Voltage Optimisation | Bauhaus Apartments

Bauhaus Apartments
  • 131 residential lots
  • 4 commercial lots
  • 10 residential levels
  • 5 levels of basement car parking
  • gymnasium
  • roof entertainment area
  • outdoor garden

Having implemented sub-metering to get a handle on their buildings energy usage, Bauhous Apartments installed 5 energy controllers. Continued metering proved the reduction in energy usage achieved and the dollars saved.

The first measurements taken in Bauhaus’ sub-metering project assessed the impact of Voltage Optimisers that were installed in February 2007.   These were installed on the recommendation of the then building manager and have been in operation to date.

Analysis of the resultant data revealed the Voltage Optimisers reduced energy consumption of fluorescent lighting by an average of 35%, and that Bauhaus was saving $2,400 dollars annually on electricity.

The equipment had cost only $3,900 initially.  If installed today the payback period would be 19.2 months at current energy prices.


3 x 16 amp Clipsal energy controllers

2 x 20 amp Clipsal energy controllers


  • A little larger than a 2 litre milk container
  • No moving parts
  • Requires no maintenance
  • Life expectance is 25-30 years

Total Cost: $3,900 (in 2007)

Sub-metering Data Analysis

3 circuits were measured for 3 weeks.  The measurements taken over the first 3-week cycle included the Voltage Optimisers connected to the garage lighting circuits.  For the duration of the second 3-week cycle, the Voltage Optimisers were disconnected. 

The measurements commenced at midnight Sunday morning and concluded 3 weeks later at midnight.  1,920 data points were recorded for each circuit.


Graph of  energy consumption for Voltage Optimisers

Data Analysis using HOBOware software

Power Factor

The Voltage Optimisers were disconnected on September 27 in anticipation of commencing measurements at midnight on September 29.  The Voltage Optimsers where reconnected on October 25 in anticipation of commencing the third 3-week cycle.  There is an obvious change in the Power Factor during this time.


Graph of Power Factor for September 2013

Power Factor September 2013



Graph of Power Factor for October 2013

Power Factor October 2013



The following table shows the decrease in consumption for the period measured and further extrapolates it to 12 months.


Total savings over the life of the equipment were then calculated and summarised:



Last Updated: 
Mon 25/01/2016

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