Id contact each utility company, gas and electric in your area...and
have THEM convince you with documentation/calculations which is best to
go with.

'In general, someone else doing your work for you will only convince you
of what will make them the most money.'

To be sure youre getting the correct story from each Utility
Company...you take what they give you by way of calculations,
comparisons, etc...and have it verfied by a non biased entity. Id have
the Utilities provide thier info, then, go about doing your homework to
see which (if either) is credible.