GUIDANCE ON ENERGY AUDITS FOR INFM MEMBERS
GUIDANCE ON ENERGY AUDITS
1. Background
The purpose of an energy audit is to determine how energy is
used in an existing facility, and to quantify it. This helps to
identify opportunities to improve the effectiveness with which
energy is used. A typical strategy for energy management is given
in Annex 1.Energy audits can be done for all kinds of installations
such as industries, utilities, commercial or office facilities, and
homes. This guidance briefly introduces energy audits relevant to
office facilities, which is most relevant for INFM members. For
more detailed information, a list of relevant information sources
is given in Annex 2.2. Types of Energy Audit
ASHRAE classification
The American Society of Heating, Refrigerating and
Air-Conditioning Engineers
(ASHRAE) defines three levels of audits: Level I, Level II and
Level III. Each audit level builds on the previous level, with
increasing complexity and thoroughness, as well as increasing
potential to identify energy savings. Based on coverage Single
Purpose Energy Audit
This type of audit provides a detailed analysis on one or more
types of equipments or projects. Examples include those that focus
only on lighting or boiler/chiller replacements, or a combination
of these.
Comprehensive Audit
It covers the entire facility. It considers the interactive
effects of equipments and their energy systems3. Process and
Methodology
Typically, the process followed would be: Review of energy
data
The audit typically begins with a review of readily available
data on historical and current energy (electricity and fuel) usage,
for the whole facility and its components. This will include energy
bills and internal logs for a few years. This information could be
used to:
Benchmark the facilitys or equipments energy use Check
variations of energy use and relate to factors such as climate,
building occupancy, maintenance schedules etc
Prioritise the areas for further study
Energy load management opportunities. This includes looking
at:
Opportunities for avoiding or reducing energy demand Shifting
energy use from peak use periods to non-peak periods
Looking at opportunities for power factor improvement
Study the efficiency, effectiveness of:
Building envelope, including the walls, ceilings, floors,
windows Motors Energy end use systems, such as the HVAC or water
pumping system
Energy generation systems, such as the diesel generator or solar
photovoltaic system Building energy monitoring, control or
automation systems Energy or environment management systems. The
equivalent ISO standards are ISO 50001 and ISO 14001, respectively.
Options in energy generation, renewable energy, co-generation and
fuel substitution
4. Energy Audit Report
The key elements of the report could be:
General facility information Introduction of the energy system
and energy flows (eg, electrical and steam distribution diagrams)
Climate data
Summary of previous audits and retro-commissioning Energy data
and measurements Analysis of the energy system, energy flows and
energy performance of equipments/systems Energy saving measures,
including their cost benefit analysis Prioritization of the energy
saving measures5. Energy auditorEnergy auditing services are
offered by Energy Services Companies (ESCOs), energy consultants
and engineering firms. The auditor needs to have a wide range of
knowledge and skills and often this will not be available in
adequate measure in a single individual. Few key skills needed are
listed below:Conducting energy and mass balance
This is used to map the energy and mass flowing through the
facility and through all major equipments. The sum of the energy or
mass outflows should equal the energy or mass inflows. With this
information, it is often possible to see opportunities for energy
saving and recovery.Knowledge of energy management options in
electrical and thermal systemsEnergy management options are
specific to each kind of equipments and detailed knowledge is
needed. Knowledge of bio-climatic designBuilding design needs to be
optimized for the bio-climatic features of the site. There are
specific design priorities for each climatic zone. For example, for
a tropical climate the emphasis would be on improving the
ventilation, while in a cold climate the emphasis would be on
improving solar access. The site features also could also give many
clues and strategies for the design. Bio-climatic design involves
optimisation of shape and orientation, design of appropriate
building envelope (optimisation of wall, roof and floor insulation;
glazing etc), optimising access to daylight, landscaping. Economic
analysis, including Life Cycle CostingEnergy modeling and
simulation
This can range from simple to complex modeling exercises.
6. Studies that could complement an Energy Audit
Few other initiatives such as environmental management, carbon
management, maintenance management, water management and Green
Procurement, share some common methodologies/procedures with Energy
Management and have co-benefits. Hence it might be worthwhile to
check if partial or full audits/studies to cover those issues,
could be carried out along with an energy audit. This is briefly
touched upon in Annex 3 ANNEX 1ENERGY MANAGEMENT STRATEGY
The energy management strategy could vary from site to site. A
broad strategy is depicted in the figure below. Step 1: Energy
demand reduction or avoidanceThe first priority would be to reduce
or avoid demand for energy. For example, the possibility for
designing a building with optimum level of daylight, thereby
reducing use of electricity for lighting.
Step 2: Energy EfficiencyThe next step is to consider how to
improve energy efficiency in energy generation systems (eg, diesel
generators) and energy end use systems (eg, air conditioning
system).
Step 3: Energy production options and use of Renewable Energy
The first 2 steps will help to minimize the energy requirements of
the facility and identify all energy flows in the system. This will
be the right stage to decide on any further changes for the energy
supply and production options. This might include looking at
options for:
Increasing or decreasing the size of existing energy production
systems (eg, adding or removing a diesel generator set)
Use of renewable energy
Co-generation
Fuel substitution
ANNEX 2
LIST OF INFORMATION RESOURCESDOE. Energy Savings Assessment
Training Manual. US Department of
Energyhttp://www1.eere.energy.gov/femp/pdfs/esa_manual.pdfDOE,
2010. A Guide to Energy Audits. US Department of
Energyhttp://www.pnnl.gov/main/publications/external/technical_reports/pnnl-20956.pdfLBNL,
2010. Industrial Energy Audit Guidebook: Guidelines for Conducting
an Energy Audit in Industrial Facilities. Ernest Orlando
Lawrence
Berkeley National Laboratory
http://minotaur.lbl.gov/china.lbl.gov/sites/china.lbl.gov/files/LBNL-3991E.Industrial%20Energy%20Audit%20Guidebook_0.pdfNRC.
EnErgy SavingS Toolbox an Energy audit Manual and Tool. Natural
Resources Canada
http://oee.nrcan.gc.ca/sites/oee.nrcan.gc.ca/files/files/pdf/energy-audit-manual-and-tool.pdfANNEX
3STUDIES THAT COULD COMPLEMENT AN ENERGY AUDIT
Environmental management, carbon management, maintenance
management, water management and Green Procurement, share some
common methodologies/procedures with Energy Management and have
co-benefits. Hence it might be worthwhile to check if partial or
full audits/studies to cover those issues, could be carried out
along with an energy audit. Environmental auditMany energy
management actions also reduces environmental impacts and hence
common strategies are possible. For example, reducing fuel
consumption in a boiler reduces air pollution. An environmental
audit could also reveal opportunities for energy recovery (such as
energy generation from waste, or waste heat recovery from the
exhaust of a boiler) Carbon/GHG auditGreenhouse gas (GHG) emissions
from a UN type facility is mostly from energy consumption, apart
from release of refrigerants.
Maintenance auditBetter maintenance practices helps to reduce
energy consumption (eg, early detection and repair of steam or
water leaks). Equipments normally are energy inefficient during
start-ups and shut-downs. Many Predictive Maintenance techniques
help to prevent or delay breakdowns, and thus avoid energy wastage
during start-ups and shut-downs. Water balancingReducing water
consumption and wastage, helps to reduce the energy used for
pumping. Water Balancing studies maps the water input, waste water
discharge, and wastage of water within facilities, followed by
analysis on how to reduce the wastage or potential for recycling or
reuse of water.
Green ProcurementMany energy management recommendations would
involve procurement actions. Both Procurers and Requisitioners
should know how to effectively implement Green Procurement. An
evaluation of the Procurement function and activities, could help
to recommend the appropriate strategy for ensuring Green
Procurement
EFFICIENCY IN ENERGY PRODUCTION, DISTRIBUTION AND USAGE
ENERGY DEMAND AVOIDANCE OR REDUCTION
ENERGY GENERATION OPTIONS
USE OF RENEWABLE ENERGY
Also called as energy assessment, energy study, feasibility
study, technical assistance report
Many utilities charge a higher rate for energy used during peak
load period. It is possible to shift some of the energy consumption
activities to non-peak periods (eg, water pumping). Many utilities
also charges a steep penalty if the peak demand exceeds a certain
level. In such cases, it is important to shift non-critical loads
to non-peak periods.
HYPERLINK
"http://www.kwsaving.co.uk/Business/pfc/pfc-simple.htm"
http://www.kwsaving.co.uk/Business/pfc/pfc-simple.htm
HYPERLINK
"http://standby.iea-4e.org/files/otherfiles/0000/0059/PowerFactorBasics.pdf"
http://standby.iea-4e.org/files/otherfiles/0000/0059/PowerFactorBasics.pdf
As per needs, this will involve measurement of operational
parameters, performance trials of key equipments and their systems,
carrying out energy and mass balance. Loading of all major
equipments will also be measured or estimated. At low loads, most
systems operate at low efficiency. At the same time, overloading
will decrease their life. Hence, it is important to ensure an
optimum loading of equipments
Also called as Combined Heat and Power (CHP). It refers to the
sequential production of electricity and heat, in either order (eg,
a diesel generator produces electricity and the waste heat from the
exhaust is used to generate steam or hot water that could be used
in the facility)
Fuel substitution is normally done to move from a polluting or
less efficient fuel (eg, any solid fuel) to a more cleaner or
efficient fuel (eg, any gaseous fuel).
