Solar CITIES

10/06/2026

Biogas pickled figs! 👩🏻‍🍳 This year, many of the figs growing in my backyard did not ripen. I found a recipe for pickled green figs online and used biogas to make them! First, quarter the figs 🔪 Then, make a brine with 1:1 water and vinegar, plus spices like garlic, ginger, allspice, star anise, balsamic glaze and salt 🧪 Bring it to a boil on your biogas stove and add the figs to blanch for 10 minutes 🔥 Store the pickles in a clean, sanitized jar and enjoy! I served mine in a caprese salad 🥗

10/03/2026

As the northern hemisphere enters autumn, temperatures fall and biogas production decreases. Inside the digester, billions of microbes slow down their metabolic processes and start to hibernate. But we can extend the “growing season” of our biodigester by insulating it! There are many different ways to insulate, or heat, a biodigester. In this video, we create a simple vinyl greenhouse frame around a Solar CITIES digester to capture more heat from the sun. Do you have a biodigester? How do you prepare it for colder temperatures?

10/01/2026

Solar CITIES' new executive director, Jonathan Sidharta-Leibovic, is featured as a spotlight member by ♻️ Professional Recyclers of Pennsylvania (PROP) ♻️

👀 Read the full profile in the link below! 🔗 🔗

09/30/2026

These noodles were cooked on a renewable biogas stove, using clean, carbon-neutral fuel made from food waste! 🤯 ♻️ 🌏 Feat. “vegetable” flavor with napa cabbage 🥬 king oyster mushroom 🍄‍🟫 and bawang goreng (fried onion). Song by

09/29/2026

FROM OUR BIOGAS ELDER: BOB HAMBURG

I want to bring an extraordinary resource back into the light.

Robert A. “Biogas Bob” Hamburg was our Biogas Elder, our friend, and a man far ahead of his time. Long before many of the ideas we now describe as circular systems, regenerative practices and integrated sustainability became common language, Bob was thinking about energy, food, organic residues, agriculture, water and human development as parts of one interconnected living system.

And for Bob, anaerobic digestion was fundamentally about biology—not machinery.

He taught us to think about our relationship with the microorganisms—and particularly the methanogenic archaea—inside a biodigester as a symbiotic relationship. Man and microbe. We provide the environment and organic materials they need; they transform those materials into biogas and nutrients that become useful to us and to the living systems around us.

Bob had the experience to back up that thinking. Beginning with Peace Corps work in Nepal in the 1970s, he spent decades researching, designing, building and teaching appropriately scaled biogas and integrated resource systems around the world. In 1980, he authored a successful U.S. Department of Energy proposal for a small-farm-scale system integrating two anaerobic digesters, two algae/aquatic plant ponds and a solar greenhouse. In 1985, he received a National Award for Energy Innovation from the U.S. Department of Energy.

Bob could have written a book.

Instead, he built a website.

Dragon Husbandry is filled with Bob’s drawings, observations, experiments, research and wonderfully unconventional way of looking at our relationship with the microbial world. Some of the graphics may show their age. The ideas do not.

We’re going to start bringing more of Bob’s work back into the light and sharing it with a new generation of biogas practitioners.

For today, I invite you simply to explore Dragon Husbandry. Don’t rush through it. Poke around. Follow Bob’s thinking. There is a remarkable mind preserved in these pages.

Our Biogas Elder still has a lot to teach us. 💚🐉

Explore

Natural Gas WITHOUT Fracking!

06/26/2026

Farm to Grid Energy! The dial is finally moving here in the US!

Dickinson College Farm has started a methane digester that will annually divert 115 tons of cafeteria waste and turn manure into energy. The secret to the digester’s success so far

06/05/2026

Congratulations to all the finalists with a special shout out to Dominic Kahumbu Wanjihia and Flexi-Biogas! Well done!

Keep on innoventing!

We look forward to revealing the winners on 8 July 2026, live at the Vox, Birmingham, United Kingdom

06/02/2026

We’re excited to share that the Solar C³ITIES Solutions team will be attending Penn State Extension’s upcoming conference on anaerobic digestion and farm-based biogas systems!
If you’ll be attending, please stop by our table display and say hello. We’ll be sharing information about:
• Home-scale and community-scale biodigesters
• Hands-on educational workshops
• DIY biodigester construction resources
• Our book: How to Build a Solar CITIES IBC Tank Biodigester
• Sustainable waste-to-energy education initiatives
• Opportunities for collaboration, sponsorship, and board involvement
Whether you are a farmer, educator, student, sustainability professional, policymaker, nonprofit leader, or simply curious about practical biogas solutions, we would love to connect with you.
At Solar C³ITIES Solutions, we believe small-scale systems can make a big impact by turning organic waste into renewable cooking fuel and nutrient-rich fertilizer while educating and empowering communities.
Come meet our team, see our display, and learn more about how simple, affordable biodigester systems can help build a more sustainable future.
We look forward to seeing you there!
Learn more: https://SolarCITIES.SolutionsCITIES
Conference information: https://extension.psu.edu/anaerobic-digestion-on-the-farm

This multi-day national conference explores on-farm biogas systems through research, policy, and practice, featuring expert presentations, discussions, and tours focused on anaerobic digestion.

05/10/2026

Celebrating innovation in action!

Dr. Thomas Henry Culhane, professor and director of the Climate Mitigation and Adaptation concentration at the Patel College of Global Sustainability, has been recognized with the USF Award for Innovation in Online Design and Teaching.

His work goes beyond the classroom—transforming how sustainability is taught by making science engaging, accessible, and yes… fun.

As President Moez Limayem shared during the ceremony, it’s this kind of innovation that strengthens our entire university community.

Congratulations, Dr. Culhane, on this well-deserved recognition and for continuing to inspire the next generation of sustainability leaders. 🌍💚