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.
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.