the 10 kilowatt model goes for the relatively affordable price of $3,500 plus the cost open installation. he revealed a commercial selection of the battery called the power pack which is designed to be infinitely available. >> you can transition the united states with 900 million, you can transition the world. you can basically make all electricity generation in the world renewable. and primarily solar. >> joining me now, david roberts and tech consultant adviser shelly palmer. david, let me start with you. you just wrote this piece about solar being essentially inevitable. how big was -- how big a problem is the battery problem? how far did musk get with this announcement? >> well i think mostly what he did with the announcement is open people's minds to the possibility. i mean currently, batteries are still too big and bulky and hold