Posting this in the local forum as I know Griddy (referral link, you'll get $25 added to your account if you signup) is fairly widely used in north Texas. For those that know nothing about it, it allows you to buy power at wholesale rates, which means if you keep an eye on things and have a little flexibility in the house, you can save quite a bit of money. Obviously, charging the cars is one of the main consumers, and normally something that can be scheduled with a degree of flexibility (as opposed to AC). There's times when the cost of power goes negative, which is great, but more often then not at some point in the week I can charge at well below 1c per kw/h. Griddy has basic IFTTT integration, and there's an API that can pull the real-time price, but what I'd really like to do is: Only allow charging when power cost is below a defined threshold Stop charging if power cost exceeds a defined threshold Same logic for Powerwall, fill it up on cheap power, so it can expend it's power during peak hours Has anybody managed to do this?