3.1 Bibliometric analysis of contributions
In this section, a bibliometric analysis of contributions will be carried out. The search on ‘SCOPUS’ and the “Web of Science’ was carried out on the 14th of April 2022. The range of the contributions included was from 2018 to 2022. The first analysis to be examined herein will be related to the year of the contributions. The results show that the number of studies relating to the relationship between the IoT, SMART cities and energy management - reduced slightly from 2018 to 2019. However, from 2019, the number of publications has been on the rise. While 2022 is still ongoing, it has been included in this study and based on the trends observed, it is projected that the number of contributions from 2021 will increase (See Figure 3 – for more information).
Conversely, the contributions by the journals in which they were published show that the top journals in which studies were obtained from are – IEEE; Sustainable Cities and Society; Sustainable; Energy Technologies and Assessments Sustainability; and Renewable and Sustainable Energy Reviews; with 38, 16, 3, 2, and 2 – respectively (See Figure 4 for a pictorial representation).
On the other hand, the contribution by nationality shows that the seven countries with the largest number of contributions are – India, China, Italy, USA, Korea, Malaysia, and the UK – with 13, 9, 6, 4, 3, 3, and 3 contributions – respectively. Figure 5 presents a map of the result.
The bibliometric analysis shows that the main authors that contributed the most to the literatures considered in this study are - S. H. Alsamhi, Chun-Wei Lu and A.N. Matheri with 3, 2, and 2 contributions - respectively (See Figure 6- for more information). Alsamhi works with the Shenzhen Institute of Advanced Technology, CAS – as an Associate Professor. His area of research includes - multirobot collaboration, space technologies, green communication, QoE, blockchain technology, QoS, and the green Internet of Things.
3.2 An analysis of the impact of the IoT on SMART cities and energy management
Based on the bibliometric analysis in this study, the six main keywords obtained from an examination of extant contributions are - SMART city(ies), Internet of things, Energy efficiency, Sustainability, SMART Grid and Cloud computing (See Figure 7- for more details). Next, each keyword will be analyzed in detail.
3.2.1 SMART City(ies)
An essential part of SMART cities is their healthcare sector. The IoT is revolutionizing this sector by making it smarter. According to Ghazal et al. [34], the IoT is improving the ability of machines - within the health care sector in SMART cities - to learning. This has an impact on improving the performance of these machines and the healthcare sector. Likewise, the operationability of the SMART cities is greatly influence by the IoT. This is because, the IoT is improving various services offered within SMART cities [35]. Key components of SMART cities are presented in Table 1.
Table 1: Key Aspects of SMART cities
SMART Aspects
|
Features
|
People
|
IoT enabled cities with diverse people (coexisting harmoniously) with varying capabilities and ability to utilize, understand and manage technologies within the city
|
Living
|
A city that operates optimally - thereby improving the quality of life of its inhabitants. Inhabitants receive the best possible standard of service enabled by advanced technology
|
Governance
|
A government whose transparency and accountability are improved by the adoption of technology. Governance within this domain is effective and efficient at delivering services to the public
|
Economy
|
It entails an open innovative and collaborative economy that enhances innovation at all levels to meet the need of the society
|
Mobility
|
A community with innovative and a sustainable transportation system
|
Environment
|
A sustainable city that is green in all aspects from energy generation, usage and transmission to waste management and service delivery - all in a bid to protect the environment
|
Source: Szum [36]
According to Rajab and Cinkelr [37], the key areas that the IoT is being applied in the SMART cities is in its management of traffic, surveillance systems of the environment, and natural resources, SMART grids & energy management, and SMART infrastructures. The key enabler of the SMART city is its ability to have and process data it needs to make informed decision and its ability to derive useful information from them. With this capability the efficiency of SMART cities is enhanced - making them data-oriented SMART environments [38].
One of the major challenges of major cities across the world is waste management. All activities that are geared towards the management of waste from the point in which they are collected to where they are recycled - encapsulates waste management [39]. The IoT is making the issue of waste management within SMART cities surmountable. This is because it is [40]-
- making it possible to track products from the point of manufacturing to the point they are recycled,
- it is leading to the development of business models that optimize the use of resources in production, and
- a system that uses sensor-based infrastructure to sort out waste effectively.
A new innovation the IoT is introducing to the management of waste in SMART cities - is the adoption and use of electric bins [41]. These bins are SMART and connected to other internet enabled devices to optimize waste management and communication with the right people - with the authority to manage waste. A different aspect of SMART cities that the IoT is improving is the traffic systems. For instance, in China, where the numbers of car owners is high, and traffic management is a major issue in big cities, the IoT is improving the management of traffic in SMART cities - through the collection and processing of data to make informed decisions [42]. An important concept the IoT is bringing to the management of traffic in SMART cities is SMART traffic management. According to Javid et al. [43], the use of IoT enabled devices, such as - cameras (for capturing data) and advanced algorithms (for processing these data) is making traffic management SMARTer. Likewise, the IoT is improving traffic in SMART cities through the introduction of Traffic Signal Control (TSC) to reduce and prevent traffic congestion [44]. Finally, the concept of Intelligent Traffic Management Systems (ITMS) is on the rise, because of the adoption of the IoT, Cloud computing, and Data analytics in the management of traffic in SMART cities [45]. This system provides the best route to avoid traffic to users based on the advanced collection and processing of data. Also, the concept of green corridor is being enhanced by the use of the IoT in traffic management [45]. Green corridor provides exclusive access to emergency services in cases of emergency – thereby reducing their response time and the efficiency of service provided.
3.2.2. Internet of things
The internet of things is a technology that is focused on communication between machine (Machine to Machine technology) to improve performance [46]. There are five primary types of IoT [47]–
- Military Things (IoMT) (This encompasses the use of the IoT for military activities such as - human-wearable biometrics and surveillance robots for combat.)
- Infrastructure IoT (This is the use of the IoT in the development and management of SMART cities)
- Consumer IoT (This involves the use of the IoT in the development of everyday appliance like voice assistance, home appliances, and light fixtures.
- Industrial Internet of Things (IIoT) (This kind of IoT is used in the development and management of industrial machines in various sectors. For example - SMART agriculture, digital control systems and industrial big data.)
- Commercial IoT (This form of IoT is used primarily in the transportation and health sector. For instance, monitoring systems and SMART pacemakers)
Key components of a SMART cities are – their infrastructure, businesses, industries, consumers, and governing body. As such, the main types of IoT that are predominant in SMART cities globally are Infrastructure, consumer, industrial, and commercial IoTs (See Figure 8 for more information).
A very important infrastructure in IoT enabling SMART cities is the Cyber-Physical System (CPS). These systems are highly intelligent systems that have the capability to learn, create a link between physical systems and the virtual world, and are controlled and monitored by computerized algorithms[48]. On the other hand, the two primary forms of the commercial IoT are the personal and SMART home IoTs [49] while infrastructural IoT are IoTs that has been deployed successfully to drive performance in various sectors of the economy [50].
3.2.3 Energy efficiency
The key importance of the SMARTness of SMART cities is their ability to be green in their production, transmission and utilization of energy. The IoT is playing a major role in ensuring key components within SMART cities – globally - use energy, efficiently. According to Hatcher [51], both commercial and residential buildings – within SMART cities – are all energy efficient through the adoption of accurate metering systems (SMART metering systems). Other factors that improve the energy management within SMART cites include [51] –
- Microgrids (low carbon microgrids that support the local generation and consumption of energy within SMART cities. These systems use advanced data analytic proficiencies to make useful predictions to enhance the way energy is managed)
- Self-learning buildings (These buildings have the potential for improving energy efficiency through the use of data mining methods and wireless sensor technology).
Humayun [52] argued that the three technologies that have enabled SMART cities to be energy efficient are – the Internet of Things (IoT), cloud computing and 5G. Key infrastructures within SMART cities that have benefited from the adoption of these technologies are - building and street billboards, street lighting, smart parking and smart homes. Paul et al. [53] concluded that green IoTs do not only have the potential to protect the environment, but they are also very potent in ensuring the efficient use of energy within SMART cities. The ability of these systems to be green is enhanced by the IoT amongst other technologies. However, without appropriate collection and analysis of data, SMART cities cannot use energy efficiently [54].
A major benefit of the internet of things in the management of energy is the rise of the concept of the Internet of Energy (IoE). The use of the IoT in distributed energy systems is to make the management of energy efficient, while considering the protection of the environment, and this is known as IoE [55]. This is making the IoE the legal background for the development of SMART cities. For instance, Building Energy Management Systems (BEMs). These systems make the use of energy by buildings more efficient using advanced monitoring systems [56]. A practical example of this system has been developed and deployed in South Korea by Korea Telecommunications (KT) known as the Smart Grid Building Energy Management System (SG-BEMS) [57]. A different example of IoT enabled buildings are the net zero energy buildings (nZEBs) [58]. The key principles behind the development of nZEBs buildings are the use the seamless connections amongst energy infrastructures, the use of renewable sources of energy, and a means to measure the efficiency of energy [59].
Other benefits of the adoption of the IoE by SMART cities include – the rise of the use of electric vehicles, SMART trackers, SMART meters, solar panels, wind turbines, SMART homes and SMART grids [60]. In-addition, the IoE is giving rise to the growth of Virtual Power Plants (VPP) in SMART cities [61]. A VPP allows various sources of energy to be integrated into one system to optimize energy supply [62]. This system is powered by decentralized power generating plants – which could all be net zero energy plants - to maximize optimal performance [63].
3.2.4 Sustainability
The main concern of IoT enabled devices relates to its ability to ensure sustainability. According to Peter and Mathew [64], the main aim of the use of IoT devices in smart cities, smart grid, e-health, etc. is sustainability. They are various aspects of sustainability that a SMART city has. According to Goodland [65], there are four main types of sustainability –
- social,
- economic,
- human, and
- environmental.
Social sustainability encompasses the creation of services and products that preserve social capital - representing the framework of a society [66], while economic sustainability seeks to ensure long term economic sustainability, while preserving the environment and ensuring social resources are preserved [67]. Social sustainability focus on maintaining social equality, while economic sustainability focuses on improving the standard of living in a society. On the other hand, human sustainability consists of all specific strategies, goals, and methods that are geared at preserving the quality of human life [68], while environmental sustainability are activities geared at protecting the welfare of human - whilst safeguarding natural capital, such as - water, land, minerals, air, etc [69]. SMART grids encompass all the four forms of sustainability, which is one of its key benefits to the society and the reason for its adoption globally.
A case analysis of SMART cities in London and New York shows that SMART cities are now becoming very important considerations in politics and are key components of techno-political projects [70]. Techno-politics can be broadly classified into two streams [71] –
- internet-enhanced politics (e-government and Politics 2.0 e.g such as - e-campaign, e-voting, and e-petition) and,
- internet-enabled perspective (emphases the importance of ICT technologies in citizen participation, politics, and deliberative processes).
The sustainability role of SMART cities is helping governments in various countries achieve their United Nations (UN) goals on sustainability. According to Ismagilova [72], SMART cities have the capacity to help governments achieve the UN sustainable goals. When considering sustainability from a SMART city perspective, Urban sustainability comes to light. Urban sustainability looks at sustainability from three dimensions – economic, environmental, and social [73]. Based on the analysis of extant literature carried out in this study, a direct correlation of the adoption of the IoT and the sustainability performance of SMART cities has been established.
3.2.5 SMART Grid (SG)
SMART grids are made up of networks of electricity grids that ensures the flow of electricity in two ways and promotes the SMART metering of the consumption of electricity [74]. Tanwar et al. [75] argued that the IoT and SMART grids are the most important components in SMART cities. This is because without energy, and the interaction / communication provided by the IoT - all other components within the SMART city will be rendered non-operational. The main advantage of SMART grids over traditional energy generation systems is its ability to ensure sustainability in production, management and distribution of electricity, while maximizing profit. SMART grids are self-sufficient structures that have the capability to quickly resolve issues associated with energy generation and transmission; limit the number of human resources used; and ensure a sustainable, safe, quality and reliable source of electricity for users [76]. According to Saidani et al. [77], sustainability and energy efficiency are the primary advantages realized from the adoption and use of SMART grids in generating power in SMART cities.
One of the reasons the adoption of SMART grids in SMART cities is growing is because of the scarcity of non-renewable energy sources and the associated environmental issues related to its use [78]. Because of the adoption of SMART cities, a new concept - Energy Internet (EI) is growing. EI is helping many sustainable sources of energy generation - to be integrated into SMART grids to improve energy efficiency and drive sustainable development [79]. EI provides a harmonized platform for trading of energy from various sources [80]. It is also making the environment SMART through the adoption and use in smart homes, smart metering, energy management infrastructures in smart cities [79]. Some of the benefits of the adoption of ICT technologies (including the IoT) in SMART grids, include [81] –
- Automation of home energy systems.
- Tracking of home energy usage.
- SMART streetlights.
- Electricity pricing that is dynamic.
- Automation of distribution systems.
Home Energy Management Systems (HEMSs) help to ensure proper energy management in homes [82]. Automating this system improves it performance & ensure efficiency in the management of energy and ensures that customers get value for the money. This reduces waste and ensures long term sustainability in energy management. On the other hand, the IoT is also solving home energy tracking usage issues that traditional systems could not solve. These issues include [83]–
- The long time it takes to process information.
- The possibility of the unit being stolen.
- High cost of human resources
- Lack of real time information on usage
EI is bringing a new way of managing energy through the adoption of peer-to-peer energy trading and sharing (P2P-ETS). In a P2P system, decentralized systems of energy generation can sell and determine the price of energy by negotiating directly with partners [84]. On the other hand, EI is also leading to the development of crowdsourced energy systems (CESs), CESs are systems that generate energy from decentralized systems and the energy generated can be traded - through crowdsourcing from various energy sources [85]. The two main components of the CES are crowdsourcee (producer) and crowdsourcer (CES operator or utility) [85].
Another notable advantage of the deployment of the IoT in SMART grids is its importance in helping to reduce congestion within the system and its ability to ensure the security of the system [86]. Others include – energy optimization, and the monitoring and control of the consumption of energy [87], [88]. Meanwhile, IoT enablers of the performance of SMART grids include - Smart Metering (SM) and Advanced Metering Infrastructure (AMI) [89]. An IoT tool that improves the performance of SMART streetlights is the street lighting intelligent diode (LED) technology that ensures the conservation and monitoring of energy [90], [91]. While SMART measurement of the utility of energy makes it possible to conserve energy and collect information on the quality of energy [92].
3.2.6 Cloud computing
Cloud computing is a paradigm for promoting on-demand convenient, ubiquitous network access to a shared pool of computerized resources (storage, networks, applications, servers, and services) that can largely work independently through visualization and multi-tenancy arrangement [93]. Over the years, the IoT has brought improvements to cloud computing to make it Edge Computing [93]. Other forms of cloud computing include - Fog Computing, Mobile Edge Computing, Fluid Computing, Mist Computing, and Dew Computing [93]. Cloud computing is very important to the development of the IoT, because cloud computing provides processing and storage services to the IoT [94]. Within SMART cities, cloud computing is improving services such as - transportation, healthcare, education, buildings, and energy [94]. The benefits of cloud computing in SMART cities can be summarized as [94] –
- Bandwidth management
- Latency Management.
- Smart Governance.
- Power Management.
- Smart Parking.
- Smart Grid.
- Smart Lighting.
- Smart Governance.
- Smart Water Management.
- Smart Municipal Service.
- Resource Management.
- Smart Building.
- Smart Transportation.
- Mobility.
- Smart Waste Management.
- Smart Energy.
- Application Classification.
- Security.
- Smart Healthcare.
- Smart Grid.
- Smart Citizen.
- Smart Education.
As the adoption of the IoT in SMART cities continues to increase, the need of the internet continues to rise. On the other, this increase leads to some data and security issues. However, the adoption of fog computing is helping resolve these issues [95], [96]. In-addition, cloud computing is revolutionizing the information system within SMART cities. According to Jinag [97], the IoT and cloud computing is improving information management and sharing in SMART cities. Furthermore, the IoT and cloud computing are important to improving services in SMART cities. These services include the overall management of power plants, colleges, transportation systems, schools, law enforcement, hospitals, universities, water supply, waste management, libraries, etc [98].