Rooftops from Wasted to Scarce Resource

Supervisors: Mohamed A. Salheen, Professor of Integrated Planning and Design – Ain Shams University, Egypt Supervisor 2: Prof. Antje Antia Stokman, Professor of Landscape Planning and Ecology – University of Stuttgart, Germany Supervisor 3: Prof. Dr. Ahmed Atef Faggal, Professor of Architecture – Ain Shams University, Egypt External Advisor: Dr. Zakaria Yahia El Sayed, Researcher at Central Laboratory for Agricultural Climate – MALR, Egypt

The Cairene urban rooftops have only recently been perceived as potential resources by two competing technologies– the Agri-rooftops 1 and the PV-rooftops 2 that transform the rooftop space from the stagnating state of wasting into a new state of exploitation. This paper summarizes a thesis that aimed at providing a comprehensive understanding of the potentials and constraints of the Agri and PV technologies’ adoption by the rooftops of residential buildings in Cairo. It is divided into three parts. Part I evaluates the current adoption

practices and identifies the determinant aspects for each technology’s adoption. Part II compares the two technologies’ adoption potential on the rooftops of multi-unit residential buildings of the middle-income context. Part III proposes implementation strategies for boosting the technologies’ adoption. The paper concludes by determining which technology has a higher adoption potential in the different contexts in Cairo.

Keywords: Rooftop Resource; Agri-rooftop; PV-rooftop; Applicability; Acceptability; Implementation Strategies

It has long been inherent that the rooftop is a left-over space conquered only by clutter and satellite dishes. However, in 2011 a number of companies started to implement Agri-rooftops in low-income and high-income residential communities in Cairo, motivated by the revolutionary spirit and the willingness to improve the built environment. In 2014, the PV-rooftops started to appear, more in the higher-income communities than in the lower, coinciding with three decisions taken by the government. The first is the removal of the subsidy on electricity (Egypt the Future, 2015).

The second is setting the target of generating 2% of electricity from solar resources (NREA Authority, 2013). The third is the Feed-in-Tariff (FIT) scheme 3 devised to help achieve this target (PV-insider, 2015). Accordingly, the research had a wider scope in part I, focusing on the current efforts and implemented cases in the higher and lower income contexts and a deeper scope in part II, analysing, in detail, the technologies’ adoption level and potential competition in the middle-income context that is overlooked in these efforts. For the Agri- or PV-

rooftop to win the competition over this context’s rooftops, it has to have a higher adoption level. According to Roger’s “Diffusion of Innovation Theory” (2003), the adoption is defined as the technology’s acceptance by the adopter. However, for such space-related technologies, not only does the owner have to accept, but also the rooftop space has to accept the technology, meaning it has to be eligible for its accommodation. Therefore, the adoption level in this research is defined by two factors: the applicability of the technology on the rooftop space and its acceptability by the rooftop owner as will be further explained in the detailed case study analysis.

This part acts as a knowledge base for the research combining empirical knowledge collected from primary data sources as well as theoretical knowledge from primary and secondary data sources.

In the background section, the benefits acquired from the two technologies’ implementation in the context were outlined, as well as the challenges expected to be faced. Also, the different systems’ types and technicalities were covered. Based on this study, the misconceptions about the Agri-rooftop’s negative impact on the rooftop structure through water leakage or added load were refuted. Also, its expected high water and electricity consumption was proved to be wrong using calculations based on data retrieved from El Sayed (2016). The profitability calculations showed that this technology is even more economically feasible than marketed. As for the PV-rooftop, its perception as a high-cost technology is confirmed to a certain extent, where its initial costs are relatively high and highly vary based on the fluctuating USD-EGP exchange rates. However, its profitability cannot be decided upon since it is strongly dependent on the electricity consumption and so has a wide-scale of variation. Furthermore, the two technologies’ status-quo in Cairo, development timeline and the involved actors in their support were defined. A compilation of these results is shown in Fig. (2) in the form of a comparison between the two technologies.

Figure 2: Comparaison of Agri and PV Background and Technicalities Source: Author based on multiple data sources

Two cases for each technology were purposively selected to represent the attempts in the two targeted contexts of the low-income and the high-income residential communities. The four cases are: The Agri-rooftops implemented by Schaduf company in Ezbet El Nasr low-income informal area; the Agri-rooftops implemented by Al Bustani company in single family houses in high-income new urban communities; the PV-rooftop project funded and executed by LOCUS foundation in El Zabaleen area in Manshiet Naser informal area, and the PVrooftops implemented by two private companies - Cairo Solar and SolarizEgypt - in single family houses in high income residential compounds in New Cairo and in Sheikh Zayed. The analysed cases, aimed at revealing the level of success of the current adoption models of both technologies in the context to be used as lessons learnt in the case study analysis. They also aim at reaching a conclusion about the extent of these contexts’ suitability to be the entry points for the technologies’ adoption in Cairo. The most critical evaluation aspects, the sustainability, and transferability of the implementation models, are shown in Fig. (3). For the low-income cases, the self-induced adoption of the Agri and PV technologies by the communities is found to be difficult, mainly because the financial capacity of this group is much lower than their motivation. Moreover, the sustainability of the implemented projects in these cases proved to be low due to the high dependence on the funds and the lack of real empowerment of the communities to self-sustain the projects. Hence, the up-scaling in this context is low, but the transfer of its models to the focus context ranges from low to average. As for the high-income cases, the self-induced adoption is identified to be average, not as high as might be expected. This is because, even though their financial capacity is high, their level of motivation and need to adopt the technologies is not as high. However, they have a higher ability to sustain these projects and the transferability of their models and systems to the middle-income context is high.

Figure 3: Evaluation of the Agri and PV On-grounds Cases in Low and High Income Contexts Source: Author 115

Having understood the success level of the adoption models in Cairo in the previous section, some other key questions appeared such as “How is it known if these technologies are applicable on a particular rooftop? ” and “ What would make this rooftop’s owners accept the technology or reject it despite its benefits?”. Due to the lack of enough literature about these relatively new technologies in Egypt, the research mainly depends in answering these questions and identifying the determinant aspects on the international literature of the two technologies. Such aspects were contextualized to the local context of Cairo through rechecking with experts and through considering aspects deduced from the cases’ analysis done in the previous section. Doing this, the research completes the conceptual framework of the determinant aspects that is applied in studying the technologies’ adoption potential. It includes the aspects related to the first factor of adoption, the applicability-related aspects (mainly space-related) and, to the second factor, the acceptability-related aspects (individual-related, grouprelated and technology-related). A more detailed outline of these aspects is shown in Fig. (4) which will be used in part II of the research.

This part represents the beginning of applying the gained knowledge to the focus context of multi-unit residenial buildings in the middle-income community of Nasr City to measure the applicability and acceptability of the two technologies, reaching a conclusion about their adoption level. It mainly depends on the empirical knowledge collected through the case study fieldwork from primary data sources. It also touches upon theoretical knowledge when introducing the context of the case study area and when using the theories and frameworks developed in the previous part to undergo the analysis.

Figure 4: Conceptual Framework of the Adoption Determinant Aspects. Source: Author

Nasr city is Cairo’s largest district, planned in 1958 in Nasser’s era as a part of the government’s socialist model of providing public housing units for its growing urban population (Al Sayyad, 2011). At that time, it was intended to attract the existing middle-income groups with more cooperative housing blocks than the privately-owned plots (Shaheen, 2013). Afterwards, with the seventies’ Open Door policy, it witnessed a number of transformations in its urban and social

fabric (Eid et al., 2010). As a result, it became a mixture of high-rise residential buildings, privately owned plots as well as cooperative housing blocks (Frochaux &Martin, 2010). The case study analysis is undergone on two residential blocks as shown in Fig. (5). They were selected in a way so that they represent the different spatial and socio-economic typologies of the residential areas in Nasr Citydistrict.

The case study focused scope lies at the intersection of four categories: (1) the building technology, (2) building use/type, (3) income group and (4) building tenure type. The case study allocation within these categories is shown in Fig. (6). The figure also shows which aspects of the case study characteristics are related to the applicability factor and which are related to the acceptability factor. Such contextual characteristics have led to two hypotheses related to the barriers that are expected to face the applicability and acceptability of the two rooftop technologies as shown in Fig. (6) as well.

The applicability analysis aimed at identifying which technology would be applicable on which rooftop in each block of different spatial typologies, thus concluding with the percentage of the suitable rooftops for crops and solar harvesting in each block. It also represented the first step in testing hypothesis (1) of the dispropor- tonality of the rooftop area to the number of units. The environmental and spatial profiling of the two blocks was done and they were compared to a number of thresholds identified for each aspect in part I. The discarded buildings in any aspect were considered inapplicable. An average of the scores of the rest of the applicable buildings was made and the results are as shown in Fig. (7). The Agri-rooftop is applicable on 75% of the rooftops of block (A) and on only one building representing 10% of the block (B) buildings. The main barriers for both blocks were the

Figure 5: The Selected Blocks’ Characteristics Source: Author based on multiple data sources

Figure 6: Case Study Scope and Rationale Source: Author

Source: Author lack of rooftop accessibility and lack of utilities provision aspects. Contrarily, the PV-rooftop is more favoured by both blocks, achieving 85% applicability percentage in block (A) and 100% in block (B). The main barrier for the PVrooftop in block (A) was the impact of casted shadows due to the varying buildings’ heights. However, for block (B), the typology in terms of the equal buildings’ heights with minimal shadow level as well as minimal obstruction level has advantaged the PV-systems in manyways.

The previous results raised a critical question of “Are these applicable rooftops profitable or feasible for the rooftop owner to take the adoption decision?”. Answering this required undergoing a detailed profitability analysis of each technology’s implementation using the Return on Investment (ROI) 4 as an indicator. To do so, the available rooftop area on the applicable buildings was identified, followed by the system sizing. The latter depends on the aim of the rooftop farm, which could either have a self-consumption project or a commercial, profitable project. The most profitable options for both the Agri and PV utilization are shown in Fig. (8). The profitability analysis has favoured the Agri-rooftops where it achieved the highest ROI when its produce is sold as a pesticide-free product. Using this profit in covering the shared building’s expenses renders higher ROI than splitting it among the units. It could also cover the self-consumption of up to 10 units/buildings with sufficient savings/units. Above that number, the economic profit will be minimal, yet the other social and environmental benefits are gained. Contrarily, the PV-rooftops provide sufficient coverage for more units/buildings, yet the amount of savings is less than the Agri-rooftop. Using the generated electricity in covering the building’s shared electricity consumption also achieves higher savings. As for the FIT option, covering the low shared expenses of block (B) is the only profitable option. The rest of the FIT options are all unprofitable with negative ROI indicating that the current FIT values are not feasible for high consumption patterns or for large numbers of beneficiaries.

Based on these results, hypothesis (1) was neither completely proved nor completely refuted where it highly depends on the type of technology and its aim, so the outcome of the rooftop areas in these blocks’ typologies could be disproportionate to the number of benefiting units or it could sufficiently cover them.

This analysis aimed at comparing the level of acceptability of the two technologies among block (A) and block (B) residents under the different rooftop ownership modes whether it is shared or private, as well as identifying the barriers and motivators facing the acceptance. A structured questionnaire was used to achieve this aim. For the respondents living in buildings with shared rooftops, to verify that their adoption decision is impacted by the shared ownership state and not by an absolute reluctance or acceptance of the technology, they were further asked about their opinion in the case of a hypothetical scenario of owning their own private roof. The results of the respondents’ acceptability of both technologies as well as the main motivators and barriers for the shared rooftop case are shown in Fig. (9). The lower acceptance level in the case of shared ownership of both technologies was expected.

Based on this, hypothesis (2) is strongly proved especially that the main barriers identified by both blocks for both technologies were the legal and organisational aspects arising from the shared ownership obstacle. Contrarily, the relatively high level of acceptance in the case of the private ownership scenario was surprising, and indicates a promising start for the acceptance of such technologies in the focus context if the lack of shared responsibility and the collective action problem were solved.

Figure 9: Left/ The Motivators and Barriers Categories for Shared Roof- top Case. Right/ The Acceptability Results’ Comparison Source: Author

Figure 10: The Adoption Level Conclusion. Source: Author

Figure 11: Categorization of ProposedImplementation Strategies. Source: Author

A compilation of the final results of the applicability and acceptability factors of the Agri and PV technologies in the two blocks was done using the conceptual framework to reach the adoption level conclusion shown in Fig. (10).

To reach this conclusion, the percentages of the overlap and the gap between the two factors were calculated, identifying by this the “gap: overlap” ratio; the indicator of the technologies’ adoption level. When (ratio<1), then the overlap is more than the gap, so the adoption potential is high and when (ration>1), the potential is low. Therefore, it became clear that case (1) of Agrirooftops on block (A) typology has the highest adoption potential, while case (4) of the PV-rooftops on block (B) typology is considered the lowest and most wasted potential.

This part is where all the lines of discussion are interweaved, reaching solid implementation strategies that can boost the technologies’ adoption. The proposed strategies are based on empirical knowledge gained during the research aswell astheoreticalknowledgefrom earlier researchand internationalprojects aftercontextualizing them.

The implementation strategies push the four outlined cases in Fig. (10) to their maximum adoption potential (maximum overlap between the two factors). Nevertheless, the aim is not these specific cases per se but rather using them as prototypes whose proposals could be replicated in similar blocks’ typologies in Nasr city or in other middle-income areas. Fig. (11) shows the categorization of the proposed strategies that went through a verification phase with the community using online surveys targeting the larger population of Nasr City in general and with the local experts using semi-structured interviews to check the proposals’ validity and actual implementability.

Other general proposals that are not case study-specific were formulated or retrieved from the literature and checked through the survey. The most promising proposal for the respondents was the implementation of pilot projects to increase the technologies’ communicability and observability, followed by the increased governmental support. Another checked idea was the individuals’ acceptance of renting another building’s roof to implement the system, which was not highly accepted unless there are regulating laws for suchagreements.

Despite the bad conditions of many Cairene rooftops, both the Agri- and PV- rooftop technologies have proved to have no negative impact on the buildings. It also became evident that the key support for the Agri-rooftop in Cairo is to raise awareness more than financial incentives, while for the PV-rooftop, it is the financial incentives whether by the government or the private sector. Both need new innovative regulations to support a more flexible utilization of the rooftop space through multiple models. For the low-income context, the Agri-rooftops are considered to have a better chance than the PV for their lower costs and potential assembly manually out of low-cost materials. On the other hand, when it comes to the high-income contexts, the PV-rooftops have a better chance, not for profitability but for expenses’ reduction. Also, the Agri-rooftops have a good chance, especially with the organic food trend. As for the middle-income case study context, the two technologies proved to have a very close potential regarding which technology wins over the other. The PV is just slightly advanced over the Agri in the overall results of both blocks, but the difference could be easily compensated. The generalization potential of block (A) results is higher due to the wide-spread of this block typology in Nasr city, while for the cooperative housing, there are other forms of block typologies that do not suffer from the same problems. After all, these blocks are not the target, but knowing the implementation strategies that can deal with the unfavourable block conditions is the added value of the analysis. In the end, the outcomes of this research could be of benefit for multiple actors involved in the field where it can be developed into a guideline informing the new companies of the determinant aspects that need to be studied when promoting the technologies. It could also be developed into a manual that targets the communities and rooftop owners, revealing to them the potentials of their rooftop valuable resource and which technology would suit them. By this, the research would have achieved its main aim of undergoing a realistic practical study that enlightens people as well as the research field about the potentials and constraints of the two technologies’ adoption in the Cairo context.

[1] Agri-rooftop: Stands for Rooftop agriculture where edible crops are harvested on rooftops [2] PV-rooftop: Stands for using Photovoltaic (PV) panels on rooftops for electricity generation from solar resources. [3] FIT: It is a policy where the electricity company buys the generated electricity from the PV-system. [4] ROI: Return on Investment; A “profitability ratio” to evaluate the benefit from investments.

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