Energy Efficiency Made Simple Vol IV 2015

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A requirement is to utilise regression analysis so that performance variables can be accounted for, such as the weather, production and occupancy, etc. to ensure the correct baseline adjustments. Option D: Calibrated computer simulation (greenfields-type projects) Computer simulation models of component or whole-system energy consumption are used to determine the projected energy savings. The simulation inputs are linked to the baseline and post-installation conditions, or performance metering before and after the retrofit. The simulation models can be calibrated by using whole-building long-term energy use data from an existing building. As a guideline we suggest the following when making a decision as to which option to use: • Look at the total project cost • Then at the expected savings to evaluate the ROI • Consider the complexity of adjustments required (derived from the complexity to measure and model the drivers) • The cost of the type of measurement requirements related to the option • The anticipated changes to post-implementation usage patterns or drivers • The risks that have to be taken on by the stakeholders • The uncertainties that need to be determined Most importantly, choose the least complex method even if it means realigning the project boundaries to be more cost-effective whilst maintaining the least uncertainties that need to be determined. Baseline For each option, and for each specific project, agreement between all stakeholders must be reached on the baseline definition (and M&V plan) as it involves, quantifying energy consumption data whilst specifying the factors that affect the energy consumption, taking into account agreed upon variables. To determine a baseline energy consumption data is required, such as meter readings of bill information relating to the electric-

can be measured [4]. Performance and operations factors are taken into account and these are factors that indicate equipment or system performance characteristics such as kW/t, or W/fixture, for example, while operating factors indicate equipment or system operating char- acteristics such as hours of operation. Option A: Stipulated and measured factors The performance and operation factors are based on a combination of measured and stipulated factors, for example, measurements can be taken as spot measurements or short-term measurements at the component or system level. Data can be used from rating plates of suppliers and manufacturers, or the components’ historical data. The cost of M&V would be dependent on the number of points measured, and an estimated range could be between 1 and 3% of the energy savings of the project. Option B: Measured factors (retrofit isolation) As with IPMVP Option A, spot or short-term measurements at com- ponent or system level are used where variations in factors are not expected. Option B applies to a retrofit or systemwhere the measure- ments can be taken separately from other measures or performance factors. No factors are stipulated in this option but it involves the need for more end-use metering than Option A, which makes it both more expensive and less subject to uncertainty. An estimate of 3 - 15% of

the energy savings of the project has been cited [4]. Option C: Utility billing data analysis (whole facility)

With Option C the complexity of the whole building analysis deter- mines the cost which could be in the region of 1 - 10% of the energy savings of the project. This option applies to the impact of a ‘bundle’ of retrofit measures on a whole building or facility. Option C relies on total building energy performance data obtained from metering at the point of entry to the facility, from baseline period to post-installation of the retrofit.

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ENERGY EFFICIENCY MADE SIMPLE 2015