Slash energy costs by 30%

This time of year, you may find yourself having an internal debate at the thermostat: stay cool or save money? If you're tired of sweating high summer cooling costs - and winter heat bills besides - these techie tools can help. Used in concert, they may save you 30% annually on energy bills, says Zeke Hausfather of Climate Culture, an online community focusing on energy consumption. And that, as you'll see below, adds up to cool cash.
NEXT: Check for drafts