Appendix 2 – What is an Energy Audit?
An energy audit allows an agency to better understand their building(s)
energy use and determine where cost effective savings can be made. There are
three audit levels under the New Zealand Energy Auditing Standard:
- Level 1 – A survey of the energy costs and a comparison to the
relevant benchmark (usually on a floor area basis). This type of audit is
inexpensive, but only shows whether or not the building’s energy
consumption is excessive – it doesn’t identify savings opportunities.
Where benchmark information is not available, an on-site visit may be
necessary to determine whether energy use is excessive. Observations made by
an experienced auditor can be very useful and may identify savings
opportunities.
- Level 2 – This is what is normally considered an ‘energy
audit’. It includes everything in a level 1 audit, plus a comprehensive
site inspection, energy balance (reconciliation of energy purchases and
end-uses) and a list of savings opportunities. It is based on observations,
one-time (snapshot) measurements and interviews with staff. Costs and
savings are estimated based on the known assumptions. This level of audit is
adequate for most buildings, unless more detailed justification of capital
expenditures is required.
- Level 3 – This is a more detailed and comprehensive version of a
level 2 audit. Savings opportunities are investigated in more detail and are
based on measurements taken over time, so they are more reliable. Costs and
savings are typically estimated to within 10% and more effort is put into
assessing the long-term financial aspects of any recommendations. Level 3
audits can be done on specific opportunities as well as on whole
‘sites’. Typically this type of audit is done for investment purposes.