Power Factor Correction

Whitby Hydro Energy Services Corp.  Power Factor Correction at the Residential Level – Pilot Project

 Report to the LDC Tomorrow Fund  

September 12, 2005

 Executive Summary

 In December of 2004 Whitby Hydro applied for funding from the EDA Tomorrow Fund to carry

out a pilot project to determine the impact of installing capacitors at residential homes on system

capacitance and generation requirements.  

The study involved 31 homes within Whitby Hydro’s distribution territory. The houses selected

were located in a new residential neighborhood and were consistent in size, age and type of

heating.  

For the pilot, a bench mark had to be established for the loading of each transformer. The three

transformers where metered for a two month period prior to the installation of the capacitors.

The information gathered  included KW, KVAR, volts and amps. Once the benchmark was

established homes fed from two of the transformers where equipped with capacitors providing

3.34 KVAR into their distribution panel. Readings at the transformer continued for an

additional two month period after the units were installed in the homes. In addition two homes

where equipped with metering devices that allowed the measurement of power factor.

 The information gathered allowed analysis to be carried out to determine if the additional

capacitance improved power factor at the home as well as at the transformer.

 

Power Factor at the transformer was the first value to be analyzed. KW and KVAR was

measured at 15 minute intervals for the pilot period (Appendix G). This information was used to

determine monthly power factors and other related billing determinants at the transformer.

 

The peak Power Factor each month was as follows:

                                March                   April                       May                       June                      July

       (PF)                      (PF)                       (PF)                        (PF)                        (PF)

TX5545          (BM) 96.6                       96.1                       95.1                        92.7                      93.0

X5554                    98.4                       98.8                        99.9                        99.1                      99.9

TX5547                  97.9                       98.5                        98.3                        97.1                      95.7

 

(Note: BM is the bench mark transformer of which capacitance was not added)

 

During the study it was quickly realized that although the study group was selected for its

consistency, variances in ON and OFF-peak Power Factor clearly indicated that there was little

or no consistency on how or when motor loads were used. Even though an attempt was made to

pick homes with similar characteristics there was enough variance in how and when motor loads

where used to cause inconsistency between the transformers. This made it difficult to determine

the full effect that the added capacitance had on Power Factor at the transformer. However,

based on the fact that KW and KVAR were being measured it was easy to see the impact the

added capacitance had on KVAR at the transformer. Also because KVAR is a factor when

determining generation requirements, this unit of measurement would allowed us to determine

the impact on provincial generation.

The improvements in KVAR was as follows:

                                 March                  April                       May                      June                     July

                            (KVAR)                 (KVAR)                 (KVAR)                     (KVAR)                 (KVAR)

 

TX5545        (BM) 4.2041                    3.3670                   3.0253                   7.1944                   7.5343

TX5554                 2.3756                   2.3999                   -.9916                   -4.3036                 -4.0268

TX5547                  3.1778                  2.6754                    .9480                    3.0449                   2.9364

 

To further verify the impact of the capacitance on power factor two homes where measured. .

These homes where fitted with capacitors that would turn on and off on twenty four hour cycles

to show day to day comparison on power factor. Typically, the average power factor when the

units where off was 87%. When the units were turned on the power factor was over 99%.

 To get a real understanding of positive impact power factor correction has on generation costs

benefit analysis was carried out to see if such a project would make sense on mass. Four

assumptions where used in this analysis:

 1. a typical home has a 5kW demand

2. the cost of new generation is about $1,000,000 an MVA

3. a typical homes power factor is improved from 87% to 99% when 3.34 KVAR of

capacitance is added

4. the cost of the Power Correction units is $450,000 installed

 With an example of 1000 homes each using the above information, the generation requirement

would be 5.75MVA (5kW/.87PF x 1000). By installing capacitance at the residential level the

requirement of the generator for the 1000 homes would now only be 5.05MVA (5kW/.99PF X

1000) or 700 KVA less.

 Therefore the cost to generate 700 KVA would be $700,000 (.700MVA X $1,000,000). The cost

to supply and install capacitance at the residential level to free up the same amount of

capacitance would be $450,000. The environment and health costs associated with the

generation of electricity are also removed making the economics even stronger.

 The pilot project showed that the installation of capacitors at the residential level is a viable option in freeing up capacitance within the province is deployed on mass. The savings can also be achieved without having the customer drastically changing their lifestyle.

Whitby Hydro Energy Services Corp. 
 
 
 
 
 
 
 
 
Power Factor Correction at the 
Residential Level – Pilot Project 
 
Report to the LDC Tomorrow Fund 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
September 12, 2005 
  
Executive Summary 
 
In December of 2004 Whitby Hydro applied for funding from the EDA Tomorrow Fund to carry 
out a pilot project to determine the impact of installing capacitors at residential homes on system 
capacitance and generation requirements. 
 
The study involved 31 homes within Whitby Hydro’s distribution territory. The houses selected 
were located in a new residential neighbourhood and were consistent in size, age and type of 
heating. 
 
For the pilot, a bench mark had to be established for the loading of each transformer. The three 
transformers where metered for a two month period prior to the installation of the capacitors. 
The information gathered included KW, KVAR, volts and amps. Once the benchmark was 
established homes fed from two of the transformers where equipped with capacitors providing 
3.34 KVAR into there distribution panel. Readings at the transformer continued for an 
additional two month period after the units were installed in the homes. In addition two homes 
where equipped with metering devices that allowed the measurement of power factor. 
 
The information gathered allowed analysis to be carried out to determine if the additional 
capacitance improved power factor at the home as well as at the transformer. 
 
Power Factor at the transformer was the first value to be analysed. KW and KVAR was 
measured at 15 minute intervals for the pilot period (Appendix G). This information was used to 
determine monthly power factors and other related billing determinants at the transformer. 
 
The peak Power Factor each month was as follows: 
 
 March April May June July 
 (PF) (PF) (PF) (PF) (PF) 
 
TX5545 (BM) 96.6 96.1 95.1 92.7 93.0 
TX5554 98.4 98.8 99.9 99.1 99.9 
TX5547 97.9 98.5 98.3 97.1 95.7 
 
(Note: BM is the bench mark transformer of which capacitance was not added) 
 
During the study it was quickly realized that although the study group was selected for its 
consistency, variances in ON and OFF-peak Power Factor clearly indicated that there was little 
or no consistency on how or when motor loads were used. Even though an attempt was made to 
pick homes with similar characteristics there was enough variance in how and when motor loads 
where used to cause inconsistency between the transformers. This made it difficult to determine 
the full effect that the added capacitance had on Power Factor at the transformer. However, 
based on the fact that KW and KVAR were being measured it was easy to see the impact the 
added capacitance had on KVAR at the transformer. Also because KVAR is a factor when 
determining generation requirements, this unit of measurement would allowed us to determine 
the impact on provincial generation. 
The improvements in KVAR was as follows: 
  March April May June July 
 (KVAR) (KVAR) (KVAR) (KVAR) (KVAR) 
 
TX5545(BM) 4.2041 3.3670 3.0253 7.1944 7.5343 
TX5554 2.3756 2.3999 -.9916 -4.3036 -4.0268 
TX5547 3.1778 2.6754 .9480 3.0449 2.9364 
 
 
To further verify the impact of the capacitance on power factor two homes where measured. . 
These homes where fitted with capacitors that would turn on and off on twenty four hour cycles 
to show day to day comparison on power factor. Typically, the average power factor when the 
units where off was 87%. When the units were turned on the power factor was over 99%. 
 
To get a real understanding of positive impact power factor correction has on generation costs 
benefit analysis was carried out to see if such a project would make sense on mass. Four 
assumptions where used in this analysis: 
 
1. a typical home has a 5kW demand 
2. the cost of new generation is about $1,000,000 an MVA 
3. a typical homes power factor is improved from 87% to 99% when 3.34 KVAR of 
capacitance is add 
4. the cost of the Power Medix units is $450,000 installed 
 
With an example of 1000 homes each using the above information, the generation requirement 
would be 5.75MVA (5kW/.87PF x 1000). By installing capacitance at the residential level the 
requirement of the generator for the 1000 homes would now only be 5.05MVA (5kW/.99PF X 
1000) or 700 KVA less. 
 
Therefore the cost to generate 700 KVA would be $700,000 (.700MVA X $1,000,000). The cost 
to supply and install capacitance at the residential level to free up the same amount of 
capacitance would be $450,000. The environment and health costs associated with the 
generation of electricity are also removed making the economics even stronger. 
 
The pilot project showed that the installation of capacitors at the residential level is a viable 
option in freeing up capacitance within the province is deployed on mass. The savings can also 
be achieved without having the customer drastically changing their lifestyle.

 

http://www.nativeworkplace.com/files/Residential_Power_Factor_Correction_Project_2005.pdf