App ·
Daluur ·
2022
Cheap hours
An energy app that finds the cheapest stretch in tomorrow's hourly prices.
Company
Daluur
Role
Product designer
Team
A product manager, three mobile engineers, and a data engineer
Year
2022
Duration
Five months
Platform
iOS, Android
Context
Daluur sells electricity at the market price, which changes every hour. Tomorrow’s prices come out in the early afternoon, and customers who shift laundry, the dishwasher, or car charging to cheap hours pay less.
In 2022 those prices swung wildly, and the app showed tomorrow as a bar chart, twenty-four bars in a row. Customers told us they looked at it every day and still didn’t know what to do.
My role
I was the only designer on the app team. I planned and ran the research, designed the flows and screens, and built the prototypes we tested.
Approach
We visited customers at home and asked them to plan the next day with the old chart. Nobody read the prices. They looked for the lowest bars and tried to figure out how long the dip lasted, counting bars with a finger.
What they wanted was a window: the cheapest stretch long enough to run what they had in mind, and a clear sense of whether it was worth the wait. A dishwasher needs two or three hours. Charging a car can take most of the night.
Solution
The home screen now opens on one line: tomorrow’s cheapest window, with its start and end time and the average price inside it. Customers choose the length once, and the app remembers it.
Under that line, today and tomorrow run as one strip of hours, colored from cheap to expensive, with the current hour marked. Drag across the strip and the app shows the average price of that stretch, which turned out to be how most people planned around the washing machine.
The bar chart is still there, one tap down, for customers who like to see every hour. A notification arrives once a day, when tomorrow’s prices are in.
Tomorrow's cheapest three hours next to tomorrow's hourly prices.
Tomorrow's cheapest window, the first thing the app shows.
Tomorrow's hours as one list, colored by price.
Result
Support started pointing new customers to the window on their first call. The strip went on to shape the charging screen for electric cars, which another designer took over when I moved to the design system.
What I learned
The chart was accurate and still no help for planning. Once the app led with a window, people stopped counting bars.