| Abstract | There is no doubt that it is critical and beneficial for Qatar to start utilizing alternative energy efficient solutions to reduce the energy consumption and sustain its natural resources. In particular, commercial buildings consume about 5,000 GWh, which accounts for 19% of the total energy consumption in Qatar, more than 65% of that is consumed by HVAC. To reduce this significant amount of energy, a promising technology can be used: Solid Oxide Fuel Cell Combined Heat and Power (SOFC CHP) with natural gas as fuel. This thesis is focused on studying the feasibility and viability of using SOFC CHP system to supplement energy use in office buildings in Qatar.
An office building model has been created in eQuest energy modeling software package with an area of 7000 m2. ASHRAE 90.1-2010 standard, Qatar Construction Specification (QCS) 2014, Kahramaa policies were considered in developing the energy consumption model in the office building. Moreover, utility costs as per local market have been introduced to the model. Based on that, energy consumption profiles and annual energy costs results were calculated. Then, (Chiappini & et al., 2011) SOFC cogeneration models were integrated in the model to investigate the performance of the SOFC CHP system in the office building. Two climate zones were considered: Qatar and Kuwait in this study. Several baseline cases were considered to optimize the HVAC system and loading profile that could utilize the SOFC to its full extent. These baselines are: electric chiller, absorption chiller, and combined electrical-absorption chiller systems were analyzed.
Performance curves were analyzed for a range of SOFC CHP system capacities (25-250 kW) in terms of energy produced, utilized thermal energy and overall efficiency. Moreover, annual energy costs for the office building were calculated with and without SOFC CHP system to assess potential cost savings. Results showed that using SOFC CHP system will lead to promising savings in annual energy costs reaching a reduction up to 67% from the baseline case. Moreover, optimum overall efficiency reached up to 73%.
In the optimum case scenario in Kuwait, the payback period was found to be 7.8 years, while the net present value was 209,005 $ at SOFC capacity of 250 kW. Applying the same system to Qatar had also led to promising results of payback period of 11.0 years and net present value of 57,742 $ at 200 kW.
Finally, an environmental impact assessment was evaluated in terms of CO2, NOx, and SO2 emissions. It was found that application of SOFC CHP system had led to a maximum reductions in CO2 emissions of 30%, NOx of 90%, and SO2 of 90%.
In conclusion, based on literature review, background information, and analysis developed in this project, it is clear that SOFC CHP system is very promising energy technology for Qatar. It is recommended to establish more researches in this subject to furnish the infrastructure of solid oxide fuel cell technology in Qatar. Future researches shall be directed towards solid oxide fuel cells material selections to enhance lifetime and durability. Moreover, researches to find the optimum exhaust thermal energy utilization systems for hot climate zones are highly demanded to enhance the overall efficiency of the system. |
