And so the battle for smart thermostat supremacy wages on. No sooner have we welcomed another warrior to the battlefield than energy provider npower's decided to start giving Nest thermostats away for free. As you may remember, Nest struck up a partnership with npower earlier this year, getting a direct line to the latter's customer base in much the same way British Gas and Scottish Power are leveraging their own. Now, to get a Nest installed for free, you need to be an npower customer (duh). Not just any old customer, though, but one signed up to the new "Intelligent Control - October 2016" gas and electricity tariff. Basically, it's a "dual-fuel" plan that promises a fixed price until -- you guessed it -- October 2016. Deciding whether the tariff is right for you should obviously be your primary concern, but know there's a Nest thrown in to sweeten the deal. npower wasn't exactly ripping customers off with its previous offer of a Nest plus installation for £99 (on a different tariff), but hey, free's free.