According the EIA (Energy Information Administration), in 2008 our homes accounted for 21% of all natural gas use in this country. 29% went to generating electricity, and another 29% went to industry. The rest went everywhere else.
Fortunately, it would appear that our efforts to improve the efficiency of our homes and heating equipment is paying off. (It may also appear that our winters are getting warmer, but, that is so much another topic for another day).
According to the EIA data on residential use of Natural gas, our residential consumption has stayed nearly constant since 1966. In fact, in many of those years it has actually gone down a slight amount! In 1966, residential customers used 4,138 Billion Cubic feet ot Natural Gas. In 2008 they used 4,866 Billion Cubic feet of the stuff.
Here is the data. This data agrees with both other EIA documents and the Natural Gas Association.
This is despite the fact that our population has grown by over 100 million people, And despite the fact that the number of single family homes has at least doubled.
Indeed ,The US census reports that in 1970 there were 46,790,055 single family homes and townhouses in the United States, By the 2000 census that number had increased to 76,313,410. Although the actual figure is not available for 2008, it is safe to assume a modest increase since then.
So, what has caused this? Good question, and I certainly don’t have the definitive answer. I do know that According to the Natural Gas association, 51% of all homes in the US are heated with natural gas. They state that percentage has remained relatively unchanged during this period. So, it must be something else.
Well, furnaces are getting more efficient. From the old clunkers of the past at 80% efficiency, to modern condensing furnaces that are better than 92% efficient. But, there are many older furnaces still out there. Only in 1992 was the Annual Fuel Utilization Efficiency required to be 80% or better. New standards are going to bump that to 90% soon.
I came across this study by the Lawrence Berkeley National Laboratory study the Average Fuel Utilization Efficiency of gas furnaces during the period since 1980 has rose from 72% to 83%, a gain of 11%. (it is on page 22)
And, we have certainly been making our homes more efficient. According to the EIA, the efficiency of our homes has improved by 35% between 1980 and 2005 from 65,000 BTU per square foot to 41,000 BTU per square foot, annually.
So, we have twice as many homes, using the same amount of gas. Have we improved our overall efficiency by 50 percent? As I said at the beginning, that is a subject for a future discussion.
For further reading. Here is an article about Furnace efficiency standards.