They can make money just from eyeballs, so they don't need to use data. Normally Google looks for data that increase the value of advertizing space but I don't have any idea what they can do with you electric meater numbers.
There could a lot of data gleaned about TV viewers , for example .. by analyzing power usage trends during tv show times. If a show is watched more , then advertisers would want to target that show more ...
If you're implying that I'm suggesting Google should give me something for free, I'm not.
Just orienting this "service" in a way that shows that the users are, freely, giving something to Google.