I recall reading somewhere that the inverter option which is offered in Japan was rather pricey . . . . something around $2K US
I would be surprised if they were to offer a US equivalent (120/240 60 Hz unit) since they have sold so few cars here. I would think it wouldn't be all that difficult to build your own version though and I'll bet it could be done for a lot less than $2K, assuming your car already has the CHAdeMO socket. A standard 12 volt to 120 AC 5 KW unit is on sale right now from Harbor Freight for $399 - That inverter would be more expensive to build than a similar one for our car because of the currents involved. A 5Kw 12 volt inverter must handle over 400 amps DC to provide the power . . . . a similar inverter running off the cars 330 volt battery pack could provide the same 5Kw drawing only 15 amps DC. If you only needed a 3Kw output, it could be done using less than 10 amps. Components for 10 amps would be extremely cheap compared to the 400+ amp components used in the $400 12 volt version
http://www.harborfreight.com/5000-watt-continuous-10000-watt-peak-power-inverter-96706.html
Keep in mind the usefulness of such an emergency power supply. Inverters cannot provide too much power for too long before the battery powering them is exhausted. If you bought a 5Kw gasoline powered genset, you could power most of your home with it . . . . probably everything except for air conditioning and do it for as long as you had gasoline to run it. With a 5Kw inverter unit attached to your car's battery, you could only get 5Kw from it for about 3 hours, assuming your cars battery was fully charged when you started
If you built a 1Kw inverter intended only to keep your rerigerator from defrosting, you could probably power your refrigerator with it for several days, *if* you weren't powering anything else with it. Your car could provide 1Kw of continuous power for only around 15 or 16 hours
A better solution would probably be something like a Honda 2000i genset. I've had one for years and I use it pretty regularly - It's a very handy tool to have available when you need portable or emergency power. Small, portable, reliable, lightweight and VERY fuel efficient because it uses an inverter so that the engine only needs to run as fast as the load requires it to - Most gensets must run at a continuous 3600 RPM even when they are powering very small loads because they must run a constant speed to output a steady 60Hz. The little Honda could provide about 1Kw for 8 or 9 hours on only a gallon of gas. If you bought such a genset, you'd find yourself using it for many things besides power outages, so you'd be getting lots more for your money - You could even use it in a pinch to recharge your car!
http://www.wisesales.com/eu2000ia-honda-generator.html?utm_source=GoogleBaseFeed&utm_medium=referral&utm_campaign=GoogleBase&gclid=CLjXyLHu3rMCFU6mPAodYV8AwA
Don