More 'story-based' Event Cards.

[tjc-schipper]

Don't just present numbers and statistics, relate it to something as much as possible.
"Highest Power this week", "User X beat their previous record!", "This week's consumption is 10% lower than last weeks!", etc.

Perhaps use these cards more as something that inspires action or guides: "You need to use 5% less power to meet this week's target!".