*2.2. Performance Expectancy (PE)*

PE did initially explain the magnitude of beliefs among individuals with regards to employing a system and its corresponding gains [15]. This definition has received global reception for having the flavour of gains from performance, which is a central element to organisations and individuals. Therefore, observing PE as widely operationalised across various studies and contexts through adaptations is no longer surprising. Ref. [32] skewed PE's definition towards the scale, a system that will assist users in uplifting their job performance. PE is also defined as the magnitude of individual perception about how a particular technology will enhance work output [8,16,25]. Ref. [33] operationalised UTAUT in a solar water heater system (SWHS) amongst Libyan households by matching the reduced electricity bills as benefits whilst striving for use of natural resources.

Ref. [24] propose that PE is a yardstick about beliefs households have towards userfriendliness and safety of rooftop solar usage. Other studies have also remarkably proven PE's role towards behavioural intention [19,34,35]. PE is seen to stamp its mark further on behavioural studies when [36] propagated PE as the most powerful force in acquiring user adoption; numerous studies have confirmed this notion [37–39]. The present study adopts the PE definition of [25] and four items from [32] towards measuring PE. Thus, the following hypothesis is formulated:

#### **H4.** *PE has a positive effect on intention to adopt solar services.*

#### *2.3. Effort Expectancy (EE)*

EE relates to the degree of simplicity accompanying with the use of technology [8,25,32]. Ref. [24] operationalised EE in measuring the extent by which individuals feel comfortable in using the system. Ref. [22] argued the existence of EE to be closely related to ease of use, being part of the Technology Acceptance Model whereas from a marketing perspective, EE is seen to express views on customers concern towards simplicity of using certain services. Meanwhile, in the renewable energy segment such as solar energy, EE can be viewed as how

easy/effortless solar energy can be used. After PE, EE is observed as one of the strongest influencers towards behaviour intention.

This observation has been confirmed through a series of research on EE's relationship towards intention, which would reiterate EE's position. Ref. [40] studied location-based service amongst smartphone users and found that EE recorded a B-value of 0.3 next to PE, which had a B-value of 0.42. A similar pattern was observed among other research outcomes [25,35,39]. Ref. [41] conducted research on users of Phablet, which is a hybrid product that combines PC and a smartphone's functionality and found that EE occasionally overpowers PE. The aforementioned study showed that EE has the highest positive value, thereby playing a dominant role in causal networks relative to other UTAUT variables; namely habits, hedonics, and price values, being operationalised. EE has also been consistently leading to behaviour intention when tested in various industries [42,43]. The present study adopts the definition of [25] and operationalises five items to measure EE: four adapted from [32] and one from [24]. Thus, the following hypothesis is presented:

#### **H5.** *EE has a positive effect on intention to adopt solar services.*
