Google-SolarCity mashup deepens reach into the American home by Kirsten Korosec @FortuneMagazine April 14, 2015, 9:37 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Much of the attention surrounding Monday’s announcement of a partnership between energy provider SolarCity and Nest, the Google-owned smart home gadget maker, has focused on free devices and energy savings. Both aspects are notable. The first 10,000 customers in California who sign up with SolarCity, the largest installer of residential solar systems in the U.S., will receive Nest’s $249 thermostat installed at no additional cost. Qualifying customers will be offered seasonal savings by tapping into solar power to cool—or heat—their home. But just like SolarCity’s MySolarCity mobile application, which debuted in December, the partnership is also about data collection in our increasingly connected homes. SolarCity’s SCTY app allows it to capture data from thousands of its customers across 16 U.S. states. Peter Rive, the company’s chief technology officer, told Fortune in December that the app is a step toward a fully connected home. When SolarCity installs panels on a rooftop, it also establishes a wireless network inside the home with a gateway that connects directly to the solar power system and the customer’s electrical power. The company uses a type of low-power wireless networking technology called Zigbee, the same standard used to control many home automation devices. “As new devices come online, we’ll be able to integrate with them,” Rive said at the time. Enter Nest Labs, the company purchased by Google GOOG in January 2014 for $3.2 billion. SolarCity will integrate with Nest’s software so that by this summer, the device will be able to regulate the home’s air conditioner, swimming pool pump, and other appliances based on the availability of solar power, according to the companies. This isn’t the first time Nest has integrated its thermostat with other products and services. The partnership with SolarCity is part of Works With Nest, a program that aims to expand the number of appliances and devices that can communicate with the Nest thermostat. German automaker Mercedes-Benz, Whirlpool WHR , Dropcam (a webcam maker purchased by Nest last June), lighting company Lifx, and Jawbone are all working with Nest. For instance, Nest’s thermostat can communicate with an owner’s Drive Kit Plus-equipped Mercedes-Benz and cool the home as the car approaches. Or, if the thermostat detects that the owner is away, it can tell a home’s Whirlpool laundry dryer to switch to a refresh mode when a dry cycle ends so that clothes remain wrinkle-free. Nest is clearly working toward a more intuitive home filled with devices that can coordinate and communicate information to boost convenience and save energy. The SolarCity partnership will help push those energy savings even further by changing how devices are used based on the availability of solar power—and, with luck, help it and Nest better understand how people use Internet-connected devices in their homes.