There are 3 places where you can see the page:
- On top of the page in the status
- Under the universal actions (easiest way to manouvre between pages
- In the Dashboard Environment. This the actual setting of the page. This value can be made dynamic for example if you want Homey to control the page. Note: With buttons and the new menu (Test version) you can go to pages directly
There is a WHEN flow card that activates when a dashboard is loaded (including a tag with the dashboard) and a WHEN flow card that activates when a dashboard is saved (easy to remoteky reload dashboards). But there is no WHEN flow card that activates when a certain page is activated.
But, this can be passed through with a button or a menu item. How exactly are you going to jump to another page in your dashboard? If you use a button for that, just configure it like this:
Set the “On click” to “Go to page”
If you create a “toggle switch”, it automatically gets pressed when it is on the “Target Page”
Fill in an output topic with any topic (unique name).
and use that topic inside homey and do whatever you want with that trigger
If you enable state caching inside the Homey Dashboard Studio settings, it automatically send the latest known values to the dashboard when it reloads. This is a default ON setting though. But it does looses the cache if you restart the app. And this might happen when a new version is automatically installed:
I don’t use Tibber, but I believe they use 15m prices (every 15 minutes) So you need to add that device. Configure NL_Netherlands and I believe you can configure the rest in the setting. I don’t know anymore 
Anyway the power by the hour is not app from me, better to ask those kind of questions in the PBTH thread
