reconjohn
commented
5 years ago It seems not every minute for the average 15 minutes but 15 minute period in order, not overlapping. If the billing cycle is a month, we just need to know just one max point for the demand charge. In this regard, why do we bother with the minute resolution? We already have the kWh data. I guess we don't need to plot power (kW) but plot energy (kWh) in hour, day, month, or year resolution rather than minute resolution.
Our demand meters measure a demand for every 15 minute period in each month. The meters record the highest 15 minute demand for the month and retain this figure until the meter is reset by our meter reading equipment. Each meter makes over 2,800 readings per month. Remember, we base your bill on the highest 15 minute reading; therefore, whether it occurs only once in the month or 2,800 times, we charge the same billing demand.
aidowu
chintanp
For a month, there are different trends between 1 min and 5 min resolutions
Below is the only maximum trend.
Average and minimum trend with 1 min and 5 mins resolutions
If we calculate the area under the curve, 5 min resolution trend shows larger variance, thus the area like - 5% to + 8% difference as below.
The area under the curve for the 15 mins interval, decides the peak demand during the billing cycle and thus the energy cost. Using inappropriate resolution will end up with the wrong demand charge. This will affect the smoothing method which plot reflects the best fit of 15 min average kW load.