Gas is an efficient power source, but it can be extremely dangerous, too. One big problem is that you can create a leak and not realize it until there's a dangerous gas build-up in your home. The smell will tip you off, but by that time, static electricity could set off an explosion.
If you have an upgrade in mind, call your local power company for information. If you smell gas in your home, don't stop to call anyone or diagnose the problem yourself. Get your family together and leave. Call for assistance from another location.