the survey question may be fundamentally flawed due to mismatched units, indicating potential issues with translation or methodology, and suggests verifying the data's nature by multiplying by 12.

Areas of Agreement / Disagreement

Participants express differing views on the clarity and validity of the survey question, with some believing it is vague or incorrect, while others focus on the method of conversion from Watts to Watt-hours. No consensus is reached on the best approach to interpret the data.

Contextual Notes

There are unresolved issues regarding the assumptions made about the data collection method and the accuracy of the reported figures. The discussion highlights potential discrepancies in how respondents might interpret the survey question.

maaariiianne
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I have a survey with data on electricity consumption per month in Watts. How can I convert the numbers into Watt-hours to compare it with another survey?
Thank you very much for your help.

Marianne
 
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Assuming the watts figures are the average number of watts over an entire month, then the number of watt-hours is the number of watts times the number of hours (in a month).
 
Hmm...I'm guessing the data is periodic recordings of the instantaneous wattage. If that's the case, then each must be multiplied by the time between recordings and then they must be added together (or vice versa) to get the total consumption for the month. For example, if the data looks like this:

12:00 10W
12:15 15W
12:30 12W
12:45 11W

Then the total consumption is (10+15+12+11)*.25hr = 12 W-hr.

This can easily be done with a spreadsheet.
 
Thank you for your answers.
I am actually using a household survey of Kenya. The question is:
During the last month how many watts of electricity did you use?
How can I use this number? If I multiply it by 24*365, the total result over the sum of all households is higher than the number in the sales statistics of the national electricity company.
 
That question is probably too vague to give useful results, unless the respondents were given more detailed instructions. I suspect most people would give the total wattage of all their appliances. But many appliances are used only intermittently for short periods of time. Exceptions would be things like refrigerators which run continuously. Even light bulbs are not usually turned on 24 hours a day. Some people might try to correct for this, but you can't count on them all doing it similarly.
 
If that's the question, it isn't vague, it's wrong. The units don't match the question. So either the question has been translated incorrectly or the survey was done wrong in the first place. If you ask 100 people that question, I suspect 90 of them will just read you the W-h number on their electric bill, but that just means that some people gave you one kind of data and some gave you another.

I'd try to see if you can get the question and the methodology clarified.
You may also be able to tell from the data itself if it is really in watts or watt-hours. What happens if you multiply the number by 12...?
 

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