• Energy Research
• 11. Sustainability close

Abstract China has set ambitious carbon emission reduction targets to combat climate change, however, there has been little scientific focus on the achievement of deep decarbonization at the provincial level. The contradiction between rapid economic development and increasing energy utilization exacerbates the difficulty of achieving this goal. Here, we explored the feasibility of fulfilling deep decarbonization in the energy system by 2050 in Sichuan, one of the leading provinces in economic growth in China. Three transition pathways sustained by imported electricity, biomass, and natural gas were developed and simulated using the EnergyPLAN model. All the pathways utilized local hydropower, wind power, and solar photovoltaic resources. These pathways were evaluated using multi-dimensional analysis considering energy self-sufficiency, environmental sustainability, and economic affordability. We found that the energy self-sufficiency rate of the 100% electricity pathway was less than 68%, whereas those of the other pathways were nearly 100%. The CO2 emission reduction differed by pathway, with 100% electricity achieving 91.52%, biomass achieving 90.48%, and natural gas achieving 58.17%. Moreover, all the pathways achieved zero direct CO2 emissions with carbon capture and sequestration (CCS) technology. From an economic perspective, the highest system cost, i.e. 1.3 times that of the reference system, appeared in the 100% electricity pathway after introducing CCS technology, and was comparable to the energy system costs of other provinces in 2050. The methods and results of this study can serve as a basis for facilitating decarbonization in any provincial energy system in the long term.

Abstract Electricity generation, transmission, and distribution have jointly constituted a major challenge in Nigeria for decades. Currently, approximately 41% of the country’s citizens have no access to electricity. In this study, an economically viable, renewable, and sustainable plan to achieve 100% electrification in Nigeria by 2030 is presented. The use of natural gas (NG), wind onshore (WON), wind offshore, photovoltaic (PV), concentrated solar power, and hydro-power plants was analyzed. Pumped hydro-storage is the only electricity storage system considered in this study. A total of 99 different scenarios resulting from the combination of the aforementioned technologies were considered. The initial investment, total annual cost, share of renewable energy, carbon emissions, and electricity production of each of the scenarios were analyzed. A one-year analysis based on hourly time-step was conducted using EnergyPLAN. Power production importation and critical excess electricity production are the deterministic factors in this study. The electricity demand in Nigeria is estimated to be 200 TWh/yr by 2030. A NG capacity of 36,000 MW will be required to meet this demand if a single power technology is implemented. The most sustainable plan is the use of combined NG and PV or NG and WON to meet the electricity demand.

Abstract Water abandonment in hydroelectricity production is a major challenge that can be solved with an increase in electricity demand. China as a country with huge hydropower installation is faced with the problem of underutilizing the hydropower potential due to inadequate electricity demand and transmission facility. In this study, we investigate the potential of hybridizing hydrogen production with hydropower stations in Southwestern China. We found that the integration of hydrogen production with hydropower stations will help reduce the country's CO2 emissions and as much as 1.18% reduction in China emission can be achieved adopting this methodology. In a hydropower station of 750 MW capacity, about 3.142 × 108 kg of hydrogen could have been produced from the abandoned water in 2019. This will also result in 351, 734, 330.9 kgCO2/yr emission reduction. We also developed a model to determine the optimized hydrogen installed capacity based on different parameters. Based on 2019 data, the CO2 emission of China will be reduced by 0.127% with the production of hydrogen from the excess electricity of a 750 MW hydropower station (Case study A) in Sichuan Province.

Abstract Agriculture and its corresponding farms are an integral part of every society/country. In recent years, the energy consumption by farms has risen as sophisticated technologies (that require a high amount of energy) are used for the pre-processing/storage of farm produce. In a bid to advance the transition toward cleaner energy consumption in farms, the thermodynamic assessment of two innovative high-performance solar-based multigeneration systems is presented in this study. Based on the identified most crucial energy needs in farms, the multigeneration systems are designed to produce electrical power, cooling/refrigeration effect, hydrogen, and domestic hot water. In comparison to existing literature, this study is novel as it analyzes the daily performance of the multigeneration systems based on the integration/comparison of two storage techniques. While thermal storage is integrated with one multigeneration system (MGS-TS), the power-to-hydrogen conversion and use of the hydrogen in a solid oxide fuel cell is considered as the storage mechanism in the second system (MGS-SOFC). To analyze the daily performance of the systems, solar parabolic trough collectors are used to produce the input thermal energy based on a 6-hour availability timeframe per day, and the storage systems are designed to power the system for the remaining 18 h. The multigeneration systems developed are analyzed using the energy/exergy approach while the economic costs of the systems are also compared. The effect of different crucial parameters including, ambient temperature, discharge periods, dispatch rates, etc. on key variables related to the systems is investigated. Based on the performance assessment of the two high-performance systems modeled in this study, the overall energetic and exergetic efficiencies are 55.37% and 53.70% for MGS-TS, and 51.12% and 46.82% for MGS-SOFC. The total daily electricity, cooling/refrigeration effect, and hot water useful outputs from the two multigeneration systems are 61,630 kWh/day, 7,939.1 kWh/day, and 125,178 Liters/day for MGS-TS; and 34,597 kWh/day, 15,504 kWh/day, and 129,686 L/day for MGS-SOFC respectively. While the performances of the two systems differ slightly, the unique advantages of each are embedded in their useful energy products.

Abstract Over the last 20 years, development in China has followed a positive trend. However, the high energy consumption has impacted the environment negatively. About 239 cities fell short of the national air quality standard in 2017 and the groundwater fell from quality 31.9% to 10.9% in 2018. In this study, the use of solar PV and onshore wind turbines for electricity generation in a particular area in China is analyzed. The integration of hydrogen production and Electric Vehicles (EVs) into the energy mix is dynamically modeled. Three storage mechanisms namely; vehicle-to-grid (V2G), V2G + batteries, and V2G + pumped hydro storage was considered. EnergyPLAN computer program is used to perform a dynamic simulation in this research to analyze the potential carbon emission reduction of the proposed methodology. The optimal PV and on-shore wind turbine capacity required for a 1 TWh/yr electricity demand and 0.02 TW/yr EVs charge demand is 400 MW and 350 MW respectively. The storage capacities are 30 GWh of V2G, 55 GWh of V2G + Batteries, and 60 GWh of V2G + pumped hydro storage with various charge/discharge hourly profiles. The proposed methodology in this research will reduce the yearly coal consumption by 495.3 kton and yearly carbon emission by 368.2 kton.

Abstract Unlike previous studies where models/methods used in determining the carbon emission are presented, in this paper, a detailed analysis of the causes, trends, and solutions to carbon emission in Africa is presented. Economic development plays a crucial role in the well-being of a country/continent, thereby, affecting energy consumption. The impact of economic development on Africa's carbon (CO2) emissions trend is first investigated. After which, three neural network models are developed to predict the future trend of total CO2 emission in the continent. Then, the use of renewable energy (RE) sources for power generation is analyzed/proposed as a viable solution for CO2 emission reduction in Africa. Finally, the impact of battery electric vehicles (BEVs) integration and hydrogen production in maximizing RE production in Africa's largest economy is analyzed. Secondary data of the economic indicators for twenty-five different African countries have been used to justify the effect of economic development on their carbon emission. From the results of the analyses, gross national income and carbon emissions in all sectors were found to be significantly positively correlated. That is, as national wealth across Africa increases, carbon emissions in the continent increase. Also, the predicted total annual CO2 emission showed that most countries will witness an increase in total CO2 emission by 2022 in comparison to 2018. The proposed RE-based method for power generation showed that the CO2 emission from the power industry can be reduced to zero for an African country. Nevertheless, the use of BEVs and the production of hydrogen will be integral in achieving this.

Abstract Reduction of greenhouse gas emissions in the building sector has become a global concern in terms of ensuring sustainable development. Thus it is imperative to investigate the utilization of clean electricity in buildings. This study proposes a novel, cost-effective commercial building-oriented power supply system for providing a comfortable environment in a shopping mall. An energy management strategy is also proposed for this system. Two types of electric vehicles (EVs) are considered, and their models are developed separately based on different stochastic behaviors. Furthermore, the integration of retired electric vehicle batteries (REVBs) in commercial buildings is one of the possible methods for achieving echelon utilization. To address the uncertainties in the system, the scenario-based stochastic optimization method is applied, which formulates the energy management problem as a mixed-integer linear programming model. Results show that by integrating only photovoltaic (PV) energy and both PV and REVBs into commercial buildings, reductions of 82.2% and 83.3%, respectively, in the expected operational cost can be achieved. This proves that the application of PV and REVBs is beneficial for commercial buildings. Moreover, the robustness of the employed method is proven through comparison with other methods.