Testimonial video for green electricity provider Ostrom NeoGrid AI is complex. Customer Dieter explains it in 85 seconds.
Dynamic rates, smart charging, credits after every charge: Ostrom's product can do a lot. To make sure everyone gets it, a real customer tells the story. Dieter, 70, drives an e-taxi in Berlin.
Wanted: happy customers. Found: Dieter.
Ostrom supplies green electricity with dynamic rates. The NeoGrid app picks the cheapest tariff, a smart meter tracks usage, and credits build up after every charge. A strong product — the only catch: it doesn't explain itself in one sentence.
That's why a real customer tells it. Ostrom had put out an online call looking for happy customers, and Dieter Sasse responded. He's 70, retired, and has been driving an e-taxi through Berlin for three years. A face you couldn't make up: his everyday life shows what the tariff can really do.
„Dieter was reserved at first. A few hours later, he said things no script could write. People open up when the set is theirs.“
Why this testimonial works
A testimonial only works if people believe it. So we kept it small: RED Komodo with photo lenses, handheld camera, a compact team, Dieter's real living room. We still lit it, though — softly, rather than high-key and polished: the light feels natural, and the driving scenes really are. The image breathes, as if you were visiting him. That was exactly the idea.
The second ingredient is time. Dieter was reserved at first, so we built the day so he could arrive at ease: conversation instead of interrogation, respect instead of stage direction. The later the afternoon got, the more relaxed his sentences became. The best soundbites in the film are Dieter's own words.
The shoot day on September 26, 2025 was planned from the start for two main formats: this testimonial and the TV spot. Then came the walkthrough with Ostrom employee Rahel and the performance ads. That way, a single shoot day gets Ostrom maximum production value out of the budget. Ostrom's performance marketing crowned the Dieter cut the campaign's winning video; the numbers are shown with the TV commercial.
„I get home, plug the taxi into the wallbox. In the morning I drive to my next shift with 80 percent battery. Easy as that.“
Seen in the film
Dieter in the rearview mirror of his e-taxi, then his living room in Berlin: he explains how he switched to an e-taxi after retiring, and why the NeoGrid app picks his power tariff. In between: his daily routine — the wallbox after his shift, the credits in the app, the underground garage in the morning. At the end, Dieter leans against his taxi outside his front door.
01 · Dieter's e-taxi on the road in a Berlin neighborhood
02 · The NeoGrid credits after charging
03 · In the underground garage each morning: 80 percent battery, just as preset
04 · Talking about credits, the energy transition, and the good feeling that comes with it
Part of a collaboration since 2024
Ostrom has trusted us with its video content since 2024: commercials, explainer videos, performance ads, and this testimonial. The same shoot day also produced the TV spot with Dieter, which ran on linear TV.
And what the commercial campaign that kicked off the collaboration in 2024 looked like is shown in our Case study on the Ostrom commercials.
What ROCC Film handled for Ostrom.
Ostrom found Dieter. We listened and filmed.
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