Community Microgrids: Navigating Roadblocks to Implementation

Located along the Pacific Ocean in California, McKinleyville Community Services District (MCSD) had been struggling for years to get a microgrid backup power solution installed. Various sources of outages – earthquakes, wildfires, and Pacific Gas & Electric (PG&E) safety shutdowns due to potential wildfire conditions – rendered their existing diesel generator backup as the only source of power to the site. At risk were systems that could not operate properly including keeping sensitive wastewater treatment plant processes active. Loss of power for more than a 30-minute duration would put the facility at risk of millions of dollars worth of potential damage to their system biology and could affect water quality discharges to public waterways. As such, having additional resiliency and another power source when the utility power was not available was critical for the facility. Northern California has recently endured various Public Safety Power Shutoff (PSPS) periods, some lasting for days, depending on the area, with no utility power available to the service area. MCSD wanted to implement a microgrid to minimize diesel generator greenhouse gas environmental impacts while keeping their plant operating and continuing service for the community in a sustainable fashion.

To solve for these issues, the district partnered with cleantech integrator, Ameresco, to optimize electrical grid resiliency while delivering both financial and environmental benefits to the community. While there was an existing grant from the local water authority, additional funding from the Inflation Reduction Act (IRA) enabled MCSD to work outside of existing grant dollars to satisfy all remaining, highly complex requirements.  Ameresco is currently working with MCSD to allow the district to recognize value from the IRA which funds 30 percent of a clean energy project once it meets commercial operation requirements. The proposed development could now benefit from dramatically lowered project costs, which needed rigorous engineering, design, permitting, and construction.

There were numerous reasons the project had not proceeded over the years. The site itself presented some unique challenges, especially the plan to co-locate the solar array in a nearby dog park, which faced widespread public opposition. By utilizing the company’s environmental planning staff, representation in public district meetings, and speaking with local constituents, Ameresco was able to identify a course of action to satisfy the public opposition and MCSD staff. Optimizing the planned battery storage system allowed for best value approach to meeting the wastewater facility or utility. Additional environmental constraints prevented siting the system at alternate preliminary locations earmarked for study, such as a large forest that blocked access for the new system, in a state with heavy oversight of tree removal.

Tackling these obstacles head-on, Ameresco proposed to repurpose a wetland pond that was not planned for reuse. Entertaining this new opportunity added potential for the project to proceed but required new environmental assessments to study the impact on local plants and animals. To be certain no endangered species might be disturbed, the teams went through the assessments with a keen eye multiple times until they were comfortable that this project could proceed. With new layouts and system designs that could produce as much energy as the treatment plant would consume, the district approved the project, permitting was granted, and the solar array system connection was approved by MCSD and PG&E.

Microgrid systems and battery technology for storing renewable energy that has been generated can cause additional system complexity. The proposed solution included a 500 kW DC (583 kW DC) Solar Array, 250 KW / 712 kWh battery energy storage, while still utilizing the existing 500 KW standby generator as backup as needed. Full integration and a controller system were implemented to tie these disparate elements together for resiliency and green power at the site. Microgrid systems are highly innovative, completely customized, and relatively new. Engineers even at the utility level are just starting to understand how to integrate them within their plants, so partners must be willing to provide the necessary training.

The project would have been incredibly difficult without a partner committed to seeing it through to implementation, despite many challenges along the way, one willing to do good by its customers and their community. The most important thing to remember with a complex engineered design is that teams will need to take time and be creative with projects. Know when you are launching a project that it is going to take a lot of work with the utility to develop the microgrid and its controls, which is a major consideration in meeting utility specifications. Understand that suppliers are limited for the necessary product solutions, like batteries. At the end of the day, getting the engineering right is critical, much more difficult than just a solar installation. Not all teams will be willing or able to do the heavy lifting to combine the pieces and parts together.

Microgrids provide a solution that is beneficial to full communities as well as industry, boasting energy resilience, supporting net zero transitions, lowering operating costs, and boosting local workforce opportunities. Because of their capacity to provide sustainable energy with long-term cost savings, microgrids are increasingly acknowledged as trustworthy sources of power for emergency and other off-grid scenarios as well as affordable options for reliable and renewable electricity. In addition to providing resilience in case of an emergency, they deliver financial and environmental benefits to the community through reduced water utility rates, reducing the cost burden placed on the general public.

By aligning the right team to design and build this project to best suit the customer’s needs, we were able to solve complex issues together, showing promise for many future microgrid projects. It just goes to show, that if you engage early, stay agile, and maintain trust with your partners, complex microgrid design projects that boost safety and reliability can see the light of day, providing the blueprint for a more sustainable world.