Elon Musk only announced Tesla's new Powerpack system tonight, but the company has already done deals with some of America's biggest companies to supply them with the new technology. Both Amazon and Target are rolling out pilot programs that will use Tesla's 100 kWh battery blocks, along with smaller companies such as Jackson Family Wines.

In Target's case, the retail giant will use Tesla's Powerpacks at certain stores, acting like more efficient generators to relieve stress on the electrical grid and draw power during shortfalls. Jackson Family Wines will use the Powerpacks in a similar way, storing electricity drawn from the grid or solar panels during quiet times and using it during periods of high energy consumption in the winemaking process to avoid energy spikes.

Amazon is using the Powerpacks as part of a 4.8 mWh pilot program in Northern California to assist in running its Amazon Web Services platform. James Hamilton, an AWS engineer, said the technology would make it easier for the company to rely on renewable energy sources. Batteries, he said, would "bridge the gap between intermittent production, from sources like wind, and the data center's constant power demands." Amazon has been working with Tesla for the last year, viewing Musk's new Powerpacks as a way to reach its ultimate goal of "reducing the technical barriers limiting widespread adoption of renewables in the grid."

In addition to businesses such as Amazon and Target, utility companies are also using the Powerpacks to store more electricity from renewable sources — Southern California Edison is adopting the batteries for use in its electricity storage systems, a move Tesla says will "increase the use of renewable energy while ensuring continued grid reliability." While the grid is usually reliable, power plants are currently built to output just-in-time power for daily spikes. Advanced battery technology could allow them to be made smaller and more efficient as Tesla's Powerpacks store unused energy for peak times.

While solar and wind plants can provide electricity, the supply is not always consistent, causing them to over- and under-produce at certain times. Tesla says its Powerpacks help "firm up" this generation of energy from renewable sources, storing excess electricity from a range of sources until it's needed. If huge companies and electricity providers continue to adopt the new tech, it could help kickstart a shift toward renewable energy sources, with Musk's fields of batteries acting as buffers.