Energy Services for INtegrated FLexible Operation

Transcript:Energy Services for INtegrated FLexible Operation:
Energy Services for INtegrated FLexible Operation of Wastewater Systems, IEDO Mauter, Stanford Contract Number | 10-01-2021 to 03-31-2023 Abstract OFFICE OF ENERGY EFFICIENCY & RENEWABLE ENERGY U.S. DEPARTMENT OF ENERGY Secondary wastewater treatment processes consume 0.7-0.8 kWh/m3, most of which is provided by the electricity grid. This translates to large electricity costs and air emissions externalities, which can both be reduced by exploiting energy flexibility resources within the wastewater treatment sector. These resources include backup energy storage (i.e., conventional batteries) as well as “virtual batteries” that shift electricity load by storing raw wastewater, primary effluent, or low-pressure compressed biogas. These underutilized energy flexibility resources are expected to support decarbonization and community benefits from the wastewater sector by halving the percentage of flared biogas, limiting local air emission damages from flaring, supporting the stability of the electricity grid, and mitigating the electricity price increases the industry is currently experiencing. This project develops automated control tools for integrated (i.e., facility-scale) planning and operation of wastewater resource recovery facilities’ (WWRFs’) energy flexibility capacity. Its innovation lies in using statistical learning on IoT sensor data and wastewater process models to design cost-effective energy flexibility upgrades to wastewater treatment facilities. Next it uses site-specific, dynamic simulation and control to facilitate real-time operation of the facility for carbon reduction and energy bill savings. During Budget Period 1 (BP1) the recipient developed the simulation-based planning library for WWRFs and used the design tool, TEA, and LCA module to iteratively search for financially optimal energy flexibility upgrades at our partner facility in Northern California. The optimal flexibility upgrades would reduce electricity bills for our partner facility by 17% for a 3% annual return on investment and a payback period as low as 6 years. LCA shows optimal upgrades are associated with a reduction in lifecycle GHG emissions, primarily due to a 45% reduction in biogas flaring. Alignment with Office Mission Background Conclusions Challenges and Impact Challenges: Wastewater consumes 0.7-0.8 kWh/m3; electricity bills are 25-40% of operating expenses Tapping embedded energy flexibility processes to reduce costs must address operational complexity and robustness Impact: 10-20% electricity bill savings due to load shifting and peak shaving 12% GHG emissions reduction due to reduced flaring and peak-hour electricity usage Increased resilience to power interruptions or electricity generation equipment failure High scalability due to tool’s modularity and potential to integrate with existing hardware Project Outline Innovation: Integrated energy flexibility control platform for wastewater