Energy Saving at Cities

Abstract

The use of renewable energies, energy saving, and efficiency are needs of global society. According to the latest estimates, global energy demand could triple by 2050 and, by then, 70% of the world’s population will live in cities. Cities are currently responsible for 80% of greenhouse gas emissions, so they have a key role to play in shifting towards a sustainable energy future. Cities are threatened not only by overcrowding, but also by rising energy demand, obsolete infrastructure, volatile energy markets, and the effects of climate change. This Special Issue aims to advance the contribution of energy saving and the use of renewable energies in order to achieve more sustainable cities.

1. Introduction

Climate change is increasing due to the anthropogenic emission of greenhouse gases. The majority of these are due to the production and consumption of energy. The challenge for the future cities is the implementation of a mechanism that minimizes the need for injection of new energy resources in them, so that a high level of self-sufficiency should be achieved through the concept of circular economy, thus partially mitigating the impacts of climate change. Using solar energy today is considered to be one of the best solutions that can be installed in buildings to help with this issue.

This Special Issue aims to advance the contribution of energy saving and the use of renewable energies in order to achieve more sustainable cities. This Special Issue sought contributions spanning a broad range of topics related, but not limited to:

• Solar energy
• The use of rooftops for energy generation
• Energy conversion from urban biomass or residues
• Energy management for sewage water
• Bioclimatic architecture and green buildings
• Wind energy
• Cogeneration
• Public and private urban energy saving
• Policy for urban energy saving
• Smart meters
• Zero-energy buildings
• Legislations, regulations, and standards of energy

2. Publication Statistics

Details of the call for papers for this Special Issue, regarding the articles submitted being published or rejected, were: 10 articles submitted (100%), 3 articles rejected (33.3%), and 7 articles published (66.6%).

The regional distribution of authors by countries for the published articles is presented in Table 1, in which it is possible to observe 20 authors from six countries. Note that it is usual for an item to be signed by more than one author and for authors to collaborate with others from different affiliations. The mean number of authors per published manuscript was four authors.

Table 1. Authors’ countries.

Country	Authors
Spain	6
Mexico	4
Palestine	4
China	3
Portugal	2
UEA	1
Total	20

3. Authors’ Affiliations

This Special Issue’s authors and their first affiliations are reflected in Table 2.

Table 2. Authors and affiliations.

Author	First Affiliation	Country	Reference
Azevedo, I.	University of Porto	Portugal	[1]
Leal, V.	University of Porto	Portugal	[1]
Abdallah, R.	An-Najah National University	Palestine	[2,3]
Juaidi, A.	An-Najah National University	Palestine	[2,3]
Assad, M.	An-Najah National University	Palestine	[2]
Salameh, T.	University of Sharjah	UAE	[2]
Manzano-Agugliaro, F.	University of Almeria	Spain	[2,3,4]
Abdel-Fattah, S.	An-Najah National University	Palestine	[3]
Perea-Moreno, A.J.	University of Cordoba	Spain	[4,5,6]
Alcalá, G.	Universidad Veracruzana	Mexico	[5,6]
Hernandez-Escobedo, Q.	Universidad Autónoma de Mexico (UNAM)	Mexico	[5,6]
Yi, P.	Sichuan University	China	[7]
Huang, F.	Sichuan University	China	[7]
Peng, J.	Sichuan University	China	[7]
Garrido, J.	Universidad Veracruzana	Mexico	[5]
Rueda-Martinez, F.	Universidad Veracruzana	Mexico	[5]
de la Cruz-Lovera, C.,	University of Cordoba	Spain	[4]
de la Cruz-Fernández, J.L.	University of Cordoba	Spain	[4]
G Montoya, F.	University of Almeria	Spain	[4]
Alcayde, A.	University of Almeria	Spain	[4]

4. Topics

Table 3 summarizes the research carried out by identifying the topics to which they belong, according to the proposed topics in the special issue. It was noted that two “Energy Saving at Cities” topics dominated the rest: “Solar Energy”, and “Sustainability”.

Table 3. Energy Saving at Cities.

Energy Saving at Cities	Number of Manuscripts	Reference
Solar Energy	2	[3,6]
The use of rooftops for energy generation	1	[3]
Energy conversion from urban biomass or residues	1	[2,3]
Wind energy	1	[5]
Public and private urban energy saving	1	[4]
Sustainability	2	[1,7]