In 2022, Enchanted Rock’s generators became the first of their kind to secure the coveted California Air Resources Board Distributed Generation (CARB DG) certification. The CARB DG certification has some of the strictest emission requirements in the world, making this certification a significant milestone not just for Enchanted Rock, but also for businesses and government facilities seeking cleaner backup power solutions.

In California, electrical generation technologies that are exempt from air district permit requirements need to meet specific criteria pollutant emission standards stipulated by the CARB. DG, meaning distributed generation, refers to electrical generation sources that are located near where the consumption of energy will occur, as opposed to centralized power plants. These types of technologies include engines, fuel cells and microturbines, all of which typically supplement electricity being supplied by the grid.

Prior to Enchanted Rock, no reciprocating engines have had low enough emissions to receive the CARB DG certification. According to CARB’s report, Guidance for the Permitting of Electrical Generation Technologies, there was little expectation that reciprocating engines could meet the standards:

“In general, reciprocating engines will have a difficult time achieving the equivalent emissions of a central station power plant. To achieve the central station power plant NOx emission level, 1 ppmvd at 15 percent O2 or 0.015 g/bhp-hr would have to be achieved, assuming the efficiency of the engine does not change. This would represent an additional 90 percent reduction from the lowest emission level achieved in practice.”

However, after rounds of rigorous testing, our reciprocating engine became the first to meet CARB’s strict emission standards. The engines, used for Enchanted Rock’s dual-purpose microgrids, ensure operational continuity for companies, critical infrastructure, and communities during unexpected power outages, and also provide grid stability services.

Distributed generation is becoming increasingly important with the looming threat of heat waves, flooding, and other extreme weather, as well as targeted cybersecurity attacks, and an aging electric grid. CARB DG-certified technologies are a trusted aspect of both sustainability and resiliency plans. The certification ensures that the technologies contribute to cleaner communities in California, supporting the health of nearby residents.

Our solutions have the advantage of lower local pollutants and noise, further mitigating the concerns of the communities where they are located. We accomplish this by utilizing natural gas, a significantly more sustainable alternative to diesel backup generators (80-96% lower emissions than Tier 4 diesel standards). Compared with other CARB DG-certified technologies, there are also vital advantages in cost, island mode transient response, and power density.

The market shift towards decarbonized backup power is already making great strides. Microsoft will be using Enchanted Rock’s ultra-low emission generators in their new data center in San Jose, CA. The project will be the state’s largest renewable microgrid to date and will ensure that Microsoft’s data center operations run uninterrupted while also contributing to the company’s ambitious net-zero goals. With a company as important as Microsoft making this move, the data center community is taking note, and microgrids like ours are on their way to replacing diesel as the new standard in backup power.

This certification process was not easy, and our technology surprised many with how clean it is (but not us!). We’re extremely proud of this certification and hope our customers can also share with pride how their backup power solutions are CARB DG certified and powering a cleaner world now and in the future.