
American energy use - yread
https://www.vox.com/energy-and-environment/2017/4/13/15268604/american-energy-one-diagram
======
dimitar
Contrary to what the article claims ("Transportation is a huge, looming, and
almost entirely unsolved climate problem") transportation can be a solved
problem. If you notice one of the graphs while transportation is the top
emitter hasn't increased much since 2005 and it is very sensitive to oil
prices.

Carbon taxes or excise taxes on fuel are the solution. They are endorsed by
most economists (often in addition to emissions trading). Taxes must be
imposed on emitting greenhouse gasses or at least on purchasing fuels; in
addition a cap must be placed on the total amount of emissions.

If you are libertarian and you feel like there are too many taxes already -
the carbon tax can either substitute other taxes or the revenue from it can be
returned to tax-payers in some form.

Vox itself recently had an article about carbon taxes in California, it
includes a part where the collected revenue is then redistributed back to
citizens: [https://www.vox.com/energy-and-
environment/2017/5/3/15512258...](https://www.vox.com/energy-and-
environment/2017/5/3/15512258/california-revolutionize-cap-and-trade)

~~~
jackfoxy
> Electricity wastes two-thirds of its primary energy; transportation wastes
> about three-quarters.

The electricity generation _waste_ I'm willing to take at face value, but only
because I am somewhat familiar with the concepts of conversion factor loss and
line loss. I find both of these assertions require digging into the footnotes
to understand better. Their presentation is a little too _hand wavy_. I'm
really at a loss to understand what the transportation waste means. Sure, you
also need to propel the mass of the vehicle. Is it comparing every other
vehicle to a bicycle? I don't know.

~~~
Retric
The fact the tailpipe on your car ejects a lot of useless heat is waste.
Similarly, a car's radiator is ejecting a lot of useless heat. Sure, tracking
this feels hand-wavy but using less fuel because you drive less is different
from using less fuel because the engine is more efficient.

However, this stuff still very simplified as lighter cars use less fuel even
without changing the % of waste energy generated.

~~~
dibujante
Heat is energy. Any heat that enters the atmosphere is energy you're giving
up.

~~~
Retric
99% of energy from gasoline ends up as heat, but saying it's ~0% useful energy
is not really meaningful.

------
philipkglass
I think that the LLNL methodology has changed over time. That, rather than
"we've become so much more inefficient," seems a more plausible explanation
for changes in useful/rejected energy since 1970. I was recently reviewing the
recent LLNL charts. It seems impossible that 2011 and 2016 are using the same
methodology:

[https://flowcharts.llnl.gov/content/assets/images/charts/Ene...](https://flowcharts.llnl.gov/content/assets/images/charts/Energy/Energy_2011_United-
States.png)

[https://flowcharts.llnl.gov/content/assets/images/charts/Ene...](https://flowcharts.llnl.gov/content/assets/images/charts/Energy/Energy_2016_United-
States.png)

They both show 97.3 quads of primary energy use, but in 2011 the chart shows
41.7 quads going to energy services while that dropped to 30.8 in 2016. The US
use of energy _lost_ over 25% efficiency in just 5 years? While keeping
primary energy use totally flat? The only way to make that work,
mathematically, is if people are reducing their use of energy services and
preferring inefficient ones for their remaining use.

I return to a simpler explanation: the chart methodology for identifying
rejected energy and energy services has changed, so you can't compare two
arbitrary charts. I wish they would keep the original charts around but also
produce a time series showing each year's results with the latest methodology.

EDIT: the 2015 chart seems to be the one that introduced new methods; compare
to 2014. There's a big shift in just one year.

~~~
Retric
Just to add the methodology is rather flexible as for example passive solar
heating is ignored.

------
yread
The diagram itself

[https://flowcharts.llnl.gov/content/assets/images/charts/Ene...](https://flowcharts.llnl.gov/content/assets/images/charts/Energy/Energy_2016_United-
States.png)

But I believe the blog adds useful context (starting with the quads)

~~~
adolph
The chart type is known as Sankey:

[https://en.m.wikipedia.org/wiki/Sankey_diagram](https://en.m.wikipedia.org/wiki/Sankey_diagram)

[https://bost.ocks.org/mike/sankey/](https://bost.ocks.org/mike/sankey/)

~~~
cwal37
Super fun diagrams. I interned at LLNL at one point and did a little work with
some Sankey variants visualizing energy and resource flows in urban
environments[1]. I think I still have the code lying around somewhere, I'd
love to return to it someday.

People at the lab who were aware of them were uniformly pretty proud of those
main energy figures. I had multiple old hands approach me at the poster
presentation who were really enamored of the design, one fellow actually said
he thought it was the best figure the lab produced. Of course, I was a pretty
dumb grad student and wasn't totally sure what I was doing, so mine don't have
the polish of the official ones. They were fun to work on though.

[1]
[https://www.flickr.com/photos/23215983@N02/albums/7215763423...](https://www.flickr.com/photos/23215983@N02/albums/72157634234830818)

------
the_gastropod
It's weird how infrequently Agriculture is ever mentioned when talking about
CO2 emissions. Transportation is _always_ brought up, but agriculture (which
is responsible for significantly more greenhouse gas emissions) is
conveniently left out.

~~~
philipkglass
According to the EPA, as of 2015 agriculture is responsible for 9% of American
GHG emissions and transportation is 27%.

[https://www.epa.gov/ghgemissions/sources-greenhouse-gas-
emis...](https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions)

Maybe you're thinking of the global level, where agriculture is comparable to
transportation and the IPCC grouping "agriculture, forestry, and other land
use" (AFOLU) is greater:

[https://www.ipcc.ch/pdf/assessment-
report/ar5/wg3/ipcc_wg3_a...](https://www.ipcc.ch/pdf/assessment-
report/ar5/wg3/ipcc_wg3_ar5_technical-summary.pdf)

I would venture that the reason that latter figure doesn't come up much in
American policy discussions is because American policies can do a lot more
about American transportation emissions than American policies can do about
foreign agriculture or deforestation.

~~~
podiki
The US also imports quite a bit of food (I'm not finding a definitive figure
right now, but seeing 15% in several places), so that complicates the
calculation a bit. Also, you'd want to see a breakdown of how much
transportation comes from agricultural activities as well, to get a better
idea of the full picture.

Still, agriculture is a big player no matter how you cut it, and your own
eating habits are a lot easier to control than overall policy or law changes
(and probably even your transportation, given the strong need for cars).

~~~
sirbearington
The US is a net exporter of food.

~~~
podiki
For a US consumer making choices and understanding the impact of what they eat
that doesn't matter, what matters is what ends up on the plate. A ton of
exports ends up as feed for animals, which can then be re-imported as well.

------
evdev
When I first saw this, the concept of "rejected energy" from the pink boxes
seemed to need some explanation. From the outside view, nothing is
"wasted"\--there's just the cost and benefit. You compare alternate sources
and alternate uses this way. Losses don't really mean anything unless they are
comparative, and the only thing that matters is the ultimate value of the
work, not what you would get if you ran a science experiment to figure out the
joules.

Even the losses in electrical transmission don't _really_ mean anything unless
compared to an alternative, which will have its own losses, and which can't
really be compared kWh but instead relative cost.

Someone can correct me if I'm off-base.

~~~
cjensen
Losses mean something because they demonstrate the efficiency of a particular
conversion, and demonstrate the overall size of the inefficiency compared to
other problems in the system. Two quick examples:

(1) LED light vs incandecent where incandescent's rejected energy is waste
heat

(2) Natural gas used to heat a house versus natural gas used to generate
electricity to run an electric home heater. The direct use rejects far less
heat.

This is information that can lead to policy. If you see a lot of waste in a
particular path that could be substituted with a different path, policy could
be used to encourage the more efficient path. For example, due to abundant
hydroelectric energy, the Northwest US used to use a lot of electric heating.
Once hydro no longer met demand, the government had a commercial campaign to
educate consumers about how they could save money by switching to gas.

~~~
ZeroGravitas
The home heating thing is interesting, since burning gas for that is roughly
100% efficient. Burning gas for electricity maxes out in the best possible
case at 60%, and then there's some tranmission loss (though I suppose gas
leaks from pipes need to be counted as well then).

But, electric heat pumps don't generate heat but, as the name suggests, "pump"
it from one place to another, so they can be more than 100% efficient,
generating something like 2-3x the input energy for air source, or up to 5 for
ground source pumps. Which puts electrity ahead again (especially as some of
that electricty can come from low carbon sources rather than gas).

~~~
Declanomous
Heat pumps only work in mild climates though. From what I understand, you
can't heat your home with a heat pump in a place like Wisconsin, where the
temperature is below 0F for a fairly substantial part of the winter.

I hadn't even heard of a heat-pump until recently, which makes sense, since
they seem to mostly be concentrated in warm, dry areas.

Edit: According to Wikipedia, I'm specifically thinking of Air-source heat-
pumps, which have a terrible coefficient of performance below 17 degrees
Fahrenheit. Geothermal is better, though I believe you still have problems
with saturation in cold climates.

~~~
atqtion
_> you can't heat your home with a heat pump in a place like Wisconsin...
Geothermal is better, though I believe you still have problems with saturation
in cold climates_

Geothermal heat pumps can definitely work in the portions of the upper
midwest. I know some people in both MLK and Madison that have heat pumps.

As far as I understand it's hit and miss, though. Depends on the particular
piece of property you're living on. And you may need an additional heat source
for occasional use (e.g. the super cold winter a couple years back I know one
of those folks were super glad they still had gas heating in addition to the
heat pump).

 _> I hadn't even heard of a heat-pump until recently, which makes sense,
since they seem to mostly be concentrated in warm, dry areas._

Ironically I'm the other way around. Didn't hear about heat pumps until moving
north. Probably because heat pumps don't make as much financial sense in
warmer climates where you're not blowing $100+/mo on heat?

~~~
Declanomous
I think we are talking about two different things. Everyone I know with
geothermal heat pumps just call them geothermal. What I have heard called heat
pumps are basically air conditioners that can also be used to heat the home.

Until recently I had no idea the air conditioner-like heat pumps existed, and
it appears that they are only useful if you live in a place with a low dew
point and relatively high minimum temperatures, since they can ice pretty
easily and don't work well below a certain temperature.

Anyways, Most of the people I know with geothermal in Wisconsin have fairly
large tracts of land, and still need to supplement with wood pellets or
something similar. I'm not sure you could fit enough of the heat exchange
loops in a typical yard in a densely populated area.

To be honest, the last time I did the math was probably about 10 years ago,
but I recall vertical systems are really not cost effective if you have access
to a city natural gas system unless you really like AC.

That being said, I'm renting right now, so I haven't kept close tabs on recent
developments.

Edit: Also, I think heat pumps are installed in warmer climates because a
dual-purpose AC that doesn't heat that well is cheaper than installing a
separate fossil fuel based system, which would be overkill as well as much
more expensive.

~~~
hx87
Air source heat pumps have become much more efficient at lower temperatures
than they used to be. The best units from Mitsubishi, Fujitsu, Gree, et al,
put out their nameplate rating down to -13 to -20F, and continue to produce
>50% of their output at COP > 1 below -30F. For new construction, or if you
need to replace your current boiler/furnace for some reason, heat pumps always
beat gas in levelized cost unless gas is extremely cheap compared to
electricity in your area.

> unless you really like AC

Given changes in climate as well as obesity rates, more and more people will
really like AC as time goes on, even in the coldest places.

------
r00fus
At some point one has to do some regression analysis, and wonder - if there's
money to be made in being more efficient, why has this efficiency virtious
circle not happened - and come to a rational conclusion.

The petroleum industry has complete dominance over government policy to the
point where we go to war. The Petrodollar and world reserve currency status is
a mighty powerful incentive to stay dirty.

~~~
dredmorbius
A few points:

1\. The Jevons paradox. Increased efficiency, by itself _increases_
utilisation of a resource. _If you want to reduce consumption, you need to
INCREASE costs._ In the context of fossil fuels, this means carbon and other
taxes, generally.

2\. Efficiency gains are typically overestimated and underrealised. More
generally, more efficient systems tend to require tighter integration and
coordination.

3\. Much efficiency within the US has to do with basic infrastructure and land
use. Housing, commercial, and industrial building design. _Land use,_ more
than anything else, which drives transportation patterns. Appliance design,
education, and more.

4\. Le Chatlier's Principle probably also applies (and the Jevons Paradox may
well be a special case / instance of this). Changes to a system in one
direction tend to lead to compensatory response in the opposite.

5\. Many efficiency technologies or adaptations are not themselves highly
lucrative, or have greater costs than the apparent economic benefits.

On that last:

Proper tyre inflation and regular tune-ups. The first ... simply has to be
done regularly. Tune-ups are pricy relative to energy savings.

Replacing incandescent lights with LED ( _Do this!!!_ ). Start with high-use
fixtures.

Proper insulation (easy) and weatherproofing (harder) of homes and building.
Increasing ceiling insulation makes a tremendous difference. Blocking and
stopping drafts and other leackages is much more intensive, and is often
hampered by poor initial construction and standards.

Wrapping water and HVAC pipes and conduits. Thermal loss within the structure
from water and space heating/cooling is another easy win.

Understanding your home's energy-use cycles and dependencies. In cold-weather
climates, thermal stratification and hot/cold zones within the structure often
lead to overheating (or cooling). Increasing insulation efficiency may
exacerbate this as blower fans run for shorter periods of time, and hence _mix
interior air less completely_. Counterintuitively, having high-efficiency,
low-speed fans within rooms to mix floor and ceiling air, or running central
blowers for longer periods of time, _even when heating or cooling aren 't
being applied,_ may significantly increase overall comfort.

------
hodgesrm
Phenomenal pictures!

The article makes the point that we could save a lot of energy by designing
less wasteful systems. Does anyone know of general numbers on the practical
efficiency of particular energy generation mechanisms as well as the consuming
apps? It's obviously a lot less than the thermodynamic limits. David MacKay's
wonderful 'Without Hot Air' [1] has some numbers but it's hard to relate them
directly to the LLNL diagrams.

[1]
[https://www.withouthotair.com/c22/page_155.shtml](https://www.withouthotair.com/c22/page_155.shtml),
for example.

~~~
olau
On the power plants side, it's about costs. I don't think it makes sense to
compare different plant types.

But you could take solar as an example - is it better to use up twice as much
roof space/desert if the overall design is cheaper that way? Probably. Yet,
all else being equal, the more efficient design is of course preferable, less
stuff to install, less material usage, so technological advances tends to push
for higher efficiency, I think.

On the consumer side, just look up the efficiency in what interests you. It
should be easy enough to find numbers online.

If you're in the EU, most household appliances have a mandatory rating from G
to A, with the least efficient appliances having a disturbing red G, while the
best have a nice green A:

[https://en.wikipedia.org/wiki/European_Union_energy_label](https://en.wikipedia.org/wiki/European_Union_energy_label)

As you can see in the example in Wikipedia, the differences between the
ratings are significant. When this thing started, you could buy a G fridge - I
think those may have been the norm. I looked up an internet dealer right now,
and the lowest rating I could find for sale is A+, with A++ being the norm. In
a year or two, A+++ is probably the norm.

It has worked like the MHz wars on PC, amazing really. As long as there's
competition and someone puts energy efficiency in the spotlight, things can
actually change.

------
revelation
What is the exact criteria by which energy ends up as _rejected_?

That seems very difficult to define and I'm afraid this "America is so
inefficient" rant is some misunderstanding of what is an imperfect measure.

~~~
diafygi
Whenever you burn something to do work, you are limited by a principle in
thermodynamics called the Carnot cycle[1]. It basically says that converting
heat to work has a maximum efficiency (depending on the situation).

So the rejected energy in this sankey diagram is partly just the consequence
of the thermodynamic efficiency limits of the situations. Also, since there
are always heat and resistance losses (the real world is not a frictionless
surface), the efficiency of converting energy into work is further decreased.

All in all, we're actually pretty good at covering heat into energy. The
rejected energy here is simply a consequence of the situation and
thermodynamics. For other situations that don't involve heat-to-work, such as
wind and photovoltaics, the Carnot cycle doesn't apply, and you can have much
less rejected energy.

[1]:
[https://en.m.wikipedia.org/wiki/Carnot_cycle](https://en.m.wikipedia.org/wiki/Carnot_cycle)

~~~
usmeteora
You are correct, but just as a point out for people, wind I am not sure, but
Photovoltaics I am positive are accumulate per panel, or per unit for newer
panels redesigned as solar roofing materials, intead of panels on roofing
materials, utilize inverters, which are some of the most lossy circuit designs
for power conversion right now.

Until inverters are made to be more efficient, this will always be a huge
bottleneck for dynamic energy input and output for the solar industry, and
should be considered as apart of the losses for a solar unit.

~~~
epistasis
>Until inverters are made to be more efficient, this will always be a huge
bottleneck for dynamic energy input and output for the solar industry,

That seems pretty unlikely, do you have any literature on that?

Inverters do sometimes become less efficient when there's less power coming
out of the panels, but getting <85% efficiency out of an inverter in any
common scenario would probably just mean that the install had been poorly
designed.

I guess a case could be made for not capturing the thermal energy from the sun
with panels and using that, but it's a strange case to make. (Probably about
as strange as getting more than Carnot limits out of petroleum. Though if the
waste heat is used in, say, steam pipes for distribution in a city, maybe not
so strange...)

------
falseEconomy
For a global view, projected for 2050, take a look at this tool from the UK
government and others:
[http://tool.globalcalculator.org](http://tool.globalcalculator.org) Select
Energy (at the top) -> Sankey (on the left) and optionally apply policy
scenarios.

~~~
dredmorbius
The IEA has a drill-down / interactive Sankey diagram for all countries:
[https://www.iea.org/sankey/](https://www.iea.org/sankey/)

------
wefarrell
I'm assuming they aren't counting mass transit as transportation because there
is no link between electricity and transportation. As a resident of NYC the
bulk of my transportation is powered by electricity. All of the subways,
buses, and commuter rail are electric.

~~~
dredmorbius
Total electrical energy use in transportation is minuscule.

All energy _other_ than petroleum, natural gas, and biofuels, is 3%.

[https://www.eia.gov/Energyexplained/?page=us_energy_transpor...](https://www.eia.gov/Energyexplained/?page=us_energy_transportationg)

~~~
wefarrell
You're right, it is in the visualization but it's so minuscule I didn't see
it.

I guess it's just so efficient relative to the other sources.

~~~
dredmorbius
That's a paradox of efficient or effective practices: they can simply fall out
of measurements.

GDP is notorious for this.

------
fulafel
Was expecting to see American energy use compared to other countries. It's not
a pretty picture per capita.

~~~
llsf
Iceland is the world champion when it comes to energy consumption per capita.
And at the same time, Iceland has 100% clean energy (geothermal and hydro).
That is why Icelanders keep their windows open, and why the country is trying
to attract aluminium industry (very energy hungry).

I still wish that US would promote better standard when it comes to thermal
insulation, water preservation, etc. I recently visited Las Vegas, and the
whole city could be case study (from freezing AC'ed hotels/casinos/cars, to
law being watered during the day).

~~~
antisthenes
It definitely does not have 100% clean energy.

They import petrol for cars at the very least.

~~~
badosu
I think parent was referring to electricity energy consumption.

It is true that this is a fraction of total energy use, but this lays the
groundwork for reaching clean energy for transportation, specially if Iceland
follows on Norway's trend for electric vehicle usage (29% market share for
2016, Iceland's on 4.6%).

------
dredmorbius
This report is on the US DoE and Lawrence Livermore National Labs "energy
flow" Sankey diagrams, released annually. This is a modelling estimate of
provisioned (rather than passive) energy generation, distribution, and
utilisation. It doesn't address end-use efficiency, particularly in
electrical, heating, and cooling appications.

For similar worldwide usage patterns, see the IEA's (International Energy
Associaton) Sankey chart:
[https://www.iea.org/sankey/](https://www.iea.org/sankey/)

David Roberts makes a large point about decreasing efficiency of US energy use
since the 1970s. This may be somewhat misleading as the chart is based on
overall statistics (fuel imports and production, power-plant generation
statistics) and engineering models of processes, rather than direct
measurements. As models change, estimates of wasted energy may also increase.

I'd pay more attention to the _input_ side, and _overall usage_ , where the
story becomes more interesting. In particular, renewable sources such as wind
and solar are now being broken out individually, a major change from earlier
years (though this has been happening in recent years as I recall). If you
look at overall energy usage trends (not immediately apparent from the Sankey
diagrams), what's most telling _particularly_ since the 1970s is how the
_current_ usage of energy is declining _relative to earlier projections_. This
is mostly good news.

If you're interested in making sense of the numbers, or converting them to
different forms, I highly recommend the GNU units utility. This is a units-
aware console calculator, with some very useful and underappreciated
capabilities, including the ability to conver between, say BTUs and the
equivalent solar panel area you'd need to provide the same energy:

    
    
        You have: 100 quadrillion btu / (1 kW/meter^2 * 0.2 * .3 * 365 days)
        You want: km^2 *
        55759.336
        / 1.7934216e-05
    

That is: the solar-cell equivalent of 100 Quads of energy would require 55,760
square kilometers of solar panels, a region about 236 km on a side.

This is available on Linux, OSX (via homebrew), and Windows (via Cygwin). Note
that OSX includes the _BSD_ Units utility, which does _not_ have the
additional definitions provided by the GNU utility.

You can convert quads to TJ, or millions of barrels of oil, or tonnes of coal.
You can compute the size of a tank or scuttle, in cubic kilometers, required
to deliver this energy. You can estimate how many solar panels, or windmills,
or hydro plants, would be necessary to provide the same energy. You can
estimate cropland and biofuel equivalents (this ... doesn't look promising
given present energy use).

More mash-notes on GNU Units here:

[https://www.reddit.com/r/dredmorbius/comments/1x9u0f/gnu_uni...](https://www.reddit.com/r/dredmorbius/comments/1x9u0f/gnu_units_utility_and_energy_resource_calculations/)

