I won a Powerwall from the first referral program and got the email. It asked me if I want to proceed with the installation or get a $3,500 credit. The referral program said it included installation. I am wondering if it will include the required inverter or not, does anyone know? I don't have solar panels and don't plan on installing them anytime soon. I also read the Solar City charges over $7,000 for a Powerwall including installation. Anyone heard of other installed costs?