In the company's earnings call, Tesla Motors CEO Elon Musk revealed that the Tesla Powerwall is currently sold out until sometime in the middle of 2016.

The Powerwall is a rechargeable lithium-ion battery that can store energy to be used by homes. It can be mounted on a home's wall and integrated into the local electricity grid, storing excess power that users can draw out when needed.

Demand for the Powerwall has been "staggering," according to Musk, with reservations for the energy storage system reaching 38,000 units.

"The response has been overwhelming. Like, crazy," said Musk.

"We're basically sold out through the first half of next year," Musk said in the conference call, adding that 2,800 Powerpacks, which is the version of the Powerwall designed for commercial use, has also been reserved.

Musk, however, admitted that he expected most of the sales of the energy storage systems under the company's new Tesla Energy program to be to utility and industry customers, as opposed to individual customers. Still, Musk retains his expectation that Powerpacks will eventually outsell Powerwalls by five to 10 times more in terms of megawatt hours.

The Powerwall provides customers with several benefits, such as being able to do load shifting. Users can choose to have the Powerwall charge up when both power demand and usage charges of power from the local grid are low, and have the Powerwall release stored energy for usage when both power demand and usage charges are high.

The Powerwall is also capable of storing excess solar energy, which will increase the consumption of users of the solar power that their own systems generate. The system can also function as a backup power source in cases of power outages.

The 7 kWh version of the Powerwall will be sold for $3,000 while the 10 kWh version will be sold for $3,500, in addition to installation fees and the inverter that the system will use.

However, with these features and prices, Powerwalls may not currently make much sense for U.S. consumers financially.

In reality, the Powerwall will mainly target users that are already self-sufficient to maintain their standing, specifically homes that are hooked up with solar panels and wind turbines that can generate electricity at certain points of the day and then have the excess energy generated to be stored in the Powerwall to be used when the solar panels and wind turbines are no longer generating electricity.

However, this does not mean that the Powerwall is a useless system for homes without solar panels and wind turbines. It will focus more on getting a bit more in savings as opposed to pushing for renewable energy.