why geyser blankets - Eskom

M&V Guideline for
Geyser Insulation
Distribution
Jacques Wheeler
Ernst Uken
M&V Workshop – March 2010

OVERVIEW
• Historical Motivation - DSM
• Geyser Blanket issues, Results
& Procedures – CPUT & DSM
• M&V Standardised Tool for
Geyser & Pipe Insulation - NWU

WHY GEYSER BLANKETS ?
ESKOM has to save 10% - 20% electricity
immediately for the next 5 -10 years
Govt aims to install 1m solar geysers over
3 years to save 600 MW, but industry does
not manufacture that many SWHs
Hence, Eskom sponsored 200 000 Geyser
Blankets to the Western Cape during 2006
power outages to reduce standing losses.
During M&V audits, CPUT M&V team also
advised householders to have temps
set at 550C

GEYSER INSULATION TEST AT CPUT

COMMENTS
Smaller impact on standing losses in
warmer climates & lower set points
Geysers scattered over a large area,
making the metering expensive
Therefore NWU M&V Team
standardised methodology to measure
impact of installing geyser and pipe
insulation

INSTALLED GEYSER BLANKET

DSM AUDIT PROCEDURE
If insulation not fastened properly - Reject
If geyser not in a working condition - Reject
If insulation not loosely fitted and material is
compressed to less than 60% of contracted
thickness - Reject
If gaps in insulation are found on top of the
Geyser - Reject
If >15% of geyser is not covered - Reject
If sides of geyser are not completely covered
- Reject

DSM AUDIT PROCEDURE (cont)
If geyser is not properly covered
at inlet and outlet ends - Reject
If pipes are not insulated for at least
3 meters or up to a wall entrance - Reject
If dampness due to geyser leakage
is found - Reject
If materials used differ (provide less
insulation) from contracted material - Reject

CPUT GEYSER BLANKET AUDIT
PROCEDURE FOR GEYSERS & PIPES
Measure water temp from tap nearest
geyser, after running water for 1 min
Is blanket material SABS approved ?
Inspect blanket installation for :
Coverage (

M&V RESULTS OF FIRST 200 000
GEYSER BLANKET INSTALLATIONS
51.9% Outlet pipes had

NWU ‘APPLICATION
APPLICATION’ TOOL
METHODOLOGY FOR GUIDELINE
Based on ‘Before Before’
and ‘After After’ testing
on a sample of 9
identical and
adjustable geysers
(100 litre/2 kW) in
apartment complex
in Potchefstroom

Baseline criteria :
Geyser temp set point
Ambient temp
Water usage
Size of geyser
Methodology (cont.)
Geyser Blanket characteristics

Metering:
Electricity Electricity consumption
Hot Hot water temperature
Temperature
measurement
Methodology (cont.)
Electrical
energy
measurement

ENERGY USE (Uninsulated and Insulated)
vs OUTSIDE TEMP

METHODOLOGY : GEYSER & PIPE
INSULATION DISTRIBUTION PROJECTS
Geyser (size and type)
Temperature (geyser set-point set point and
ambient)
Number of geysers
Location of geysers (inside, outside or in
ceiling void)
Insulation (type and percentage coverage)
Decay rate

Methodology (cont)
Characterisation and metering procedure
Geyser set point (Ts)
Ambient temperature (Ta)
Power consumption (kWh)
Measurements on geyser:
Without geyser blanket
With geyser blanket
With GB and 3m pipe insulation

FORMS
Metering procedure With blanket : (repeat for
& characterisation each type of insulator)

Geyser Insulation M&V Application
Tool
Inputs into the statistical model :
Number of geysers
Set point
Size of geyser
Type/make of geyser
Location of geyser
Ambient temperature

Geyser Insulation M&V Tool
Inputs into the statistical model (cont.):
Type of insulation
% coverage of geyser with blanket
% coverage of pipe with insulation
Decay rate

Geyser Insulation M&V Tool
M-values, values, characteristic to a certain geyser size,
geyser type and insulation type:
M1 – without GB
M2 – with GB
M3 – with GB and pipe insulation

Geyser Insulation M&V Tool
Output:
Baseline – hourly Watt values
Actual – hourly Watt values

Using Standardised Tool for Geyser
STEPS :
insulation distribution projects
1: Complete fieldworker forms
2: Enter fieldworker forms into application
3: Generate results using the tool
4: Conduct follow-up follow up visit (decay rate)
5: Enter follow-up follow up results into application
6: Generate results using the tool

Fieldworker form :
GEYSER INSULATION

Fieldworker form :
DECAY RATE of GEYSER INSULATION

TABLE :