US BTU Usage

Vtcodger
Last Update: Thu Sep 1 07:50:31 2016

US BTU Usage

The great petroleum price runup of 2006-8 should be enough to convince reasonable people and possibly even some Americans that a world with high energy prices is going to be a different world than that we live in. One strategy for dealing with high energy costs is to use less energy. It is easier to do that if we understand what energy is used for in the US.

In these essays, I use BTU/capita a lot. That's the average number of British Thermal Units used by one quite imaginary typical person per day. It is not any person's actual consumption because is includes such things as the electricity required to run the fancy light shows in Las Vegas and the energy hungry Aluminum smelters in Tennessee and the New York City subway -- all divided by 300,000,000 people. Nonetheless, a lot of US energy usage actually is at the discretion of 300,000,000 individual Americans. And reducing the energy usage is going to depend on their individual lifestyle choices.

In a later essay, I'll discuss what Americans can do to reduce their energy footprint without returning to the stone age. In this essay I want to identify what America's roughly 900,000BTU per person per day are used for. Rather than use BTU throughout which would result in horrendously large numbers at times, I'll use percentage of total usage initially, then convert that to BTU/capita.

US Energy Usage

I'm basing this discussion on the Wikipedia article on "Energy in the United States" because it has the right numbers collected together. I have checked and the numbers look to be consistent with other sources. My experience has been that no two sets of energy numbers of any sort ever actually agree completely, but that the discrepancies are usually small enough to ignore. The principle problem is that the numbers are from the 2002-2004 timeframe. Percentage usage does not change as rapidly as absolute amounts. So, the Wikipedia entry probably isn't what you'd want to use for high precision planning. But it is good enough for this essay.

One possible breakdown of energy usage is into the four categories: industrial(33%),commercial(17%),transportation(28%), and residential(21%). Each of these needs to be broken down further. I've assumed the typical BTU usage per person is 900,000. The columns miss adding correctly by a couple of percent. I'm pretending that the problem is rounding error, and I'm ignoring it for the time being.
Category-Subcategory Percentage of Total Usage BTU/c
Industrial-Chemicals 7.26% 65300
Industrial-Oil Refining 5.28% 47500
Industrial-Metal Refining 4.62% 41600
Industrial-Other 15.84% 142600
Transportation - gasoline 17.36% 156200
Transportation - diesel 5.88% 52900
Transportation - aviation 3.36% 30200
Transportation - other 1.48% 13300
Commercial - lighting 4.25% 38250
Commercial - heating 2.21% 19890
Commercial - cooling 1.87% 16830
Commercial - refrigeration 1.02% 9180
Commercial - water heating 1.02% 9180
Commercial - ventilation 1.02% 9180
Commercial - electronics 1.02% 9180
Commercial - other 4.59% 41310
Residential - space heating 6.72% 60480
Residential - water heating 2.73% 25470
Residential - lighting 2.52% 22680
Residential - refrigeration 1.68% 15120
Residential - electronics 1.05% 9450
Residential - clothes clean-dry 1.05% 9450
Residential - other 2.94% 26460
Other .9% 9000

Many things are as we would expect. A lot of energy is used by cars and trucks. Duh. On the other hand, it might be a surprise that electric lights use twice as much energy as all the aircraft in the country. Heating hot water uses half again as much energy as refrigeration. In later articles, we'll be interested in where energy savings can be made. It is fairly obvious that a modest percentage decrease in use by cars has more impact than a large percentage change in residential electronics energy usage. To assist in that sort of analysis, let's reorder the table by percentage of total energy usage.
Category-Subcategory Percentage of Total Usage BTU/c
Transportation - gasoline 17.36% 156200
Industrial-Other 15.84% 142600
Industrial-Chemicals 7.26% 65300
Residential - space heating 6.72% 60480
Transportation - diesel 5.88% 52900
Industrial-Oil Refining 5.28% 47500
Industrial-Metal Refining 4.62% 41600
Commercial - other 4.59% 41310
Commercial - lighting 4.25% 38250
Transportation - aviation 3.36% 30200
Residential - other 2.94% 26460
Residential - water heating 2.73% 25470
Residential - lighting 2.52% 22680
Commercial - heating 2.21% 19890
Commercial - cooling 1.87% 16830
Residential - refrigeration 1.68% 15120
Transportation - other 1.48% 13300
Residential - electronics 1.05% 9450
Residential - clothes clean-dry 1.05% 9450
Commercial - refrigeration 1.02% 9180
Commercial - water heating 1.02% 9180
Commercial - ventilation 1.02% 9180
Commercial - electronics 1.02% 9180
Other .9% 9000

OK, now we have a basis for comparing various conservation ideas. For example water typically comes out of pipes from wells or reservoirs at about the average annual air temperature of the area -- 50 to 55 degrees Fahrenheit for most of the US. As a first approximation (and it is REALLY approximate) turning the heating thermostat down will save t/k*100 where t is the amount of the decrease in thermostat temperature and k is the difference between the thermostat setting and the ground water temperature. So, if we assume that the average temperature is 52.5 degrees and that houses and businesses are heated to 76 degrees, the savings from changing the setting to 68 degrees would be about (76-68)/(76-52.5) = 8/23.5 = 34%. We then look into the tables and find the residential (6.72%) and commercial (2.21%) heating consume 8.93% of US energy. If we save 34% of that 8.93%, we will cut US energy consumption by .34*.0893*100 = 3.08%. Three full percentage points. Well worth considering. More on this in another chapter.

One final detail. The top six items on our list Transportation-gasoline, Industrial-Other, Industrial-Chemicals, Residential-space heating, Transportation-diesel, Industrial-Oil Refining account for 60% of US energy usage. It may help to break them down into smaller divisions so we can see a little more clearly where energy usage reductions can help and where they can't. Here's a breakdown:
Transportation - gasoline - cars 7.16% 64441
Transportation - gasoline - light trucks 5.58% 50420
Transportation - gasoline - SUV 1.93% 17418
Transportation - gasoline - other 1.42% 12834
Transportation - gasoline - minivan 1.22% 11001
Transportation - gasoline - motorcycles .06% 125
Transportation - diesel - Trucking 4.41% 39675
Transportation - diesel - off-highway 1.18% 10584
Transportation - diesel - non-Truck Highway 0.29% 2646
Industrial-Chemicals-Miscellaneous 3.19% 28732
Industrial-Chemicals-Ethylene and coproducts 2.13% 19133
Industrial-Chemicals Ammonia and Urea 0.78% 7052
Industrial-Chemicals Chlorine 0.25% 2286
Industrial-Oil Refining 5.28% 47500
Industrial-Metal Refining 4.62% 41600
Industrial-Miscellaneous 12.01% 142600
Industrial-Cement Manufacture 0.33% 2970
Industrial-Wood Production 0.50% 2500
Industrial-Pulp and Paper 3.00% 27000

[http://web.archive.org/web/20070211171911/http://ies.lbl.gov/iespubs/44314.pdf]

There are still a couple of items there like "Industrial-Miscellaneous" that could use further breakdown, but there are only so many hours in a day. And maybe they really do consist of dozens of small, independent usages that can't easily be organized into broader categories.

Anyway here is the final list ordered by percentage of US consumption.
Category-Subcategory Percentage of Total Usage BTU/c
Industrial-Miscellaneous 12.01% 142600
Transportation - gasoline - cars 7.16% 64441
Residential - space heating 6.72% 60480
Transportation - gasoline - light trucks 5.58% 50420
Industrial-Oil Refining 5.28% 47500
Industrial-Metal Refining 4.62% 41600
Commercial - other 4.59% 41310
Transportation - diesel - Trucking 4.41% 39675
Commercial - lighting 4.25% 38250
Transportation - aviation 3.36% 30200
Industrial-Chemicals-Miscellaneous 3.19% 28732
Industrial-Pulp and Paper 3.00% 27000
Residential - other 2.94% 26460
Residential - water heating 2.73% 25470
Residential - lighting 2.52% 22680
Commercial - heating 2.21% 19890
Industrial-Chemicals-Ethylene and coproducts 2.13% 19133
Transportation - gasoline - SUV 1.93% 17418
Commercial - cooling 1.87% 16830
Residential - refrigeration 1.68% 15120
Transportation - other 1.48% 13300
Transportation - gasoline - other 1.42% 12834
Transportation - gasoline - minivan 1.22% 11001
Transportation - diesel - off-highway 1.18% 10584
Residential - electronics 1.05% 9450
Residential - clothes clean-dry 1.05% 9450
Commercial - refrigeration 1.02% 9180
Commercial - water heating 1.02% 9180
Commercial - ventilation 1.02% 9180
Commercial - electronics 1.02% 9180
Other 0.90% 8100
Industrial-Chemicals - Ammonia and Urea 0.78% 7052
Industrial-Wood Production 0.50% 2500
Industrial-Cement Manufacture 0.33% 2970
Transportation - diesel - non-Truck Highway 0.29% 2646
Industrial-Chemicals - Chlorine 0.25% 2286
Transportation - gasoline - motorcycles 0.06% 125

OK, see we know what energy is used for in the US. The next essay will deal with where the energy comes from.