The Rooftop Character That’s Unlocking Rooftop Solar for Renters

What unsustainable behaviour needs to change:

Tenants usually assume that rooftop solar is only for homeowners. When people picture solar power, they imagine installing their own PV modules — something renters cannot do. This mental model forms a strong barrier: solar is not for me.

Combined with low involvement, ‘switching friction’ and the invisibility of electricity (“power just works”), many tenants stick with generic grid electricity even when cleaner, cheaper power is generated right above their home.

The Green Nudge:

By borrowing a beloved Scandinavian rooftop figure, the German energy brand Karlssonn from energy provider ALVA creates instant emotional closeness: ’something on the roof‘ feels warm and personal, not technical or exclusive.

The tagline „Your power from the roof“ frames the core promise — you don’t need to own a house to have your own power. Even the name itself does some cognitive heavy lifting: the strong consonant opening (punchy first sound), light wordplay and distinctive spelling boost salience (help it grab attention), make it more memorable and likeable.

Plain-language explainers clarify that no installation is needed. Pre-filled signup forms and building-level activation create soft defaults. Behind the scenes, a bias-aware communications toolkit addresses ‘status-quo inertia’ (sticking to what’s familiar), ‘present bias’ (favouring the short term) and ‘complexity aversion’ (avoiding what feels complicated).

The results: Early adopter buildings reached 60%+ tenant uptake, far above the 35–40% market baseline, with new buildings achieving up to 90%. The brand and explainers also significantly improved understanding of tenant-accessible rooftop solar, closing a critical awareness gap.

The Business Case: When the brand itself removes barriers, commercial performance follows naturally:

• Higher asset utilisation: More tenants choosing rooftop solar lifts self-consumption and speeds up PV payback.
• Lower acquisition costs: A memorable, behaviourally designed brand compresses the funnel and replaces costly switching pushes.
• Lower churn: Tenants feel a sense of ownership (‚my power from my roof‘), strengthening loyalty compared with generic utility offers.
• Scalable model: The brand-led nudge is transferable across buildings and cities, supporting revenue growth without eroding margins.

Karlssonn proves that when behavioural insight shapes brand strategy from the start, it becomes a core business lever.

Which other brands could use storytelling to make sustainable choices feel personal?
Share your thoughts: hello@green-nudges.com

From Nicolai Shimmels, Director of OH, BEHAVE c/o ressourcenmangel, where he brings behavioural strategy and creative brand building together to make sustainable choices intuitive for mainstream audiences. He and his team specialize in the energy sector, helping utility and energy providers design behaviour-led solutions.