Elon Musk and Tesla to announce 'major new product' on 30 April - but it is not a car

Tesla is to reveal an all-new product on 30 April, but it will not be a car, says company chief executive Elon Musk.

Tweeting on 30 March, the eccentric billionaire said he will reveal a "major new Tesla product - not a car...at our Hawthorn Design Studio". The unveiling will take place at 8pm local time (4am GMT).

Founded in 2003, California-based Tesla has so far produced just two products, both all-electric cars. The first was the Tesla Roadster in 2008, a roofless sports car similar to the Lotus Elise, but which sold in very low numbers. The second product, the Model S, is a luxury saloon car which was introduced in 2012 and since then more than 50,000 have been sold around the world.

The news of an announcement comes in the wake of Musk suggesting the batteries of electric cars could be used to power our homes. To cheer up investors after reporting a loss for the fourth quarter of 2014, Musk outlining vague plans for a home battery.

The battery pack could resemble the system used by the Toyota Mirai, a hydrogen fuel cell-powered car which lets owners remove the battery and use it to power their house; when fully charged, Toyota claims the battery can power an average home for a week.

Alternatively, Tesla could follow the Nissan Leaf, an all-electric car which can be used as a temporary generator to power a home in an emergency.

On an earnings call in 2014, Musk revealed plans to power consumers' homes, not just their cars. "We are trying to figure out what would be a cool stationary [battery] pack. Some will be like the Model S pack: something flat five inches off the wall, wall mounted, with a beautiful cover, an integrated bi-directional inverter, and plug and play."

During that same call, Tesla's chief technical officer, JB Straubel, said long-term demand for stationary energy storage is "extraordinary," adding: "We've done a huge amount of effort there and have talked to major utilities and energy service companies."

As of February this year, Tesla was still deciding on an exact date to release the home battery pack, but at that point Musk described it as "really great".