Tham khảo tài liệu 'energy efficiency part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Energy Efficiency Policy 23 M V approach boils down to the fact that the absence of energy use can be only determined by comparing measurements of energy use made before baseline and after post-retrofit implementation of energy efficiency measure or expressed in a simple equation Energy Savings Baseline Energy Use - Post-Retrofit Energy Use Adjustments 2 The baseline conditions can change after the energy efficiency measures are installed and the term Adjustments can be positive or negative in equation 2 aiming at bringing energy use in the two time periods before and after to the same set of conditions. Conditions commonly affecting energy use are weather occupancy plant throughput and equipment operations required by these conditions. These factors must be taken into account and analysed after measure is undertaken and adjustments have to be made in order to ensure correct comparisons of the state pre- and post-retrofit. This kind of M V scheme often referred to as ex-post may be very costly but they guarantee the detections of real savings. The costs are related to the actual measurement . to the measurement equipment. To avoid a large increase in the M V costs only the largest or unpredictable measures should be analysed through this methodology. Individual energy efficiency projects might also be evaluated using well reasoned estimations of individual energy efficiency improvement measures impacts. This approach ex-ante means that certain type of energy efficiency measure is awarded with a certain amount of energy savings prior to its actual realisation. This approach has significantly lower costs and is especially appropriate for replicable measures for which one can agree on a reasonable estimate. There are also some hybrid solutions that combine ex-ante and expost approaches in bottom-up M V. This hybrid approach is often referred to as parameterised ex-ante method. It applies to measures for which energy savings are known but they may differ depending .
