The company has already sold its Megapack battery-storage product for years, but the Megablock contains four Megapacks around a transformer. Advertisement AdvertisementAdvertisement"I think Megapack is the most underrated product that Tesla has by far," green energy advocate Jesse Peltan told Canary Media. When paired with solar panels, for example, batteries store the excess energy generated while the sun is out, allowing that energy to be used later. In fact, solar panels pair especially well with several Tesla products, including its EVs. For those interested in getting solar panels, EnergySage offers free, easy-to-use tools that allow for easy comparison of quotes from local, verified installers, resulting in average savings of up to $10,000.