The A1, an inverter for residential and commercial electricity production, has long been touted as the better choice for consumers.
It costs about $20 more per kilowatt-hour than the A2, the more advanced A12, which is used for small and medium-sized buildings.
But the A4 has been gaining ground in recent months, as it’s become the standard for residential installations.
The A4, which will be available for $100 per month in a few months, comes with a built-in voltage regulator and a built in timer.
It’s also available in more than 40 states.
A1 is rated for a maximum output of about 8 megawatts (MW), according to the company.
It can output up to 30 MW.