Case Studies
Comparison of Energy Consumption- Period of study is Feb-March 2011 & 2012
A 260kVA PropSava SCRV voltage optimiser was installed and commissioned by Mojarra at a mixed retail and commercial office building at 138 Queen Street Campbelltown on 1 February 2012 for Southern Ocean Investments Pty Ltd. The predicted energy saving and maximum demand saving by reducing supply voltage to 220V was 11%. Achieved energy saving was 14.6% after allowing for temperature differences in the pre and post installation periods.
Reduction in kWh Energy Consumption
As can be seen from the table and graphs below the site has experienced a significant reduction in kWh energy consumption (26%) and kVA maximum demand (20%) since the PropSava SCRV was installed.
| kWh/Month | 2011 | 2012 | % change | |
| Feb | 42,999 | 35,818 | 17% | PropSava Commissioned 1 Feb 2012 |
| Mar | 45,409 | 29,543 | 35% | A change in metering occurred on 17 March |
| Average | 44,204 | 32,681 | 26% |
| kVA Max Demand | 2011 | 2012 | % change | |
| Feb | 174 | 129 | 26% | PropSava Commissioned 1 Feb 2012 |
| Mar | 168 | 134 | 20% |
Temperature Analyse
To ensure that energy saving claims are reasonable we have taken into account the differing weather conditions from 2011 to 2012 as measured by average daily temperature in our analysis below.
This analysis can be summarised in the table below where we have taken an average from days in February and March 2011 with the same temperature as days in the study period for 2012.
As can be seen there is a 14.6% saving after correcting the data for daily average temperature.
| kWh/day | 2011 | 2012 | Saving |
| Average weekdays | 7,974 | 7,082 | 11.2% |
| Average weekend day | 2,006 | 1,442 | 28.1% |
| 7 day week | 9,980 | 8,524 | 14.6% |
Decision
We have analysed energy consumption against average daily temperature from February to March 16 to ensure the integrity of the energy savings calculations.
Graph below: Average Weekday reduction in energy consumption due to Voltage Optimisation adjusting for difference in temperature is 11.2%.
Graph below: Average Weekend reduction in energy consumption due to Voltage Optimisation adjusting for difference in temperature is 28.1%.
- Conclusion
As can be seen by the above analysis the site is experiencing a saving of 14.6% in energy consumption as compared to the same period and temperatures the previous year.
The site is also experiencing at least a 20% reduction in maximum demand. Both actual savings are in excess of the 11% saving prediction.