Tesla’s solar products will soon only be sold together with the company’s Powerwall battery, CEO Elon Musk announced on Twitter. Integrating them into a single product will making installations easier and home backup more seamless during outages, according to Musk. The change will affect both Tesla’s Solar Panels (which sit on top of an existing roof), and Solar Roof (which replaces a home’s existing roof slats).

The new policy was announced just hours after Musk responded to a tweet from Ark Investment Management’s director of research Brett Winton, who had complained that his Tesla solar panels hadn’t generated any electricity since installation because he was waiting on his local utility company to approve the connection.

“Did you buy a Powerwall?” Musk tweeted at Winton, “Utility permission is required for flowing electricity back to grid, but usually not if stored in our battery.” Bloomberg notes that Ark Investment has been a big supporter of Tesla, and holds “significant stakes” in the company.

Signs of Tesla’s intention to bundle its solar products with the Powerwall were reported last month by Elektrek, who spotted that the company was only accepting new Powerwall orders when combined with a Tesla solar panel project. Powerwall supply shortages were thought to be to blame for the shift, with demand and wait times increasing for the home battery solution. In the fourth quarter of 2020, Tesla installed 86 mega-watts (MW) of solar energy, a 59 percent increase compared to the same period the previous year.

Alongside the change, Musk announced an upcoming software update for the Powerwall, which he says will enable upwards of a 50 percent power increase depending on production date. The current Powerwall is rated to provide 5 kW of real power (7 kW peak) in North America, but in a tweet the CEO said that Tesla’s newest units can “probably” provide as much as 10kW continuous, and “double that in peak” under the right circumstances.

The changes come after Tesla faced criticism for substantially raising the prices of some of its solar products. Earlier this month one customer reported that the company had told them a $35,000 solar roof order would now cost them $75,000, while the price of the accompanying batteries would increase from $30,000 to $35,000.