Blog of Urs Riggenbach

Video Blog: Welcome to Pier 9!

Posted Wednesday 1 March 2017 by Urs Riggenbach.

The first month at Pier 9 have gone by in a breeze. Here are some impressions from the amazing workshops at the Pier. Everything from laser cutting, CNC milling to 3D printing is there, waiting to be used for our solar design work!

First days at Autodesk Pier 9, San Francisco

Posted Thursday 16 February 2017 by Urs Riggenbach.

It has just been a few days that Will Cleaver and Urs Riggenbach have touched down in San Francisco and started their Impact Residency at Autodesk, Pier 9. During the first days, they have been participating in workshops teaching the advanced CNC equipment at the facility. During this process they have laser cut a 3mm sheet of plywood with our logo, showing how to transform digital vectors into real world objects.

Watch the video

First steps on the EPILOG Laser Cutter.

Impact Residency Program Starting at Autodek Pier 9

Posted Thursday 2 February 2017 by Urs Riggenbach.

Two of our team members just reached San Francisco, where they’ll be working at the Autodesk Pier 9 facility as part of the Impact Residency program granted to us by Autodesk Foundation.

Stay tuned in the coming days for updates from their side!


Update from Kenya: The SOL5 generates income
and supports the entrepreneurs

Posted Wednesday 12 October 2016 by Urs Riggenbach.

It is one thing to build and install the SOL5 solar concentrator, but it’s another one to use it. Knowing this, we did our best to train the two community businesses in Kenya where we’ve installed our SOL5 models in April/May. Now it has been four months since we’ve left Kenya, but with the usage reports we’re getting from the field we are confident to say: The SOL5 is used and useful, generates income, and supports the entrepreneurs.

SOL5 Pilot Field Data

Below are the key metrics of the field data generated over the last months. Much potential exists to improve these metrics, especially focusing around the issue of effective use that we’ll cover in another post.

SOL5 Roaster - Peanut Business

Metric Before After
Charcoal use / year 16 542 kg kWh 0 kg
Charcoal cost / year 803 € 0 €
Health Risks High risk No risk
SOL5 Roaster at the Yier Ngima Peanut Butter Cooperative.

SOL5 Oven - Bakery Business

Metric Before After
Electricity use / year 11400 kWh 3400 kWh
Electricity cost / year 990 € 297 €
CO2 emissions / year 6850 kg 2055 kg
SOL5 Oven at the Koptige Bakery.

Above are the key metrics from our pilots showing how much money the entrepreneurs save each month using the SOL5. In addition to the money, the businesses reported that they now produce more, at higher quality and with healthier working conditions.

More productive: The bakery was suffering from frequent power cuts. Sometimes it was impossible to bake without electricity, and sometimes an oven would stop working midway and the bread batch was lost. Now, with the SOL5 Oven, they do not depend on the unstable electricity grid anymore and are producing more.

Better quality: The roastery reported that with the SOL5 the peanuts do not get the smoky taste that they used to get with their previous charcoal roasters. Now, without the smoky taste they have a higher quality produce.

Better working conditions: When using charcoal and firewood as fuel, smoke is a big factor affecting worker’s heath. The ladies at the roasting business are pleased that there is no unhealthy smoke emission with the SOL5.


...And all of this while making monthly savings and reducing CO2 emissions.

More than ever are we convinced that GoSol’s SOL5 is a changemaker technology. Stay tuned!

Lady at Koptige Bakery taking out freshly baked muffins out of the SOL5 Oven installed in May 2016.

Predicting the Next Billion Solar Concentrators

Posted Thursday 11 August 2016 by Urs Riggenbach.

Solar concentration is going to change the world, period. There, we said it. And we want to make it very clear: Solar concentration will play a key role in providing energy access to the poor, reversing deforestation, and mitigating climate change. It will also play a key role in cross-cutting issues of gender equality, economic re-localization and resilience. Why are we saying this now? Because it is bound to happen, and a prediction can only be made before the fact.

What is solar concentration?

A solar concentrator bundles sunrays using mirrors to a focal point.

A solar concentrator is a machine that concentrates the energy of the sun. The concentrated solar energy is most often used directly as heat, or converted into other energy forms such as motion or electricity.

Solar concentrators have the potential to be powerful, cost-efficient and multi-use. As the technology makes direct use of free and abundant solar energy, it could rapidly spread cheap, renewable and sustainable energy access at a global scale.

The right kind of solar?

There are many solar concentrating systems out there, but GoSol’s suite of solar concentrators is unique in its price point, short payback period and high power output. In short, GoSol’s tech is a solution that bridges the gap between "not-powerful-enough" solar cookers and "too-large-to-be-feasible" industrial solar concentration fields in terms of small scale commercial processes. Until now the spectrum in between has largely been overlooked and to date no solution exists to power small-scale commercial activities so common across the developing world.

Charcoal baking oven in Kenya: Many commercial activities are run on charcoal.

Enter’s solar concentrator that provides energy at the small-scale commercial level at which today most of the world’s firewood and charcoal fuel is burned. No kidding: Just like two thirds of today’s food is still produced by family farmers and not industrial agriculture [1], it is thousands of millions of small entrepreneurs in the developing world that undertake much of today’s economic activity and share a significant proportion of global fuel consumption.

Because energy poverty strikes the small entrepreneurs the strongest, these entrepreneurs are not only limited in their productivity, but forced to use low quality energy sources that are more polluting, deforesting and greenhouse-gas-intensive as alternatives. Sustainable alternatives, such as photovoltaics, are still too expensive for most entrepreneurs that cannot cope with a 15 to 25 years payback time. In the developing world, energy poverty is the difference between using firewood or charcoal as opposed to using propane or coal; it’s not a choice between sustainable or not, but a choice between multiple unsustainable options.

To halt greenhouse gas emissions and deforestation, it is thus not only on industry to switch to cleantech, as millions of small entrepreneurs need to switch at the same time to renewable energy.

To have maximum impact on livelihoods and the climate, the right kind of solar should provide a viable solution to these entrepreneurs that pays back quickly and acts as a true upgrade to their current energy consumption habits. It has to be producible locally, maintainable locally, and make best use of locally available materials. It has to be scalable to suit different temperatures and power outputs, and adaptable to different use cases ranging from baking to roasting, cooking, pasteurizing, and so on. It is not an easy task but at GoSol we believe to be on the right track toward this game-changing solution.

How and Why to Spread a Billion Solar Concentrators ?

Local construction with artisans in Kenya.

We’re faced with several anthropogenic feedback loops that could cause total disaster if left unchecked. Conversely, a feedback loop of local solar development and innovation has the potential to scale faster than the problems we face and faster than any industrial solution. Though industrial renewable projects, when actually renewable, are good too, they are too capital intensive to scale globally in a short period of time.

One single GoSol SOL4 model replaces as much as 9 tonnes of wood per year. In many areas this can make the difference between the regeneration of the ecosphere or continued deforestation and eventual desertification.

One billion SOL4 solar concentrators would displace an amount of energy equivalent to all biomass burning today, radically reducing deforestation and pollution. One billion SOL4 solar concentrators would produce about 2,000 gigawatts which is roughly 4 times as much as all the nuclear energy being produced today.

OK, so who’s going to do this?

This energy transition is going to be a big win for all of us and making it happen will require a coming together of many stakeholders from diverse positions. This is why we’ve been bringing together diverse partners that can create the ecosystem needed to accomplish our vision.

At our mission is to eradicate energy poverty and minimize the damage of climate change by breaking down the barriers to solar energy access. We see it essential to bring our technology to its world changing potential in order to have true, rapid and holistic impact.

To get an idea of how we’re progressing, read more about our educational philosophy in our SolBook post, and watch the video of our Kenya project in cooperation with World Vision / Weconomy here .

SolBook: Preparing the Next Generation
of Solar Builders and Entrepreneurs

Posted Tuesday 2 August 2016 by Urs Riggenbach.

The SolBook is a resource for integrating’s empowering knowledge into school’s curricula. It will contain lessons on the physics, ecology, economics and entrepreneurial aspects of thermal solar energy. This book will take on the energy problem of today and makes it approachable for teachers and educational institutions that want to empower their students.

Breakthrough in Kenya with Weconomy / World Vision: GoSol's solar concentrators save money, time and energy.

What is the SolBook?

We want to create an educational textbook containing all the information needed for anyone to start using the power of the sun to save money, reduce pollution and to create a more sustainable planet.

The SolBook, available as Ebook, Paperback and Hardcover for pre-order is our approach for a rapid and massive distribution of knowledge on solar entrepreneurship. People who pre-order their SolBook help funding the creation of this book. The raised funds go directly into the production of the books as well as help fund our ongoing project in Kenya. Find out more on the SolBook page.

Education to solar energy is key

Education has the potential to equip the young generation with the vital tools they’ll need to fix the planet. At we are already sharing our DIY construction guides for 2 solar concentrators though membership.

Our partnership with Weconomy and World Vision allows us to potentially spread our knowledge in the over 90 countries where they work. We are getting many requests from educational institutions that want to teach solar. Now is the time to respond and create the educational material needed to empower the next generation of solar entrepreneurs. And we want to do this with you.

Why Now?

After reaching the technological breakthrough in baking, roasting and cooking, GoSol’s natural next step is to work with educational institutions to build up the capacity globally for solar entrepreneurship.

Even though there are many great tools out there for humanity to mitigate the globe’s ever increasing problems, it is still possible for young adults to grow up in today’s world not learning about centralized energy and how it’s affecting our planet.

Now enters the SolBook, an educational textbook containing all the information needed for anyone to start using the power of the sun to save money, reduce pollution and to create a more sustainable planet.

“Once the technological breakthrough is achieved, the real work only begins: the work of raising awareness and integrating an innovation into today’s society.”

Urs Riggenbach, Project Manager at

Consider pre-ordering your SolBook today, or tell a friend about it!

Building the Direct Solar Economy

Posted Thursday 26 May 2016 by Urs Riggenbach.

Discover what has been accomplished in Kenya in partnership with Weconomy, Suomen World Vision and World Vision Kenya. It’s so powerful to see that these bakers and organic peanut butter producers. They are the seeds of an emerging direct solar economy.

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