Is it possible to grab a value via this api and display it on a dashboard tile? e.g. I would want to display the KwH for the day and cost (both available feeds).
Yes but you would have to write a driver to do this. Take a look at the weather apixu driver. That one does the same thing for a weather icon. Yes, it does a lot of other things too but you can't do something like that with rule machine.
