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Our Origins

At its outset, Monarch Bioenergy represented a new paradigm in the agricultural industry when Smithfield Foods and Roeslein Alternative Energy (RAE) began their joint venture in 2018. Hog waste could now be transformed into environmentally beneficial renewable natural gas (RNG). Monarch’s difference went beyond just typical RNG production. Monarch created a new model for how conservation, ecology, and economics could provide a sustainable and profitable way to produce clean energy at scale while reducing greenhouse gases.

Rudi Roeslein, the founder of RAE, has long championed the power of prairie grass to provide carbon sequestration, reduce agricultural runoff, and provide pollinator habitat to enhance biodiversity. Prairie is also a biogas feedstock, which we can convert and utilize via regular rotational prairie harvests. These harvests are necessary for the long-term health of prairie fields.

Following RAE’s lead, Monarch recognizes the environmental value of prairie grass and assists in the prairie’s re-establishment while also supporting the Environmental Defense Fund’s Monarch Butterfly Habitat Exchange. Monarch’s evolution took a significant leap when TPG Rise made an investment in 2022. Now Monarch is producing more carbon-negative RNG across more hog farms, planting more prairie grass, and supporting more wildlife habitats than ever before. And we’re just getting started.

Our Mission

To leverage the overlooked role of agriculture in achieving a sustainable future by utilizing the untapped potential of farms and prairie in decarbonizing the world. We strive to serve as a leading source of innovation while fostering a healthier and more prosperous planet.

Our History


Roeslein Alternative Energy signed an agreement with Smithfield Hog Production, then known as Murphy Brown-Missouri, to develop natural renewable gas facilities.


RAE began installing impermeable covers and flare systems on 88 manure lagoons across nine hog farms in Missouri.


Captured biogas is purified into Renewable Natural Gas and first injected into the ANR natural gas pipeline, one of North America’s largest natural gas grid systems.


88 lagoons across the nine hog farms are completed, producing pipeline-quality RNG at scale.

Monarch Bioenergy LLC was established as a joint venture between Roeslein Alternative Energy and Smithfield Farms.


Monarch Bioenergy’s RNG set a record for the lowest carbon intensity (CI) scores ever achieved at the California Air Resources Board (CARB).


Monarch began construction on a growth pipeline of facilities across Colorado, Iowa, Missouri, North Carolina, and Oklahoma.


TPG Rise Climate made a strategic investment and became an equal partner in Monarch.

Our Values

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Just as a common caterpillar transforms into a spectacular Monarch butterfly, we take ordinary biomass that would otherwise go to waste and transform it into products of immense value: renewable natural gas, organic fertilizer, and clean water.



We are grounded in respect for the land, animals, water, air, and everyone on the planet who relies on them. Respect also applies to how we treat one another: our employees, colleagues, partners, and investors.

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We are engineering-driven pioneers. We are industrious innovators. We are inspired by the wonders of nature and science, recognizing agriculture’s overlooked role in a cleaner, healthier, and economically viable future.



We are careful and responsible protectors of all our resources, recognizing their climate-positive environmental impact. Our spirit of innovation is deeply rooted in conservation.



We don’t underplay the challenges and dangers of climate change. But, we are hopeful and confident our efforts will produce significant carbon reductions in the environment.



We are passionate practitioners of maximizing and optimizing existing natural resources to create sustainable energy and products, all without waste.