This is something that I have been thinking about for a while now.
You can run probably 500' to 600' of vacuum and pressure hose with the gas vac system but still need a generator for the electric 115 volt pumpout system.
If you were to work in a building and don't feel like running 500' to 600' of vacuum and pressure hose, you could use the electric system and find electric outlets for the vacuum system and pumpout and just run the long pressure hose.
Something I talked to Jerry about the other day is that if you have his system and want to do more interior tile/grout cleaning but it will be too far from the trailer, you can buy the electric pressure washer with the hot water kit and run the waste drum w/ pumpout and the electric vacuum system. This would be like running a portable tile/grout extractor but less expensive.
There are many ways to do this type of cleaning, a lot of great things will be seen and talked about in Milwaukee along with showing the new 40" vacuum surface cleaner.