Blog of Urs Riggenbach

Our Gift to the World:
The Lytefire Construction Guide Available Now!

Posted Tuesday 24 December 2019 by Urs Riggenbach.

Today we release the Lytefire 4 Construction Guide to help solve the climate change crisis. It is immediately available for free on the Website.

Available for download now on

After years behind the screen, in the field, working with entrepreneurs to develop solar technology that brings value to people and impact to the planet, we are really happy and grateful we can share this gift with you.

We invite you to build, use, and share. We are here and we will continue on this path, working with users, entrepreneurs, investors, sponsors and education partners - it will take all of us to spread solar energy in the limited time we have to avoid catastrophic climate change.

With the Lytefire 4 construction guide available for free, we allow anyone in the world to build our technology and start using solar energy at a fraction of the cost of other energy sources. We intend to release a lot more construction guides and educational material for entrepreneurs as we continue on this path.

But that’s not all! With the release of the Lytefire 4 construction guide we are also launching the Lytefire campaign to bring to market the Lytefire 5, our most powerful solar concentrator for entrepreneurs. We are also calling on investors and sponsors to join the effort to spread solar energy through product sales, open source construction guides and education. If you want to collaborate with us - check out the different options on and get in touch with us!

We are immensely grateful to have reached this point. Our belief that solar energy could not only be good in itself but inspire a more sustainable society as a whole is what brought our team together. Knowledge is the most fundamental approach to empowering people, and free knowledge means it can spread wide and fast. We want to thank all our partners, supporters and investors who have supported us over the years. Without you, we would not have reached this milestone. Thank you all!

GoSol Partners, Clients and Sponsors

Learn more and get involved:

GoSol Event on 14th of November at ResponsAbility, Zurich

Posted Sunday 3 November 2019 by Urs Riggenbach.

Swiss Impact Investing Network (SIIN) and GoSol are welcoming you to join us for an impact talk on the topic of How to Build a Business Model for Maximum Impact. The event is happening on 14th of November at ResponsAbility headquarters in Zurich, at 18:30.


Register here:


More about this Event

Join us for the "Impact Talk" Event about "How to Build a Business Model for Maximum Impact:" with the founders of


18:15 Registration

18:30 "How to Build a Business Model for Maximum Impact:" with the founders of

Followed by Q&A

19:30 Socializing at Café Gloria, Hohlstrasse 59, 8005 Zürich


Making a business profitable is difficult enough, having impact even harder. GoSol’s co-founders share their history of building and rebuilding a business model that puts impact first.

We’ll discuss challenges and strategies for finding an impact maximizing mission, developing impact-oriented technology and products, building the right team and why raising impact finance is important.

We’ll also share from our personal experience of staying motivated and persistent in face of the ever growing challenge of climate change and poverty and hope to motivate others to do the same.

About the Speakers

Urs Riggenbach, Chief Operating Officer, Switzerland

"A sustainable society needs a sustainable source of energy."

Urs has an international Baccalaureate from the United World College, India and BA in Human Ecology from the College of Atlantic, US. As chief operating officer, Urs follows closely all projects, financials and administration processes and supports the team in management and planning. As full-stack web developer he manages the company’s IT infrastructure, security policy and software development, always striving to optimize workflows. Urs has developed solar concentrators in Nepal and EU. Always willing to challenge himself, he can’t rest until the world is a better place for all.

Eerik Wissenz, Executive Director & CEO, Finland

"An energy solution must be low capital (the lower the better), yet power a viable economy, and be locally buildable and maintainable with little or no imports."

Co-founder and CEO of Solar Fire Concentration Oy. Finn and Canadian, Eerik studied mathematics at Ottawa and Carleton University. Quickly took a hiatus to dedicate himself to developing solar thermal technologies. Eerik developed solar concentrators in Mexico, Cuba, India and EU. Eerik has the vision of a fair solar thermal economy and he’s in charge of the strategy and the development of the company. He gave lectures at Tampere Applied Science University in Finland, Autodesk University in Los Angeles, Johannesburg, London, and Berkely University.

This event is organized in collaboration with SIIN - Swiss Impact Investing Network. More about SIIN here

Several GoSol Events are happening in Switzerland this September

Posted Wednesday 4 September 2019 by Urs Riggenbach.

Read in German

We are excited to extend our invites for two events that will happen in Switzerland this September.

Since a few days we have an additional Team Member with us here in Solothurn, Switzerland, and we’re busy completing a SOL5 solar concentrator .

After recent projects started up in East Africa, the Philippines and Brazil, we now also want to start in Switzerland roasting, drying, cooking and baking with direct solar energy!

Join us:

  • Saturday, 14. September for a live demo event at the Rosegghof Farm, starting at 14:00.
  • Tuesday, 24. September we are holding an evening event in the city of Solothurn, presenting on how direct solar energy can pave the way into a climate neutral future. With us will be Beto Borges of Forest Trends to present our work in the Amazon, as well as Lorin Symington from our team sharing on his experience in the Philippines and East Africa.

We look forward to starting many good discussions at our events. The events will be partly German, partly English. Please see the individual event infos below.

GoSol Experience Event - Experience the Direct Solar Energy!

Saturday, 14. September 2019 at Rosegghof,
14:00 to 17:30 Uhr

We are visited from Canada by Lorin Symington, who tells us about the beginnings of GoSol and makes several live demos with our solar units.


  • 10am: Start of setup of the solar units at the Rosegghof farm, interested people are welcome to join
  • 14:00: Welcome-Apéro with Solar Snacks, short presentation about GoSol by Urs Riggenbach and Lorin Symington,
  • 14:30: Live-Demos of the SOL4 und SOL5 solar concentrators for baking, roasting, drying and cooking
  • After 15:00 Uhr: Workshops with solar energy: Solar roasting, distillation of essential oils, pizza baking, etc
  • until 17:30 / Open End

Location: Rosegghof, Weissensteinstrasse 76, 4500 Solothurn

Signup/RSVP: Please fill our form or send an email to

(This event happens only with sunny conditions, the alternative date is Sunday, 15th of September. Please RSVP to the event.)


GoSol Impact Event - Direct Solar Energy and the Path toward a Climate Neutral Future!
Tuesday, 24. September 2019
18:30 - 20:30, Kino im Uferbau, city of Solothurn, Switzerland

GoSol combines vision, technology, education, collaboration and entrepreneurship. In this event we have visitors from Brazil and Canada and present our work, especially our project in the Amazon. How can we enable sustainable economies even in poorer countries in the age of climate change? How can direct solar energy also spread in Switzerland? Using concrete examples, we share our experiences and present our plan for a climate-neutral future.

Time and Date

Tuesday, 24. September 2019, 18:30 - 20:30 Uhr

Place and Schedule
im Uferbau
, Ritterquai 10, 4500 Solothurn, Switzerland

  • at 18:15 - Doors open
  • 18:30 - Presentations and interactive Parts
  • ca. 20:00 Uhr - GoSol: What’s next? Summary and start of Apéro
    Riche with Solar Snacks


  • Judith Bernet, Geographer and Moderator, Solothurn


  • Urs Riggenbach, Chief operating officer GoSol,
  • Lorin Symington, Chief Fabricator GoSol, Canada
  • Beto Borges, Director, Communities Initiative, Forest Trends, Brazil
  • Kurt Baumann, teacher and artist, Aarwangen

We look forward to to the event!


This was TBLI Conference Zurich 2019

Posted Saturday 20 July 2019 by Urs Riggenbach.

Last month I attended the TBLI Conference in Zurich. The conference brought together impact investors and companies with a commitment for real impact.

This was certainly one of the best conferences I’ve attended. Many participants shared in the impact-maximizing spirit, ready to learn about scalable impact solutions, have their own views challenged and motivated to figure out how we can use the ressources at hand to avoid climate and economic collapse. I look forward to collaborating with the many new contacts made.

TBLI stands for tripple bottom line, the concept of measuring a business not only on financial, but also on social and environmental returns. Learn more on TBLI here

Forest Trends about GoSol in the Amazon

Posted mercredi 26 juin 2019 by Urs Riggenbach.

We started our cooperation with Forest Trends last year in the Amazon with the Surui. Today, the US based NGO reported that "The pilot installation of the SOL5 GoSol unit for drying the babaçu mesocarp [tree nuts] has significantly reduced from 4 days to 5,5 hours." We are clearly going to continue the good work together and we wanted to introduce you to Beto Borges, Director of Forest Trends’ Communities Initiative.

→ Beto, can you introduce yourself and Forest Trends briefly ? Since how long are you working there and what’s your role ?

Together with partners around the world, Forest Trends pioneers innovative finance for conservation - promoting healthy forests, sustainable agriculture, clean water, robust climate action, protected biodiversity, and strong communities. For the past 13 years, I have been the director for Forest Trends’ Communities and Territorial Governance Initiative, promoting economic, political and cultural innovations with indigenous people and local communities. I have over 30 years of experience working with indigenous and other traditional forest communities to benefit from conservation and economic incentives that recognize their forest stewardship practices. A Brazilian national, I graduated from UC Berkeley in Natural Resource Management and have an MBA in Strategic Leadership focused on social responsibility.

Beto Borges of Forest Trend's Communities Initiative (left), has worked for over 30 years in partnership with indigenous peoples of the Amazon.

→ What are the most significant challenges facing Indigenous Communities in the Amazon today ?

The Amazon is home to approximately 1 million indigenous people with rich and diverse cultures. These unique cultures, as well as the region’s biodiversity, forest resources, and carbon storage are under alarming threats from large-scale infrastructure and extractive projects that largely proceed with inadequate enforcement of measures designed to reduce environmental and social impacts. The key threats are a massive boom in oil and gas exploration, mining, rampant illegal logging and the rapid spread of ranching and farming. Despite these mounting pressures, indigenous communities of the Amazon are deeply committed to creating a sustainable future for their people on their lands. Yet few viable economic opportunities exist for them.

→ The very first pilot with SOL5 is very successful it seems. Now how do you see the next steps happening so that the Surui can actually integrate SOL5 tech in their supply chains ?

Developing sustained income streams from harvesting, processing and selling babaçu products is still in early stages for the Surui People in the Brazilian Amazon. The pilot installation of the SOL5 GoSol unit for drying the babaçu mesocarp has significantly reduced the drying from 4 days to 5,5 hours, which is fantastic. One of the Surui’s associations, SOENAMA, already have FSC certification for their babaçu and are trying to sell it to local schools for integrating in meals for the children. Selling to local schools will be a very important step in consolidating their babaçu supply chain.

SOL5 dryer installed at the Surui's village.

→ Do you think that it can be extended to other communities in South America ?

We are confident that appropriate technology such as GoSol’s solar dehydrators and ovens can be a powerful and liberating tool for multiple forest communities in all the Amazon and throughout Latin America. The low cost of building these units, wide local availability of materials needed and the relative basic requirements for operating them, make them highly scalable in the region.

In addition to their viability, these units can be easily adapted to process a great variety of forest and agroforestry products, such as cacao, coffee, bananas, Brazil nuts, among others. Therefore, GoSol’s solar technology combined with Forest Trends’ years of on the ground experience working with forest communities, can directly contribute to increase income opportunities for indigenous and local communities.

As forest communities are strengthened, so is their stewardship of the forests, biodiversity, water and carbon for the benefit of themselves and humanity as a whole.

To read more about our ongoing work with Forest Trends, read here.

GoSol’s Guest Lecture at University of California, Berkeley

Posted Saturday 27 April 2019 by Urs Riggenbach.

UC Berkeley campus, California. © Wikimedia

In February 2019 we kicked-off a collaboration with UC Berkeley’s MDP department, focused on modeling the impact the GoSol solution can have at a global scale. As part of the cooperation, Eerik and I were invited to present a guest lecture to the master students. Our lecture covered our lessons learned while starting up GoSol, and focused on what it takes to maximize impact when building new business and technology. Here I’m summarizing two key barriers to overcome, Understanding Your Users and designing a Viable Technology.

We started with a general introduction and by acknowledging that starting a business, and on top of that a mission driven one, is inherently difficult and one has to break a multitude of barriers to gain success.

Understanding Users

Co-Founder Eerik Wissenz giving a guest lecture at UC Berkeley's MDP Department.

After analyzing the state of the world and identifying the biggest potential for having impact, the next step is to work toward solutions and test them in the field.

A key challenge at the start is getting access to your potential end users, which may live half way around the world. Not only would it be expensive to test your solutions with these end users, it would require multiple trips back and forth to identify, contact, build a relationship with, install, monitor and follow-up with these end users. Running a piloting phase can quickly become an overwhelming undertaking.

At GoSol we partnered up with World Vision at that stage - World Vision has an innovation program called Weconomy facilitating western companies to work with their beneficiaries to co-create solutions. Through the program we were able to identify the best users, understand their requirements, pain-points and current energy usage. In a later step we then installed the technology with the most ideal pilot sites, and through the World Vision program were able to keep tabs on its usage even when were not onsite, as our local partner World Vision was collecting the data and monitoring the use in the field.

Viable Technology

Slide from GoSol's guest lecture at UC Berkeley. ©

As you are developing your solution, you have to ask yourself ’what are the critical requirements for it to become scalable.’

We gave the example of the GoSol SOL5, that was designed to tackle poverty and the consumption charcoal, firewood and fossil fuel consumption in the developing world.

According to our analysis, a viable technology in this context had to have the following properties to be able to outcompete existing, polluting fuel sources:

- Low Capital: The technology had to have a cost that can be refinanced in less than 5 years, ideally over the course of one season in order to be compatible with the way farmers and SME’s in the developing world invest. Where western companies can for example invest in solar panels with payback periods of 15 years or more, we had to lower cost to get below the 5, ideally 3 year mark.

- Quick returns: The other factor, apart from initial cost of the technology, is how much value the technology makes for the end user. If they are able to save bags of charcoal each day, the use of the technology has direct costs savings. For new businesses starting up that have no comparable benchmark, the use of our technology should lead to a higher profit margin as their cost of production is minimized with the fuel savings. Through the 2 year piloting phase in East Africa we were able to reach payback within less than 1.5 years.

- Usability & Maintenance: We had to design the technology from the ground up to be maintainable at the local level. Because replacement parts and maintenance services would be expensive to import once the technology is deployed, failure from wear and tear could lead to the abandonment of the technology. Having end users be able to maintain the system themselves would minimize this risk of downtime or abandonment, and keep maintenance costs low. Solving this challenge led to the development of our educational courses and programme, where we do not only provide the short training on how to use the technology, but provide a rich educational program that can train and equip new entrepreneurs to use and maintain the technology themselves.

- Further considerations: In developing an energy solution we also asked ourselves how the technology could be globally applicable, from supplying thermal energy to industry and small entrepreneurs alike. To have a global impact the technology should not only work in western infrastructures but even remote and off-grid villages. The technology should also be fabricated and deployed rapidly, without any bottlenecks to production, rare-earth metals or cost-prohibitive materials, fabrication, transportation and installation processes. Furthermore, we aimed at developing an energy source that would tackle a large percentage of global energy consumption. We found that over 50% of energy is consumed in the form of heat, and solar thermal energy can provide much of this thermal energy.

Other topics

Urs Riggenbach presenting at GoSol's guest lecture at UC Berkeley's MDP Department.

We went on to advise students on how to build their team, how to get through the piloting phase, how to attract funding at various stages of business development and how to constantly build your business model to drive your business towards its mission.
We rounded the lecture off by sharing more personal experience on staying motivated on our path, reassuring the class that it takes a lot of persistence to build up mission driven organizations, and then had a great Q&A session with the engaged students.

Announcing GoSol - UC Berkeley MDP Collaboration

Posted Friday 15 February 2019 by Urs Riggenbach.

We are happy to announce the start of a collaboration with the MDP program at UC Berkeley, California.

UC Berkeley’s Master of Development Practice (MDP) equips the next generation of professionals with the knowledge, skills and interdisciplinary experience needed for sustainable development in the direction of the UN Sustainable Development Goals (SDG).

GoSol’s work has been documented to impact 7 SDGs and our experience and unique model make for a great collaboration case with the master students interested in both theoretical and hands-on experiential learning.

Our cooperation will focus on the development of impact measurement and modeling methodologies and systems. As GoSol’s impact scales, so do the challenges of tracking and modeling the impact of our technology, products and projects.

We’re excited about the cooperation start and look forward to start engaging the students very soon.

More about the MDP program:

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