TULARE, CA – California Bioenergy LLC (CalBio) is significantly expanding its renewable energy operations with the addition of eight Mainspring Linear Generators at its biogas upgrading facilities in California’s Central Valley. The move will bring CalBio’s total deployed capacity to 5.3 megawatts (MW) across five sites by the end of 2026, solidifying its position as a leader in waste-to-power technology within the state’s agricultural sector.
The new generators will be installed at CalBio’s North Visalia and South Tulare cluster biogas upgrading sites, each receiving a 1 MW unit. This expansion builds upon a partnership initiated in 2022, when CalBio became the first dairy digester developer in the United States to utilize linear generators powered by dairy biogas, beginning with a 1 MW installation at its Hanford cluster upgrader. Subsequent deployments at Buttonwillow (1 MW) and a standalone dairy digester project in Merced County (1.5 MW) have steadily increased the company’s portfolio.
The deployment of Mainspring’s linear generator technology is driven by its unique capabilities, including fuel flexibility, rapid response times, and low emissions. According to CalBio Chairman and CEO N. Ross Buckenham, the company’s commitment to innovation, efficiency, resilience, and cost reduction is paramount to leading the state in dairy methane emission reductions while simultaneously supporting local family dairies and communities. “We’ve seen what linear generators can achieve, and we are proud to be leading in delivering the valuable benefits of Mainspring’s power design to the dairy industry,” Buckenham stated.
California’s Central Valley, a major hub for dairy farming, faces significant challenges related to methane emissions from livestock. Dairy digesters capture biogas produced from manure, preventing its release into the atmosphere. This biogas can then be upgraded to renewable natural gas (RNG) or used to generate electricity. CalBio’s approach, utilizing Mainspring’s linear generators, offers a pathway to convert this waste product into a valuable energy resource.
The linear generators produce fewer than 1.5 parts per million of nitrogen oxides (NOx), meeting California’s stringent air quality standards without the need for additional after-treatment systems. This is particularly important in the Central Valley, where air quality is a persistent concern. The technology’s ability to operate efficiently on biogas, a variable fuel source, is also a key advantage.
The expansion is expected to deliver an annual greenhouse gas reduction of approximately 1.9 million metric tonnes of CO₂ equivalent, comparable to removing over 430,000 petrol passenger vehicles from the road, according to CalBio. This contribution aligns with California’s ambitious climate goals and its efforts to reduce methane emissions from the agricultural sector.
The project also aims to strengthen energy resilience in rural communities. By generating power locally, CalBio reduces reliance on the traditional grid and provides a more stable energy supply for dairy farms and surrounding areas. This localized energy production can be particularly valuable during periods of grid instability or extreme weather events.
CalBio’s model of aggregating biogas from multiple farms within clusters is a key component of its success. This approach allows for economies of scale and reduces the logistical challenges associated with collecting and processing biogas from individual farms. The company operates these clusters across California’s Central Valley, providing a centralized infrastructure for biogas upgrading and power generation.
The partnership between CalBio and Mainspring Energy highlights the growing interest in innovative technologies for renewable energy production. Mainspring’s linear generator technology represents a departure from traditional combustion-based power generation, offering a more efficient and environmentally friendly alternative. The success of these projects could pave the way for wider adoption of linear generators in other biogas applications.
The expansion of CalBio’s operations underscores the potential for agricultural waste to contribute to a more sustainable energy future. By harnessing the power of biogas, the company is not only reducing greenhouse gas emissions but also creating new revenue streams for dairy farmers and strengthening the energy resilience of rural communities in California.
