Jason Li | MEL Candidate | Dec 17, 2021.
Mentor: M.K. Anand, Community Power
Abstract
This study provides a feasibility analysis on utilizing renewable energy for a remote, off-grid community to electrify its heating. A PV-based hybrid energy system (HES) is of specific interest in this study. The required heating demand in the community was analyzed using HOT2000 and eQUEST. The HOMER Pro software was used to simulate the operation of HES considered and come up with feasible energy solutions with respect to all possible system configurations. Comparative analysis and sensitivity analysis were carried out for the feasible solutions. The results indicate that operating a diesel/battery system is the most cost-effective solution. The PV/diesel/battery hybrid system requires a slightly higher cost, but emissions are significantly reduced compared to the diesel-battery system. The PV/battery system offers a 100% renewable solution, but a huge upfront cost could be required as a tradeoff.
Introduction
This study is looking into a remote, off-grid community in British Columbia that is currently reliant on wood fuels for heating. Due to multiple factors including pine beetle invasion, the supply of wood is running low. The community is in urgent need of electrification of its heating in a sustainable and affordable way.
The purpose of this study is to explore the technical and economic feasibility of electrifying heating in the community with a specific focus on utilizing solar power to cover the heating demand. A standalone PV-based HES is considered and analyzed. The results are expected to provide an economic and environmental evaluation of the proposed energy solutions for supporting the additional electric heat load in the community.
Methodology
The methodology can be divided into two stages. In the first stage, the required heating demand of the community was analyzed using existing community data and energy analysis tools HOT2000 and eQUEST. In the second stage, the HOMER Pro software was used to perform simulation and optimization for the PV-based HES considered.
Twenty-five HOT2000 household models were provided by Community Power. The models were modified to replace the existing heating systems with electric heat pumps. The annual electric heat load was estimated in HOT2000. The eQUEST software was used to obtain the hourly electric heat load data of a typical household in the community throughout the year. The annual and hourly load data were used as the input for the HOMER Pro’s simulation.
The HOMER Pro software was used to simulate the operation of the HES for all possible combinations of the components considered. As a result, it returned feasible energy solutions with the optimum system configurations, the optimal sizes of individual components, and economic and emission parameters. Finally, cost analysis, environmental assessment, and sensitivity analysis were carried out for the feasible solutions.
Results and Discussion
A total of 9,932 solutions were simulated, out of which only 8,132 were feasible solutions that can meet the load demand and 1,800 were infeasible solutions due to the capacity shortage constraint. The feasible solutions were prioritized based on minimum values of total net present cost (NPC). The optimization results can be categorized in following system configurations:
1.Diesel Generator Only (Base Case)
2.Diesel/Battery
3.PV/Diesel/Battery
4.PV/Battery
For comparative cost analysis, the most cost-effective solution is the diesel/battery system which leads to a reduction of 33.2% in both total NPC and levelized cost of energy (LCOE) as compared to the base case.
For comparative environmental assessment, the PV/battery system is absolutely the cleanest solution since 100% of electricity is produced from solar energy. The second cleaner option is the PV/diesel/battery hybrid, with 26.9% of solar penetration and 46% reduction in total emissions as compared to the base case.
For sensitivity analysis, diesel price and capacity shortage constraint were considered. The PV/diesel/battery hybrid is less sensitive to diesel price fluctuations, which means better system independence. By allowing a small percentage of capacity shortage, the capital cost of the PV/battery system can be significantly reduced.
Summary of Optimization Results
Comparative cost analysis
Comparative environmental assessment
Conclusion
To summarize, the diesel/battery hybrid is recommended as the most cost-effective solution for the community. Taking environmental and human health benefits into consideration, the PV/diesel/battery hybrid could be a good option with an increment of 6.4% in costs and a reduction of 27.1% in total emissions compared to the diesel/battery hybrid. The PV/battery system provides an alternative for the community to achieve 100% renewable generation to cover the heating demand, but a much higher initial cost is required as a tradeoff.
The optimal choice would depend on the specific needs in the community. By considering the diesel price fluctuations and capacity shortage allowance, the PV-based systems could have an opportunity to gain additional operational and economic benefits.
Contact
Jason Li
Email: jason101646@gmail.com
Phone: 6048619282