Tesla Inc said SolarCity co-founder Peter Rive is leaving the company, eight months after the electric car maker bought the biggest U.S. residential solar panel maker.

SolarCity was founded by Peter Rive and his younger brother Lyndon in 2006 with financial backing from their cousin and Tesla chief Elon Musk. Former SolarCity Chief Executive Lyndon Rive announced his resignation in May.

Peter Rive will be leaving the company to explore new opportunities, a Tesla spokesperson said in a statement.

Tesla bought SolarCity for $2.6 billion last year, paving the way for Musk's ambitious plans for a carbon-free energy and transportation company. The sale came as investors worried about the solar panel installer's debt-fueled growth.

Under Tesla, SolarCity has slowed installations and focused on the most profitable projects that generate cash upfront.

Rive was overseeing the development of solar roof tiles, which are expected to go into production this summer.

"Peter's responsibilities, including work on Solar Roof, will be distributed among Tesla's existing engineering teams," Tesla said.