An app-controlled wireless lighting system lets you manage your home’s energy usage from your pocket. Some apps allow you to control several elements remotely—turning lights on or off, setting your thermostat, monitoring home security and unlocking doors. You can find smart lighting starter kits for under $100, or a smart thermostat for less than $200.

A leak detection system with a solenoid valve (approximately $200 to $500) signals when your pipes malfunction—or, in some cases, if a tap is left running. It then shuts off the water, potentially preventing a flood and saving you thousands of dollars in home repairs.

Low-emissivity (low-e) windows capture the sun’s warmth and then emit low levels of radiant thermal energy—helping heat your home. You’ll pay about 10 to 15 percent more for low-e glass, but you may reduce energy loss by up to 33 percent on average.

Solar power has been around for a while, but recent advances have brought the cost down—with many tax advantages still in place. From 2009 to 2016, the installed cost of a system that uses solar energy to heat and cool your home dropped by more than half, according to the National Renewable Energy Laboratory. Savings vary depending on your location and your electricity rates: You may save as much as 50 percent.

Your water heater is your home’s second-highest energy user. A solar heater can cut your hot water costs in half, according to the U.S. Department of Energy. Or you can use technology to heat your water more effectively: A recirculation system, usually costing less than $400, delivers hot water instantly. That’s an important benefit, since much of the water we use for showering goes down the drain as we wait for it to heat up.

Leaving a computer on 24/7 can cost you close to $80 a year in energy costs, while leaving a TV on half the day may cost even more. Energy monitors pinpoint how much energy you use and which devices drain power. Systems vary in price and sophistication: You can monitor one appliance, or you can install a system in your main breaker to check the entire house. Some systems even transmit the data to your smartphone or computer.

You can get a smart refrigerator with a built-in computer to keep an inventory, helping you avoid food waste and making your grocery runs more efficient. Or use your smartphone or computer to turn your oven off remotely, so it doesn’t run longer than necessary. Expect to pay upwards of $3,500 for a smart fridge and $1,400 or so for a smart electric range.

If you’re not sure where to get the money to pay for upgrades, you might consider tapping your home equity. You can enjoy the improvements—and their cost savings—right away, and you could potentially increase your home’s value when it’s time to sell. Learn more about a home equity line of credit from Bank of America.