My family of five lives in a 2300 sqft two story detached SFR. We put up 7500W of solar panels in 2014. In the first 12 month period they generated about 10,000 kWh, which was roughly double our annual household usage. A surplus of about 5k kWh per year.
Then we bought a 100% electric car. Our power bills went up by about $25/mo, but our gasoline bills dropped by far more than that. The solar panels still generated a net surplus over the following year of about 1000 kWh.
Then we replaced our gas furnace with an electric heat pump, which is also an air conditioner. Our natural gas bill dropped about $300/yr, all of it the winter. Our power consumption is up enough that I don't think we are electricity neutral anymore, but our costs are way down and our carbon emissions are way down.
Our regional electricity generation is mostly hydropower anyway, so any opportunity to replace fossil fuel burning with local electricity is a net positive, whether that electricity comes from your roof or from the grid. Cost wise, my family profits more by using ALL of our rooftop generation to displace gasoline or natural gas instead of selling any net surplus back to the grid at 7.5 cents/kWh, so the optimal solution for us is to be just barely net negative on household usage. We're pretty close.