*2.3. Construction of Residential Load Profile*

Typical residential load demand variation in India has two noticeable time periods where the load requirement is high. The morning time of 6 a.m. to 10 a.m. where the residents are getting ready for school and office is a period of relatively high power consumption as is the time period from around 6 p.m. to 11 p.m. wherein the family comes back home to regroup. The power requirement during weekends is also more than that during weekdays. According to the weather conditions prevailing in India, the average household electricity consumption increases further during summer seasons as air

conditioning is required. There will be a noticeable dip in the power consumption in the night during the winter months [33,34].

**Figure 2.** Seven day profile of June 2019 (**a**). Solar PV variation and load demand (**b**). Expected battery charge and discharge cycle.


**Table 1.** Summary of June 2019 profile (no scale down, SE = 1).

In the present work, realistic variation of electricity consumption has been incorporated by sourcing data from real-time measurements (https://.prayaspune.org/ accessed on 15 January 2020 of the load requirement of a residential apartment complex of

120–145 dwellings in Pune, India [34,35]. Prayas energy group is a non-governmental and not-for-profit Indian organization. As part of one of its projects, the organization recorded real time power demand of residential apartment based in Pune for various appliances, weekends and weekdays over an extended period. The data collected at fifteen-minute intervals over a full week in June 2019 was used to construct the power demand profile. The data were numerically interpolated to generate minute-by-minute variation which is shown in Figure 2a in the form of average value per household. Because of aggregation over a large number of dwellings, the average consumption of power per dwelling does not show sudden spikes associated with the switching on or off of large power consuming devices such as the air conditioner or the washing machine [36].

Salient features of the load variation over the week are listed in Table 1. It can be seen that the maximum load per household over the seven-day duration is 303 W while the minimum is 156 W, that is, a ratio of about 2. This is in contrast to the PV output which has a maximum power of 1670 W, i.e., more than five times the maximum load. This wide disparity between source output and load is characteristic of solar PV-residential load applications. The battery needs to be capable of tackling these wide variations.
