In the coming decades, the energy bills associated with adapting to rising temperatures in Marrakech could transform into a significant challenge, as recent scientific research indicates that the demand for energy required to cool buildings may increase by approximately 40% by the year 2090 if high emission scenarios materialize. This research, published in the journal "Environmental Challenges" by Elsevier, explores the nexus between climate change predictions, urban heat island phenomena, and energy consumption in buildings, while examining the impacts of these factors on three different urban fabric patterns in Marrakech.
The researchers utilized Meteonorm data to generate future climate forecasts, Urban Weather Generator for simulating urban climates, and the EnergyPlus program to calculate energy needs for buildings. The simulations considered scenarios for the years 2030, 2050, 2070, and 2090 under three different emission trajectories.
Cooling Demand Surges by 40% while Heating Needs Plummet by 85%
Under the RCP 8.5 scenario, representing a high-emission pathway, the research predicts that the total electricity consumption in the modeled buildings will rise by about 19.2% by 2090, reaching 146,104 watt-hours per square meter annually. This figure conceals a more profound shift in consumption patterns, with the energy required for cooling increasing from 67,593 to 94,630 watt-hours per square meter annually, reflecting a nearly 40% surge, while the demand for heating is expected to decline dramatically by about 85%, decreasing from 4,170 to 632 watt-hours per square meter annually. These figures highlight a significant transformation in the energy balance of buildings, where the need for heating diminishes with rising temperatures, while the demand for cooling escalates, indicating a gradual shift in energy pressure towards the hotter months.
In comparison, the less severe RCP 2.6 scenario predicts a more modest increase in total electricity consumption, limited to around 2.6% by 2090, amounting to approximately 125,773 watt-hours per square meter annually, whereas the increase is about 8.8% in the RCP 4.5 scenario.
Assessing Different Urban Patterns: Old City, Modern Developments, and Unstructured Areas
The simulations encompassed three distinct urban patterns in Marrakech: the old city, the Asil neighborhood as a model of a planned modern area, and the Zik neighborhood representing unstructured urbanism. These locations were selected to illustrate clear differences in density, building forms, street widths, and urban structure. The research relied on three-dimensional models of these areas and validated the performance of the urban climate model by comparing it with field measurements taken in the old city, demonstrating the model's good capability to simulate urban temperatures.
Despite the apparent differences among the three urban fabrics, the research found that variations in total energy consumption remained minimal, staying below 0.3% across different scenarios. This suggests that under the conditions of the utilized model, the trajectory of rising temperatures is a more significant factor than morphological differences between neighborhoods.
Furthermore, the results indicate a seasonal change in the impact of the urban heat island effect, where the cooling costs associated with it increase during winter under the high-emission scenario, while the temperature differential between the urban area and its surrounding environment diminishes during the hottest summer months as external temperatures also rise.
The implications of these findings extend beyond mere thermal comfort within homes, as the growing reliance on air conditioning signifies an increased demand for electricity, particularly during extreme heat periods. This situation presents challenges for grid planning and its capacity to accommodate future loads. The research suggests that the increase in cooling demands under the RCP 8.5 scenario by the century's end approaches an additional 27,000 watt-hours per square meter compared to the current situation, representing about 22% of the total current electricity consumption of the typical building used in the simulations.
Moreover, the findings connect the energy challenge with urban planning options, emphasizing the importance of insulation, shading, and mitigating heat accumulation within urban areas, as well as improving building designs. However, the research highlights that these local interventions may have limited effects if global emissions trajectories continue on an upward trend. It is important to note that the 40% increase should not be interpreted as a definitive forecast for the energy consumption of all buildings in Marrakech by 2090, as the study relies on a standardized model building and tests it across different urban climates, while actual buildings in the city vary significantly in age, construction materials, insulation, air conditioning features, and resident behaviors—limitations acknowledged by the research itself.
The key takeaway emphasizes that the future of energy demand in Marrakech is closely linked to the trajectory of emissions over the coming decades, with consumption growth remaining limited in lower-emission scenarios, while the need for cooling escalates sharply in more severe scenarios, transforming rising temperatures into a challenge that impacts urban planning, electrical networks, and the cooling costs borne by households.
As reported by hespress.com.
