This company built a house last year and claimed it would:

"offsets minimum utility charges, and offsets mortgage payment"

The house needs about 4, 000 more watts of solar on it to be net-zero (offset electric bill) and will never be able to offset the mortgage payment.

They just finished another one (photos attached) and the signs claim it will:

"eliminate gas & power bills"

The house has a small (1.8kw) solar array and has a gas powered fireplace, gas powered range, gas powered hot water heater and a gas powered furnace. So, there is no way the house can eliminate your gas bill.