Data on electrical energy conservation using high efficiency motors for the confidence bounds using statistical techniques

In this article, we describe details of the data used in the research paper “Confidence bounds for energy conservation in electric motors: An economical solution using statistical techniques” [1]. The data presented in this paper is intended to show benefits of high efficiency electric motors over the standard efficiency motors of similar rating in the industrial sector of Pakistan. We explain how the data was collected and then processed by means of formulas to show cost effectiveness of energy efficient motors in terms of three important parameters: annual energy saving, cost saving and payback periods. This data can be further used to construct confidence bounds for the parameters using statistical techniques as described in [1].


Value of the data
The data highlights the benefits of using high efficiency motors in place of existing standard efficiency motors in industrial sector of Pakistan in terms of annual energy savings, cost savings and payback periods.
The annual energy consumption and annual operational cost are compared for a sample data of 20 standard and energy efficient motors (EEMs).
The data described in this article supports the step by step statistical analysis in terms of confidence bounds for the three parameters: annual energy savings, cost savings and payback periods for EEMs.
The confidence bounds based on the discussed data which are presented in associated research paper [1] can be used to attract financers for large scale purchase and replacement of standard motors (SMs) by EEMs to conserve sufficient amount of electrical energy.
The procedure described in this article and the underlying research paper [1] can be used by researchers for processing the data related to high efficient motors in other countries (the data in Refs. [2][3][4][5][6][7][8][9][10]) in order to generate encouraging confidence bounds to promote electrical energy conservation using EEMs [1].

Data
The data in this work describe general information about existing low-efficiency motors at surveyed sites, like: motor application type, utility rate being used, annual operating hours and related information from motor nameplates. We also present the comprehensive values of some important parameters for each standard motor in the sample like: input volts, input amperes, input kW, operating speed (in rpm) and power factor.

Experimental design, materials and methods
The data presented in this article is basis for the statistical analysis in terms of confidence bounds as discussed in [1] for the annual energy savings, cost savings and payback periods of EEMs when replaced for SMs. To acquire the necessary data, some industries based at Pakistan were surveyed and data on existing standard efficiency motors were noted while personal visits. We describe in next section, the acquired data, its processing using different formulas and its descriptive statistical analysis which is required for the construction of confidence bounds. To gather the best possible sample of existing standard efficiency motors, we surveyed the industries where majority of the motors were installed. Surveyed industries included: Pakistan Steel Mill (PSM), Karachi; Thermal Power Station, Jamshoro; Regional Control Centre, Jamshoro; and, Water Works/Pumps, Hyderabad. The data was obtained in the year 2011 while personal visits to the surveyed industries. Some photos of motors at survey sites are given in Figs. 1-3 according to their applications. The important electrical parameters related to the installed standard efficiency motors were noted on the motor data and energy consumption form, a sample in Fig. 4. For reference, a completely filled form for 2HP motor can be found as Fig. 1 of [1]. The comprehensive data measured and noted in these forms for all 20 sample SMs is gathered in Table 1. The values in Table 1 can be used to calculate power (in kW), annual energy consumption (in kWh/year) and annual operational cost (in Rs./year) for the 20 sample SMs.
Similar rating EEMs with price and efficiency detail comparison with those of SMs (as per Table 1 in [1]), when processed with the cost effectiveness formulas and conditions given in [1], resulted  encouraging values of annual energy savings, cost savings and payback periods. An example of such calculation is given here to support the statistics in the main paper, i.e. Ref. [1].

Example calculation of cost effectiveness parameters for a 2HP motor
The following analysis for 2HP motor operating at 75% of full rated load illustrates how to determine the cost effectiveness of obtaining an energy-efficient versus a standard efficiency motor for the initial purchase case. The formulas are used from Ref. [11].
In this example, installing an energy-efficient motor reduces utility billing by Rs. 5509.96 per year. The simple payback for the incremental cost associated with an energy efficient motor purchase is the ratio of discounted list price premium (see Table 1 in [1]) or incremental cost to the total annual cost savings. A list price discount of 75% is used in this analysis.
Thus, the additional investment required to buy this energy efficient motor would be recovered within 0.22459 years.
Similar analysis for other motors in the sample lead to the 20 values for each parameter: annual energy saving, cost saving and payback periods for replaced EEMs for SMs. Fig. 5 shows the break-up of total energy consumption by sampled SMs in terms of energy consumption by similar rating EEMs and corresponding energy savings. Fig. 6 describes that the sum of annual operational cost on an EEM and its corresponding cost savings equals the annual operational cost on similar rating SM. Finally, the  data described in this article is further analyzed statistically in Ref. [1] to construct the confidence bounds for energy conservation parameters.

Transparency document. Supplementary material
Transparency document associated with this article can be found in the online version at: http:// dx.doi.org/10.1016/j.dib.2016.06.004.