Real power or apparent power measurement?
The research question:
What is the difference between real power and apparent power in a domestic property. (Trystan's house)
The experiment has been running for 8 days, here are the results so far:
| Day | Real | Apparent | % of app |
| 1 | 21.0 | 21.9 | 96% |
| 2 | 10.5 | 11.1 | 95% |
| 3 | 11.3 | 11.9 | 95% |
| 4 | 13.7 | 14.7 | 93% |
| 5 | 14.9 | 16.1 | 93% |
| 6 | 21.1 | 22.0 | 96% |
| 7 | 15.3 | 16.6 | 92% |
| 8 | 20.6 | 21.8 | 94% |
Average real power % of apparent power so far: 94.27%. Max difference is 8%
What if we then take 0.9427 as a correction factor and multiply the apparent reading by 0.9427?
The resultant approximation of real kWh per day is within 3% : (min 98.05% max 102.27%)
Domestic property 2: Glyn's house
| Day | Real | Apparent | |
| 1 | 8.1 | 10.6 | 76% |
| 2 | 8.8 | 11.4 | 77% |
| 3 | 9.9 | 12.4 | 80% |
| 4 | 10.4 | 13 | 80% |
Real power derived kWh/d is on average 78% of apparent power derived kWh/d
Conclusions so far
Significantly different averages between test houses? Daily variation in a particular house is fairly stable.. More data required
We will continue to run this for as long as the monitoring systems are installed and keep updating this. To make this comparison really useful we will need much larger data sets and it would be great to get data from several houses as there will be differences depending on the mix of loads in different houses. If you want to take part please do! lets do some collaborative research.