14 | P a g e Both the City of Johannesburg and the Gauteng Province have clearly stated policy positions on energy security and climate change. One of the four major outcomes of the City’s consolidated and updated Joburg 2040 Growth and Development Strategy (Joburg 2040 GDS) is the provision of a resilient, liveable and sustainable urban environment, underpinned by infrastructure supportive of a low-carbon economy (CoJ 2011, p.9). The provincial Integrated Energy Strategy (GIES), amongst other pronouncements, also seeks to move the province to a low-carbon economy by scaling-up renewable energy options in order to enhance its climate change resilience and adaptation (Department of Local Government and Housing 2010; Colloquium et al. 2012; Africa 2009). However, both these key policy and strategy documents of the CoJ hardly recognise the potential of the rooftop real estate within the CoJ as a source of solarPV energy production, rainwater harvesting or urban rooftop food production. Yet the implementation of all of these, following an assessment of their potential, should constitute a holistic and uncontested city or provincial transition to a low-carbon and climate-change resilient economy. RooftopPV mass rollout promises significant socio-economic benefit for all stakeholders, yet its potential, benefits and challenges are not clearly characterised within the CoJ. In a broad sense, the research problem, and the research answers that are pursued, will contribute to the body of knowledge on rooftopsolarPV generation in the South African context, especially in an urban or inner city locality. Although there are always valuable lessons to be learned from countries and cities that have acted as pathfinders in the rollout of rooftop systems, there are unique local contexts and circumstances that must be assimilated into any local approach for rooftopsolarPV systems. Thus, locally generated information and knowledge about the challenges and opportunities presented by large-scale roll-out of rooftopPV systems in an urban or city environment has become urgent.
Willing (2008:74) argues that, a case study is not by itself a study methodology but a research approach. To provide a rounded understanding of social phenomenon case study researchers employ different methods. A case study then, according to Leedy and Ormrod (1984:149), Creswell (1994:85) and Neuman (2006:40), is a detailed analysis, investigation or exploration of a social phenomenon bounded by time, activity and space. Yin (1994:23) defines a case study as an empirical inquiry that investigates social phenomenon within its real life context when the boundaries between that particular social phenomenon under study and context are blurred. These definitions emphasise the fact that a case study is characterised by a clear unit of analysis that bound space and that a case study is bound by time. Furthermore in case study the context is thoroughly studied so as to understand the social phenomenon in its totality as well as in its real life situation. In this study the unit of analysis is the institutional arrangements in place for implementing of the new governance model in the City of Johannesburg as approved by council in the term of local government commencing in 2006 to 2011 as a pilot then.
Received: 1 January 2018 – Revised: 21 February 2018 – Accepted: 22 February 2018 – Published: 5 June 2018 Abstract. As water demand increases rainwater harvesting (RWH) systems are increasingly being installed for water supply but comprehensive hydrologic design guidelines for RWH do not exist in many parts of the world. The objective of this study was to develop guidelines for the hydrologic design and assessment of rainwater harvesting (RWH) systems in the City of Johannesburg, South Africa. The data for developing the guidelines were mainly obtained from multiple daily simulations of potential RWH systems in the city. The simulations used daily rainfall from 8 stations and demands based on the probable non-potable uses of RWH systems – toilet flushing, air conditioning and irrigation. The guidelines were confined to systems that would typically fill up in the wet season and empty towards the end of the dry season of the same year. Therefore, supply-to-demand ratios ranging from 0.1 to 0.9 were applied. Two generalized design charts of dimensionless relationships were developed. One relates the yield ratio with supply-to-demand ratio and reliability while the other relates the yield ratio with the storage-to-demand ratio and reliability. Reliability was defined as the probability of exceedance of annual yield in order to incorporate the large inter-annual variability of rainfall experienced in the region. The analyses and design of an example RWH system is used to illustrate the application of the design charts.
Newtown is located in the western sector of the Johannesburgcity centre, and covers an area that stretches from the marshalling yards and railway lines to the north, the M2 motor-way in the south, West Street in the east and Quinn Street in the west. At the turn of the 19/20th century, the Newtown precinct was originally known as the Brickfields. The area was home to a racially mixed working-class population of approximately 7 000 residents. Bricks were manufactured there, using the abundance of clay-rich soil to be found in the area. In the late 1890s, the brickworks were closed down to make way for the Kazerne Marshalling Yard, which was the first of its kind in Johannesburg. Until early 1904 the area remained working-class and with a mix of racial groups that included Africans and Indians. When bubonic plague broke out in the area, the members of these two race groups were compelled to move out by the JohannesburgCity Council, in one of the first forced re- movals to take place in Gauteng (Beavon 2004: 77). The African residents were relocated to Klipspruit, and the Indian residents to Pageview. The area was declared insanitary, and Brickfields was burnt to the ground. The JohannesburgCity Council then bought back the land. By October 1904 the Council had had it surveyed and re-planned, and had renamed the area Newtown. The precinct was reinvented as a hub for agricultural trade by the introduction of a fresh produce market, an abattoir and a mill. A new power station, which be- came one of Johannesburg’s main sources of power, was also built there. Newtown continued to house a number of working-class residents, and was the site of two major worker protests, the 1911 Tramway Strike and the 1918 Wage Campaign. In the 1930s, the open area in front of the market was named after Mary Fitzgerald,
Scrolling the stream of Facebook posts and updates is a norm for all 20-somethings, in search of both what your friends are up to, and for what events are being held in the areas around you. One afternoon while doing just that, a small red bubble appeared on my screen, alerting me to a notification from one of my Facebook connections. Sunset Sessions had invited me to an event they were hosting at Dukes the following weekend. The event promised to be unforgettable, with a stellar line-up of DJs that would be playing until the early hours of the morning. For research purposes, of course, I selected to “attend” the event, and continued to scroll the stream of posts on my virtual timeline. A few minutes later, another red bubble appeared on my screen. This notification was from a friend who had seen my RSVP. He “commented” on my activity, enquiring whether or not I go to parties on the ground anymore, owing to how many rooftop events he had seen me RSVP to during the span of my fieldwork.
The solar cell is a semiconductor device, more precisely, a special type of diode. Incident light generated free electrons which are separated by internal electromagnetic field as a consequence of the potential difference. Crystalline silicon cells are usually manufactured from silicon wafers. The wafers are sawn out of single or multi crystalline silicon ingot. Multi- crystalline silicon is composed of large crystal gains. Multi-crystalline silicon cells are slightly cheaper, but have a somewhat lower efficiency compare to single crystalline. The mono-crystalline silicon PV Module has been selected for this project. High-performance photovoltaic modules made of mono-crystalline silicon solar cells with power 250W module. The electrical properties of PV device are given: at Standard Test Condition (STC); these are cell temperature 25°C, solar irradiance 1000Wm -2 and solar spectrum air mass 1.5. A rule of thumb is that a square foot of single PV module area produces 10 watts of power in bright sunlight . Anti-reflex coating to increase light absorption. Only modules will be delivered that have the specified power or more for high energy yield. It is improved temperature coefficient to reduce power losses at higher temperatures and high power performance even at lower irradiations.
According to Ministry of New and Renewable Energy [MNRE], India has the poten- tial of generating 124 GW of electricity from RooftopPV installation. The estimation was done on the basis of census data available on percentage of concrete roof and pop- ulation. The problem with this kind of estimation is three-fold: 1) census data is availa- ble in every ten years; whereas, land-use pattern of Indian cities is very dynamic. For successful implementation of JNNSM, up-to-date data is required in every three to four years; 2) In India, census data for dwelling units is available for wards [administrative divisions within cities] which are different from electricity distribution zones. As a re- sult, estimated solarpotential from census data cannot be compared with the electricity demand of that area.
In step 1 of Table 4.2, several datasets were compiled and examined from various private, municipal and regional sources before any data processing or analysis took place. Air photo imagery was taken of the City in 2010 at a resolution of 30cm. Each of the 98 air photo tiles were examined for completeness and to get a sense of how current the imagery was compared to known construction projects throughout the City. Several known construction areas throughout the City were examined in addition to a visual assessment of every air photo tile. Building footprint polygons created in 2012 were also obtained through the City of Waterloo and used to determine the various developments or changes to the land use (e.g. several condos have replaced smaller two storey homes in recent years, as shown by Figure 4.2). The land use layer, created in 2011 and obtained from DMTI Spatial enabled the analysis of building footprint data by several groups. Results could then be quantified based on land use type which allowed for better analysis on which land use had the greatest potential for the development of rooftopsolar power. There were 7 different types of land use found throughout the City. These categories included:
There are additional factors that could increase or decrease the actual potential for the city. Other studies have gone along different lines regarding assumptions to perform such an estimate. A study by Wiginton et al.  assumed that shading would result in the exclusion of 70% of the total available area for the use of rooftop- mounted PV systems. The application of their exclusion factor to this study would reduce the rooftop-mounted PVpotential for Guelph to 54% of the 2005 electricity demand, assuming the second scenario. This does not take into account the exclusion of inclined north-facing rooftops  which are typically avoided for economic reasons but, as shown in this study, exhibited potential. The roof of each structure has various details relating to orientation, segmentation, shading, and penetrations that alter the area available and period of insolation. Although these require assessment on a case-by-case basis, strat- egies exist for incorporating details of shading losses with LiDAR (e.g., Nguyen and Pearce ). There is the po- tential to use existing surfaces, including walls, via mounting or modification with commercially available or forthcoming technologies including PV noise barriers , parking canopies, solar shingles, windows, and paints. For systems in high latitudes, there is the option of attaching booster reflectors to panels [62,68]. There are azimuth or dual-axis tracking systems that adjust panel orientation and follow the Sun in the sky while minimizing the angle of incidence, θ, and maximizing beam insolation. There are also technologies that utilize different or multiple spectrums of light and/or heat that could change the paradigm of energy conversion (e.g., Johnson thermoelectric energy converter ). There are differences between resource availability and demand over various time scales that make infrastructure essen- tial to the expansion and use of renewable energy. These topics relate to ongoing work in areas of energy-use de- mand reduction, large-scale heat and electricity storage, and distribution and systems control (e.g., smart grids). This assessment relied on historic data, and future poten- tial of solar technologies could be impacted by global cli- mate change. The work of Crook et al. focused on the effects of climate change on surface temperatures along with direct and total insolation . They noted that areas could expect increases or losses of potential de- pending on the solar technology employed. They also acknowledged that dust, wind, and precipitation could play important roles and require further investigation. These are factors for which we did not account.
The five main sectors that have contributed to 94 MW privately installed solarPV systems by March 2016 are commercial, agriculture, industrial, residential and mining consumers. The commercial sector has the highest installation of 59%, and the mining sector the lowest with 2% installation (Figure 4.15). However, this picture may change as sectors continue to install PV systems for their own generation. The commercial sector comprises mainly institutions that are service-providing facilities and equipment of businesses, national and local government institutions. These are non- manufacturing business establishments such as hotels, restaurants, wholesale businesses, retail stores, warehouses, storage facilities, and health, social and educational institutions. There is a drive to demonstrate the ability for renewable energy to contribute to the total energy mix in South Africa. Hence, most commercial buildings are having rooftopsolarPV installed for power generation given the increased electricity tariffs and decline in PV module prices.
This paper introduces Andalay AC, the first fully plug-and-play AC solar power system. It discusses how Andalay AC is the only rooftop system to take advantage of mainstream home AC electrical wiring standards, doing away with the need to work with dangerous DC circuits and resulting in faster, safer, more profitable installations with reduced engineering, inventory, supply chain and training requirements. And it examines how the innovations encompassed in Andalay AC not only revolutionize the way solar installation companies can do business, but also how consumers can benefit from the full promise of rooftop energy generation.
From the analysis of different countries it is evidenced that regulations need to change from time to time to make RTPV a success. With this in view the regulatory framework in India from solar has been continuously evolving. The solar energy cost declined from INR 17/kWh in 2011 for meeting solar RPO obligations of various states to INR 4.63/kWh in 2015 as lowest though solar bidding route for a plant in the state of Andhra Pradesh. Model net metering guideline to allow deemed RPO for utilities against the electricity consumption from net-metering based solarrooftop-only against self con- sumption by consumers is defined as obligated entities  . For better forecasting of solar/wind generation for the purpose of grid integration, Renewable Regulatory Fund (RRF) regu- lations in 2010 as per the provisions of the Indian Electricity Grid Code Regulations, 2010 were introduced  . However, present regulations on connectivity do not recognize rooftop connectivity at low voltage (say 230/415V). Regulations to remove prevailing cross subsidy (subsidizing a particular group of consumers and recovering the cost by charging higher price from another group) so that tariff can become more attractive and execution guidelines for energy account- ing process and Time of Day (TOD) settlement to connect at HT lines level and LT level consumers need to be evolved.
A maximum power point tracking (MPPT) technique is required to extract the maximum power from SolarPV (SPV) array. Various MPPT techniques are presented in the literature [9-10] which includes perturb and observe (P&O), incremental conductance (INC), constant voltage, open circuit voltage, short circuit current, extremum seeking control and techniques based on artificial neural networks, fuzzy logic, genetic algorithms. INC technique has been implemented in present work and works well than other available techniques . This method utilizes the fact that the slope of PV array output curve is always equals to zero at maximum power point (MPP). This curve has positive slope for values less than MPP and negative for which has values more than MPP.
Usually the payback time is computed as the time at which first cost and annual expenses with compounded interest equal the total savings of energy cost with compounded interest, ref. . Figure 3 shows the present value of the cost and benefit of the subject combined system at Christchurch showing the point of intersection where the costs equal the benefits for different system lifetime of 5 – 30 years. The relation describing the payback time of the proposed combined system for different energy prices at different locations in New Zealand is presented in Figure 4. The same relationship for the grid connected photovoltaic system without combination with the solar thermal unit is presented in Figure 5 while Figure 6 shows the relationship regarding the solar thermal unit without the GC-PV.
The objective of this study is to present the financial feasibility of 100kw rooftop grid connected solarPV power plant in surat municipal corporation. Financial analysis has been performed with present system cost based on life cycle cost of energy. Standard financial procedures have been used and sensitivity parameter study and work of GERC data with Real practical project work, main focus on various factor, NPV, IRR, bill of Material, the financial interest rates, operational and maintenance cost and Payback period. here feasibility analysis results were discussed and presented in conclusion.
A technology that converts sunlight directly in to electrical energy is called solar photovoltaic (PV) .Direct current is the output of the solar cell and the major component of solar photovoltaic system consists of PV array, a battery storage unit, an inverter and a charge controller. The number of PV cells together forms PV modules, which further interconnected in series and parallel manner to form PV arrays in desired voltage and current output levels.
As time moves on exponential increases in the level of PV module waste will continue to be an increasing concern to manufacturers, consumers and recycling specialists alike. Herein, we report a comprehensive characterisation study used as a preliminary, forward-thinking step in research and development towards an energy harvesting and recycling solution to deal with an imminent increase of PV module waste in the future. An indication of the potential energy inherent from the used polymers of decommissioned or end of life PV modules is discussed. Not only can it have energy value, but it could also aid in the delamination phase with relatively clean results com- pared to other chemical and mechanical methods. On the basis of weight percentages of EVA and PV backsheets per PV module reported by Corcelli et al. (6.55 and 3.6 wt.%, respectively) 38 , the weight of an average 60 cell c-Si
The experimental investigations were carried out using a prototype of RTSC installed on the top of an office construction in the Solar Research Site (SRS) in UTP. The period of measurements lasted for 4 months starting from August till end of November 2014. Set of measuring instruments were used with measuring program allow monitoring of the operational parameters over the day. The data acquisition was starting at 10.00am and continues till 4.00 pm.
From the table above, the mean south facing insolation column shows some variation in the solar energy received on building roofs, which can be attributed to shading and the roof geometry. Even more drastic however, is the variation in the fraction of south facing roof space by land use class. A map of the rooftopsolar energy density across Metro Vancouver can be seen in Figure 4. From this information, strategies could be envisioned that might be implemented based on the density of rooftopsolar energy. For example, industrial areas tend to have a high density of rooftop space available for solar installations, which may be suited to commercial solar leasing opportunities, while single family areas are perhaps better suited to individual homeowner investments.