4.2. Existing Usage Behavior Analysis
In order to achieve another objective of categorizing the sampled occupants from case buildings into various energy usage categories, usage habits were inquired through the questionnaire survey. The self-reported energy usage behavior is extracted for performing further analysis which utilizes average energy usage by commonly available equipment in office buildings. The standard usage values are taken from different sources including PEPCO [
67], ASHRAE 90.1 [
68], USGBC, and Energy Star as shown in
Table 5.
These usage values are used in order to rank the equipment category based on energy usage per square foot area using Equation (1) or per hour using Equation (2). The value of 61 ft
2 is sourced from Time Saver Standards [
91] which is the average area of office spaces found in buildings under study.
These calculations are performed to find the weight of each equipment category during working and non-working hours, as shown in
Table 6. The hourly usage values are based on the typical office schedule of 9 am–6 pm. Depending upon the types of equipment and their hourly usage, their relative weight in overall usage is calculated. The HVAC systems consume more energy than all other equipment, thus a weight of 0.394. This is in line with the findings of Masoso and Grobler [
94] who figured out an average HVAC usage of 72% for hot and dry climates of Botswana and South Africa. Secondly, despite their low hourly usage, desktop computers consume a lot of energy as compared to other equipment due to their extensive use throughout the day. On the other hand, the lighting system found in these buildings is BMS controlled, which implies that it operates on a fixed schedule that varies from building to building and with the occupant schedule. In the case of the artificial lighting system, BMS is programmed to switch them on during working hours only. So, there is no possibility of lights remaining switched on during non-working hours. However, the downside of these automatic lighting systems is that the occupants have no control over lights, thus eliminating the impact of their behavior in energy saving.
The use of daylighting has the potential to save a large amount of energy as it provides an appealing environment and a pleasant workspace that can increase both performance and productivity [
95]. Field studies and simulation analysis show that daylighting has the potential to save energy from 30–70% [
96,
97,
98]. The data obtained from the case buildings reveals that most of the occupants complain of not having enough daylight which can be associated with their working position, office layout or operating style of blinds and windows. After getting the weight of each equipment, an individual score is calculated for each respondent using Equation (3), where
Wi is the weight of equipment and
Ki is the individual use score of equipment as reported by respondents.
The values of the individual score range between 2.96–6.7 which are equally divided into 3 ranges, as shown in
Table 7, along with the frequency of respondents in the given category. The higher values show the score of HEC and the lower values represent LEC. Accordingly, 24 occupants are categorized as LEC, 54 as MEC, and 23 as HEC, giving a seemingly normal distribution where most of the respondents are in the middle.
4.3. Agent-Based Modeling (ABM) Simulation Analysis
The simulation starts with initial values of LEC, MEC, and HEC as per
Table 7 and shows the effect of all parameters on occupants. If there is a change in the category of a consumer, it updates the occupant category and jumps to another time interval for the next iteration.
Figure 4 shows the results of simulation over a 3-year period. Initially, the effects of advertisements and interaction in converting usage behavior are visible. Though advertisements seem successful in preserving LEC, the peer-to-peer influence of HEC is negatively effecting the MEC in the form of a sustained increase in HEC and a decrease in MEC. To curb this energy inefficient behavior, the first energy event is simulated after 12 months. It seems without an energy event or any training, people are influenced by irresponsible usage behavior of HEC. This influential effect is highly noticeable in MEC who are adopting bad usage habits. It is possible that occupants are unaware of energy-saving techniques or are too busy to consider it, hence becoming careless towards energy conservation. Further, seeing senior influential colleagues as HEC may also trigger such bad behaviors.
Nevertheless, it is encouraging that LEC occupants sustain their behavior over a longer period because of having adequate knowledge and ingrained habits of energy-saving and sustainability. To spread the knowledge of energy saving, energy events are arranged. The efficiency of these events is set to 50% which means that after attending the event, half of the occupants will be influenced to change their usage behavior. Accordingly, the first energy event causes a major change in behavior with an increase in the number of LECs either from MEC or directly from HEC pointing to their effectiveness. The number of HEC has drastically decreased due to conversion into other categories. As evident from
Figure 4, the number of MEC occupants is in the middle as opposed to being at the top before the energy event. So, after the first energy event, 19 HEC, 32 MEC, and 50 LEC occupants are carried forward to the next stage of simulation.
Between 12–24 months, the behavior sustaining capability of occupants is quite evident. It is probably because energy events only mean to spread awareness of the benefits of energy-saving, not impose energy-saving habits on the occupants. Imposing will be counterproductive because when something is imposed, people tend to retaliate. Therefore, such events should only encourage the ideas, highlight the importance, and raise awareness among the occupants. The behavioral change and subsequent adoption resulting from such sessions should be at the disposal of the occupants. Such self-realized behavioral changes are usually long term and more sustainable than the ones imposed on the occupants [
89]. With minor changes, occupants sustain their behavior throughout the year. The next energy event is organized at the end of 24 months which causes a high change in the number of MEC converting to LEC.
Figure 5 displays the density of the occupants who experience the behavior modification from the beginning of the simulation to the end after the 36 months period. As a result, most of the occupants have changed their category and are converted into LEC. At the end of the simulation, the number of LEC is 81, MEC is 16, while HEC is only 4.
The evolution of occupants in their energy use behavior is sensitive to the input parameters given in
Table 3. A sensitivity analysis reports that the most significant parameter is energy events due to a considerable efficiency of 50%. Other modification techniques, though garnering more lasting and sustainable results, have much lower efficiency and thus the overall evolution is much less sensitive to them.
4.4. Energy-Saving Estimation Due to Behavior Modification
In order to show the significance of the results obtained from the simulation model and putting them in perspective, possible overall energy saving must be estimated. For this purpose, the amount of energy consumed by an occupant should be known. Usually, published usage is an average of the usage per capita and may only be roughly attributed to MEC. In order to know the hypothesized non-linear difference between MEC and the other consumer behaviors, the data is almost nonexistent. Therefore, heuristics are applied to get upper (HEC) and lower (LEC) ranges of an average consumer (MEC). To establish these values, the two most commonly used electricity usage equipment are considered i.e. lighting and air conditioning (AC). Currently, three different types of equipment exist for both categories in the market based on their energy demand. For example, in the case of lights, fluorescent, compact fluorescent, and LED lights are considered. Similarly, window AC, split units, and inverters are considered for air conditioning. So, based on their electricity usage, all of them are categorized as high, medium, and low energy consumers. A comparison of these systems and their percentage increase in usage is given in
Table 8.
The medium value is considered as the base value, while the rest of the calculations are made accordingly. In the case of the lighting system, the percentage increase form low to medium and medium to high is quite extraordinary. The underlining reason is that technology has significantly improved from fluorescent tube lights to LED lamps. In contrast, despite improvements in technology, the difference is much lower in the case of air conditioners. This is because electricity usage is already too high and improvement in technology can only marginally reduce it. Although estimations based on these statistics can be challenged owing to smaller samples, larger standard deviation, and major differences between the usage of each system, it is assumed that these heuristics offer a logical value for the non-linear usage behaviors. Further, three usage scenarios as explained in
Table 1 have been considered in order to decide about the category of the occupants. Based on these, the usage rates are estimated as given in
Table 9.
The per capita energy usage in Pakistan for the year 2018 is reported to be 522 kWh [
99] which can be considered as a standard value for MEC as it reflects the national average. Compared to developed countries such as the United States with 11,851 kWh, the UK with 4749 kWh, and Australia with 9774 kWh for the same year [
100], the average usage in Pakistan is much lower due to power shortage and lower economic conditions of its people. Thus, it falls in the same group as Sri Lanka with 561 kWh, and North Korea with 547 kWh [
101]. As hypothesized previously, MEC is not equidistant from LEC and HEC. As per the findings reproduced in
Table 8, it is evident that the average percentage increase from low to medium and medium to high is different from LEC to MEC and MEC to HEC, as shown in
Figure 6.
This implies that HEC occupants are consuming far more amount of energy than that saved by the LEC occupants. Thus, a change of behavior from MEC to LEC will need lesser efforts as needed for changing from HEC to MEC. This is empirically established by looking at the trend of behavior adoption in simulation as at the end of year 1 (from
t = 0 months to
t = 12 months); the LEC occupants have increased by 40% as opposed to a mere decrease of 17.4% in HEC occupants and 22% in MEC occupants, as shown in
Table 10. It can be seen that at this stage that the conversion rate of MEC is better than the HEC. Though it is assumed that the change of occupant behavior will not be progressive, such that HEC may convert into MEC and then into LEC or directly into LEC, at the end of year 1 the energy saving will be quite small due to lesser conversion of HEC occupants who account for massive energy usage. This lack of willingness to change the behavior by HEC occupants as conveniently as that showed by the MEC occupants is partly based on the fact that the ‘information deficit’ model, based on which most of the information-intensive public education campaigns are based on Owens and Driffill [
102], which assumes that increasing knowledge and awareness causes a positive change in energy usage behavior [
103]. However, the evidence on behavior modification due to increased knowledge and attitude change suggests that such an effect is weak and short-lived [
104]. The situation exacerbates in the face of generic and nonspecific information, rather than tailored information [
105]. This implies that increase knowledge and awareness do not necessarily cause behavior modification, because knowledge is not a motivator for engagement in the desired behavior. However, a lack of knowledge and awareness might be a barrier [
106]. Additionally, changing old habits is difficult when the motivation is not too high. Occupants typically do not have a direct financial interest in energy saving. Even among those who are motivated to conserve energy for non-financial reasons, not paying for their energy usage also means that occupants are not prepared to consider the energy used for workplace behaviors and have a little context for how much they have used compared to previous usage [
107]. Finally, if someone has a higher usage tendency, it will not be quick and easy for them to improve their behavior.
However, consistency is the key. After constant exposure to energy-saving habits and awareness campaigns, a significant positive change is witnessed in the form of a 53% reduction in HEC occupants at the end of year 2 (from
t = 13 months to
t = 24 months) and 56% reduction at the end of year 3 (from
t = 25 months to
t = 36 months). The effect of constant exposure is also evident in MEC in the form of a dramatic reduction of 57% at the end of year 3. This is a major achievement that justifies the investment in energy-saving interventions and financial incentives since monetary motivations drive energy-saving behavior [
108]. So since the office occupants do not typically pay their bills [
107], they can be motivated by chances of winning prizes [
109].
The table further shows the energy consumed by occupants in each category calculated with the help of usage rates.
The impact of this behavior modification on energy usage is quantified through the number of occupants and the usage rates obtained from
Table 9. At the end of year 1 (
t = 12), the total energy saving is 6.5%. Similarly, at
t = 24 and
t = 36, simulated energy savings are 16.3% and 27.9%, respectively, highlighting that energy saved in year 1 is 6.5%, year 2 is 9.8%, and year 3 is 11.6%. Hence, there is an increasing trend in total energy saving per year. The difference between the 1st and the 2nd year is substantial and continues to grow throughout the simulation period. At the end of year 1, the first energy event is organized causing a decrease in the number of HEC and MEC occupants and an increase in LEC occupants. The increasing number of LEC occupants is the sign of positive change in behavior that causes a reduction in total energy usage. At the end of the simulation, a very large number of occupants are converted to LEC, and only a few HEC occupants are left. Hence at this stage, 27.9% cumulative energy savings are realized. Referring to
Table 4, the average energy gap due to buildings is 15.5%. Thus, by only changing the behavior of occupants by employing the above-mentioned techniques, the average electricity saving of 9.3% can be achieved every year. Interestingly, this saving potential falls well within the ranges reported by several other studies [
110,
111,
112,
113,
114]. This 9.3% saving, when generalized to the level of an entire country, presents stimulating opportunities. For example, in Pakistan, all the sectors combined consumed a total of 110,890.13 GWh in 2017–2018 [
115]. A mere 9.3% saving will result in a saving of 1177.258 MW which is almost double of generation licenses, with a cumulative installed capacity of 652.54 MW, issued in 2018–2019. This number is close to the installed capacity of wind power in the country (1235 MW) [
116]. Since the overall energy usage in Pakistan is lower than the developed countries, this 9.3% saving can mean a saving of 2463.6 MW in the Australian energy context for the year 2017–2018 [
117] or 119,165.5 MW in the USA energy context for the same year [
118].
Though these figures show the significance of saving potential, still, in order to statistically validate these claims, analysis is performed on the estimated usage. It is hypothesized that before and after the behavior modification, usage will be significantly different. Single-factor ANOVA is applied to the pre- and post-modification usage figures. Initially, using a 95% confidence level, the p-value comes out to be 0.075 which is outside the significant range. However, at a 90% confidence level, the p-value comes within a significant range. Additionally, the F-statistic at this level is significant since Fcritic < F (3.776 < 4.6). It is opportune to mention that the already lower per capita usage of Pakistan has greatly influenced the results and the test has failed at 95%. In case the same study is repeated in countries with higher per capita energy usage, such as Australia or the United States, it is expected that significant findings will be achieved at a higher confidence level.