Ingenieur Vol. 75 ingenieur July 2018-FA - Page 67

determine actual savings created within an individual facility by an energy management programme. Its objectives are: a) To determine how much savings have been achieved; b) To prove that the energy savings projects have been successful; and c) To quantify the performance of an implemented Energ y Conser vation Measure (ECM) by measuring and verifying the energy savings. In order for M&V outputs to be commonly accepted by all stakeholders, they need to adhere to certain protocols. One such protocol is the widely-accepted International Performance Measurement and Verification Protocol (IPMVP) developed by Efficiency Valuation Organisation (EVO), an international non-profit organisation. Based on the IPMVP, energy saving is fully expressed as: Savings = (Baseline Energy – Reporting Period Energy) ± Routine Adjustment ± Non-Routine Adjustments Where, Baseline energy = energy consumption measured during the baseline period, Reporting period energy = energy consumption measured during the post-retrofit performance period, Routine adjustment = adjustment due to regular changes in independent variables (such as changing weather conditions, varying production levels), and Non-routine adjustment = adjustment due to one-off or infrequent changes in energy use or demand that occur due to changes in static factors (such as building façade changes, extreme weather events, building extensions and changes to equipment). Generally, there are two methods of measurement in M&V, as shown in Figure 1: 1.) Retrofit isolation method This type of measurement method is selected to measure the performance of the energy saving measure (ECM) only at the retrofit point. The retrofit isolation method usually requires a dedicated meter. There are two options available under this method: Option A: Savings are determined by field measurements of the key performance parameters (such as chiller power) which define the energy use of ECM. The parameters not selected for field measurement are estimated from an established basis. (e.g. lighting retrofit- power is measured meanwhile operating hours are estimated based on facility schedules). Option B: Savings are determined by field measurement of all the parameters. (e.g. chiller system retrofit). 2.) Whole facility measurement This type of measurement method is selected to measure the impact of ECM on the total energy use in the facility. The measurement often uses M&V Method Retrofit Isolation Option A Whole Facility Option B Option C Option D Figure 1: M&V Options 65