Harshil Trivedi, MEL Candidate | December, 2020
APPP 506 – Master of Engineering Leadership Capstone Project, University of British Columbia
Abstract
A Northern Albertan Nation has engaged Community Power to explore options for renewable energy generation with the goals of reducing electricity expenditure, establishing energy sovereignty, and reducing negative impacts on the environment. Based on the initial evaluation of renewable energy alternatives, biomass emerged as the most potential source for power generation. This feasibility study for biomass power generation is performed by validating load data, analyzing technologies & their commercial availability, and financial viability. Two biomass CHP (combined heat & power) technologies, Gasification with IC Engine and Organic Rankine Cycle, are considered in this study. Three suppliers are approached and their technical & cost evaluations are performed to obtain the most economic configuration for the Nation. The rates for selling electricity back to the grid are dynamic and uneconomical, hence the selected scenarios are offering optimum output for the community consumption with minimum sell to the grid. Different configurations were simulated, the result indicates the most viable solution as 140 kWe biomass CHP plants at community A and B, while 49 kWe CHP unit for community C. Additionally, thermal energy produced from the CHP plant will reduce the consumption of propane for residential heating. Carbon offset through biomass generation will decrease GHG emissions from Alberta’s carbon-intensive energy mix.
Introduction
Many of the first nation communities in Canada rely on utility companies for electricity. The utility companies have higher transmission and distribution cost for the remote locations, that results in expensive electricity for the communities. They are also using inefficient energy sources such as propane, diesel/furnace oil for heating. It results in significant expenditure on energy consumption for community members. Renewable sources of energy are the most affordable & sustainable alternatives to improve this scenario, which also helps Nations to become self-sufficient in energy requirements. These projects reduce environmental impact and aid to achieve the energy transition targets of Canada. The government and other agencies support renewable energy initiatives through financial schemes as part of sustainable energy drive. Biomass is one of the potential sources that offer electricity at a reduced cost along with supplementary heating, for the communities.
Project Background
The Nation is located in Northern Alberta. It consists of three communities; A, B & C with a total population of ~4200 as of 2019. The total residential annual energy consumption is 7400 MWh among 591 homes, which is 73% higher than the average household consumption of Alberta. Also due to the remote location, transmission and distribution charges contribute to 70% of the total energy bill.
Community Power was engaged by the Nation to explore options for renewable energy generation. In the initial study, various renewable energy sources such as Solar, Wind, Hydro, Geothermal, and Biomass were evaluated. A cost-benefit analysis was performed for solar and biomass options considering different scenarios of the Nation’s energy requirement. Biomass power generation was the most viable option with positive net present values (NPV) for all three communities. This project is focused on the study of biomass power generation with a detailed analysis of available technology suppliers in the market, its compatibility, and firm cost estimation to secure the funding for the project.
The primary objectives of this project are
- Analyzing the load profile of community & validating assumptions of the initial study
- Study of various biomass CHP technologies & exploring potential suppliers for the system
- Project cost estimation, financial feasibility analysis, and GHG emission study
- Recommendation based on techno-commercial evaluation
Research Methods
Research papers and project reports on similar biomass energy were studied, mainly biomass electrical generation technologies study for Yukon government, Pembina Institute’s report on power shift in indigenous communities, Biomass CHP installation at Kwadacha Nation, etc.
Nation’s electricity consumption data was collected from ACTO and data validated with the initial study. Biomass combined heat & power (CHP) unit manufacturers were contacted for plant configuration, technical know-how, installation, and commissioning requirements, maintenance scheduling, and costing. The electricity requirement was modeled in HOMER Pro and analyzed for different manufacturers’ models to arrive at the most efficient solution for the Nation.
Analysis & Results
Electricity consumption data from 2015-19 are collected for the analysis. The study is based on residential electricity consumption only. The average annual energy consumption per home is 12.52 MWh/year. The number of homes in each community was estimated to calculate the energy requirement of the individual community.
There are four biomass technologies commercially available in the market i.e., Gasification with Internal Combustion Engine, Organic Rankine Cycle, Brayton Cycle, and Stirling Engine. During the initial study, it was concluded that 100 kW to 200 kW units are best suited to the Nation’s requirement. Gasification with IC Engine and Organic Rankine Cycle (ORC) are the recommended options for this range.
In the gasifier & IC engine CHP, biomass gasification is achieved through the partial oxidation of the biomass feedstock. The gas is further cleaned in filters and fed to the IC engine for power generation through a connected generator. The heat generated during the combustion process is extracted through district heating and can be supplied to the heating load.
The ORC system consists of a hot water boiler, which uses biomass as fuel; a closed-loop working fluid that is vaporized in the boiler and expanded in the turbine. Power is generated electricity through a turbine coupled generator. The remaining heat is extracted in the district heat exchanger.
Though both technologies are available in the market, Gasification with IC engine has better electrical efficiency for the lower output requirement. There are many suppliers available for it, which offers the turnkey solution for the gasifier & IC engine. ORC system has a larger output range and able to process higher moisture content in biomass. However, only a few manufacturer’s offers such complex turnkey solution. ORC system often requires integration engineering for EPC projects, which is not an economic option for small power requirements.
Spanner Re2 (Germany), Volter (Finland), and Syntech Bioenergy (USA) are contacted and evaluated for further analysis. All three suppliers offer compact CHP modules for biomass gasification with IC engine. The spanner has 49kWe and 70kWe models, Volter has a 40 kWe model, while Syntech Bioenergy’s BioMax Gen2 offers 165 kWe output. Based on technical and commercial offers, the EPC cost of equipment varies from $8900/kWh to $12500/kWh depending on the size and manufacturer of the CHP unit. This includes module cost, logistics up to site, installation & commissioning. Auxiliary cost during the project phase is ~1500 CAD/kWh, which includes a warehouse for the 10 days of biomass storage, wood chipper, and site inspection. During the plant operation, biomass fuel cost is considered as 30 CAD/tonne and O&M cost of 0.04 CAD/kWh.
The HOMER Pro model was prepared to calculate the optimized output. It is observed that Spanner Re2 units are best suited to the Nation’s load profile & energy requirement. After evaluating all simulations, the below table shows the final recommendation with its financial factors. An additional option of a common plant at one location for all three communities and energy will be distributed through connected gird is evaluated as indicated in the last column.
| Community A | Community B | Community C | Common for 3 | |
| Plant capacity | 140 kWe | 140 kWe | 49 kWe | 350 kWe |
| Plant configuration | 2 x 70 kWe | 2 x 70 kWe | 1 x 49 kWe | 5 x 70 kWe |
| Initial Investment | $ 1.65 M | $ 1.65 M | $ 0.60 M | $ 4.12 M |
| NPV | $ 2.2 K | $ 60.3 K | $ 13 K | $ 95.5 K |
| ROI | 2.3% | 2.6% | 2.5% | 2.5 % |
| IRR | 4% | 4.4% | 4.2% | 4.3 % |
| Simple Payback | 13.6 years | 13.1 years | 13.3 years | 13.3 years |
Conclusions
With recommended plant configuration, biomass electricity generation caters to 43% of the total residential electricity requirement of Community A and 30% for Community B & C. Additionally, CHP will produce 5200 MWh annual thermal energy, which will reduce the demand for propane and other less efficient fuel used for residential heating. Total biomass electricity generation will offset 1450 tCO2e of GHG emission annually. This plant will reduce Nation’s dependency on utility companies, create jobs for local people, and contribute to the sustainable energy transition.
Contact
Email: harshil273@gmail.com
LinkedIn: https://www.linkedin.com/in/harshil-trivedi-004903110
References
Community Power. (2020). Renewable Energy Opportunity Assessment.
Dave Lovekin, B. D. (2016). Power purchase policies for remote Indigenous communities in Canada.
Dylan Heerema, D. L. (2019). Power Shift in Remote Indigenous Communities. Pembina Institute.
Preto, D. F. (2014). Evaluation of Commercially Available Small Scale Biomass Electrical Generation Technologies Appropriate to the Yukon.
[ORC system]. (n.d.). Retrieved December 15, 2020, from https://img.favpng.com/21/13/18/fossil-fuel-power-station-coal-biomass-electricity-generation-png-favpng-mw5Ubg7Sdj3WkEVkJK6hJs9Tt.jpg
[Gasifier]. (n.d.). Retrieved December 15, 2020, from https://www.holz-kraft.com/en/products/biomass-chp.html
Kwadacha Nation biomass project [Digital image]. (n.d.). Retrieved December 15, 2020, from https://electricity.ca/wp-content/uploads/2018/04/BC-Hydro_Kwadacha_CEA_Photo-1_Biomass-CHP-Plant.jpg