Thanks for the info, very good.
I needed to pick two values, so I did this:

#!/bin/bash

energy=`curl 'http://www.energyhive.com/mobile_proxy/getCurrentValuesSummary?token=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' | jq -r .[].data`


tot=`echo $energy |cut -f2 -d":"|cut -f1 -d"}"| tr -d ' '`
car=`echo ...