# Sustainability Assessment on an Urban Scale: Context, Challenges, and Most Relevant Indicators
## 3 Results and Discussion Regarding the Selected Indicators within the Potential Categories
### Energy Saving Measures  
This category focuses on analysing the issues related to energy-saving measures, which are addressed by the studied sustainability assessment methods through five indicators (Figure 4). Energy-saving is a matter of concern since climate change is one of the most significant challenges faced by all nations. Since the Industrial Revolution, the levels of long-lived greenhouse gases (CO\({}_{2}\), CH\({}_{4}\), N\({}_{2}\)O) have dramatically increased [33]. This demands that the renewable energy share in the total energy generation and consumption is urgently increased [34]. In this regard, using renewable energy sources, such as geothermal,solar, wind, biomass, and biofuels, to meet the growing energy demand will help to keep the pollution of sources at a minimum and promote long-term economic growth [35]. SDG 7, which ensures access to affordable, reliable, sustainable, and modern energy for all, is related to this category, aiming to develop international collaborations and investments in energy infrastructures and clean energy technology. ISO 37120 sets the condition for calculating the total end-use energy derived from renewable sources and public street lighting electricity consumption. Moreover, infrastructure energy efficiency, to reduce the environmental harms from energy used for operating public infrastructure, attention to the municipality's installations in urban areas, specifically public street lighting, is considered an indicator by ISO 37120 and two other tools. Therefore, the essential indicators for assessing the energy-saving measures are:  
Infrastructure energy efficiency: This indicator promotes a reduction in energy consumption through energy-efficient public infrastructure. This indicator is covered by SBTool(tm) (2018), BREEAM-C (2012), and LEED-ND (2018) and supported by SDGs and ISO 37120. An example regarding the focus of the indicator is the development of street-smart lighting in Indonesia, which was promoted under the Nationally Appropriate Mitigation Action [36]. The indicator aims to cut emissions and increase energy supplies by substituting conventional street lighting with more efficient technologies and strategies in cities and urban areas.  
Percentage of total end-use energy generated on-site, derived from renewable sources: This indicator addresses the energy locally produced from renewable sources in the region. It is covered by SBTool(tm) (2018), SNTool (2020), and LEED-ND (2018) and supported by SDGs and ISO 37120. The availability of energy efficiency technologies and the costs of adopting these technologies, which are two aspects typically considered when developing effective energy-efficient buildings and urban communities [37], are considered in this indicator.  
Centralized energy management system: The focus of this indicator is on controlling the use of energy for the timely identification of problems in the network and systems, increasing the potential of flexible loads in demand response. Additionally, district heating and cooling energy systems can be of added value to this indicator. This indicator is addressed by SBTool(tm) (2018), BREEAM-C (2012), and LEED-ND (2018) and supported by SDGs. Energy management systems (EMS) are automation systems that collect energy measurement data from the field and make it available to users through graphics, online monitoring tools, and energy quality analysers, thus enabling the management of energy resources [38]. The Smart City project of Malaga in Spain is an example of this [39]. Some of the centralized energy management systems applications are the use of advanced smart meters to enable remote management for energy efficiency improvements, forward-looking demand management systems, employing a light-emitting diode (LED) street lighting network, and micro-nano generation and high-technology energy storage setups [40]. Additionally, this approach can be used to integrate renewable energy sources, such as solar, wind, etc.