Background
There is growing interest in wastewater heat recovery as an innovative approach to decarbonizing buildings. The process uses heat exchangers and heat pumps to exchange heat with wastewater, recovering heat in winter and dumping heat in summer. Waterloo Region Community Energy recently released a report1 explored the potential for wastewater heat recovery in the region. The report highlighted a main sewer line that crosses through campus with potential for a wastewater heat recovery project. In addition, Enbridge Gas is currently offering incentives2 for heat recovery projects as part of their demand side management commitments.
For the University of Waterloo, wastewater heat recovery has the potential to significantly reduce the energy and fuel needed to operate the district heating system and the system can be reversed to provide cooling in the summer months. The University of Waterloo aims to reduce its operational emissions by 35% below 2015 levels by 2030 and it plans to achieve carbon neutrality by 2050. Natural gas used primarily for space conditioning is the single largest source of campus emissions, accounting for 92% of total emissions (scope 1 and 2). This work supports:
- Action 38 of the Shift Neutral Climate Action Plan: Conduct a feasibility study on renewable energy sources and an appropriate portfolio that would diversify Waterloo’s energy supply, minimize emissions, and meet suitable portions of campus needs.
- Sustainable development Goals 7 and 13, for affordable and clean energy and climate action.
Scope of Work Could Include
- Research the best practices for use of wastewater heat recovery for space conditioning (heating and cooling) in institutional buildings.
- Model the heating and cooling loads that could be supplied by wastewater heat recovery from the municipal line running through campus or branch lines connected to individual buildings.
- Partnering with Plant Operations to use temporary meters to identify heating/cooling loads that match the wastewater heat recovery potential.
- Conduct a cost analysis of wastewater heat recovery including estimated upfront and installation costs, projected maintenance costs, and projected operational costs at current electricity prices.
- Detail any incentives available for the technology.
- Calculate the greenhouse gas emissions impact of installing a wastewater heat recovery system.
- Outline any further considerations that should impact a decision to install wastewater heat recovery.
Resources
Data is available through the Sustainability Office for natural gas consumption for the district heating system overall but not for specific buildings. The Sustainability Office can facilitate engagements with Plant Operations to meter the heating/cooling loads of specific buildings.
Stakeholders
- Sustainability Office
- Plant Operations
Proposed Deliverables
The details of the deliverables are flexible but must meet the requirements set out by the course instructor. Some proposed deliverables include:
- A work plan early in the term outlining key milestones and responsibilities.
- Updates on progress at least once during the term.
- A final report outlining the outcomes of the study.
1 https://wrcommunityenergy.ca/wp-content/uploads/2021/11/Waste-Water-Heat-Recovery-Report-FINAL.pdf
2 https://www.enbridgegas.com/business-industrial/incentives-conservation/energy-solutions-byequipment/industrial-process-equipment/heat-recovery