Measurement and Verification of the Lighting Retrofit at by gyvwpsjkko


									Industrial and Commercial Use of Energy Conference 2004

Measurement and Verification of the Lighting Retrofit at the NER building
                                       Mr. GJ Martins and Prof. LJ Grobler
                                  North-West University, Potchefstroom, South Africa


The NER building in Pretoria retrofitted it’s lighting            Southern wing, separated by the lift lobby area.
system by replacing it with a more efficient lighting
system. This project forms part of Eskom’s DSM                    2.1.1. Original Lighting System
programme. The aim of the retrofit was to reduce the              The original lighting system contained Cat Eye (50W per
energy consumption, maximum demand and energy                     fitting) lamps, 3-Tube Fluorescent fittings (36W per tube)
cost of the building without compromising the lighting            and CFL (13W per lamp) lamps. The fluorescent fittings
quality and levels. Wherever possible the aim was                 were driven by electro-magnetic control gear. The
rather to improve on these levels.                                basement floors contained only 2-Tube fluorescent
                                                                  fittings (65W per tube) driven by electro-magnetic control
The aim of the measurement and verification process               gear.
was to determine the actual impact of the lighting
retrofit looking at the energy use, demand and cost as            The original installed capacity for the NER building was
well as the level of services provided by the new system.         64.9kW.

This paper presents the procedures and methodologies
followed to measure and verify the DSM impact of the
NER project. It will focus primarily on the methods
used to establish the baseline and the type of
measurements that were needed. It will also explain
how the savings were determined and finally give the
results that the project actually achieved.


The objective of the project was to measure and verify the
energy consumption, demand, and energy cost savings, as
well as emission impacts, due to the office lighting retrofit
at the National Electricity Regulator (NER) building. The         Figure 1: Typical office space of the NER building before
impacts needed to be determined to verify the cost                retrofit.
savings for the client and the ESCO, as well as the DSM-
impacts obtained for Eskom. This paper presents a                 2.1.2. Proposed Lighting System
description of the measurement and verification process
followed at the NER building.                                     The original lighting system was to be replaced with more
                                                                  efficient lights. According to NER personnel the Cat Eye
                                                                  (50W) fittings and the 2-Tube CFL (13W per CFL)
2.     NER BUILDING PROFILE                                       fittings were to be replaced by 300mm x 300mm fittings
                                                                  containing two CFLs each (11W per CFL). The-3 Tube
2.1.   BUILDING DESCRIPTION                                       fluorescent fittings (36W per tube) with electromagnetic
                                                                  control gear were to be replaced by 2-Tube fluorescent
The building houses the administrative offices for the
                                                                  fittings (36W per tube) with electronic control gear.
NER and is situated in Arcadia a suburb of Pretoria. The
NER offices consist of five floors consisting of office and
                                                                  The Basement 2-Tube fluorescent (65W per tube) fittings
administrative space. The building also has two basement
                                                                  were to be replaced by 1-Tube fluorescent fittings (36W
floors used for parking. The offices are located from the
                                                                  per tube) with electronic control gear.
4th floor upwards to the 8th floor. The 4th, 5th and 6th floors
are identical and have identical lighting systems and
                                                                  2.1.3. Actual New Lighting System
quantities [1]. The 7th and 8th floors are different from the
rest. The 7th floor mainly consists of offices. The 8th floor
                                                                  The new lighting system, decided upon by the ESCO and
contains conference rooms and various meeting rooms as
                                                                  the NER, for the offices consists of 2-Tube fluorescent
well as offices.
                                                                  fittings (2x36W tubes) with electronic control gear and
Each floor is divided into two wings, a Northern and              300mm x 300mm fittings that contain two PLS-11 lamps
Industrial and Commercial Use of Energy Conference 2004

(2x11W lamps per fitting) [2].                                 the NER the building operating hours are from 07:00 in
                                                               the morning till 18:00 in the evening. This however had to
It was found that the 300mm x 300mm fittings contain           be verified using permanent meters. These meters will log
electromagnetic control gear. These control gears              the operating hours as well as the lighting loads after
consume an extra calculated 23W per lamp (Total                implementation of the retrofit has been completed.
consumption indicated on control gear are 0.155A
                                                               For the purposes of this project the various floors of the
including lamp).
                                                               NER building was divided into 4 groups according to
                                                               their layout [3]:
Floor 8 still contains 22 cat eye lamps (1x50W), these are
mainly situated in the reception area and were kept for                 Group 1 – The 2 basement floors
aesthetic reasons. There are also a few fittings containing
2-CFL lamps (13W per CFL). These are located in the lift                Group 2 – Floors 4, 5 and 6
lobbies and the balconies. All the hallway lights on each
floor only contain 300mm x 300mm PLS-11 fittings.                       Group 3 – Floor 7

                                                                        Group 4 – Floor 8
                                                               The groups consist of a number of identical zones (floors)
                                                               each with one distribution board (DB) supplying two
                                                               Each group has certain operating hours and a certain
                                                               demand. It was assumed that the operational hours before
                                                               and after implementation would be the same since no
                                                               changes were made to the control system.

                                                               The lights of the Northern and Southern zone of each
                                                               floor are controlled through switches that switch all the
                                                               lights off when disengaged (except the hallway lights and
Figure 2: Typical office space and hallway of the NER          the basement lights which stay on 24 hours a day). The
building after retrofit.                                       lighting control is relayed to security. Therefore only a
                                                               section of a floor can be lit after hours if need be and not
Figure 2 shows the typical layout of the lighting in the       the entire floor. This control ensures that the lights are
NER building. On the left of the picture are the two tube      switched off after hours. This had to be verified by
36W fluorescent fittings and on the right of the picture are   permanent meters. The hallway lights and the basement
the 300mm x 300mm PLS-11 fittings in the hallway.              lights operate 24 hours a day. There are a total of 30
                                                               measurement points in the building for this project
The original installed capacity for the NER was 64.9kW         (located at 7 DB boards).
before project implementation. The proposed system’s
installed capacity was 27.6kW. The actual installed
capacity after the project implementation was 38.7kW.
This means that the installed capacity was reduced by
26.2kW from the original installed capacity.

To determine the baseline (what the energy use would
have been) for this project it was necessary to quantify the

         The actual lighting         load   (kW)     before

         The actual operational hours of all the lights        Figure 3: DB Board showing switches for the two zones
         before implementation

The same parameters also had to be quantified after            On the bottom left corner of Figure 3 the two contactors
implementation to determine the impact of the retrofit.        for the Northern and Southern wings can be seen. These
The operating hours of the building before and after DSM       control the lighting for the offices for the Northern and
was assumed to be the same. According to personnel at          Southern side and can individually be switched on or off
                                                               by security as the lights are needed.
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To obtain the load profile of the lighting system it was            monthly basis.
necessary to determine the lighting load of all the
different groups. To construct the baselines notch tests
were performed in conjunction with the installation of
data loggers on 15 lighting circuits on the various floors          5.         ENERGY SAVINGS ACHIEVED
covering all the different groups. The following metering
                                                                    Permanent loggers were installed on all the floors except
equipment was used:
                                                                    the basement floors to be able to measure the actual load
             One (1) handheld multi-meter                           after implementation. Two loggers were installed per floor
                                                                    in order to measure the two zones separately. Only a notch
             Five (5) three channel data loggers and fifteen        test was performed on the basement floors to obtain the
             (15), 50Amp CT’s                                       new load of the basements as the basement lights operate
                                                                    constantly at 24 hours a day. The load was recorded in ten
Floor 1, 2 and 3 are not part of the NER offices and was
                                                                    minute intervals for the first two months and then
therefore left out of the calculations and measurements.
                                                                    converted to 30 minute intervals.
Table 1 below shows some of the information obtained
                                                                    The measured data was retrieved from the meters on a
from the light count. This data was used to verify the
                                                                    monthly basis. It was processed and compared to the
measured baseline.
                                                                    constructed baseline data to obtain the monthly savings
                                                                    achieved. Table 3 below shows the calculated savings
Table 1: Light Count Data
Type of Lights                Total     Watt/Fitting    Installed
                                                                    obtained for November 2003 as a result of the retrofit.
                              Amount    [W]             Capacity
                                                        [kW]        Table 3: Savings for November 2003
2-tube fitting lamps            90            156         14.04                E/Cons    Cost                     Emissions (kg)
                                                                                MWh      Rand      CO 2      NO X     SO X     Particles    Water
(T12,5ft,magnetic ballast)
                                                                    Baseline       37.0 R 7,356   32,991.6    131.3     279.6        10.7      44.8
Cat eye lamps                  368             50          18.4     Actual         18.4 R 3,610   16,385.5     65.2     138.9         5.3      22.2
2-tube fitting CFL lamps       110             26         2.87      Savings        18.6 R 3,746   16,606.1     66.1     140.7         5.4      22.5
3-tube fitting lamps           193            153         29.53
(T8,4ft,magnetic ballast)                                           From the table it can be seen that the savings obtained for
Total                                                     64.84
                                                                    November is 18.6MWh and R3,746. The emission impacts
                                                                    related to the savings are also shown in Table 2.
The total installed capacity for all the floors of the NER
building was calculated as 64.84 kW from the light count            The impact of the project on the different Eskom Time Of
data and the total baseline power demand was measured               Use (TOU) profiles was also calculated and is shown in
as 64.89 kW. Table 2 below shows the obtained                       Table 4.
measurements of each group for the whole building. The
kW values were obtained by multiplying the amps with                Table 4: Impacts in different TOU
the power factor and the measured volts. The power                                        Weekday (MW)                Saturday (MW)    Sunday
factors were taken as average power factors for the                            Morning
                                                                                Peak    Standard
                                                                                                   Peak    Off-Peak Standard Off-Peak Off-Peak
combined lights of each group.                                      Baseline      0.064     0.063    0.061     0.031    0.061    0.045    0.050
                                                                    Actual        0.031     0.030    0.030     0.018    0.029    0.023    0.024
                                                                    Savings       0.033     0.033    0.031     0.013    0.032    0.022    0.026

Table 2: Baseline measurements
                                                                    As can be seen above the average weekday impact in the
 Group           Total Amps            PF      kW                   morning peak period for November was 0.033MW with a
      1               70.02            0.9      13.96               standard impact of 0.033MW and an evening peak impact
                                                                    of 0.031MW [4]. As can be seen from the above table the
      2               135.3            0.9      27.03
                                                                    impacts also occurred on Saturdays and Sundays as the
      3                44.1            0.91     8.82                building lights are also operated on these days. From the
      4                76.1            0.9      15.06               permanent meters it was also observed that the operating
     Total                                      64.89               hours of the building were not from 07:00 – 18:00 but
                                                                    ranged from 06:00 to 23:00.

4.      DATA AQUISITION                                             Monthly savings could be calculated for August through to
                                                                    December as the project implementation was finished by
Ten permanent data loggers were installed (two per floor)
                                                                    the end of June 2003. The permanent meters were
on the lighting system in the NER building. These were
                                                                    commissioned in early August. The monthly savings data
installed to obtain measurements at 30 minute intervals.
                                                                    was extrapolated to obtain an annual saving of R43,109 for
The loggers were connected to a cell phone modem.
                                                                    the project. The predicted saving before retrofit of this
                                                                    project, based on operating hours from 07:00 till 18:00 for
The logged data was retrieved from the different meters
                                                                    weekdays only, was R34,502. The R43,109 saving can be
by dialling the modem, connecting to one specific meter
                                                                    attributed to the longer operating hours. The extrapolated
at a time and downloading the data to a personal computer
                                                                    savings data is represented in the table below.
(PC). This was done for each meter individually on a
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Table 5: Annual extrapolated savings                                                 as a Certified Energy Manager (CEM) as well as a
                      Rand        CO 2      NO X
                                                 Emissions (kg)
                                                     SO X     Particles    Water
                                                                                     Certified Measurement and Verification Professional
Baseline       432.6 R 86,817   385,869.3   1,535.7  3,270.4      125.5      523.4   (CMVP).
Actual         218.9 R 43,708   195,214.3     776.9  1,654.5        63.5     264.8
Savings        213.7 R 43,109   190,655.0     758.8  1,615.9        62.0     258.6
The extrapolated annual average TOU impacts are                                      The paper is presented by GJ Martins.
provided in Table 6.

Table 6: Average extrapolated TOU impacts
                       Weekday (MW)                Saturday (MW)    Sunday
            Morning            Evening
             Peak    Standard   Peak    Off-Peak Standard Off-Peak Off-Peak
Baseline       0.064     0.062    0.060     0.029    0.053    0.043    0.045
Actual         0.031     0.031    0.030     0.017    0.026    0.022    0.022
Savings        0.033     0.031    0.030     0.012    0.027    0.021    0.023

6.         CONCLUSION
This paper describes the measurement and verification
process of the lighting retrofit at the NER building. The
installed capacity of the building was reduced from 64.9kW
to 38.7kW which resulted in a annual saving of R43,109
and a annual energy reduction of 213.7MWh.

[1]        Grobler LJ, Martins GJ, Measurement and
           Verification Plan: National Electricity Regulator

[2]        Grobler LJ, Martins GJ, Post Implementation
           Report: National Electricity Regulator

[3]        Grobler LJ, Martins GJ, Baseline Report: National
           Electricity Regulator.

[4]        Grobler LJ, Martins GJ, Savings Report: National
           Electricity Regulator.

8.         AUTHORS
Principal Author: Cobus Martins
holds a B Eng degree in Mechanical
Engineering from the North-West
University, Potchefstroom, South
Africa. He is currently busy with his
M Eng.

Co-Author: Prof LJ Grobler is an associate professor at
the School for Mechanical and Materials Engineering,
North-West             University,
Potchefstroom, South Africa. He
specialises in energy management
and process energy optimisation.
He is certified by the Association
of Energy Engineers in the USA

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