Solarize Switzerland – Nudging the Adoption of Renewable Energies


Quickly reach your climate targets

Cheaper than subsidies

Easy and automated

Solarize Switzerland – an initiative at the University of Lausanne, IDHEAP is a non-profit project offering a helping hand to interested cantons, cities, and municipalities. Our goal? To give administrations the tools to nudge citizens and other entities across Switzerland to adopt solar energy systems, simplify bureaucratic processes, and make sustainable living a cost-effective reality for citizens. Research has shown that, next to economic considerations, complicated processes and administrative rules are a key factor in people’s decision to adopt solar energy systems. In our quest to meet both international and national climate targets, we recognize the pressing need for effective action at all levels of government to curb carbon emissions. We believe that behavioral research and nudging can be key elements in this, helping governments to motivate citizens and other groups to adopt renewable energy solutions without using subsidies. Beyond the city of Schaffhausen, we are excited to build off our pilot project’s achievements.

How does it work?

Solarize Switzerland is dedicated to promoting the adoption of solar power in Switzerland based on insights from behavioral research. The project’s primary goal is to increase the uptake of solar energy systems among citizens and other groups by encouraging individuals and entities to adopt photovoltaic systems. This initiative operates by offering personalized, largely automated letters generated from the data of Sonnendach website to cantons, cities, and municipalities across Switzerland. These letters provide information harnessing different incentives for adopting solar energy, and they can be produced in multiple languages, including German, French, Italian, and English. In the future, the project aims to expand its outreach beyond homeowners, building on its success in this area. By offering tailored nudging strategies and information, Solarize Switzerland seeks to play a vital role in Switzerland’s transition to sustainable and renewable energy sources.


1. Identify beneficiaries: find suitable owners using public data.

2. Prepare nudges: create personalized letters automatically
3. Send letters: distribute letters and evaluate feedback

Who are we?

Solarize Switzerland is a non-profit based at the University of Lausanne, IDHEAP. Our service point helps interested cantons, cities, and municipalities implement projects, like that in Schaffhausen, to encourage and motivate citizens to install Solar Panels.

Our Schaffhausen Pilot Project

In partnership with the University of Lausanne and ETH Zurich, the city of Schaffhausen launched a research project in 2022 with the aim of promoting the uptake of photovoltaic (PV) systems to utilize solar energy. The project used behavioral science-based and tailored approaches to promote and motivate homeowners to install photovoltaic (PV) systems or solar panels on their roofs. The results of our Schaffhausen pilot project are highly promising and pave the way for future research and practical applications. Le projet a utilisé des approches basées sur les sciences comportementales et adaptées pour encourager les propriétaires fonciers à installer des systèmes photovoltaïques ou des panneaux solaires sur leurs toits. Les résultats de notre projet pilote à Schaffhouse sont très prometteurs et ouvrent la voie à des recherches et applications futures.

Exemple en version simplifiée

“We have launched, in collaboration with the University of Lausanne and the ETH Zurich, a research project aimed at promoting photovoltaic installations on the roofs of private homes. The emphasis was placed on personalized mail optimized from a behavioral economics point of view, addressed to owners, which made it possible to more than double people’s interest in photovoltaic installations. One in seven people signed up for impulse counseling offered in the letter. »

Testimony of Ramon Göldi, Smart City Schaffhausen

Specifically, three different letters were sent to private homeowners. Different letters focused on either providing general information about PV, an analysis of their roof’s viability for PV referencing their neighbor’s successful installations, or a similar viability analysis accompanied by financial opportunity cost of not installing solar panels. The latter two analysis-based letters made possible thanks to open administrative data from the Sonnendach website, elicited greater responses than the letter with general information on PV with the financial loss analysis prompting 15.3% of recipients to book a consultation appointment and taking further steps towards photovoltaic adoption.

Solarize Switzerland going forward

Solarize Switzerland is looking to broaden its impact, extending beyond homeowners to include Small and Medium Enterprises with substantial roof spaces, agricultural holdings, farms, tenants interested in balcony solar solutions, and condominium owners. Our project offers cantons, cities, and municipalities the opportunity to leverage our expertise in generating personalized, automated letters using data. These services are available in multiple languages (DE, FR, IT, EN) across Switzerland.


Contact Us

Interested in learning more about the project or participating in Solarize Switzerland? Please do not hesitate to contact us.

Contact Form

Our Team

Prof. Dr. Oliver Neumann

Université de Lausanne, IDHEAP

Professeur asssistant in Public Management

Contact: oliver.neumann@unil.ch

Zoe Bank

Université de Lausanne, IDHEAP

Project Manager and PhD Student

Contact : joycezoe.banks@unil.ch

Flurin Pfalzgraf

ZHAW Winterthur

Bachelor of BWL student

Roman Schenk

ZHAW Winterthur

Bachelor of Computer Science student

Jakob Kisker

INNOArchitects

Product Developer