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.
Things like transmission system losses (for electricity) and ICE efficiency (for vehicles, only about 20% of the energy in fuels is converted to useful things like motion).
More or less rejected means "lost as heat before we can do something useful with it".
Sure, but where do we stop? At the customers electricity socket? Behind all power supplies, but before the specific device?
Computers will turn essentially all power entering them into heat. But then by that measure we can never make an efficient computer but would have to look at something like flops/W to give us actionable information.
What is a measure we can apply consistently to computers and cars and get actionable information?
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.
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.
>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...)
Power plants are about 35% efficient, and then you lose another ~10% of what gets sent out from transmission losses...so your total efficiency for electrical generation is around 30%. [1]
Ideally, that waste heat would be put to some use...that's called co-generation [2]
Its also worth pointing out the scale of the problem, with a simple one stage plant design, like a very stereotypical nuke or coal plant, a cold side around outdoor temps and a hot side around 1000F means 30-something percent efficient. And at 1000F or so, the steam pressure will be handwavy a bit less than 2000 PSI.
So simply running hotter is not a realistic solution to get above 30 or so percent, not at current technology levels. That's where strange staged and cogeneration schemes are applied to boost efficiency.
Low grade process heat is surprisingly useless in practice, unfortunately. Also economics and politics smack up against engineering ideals, where massive vertical integration would result in higher efficiency but short of nationalizing all industry or allowing massive monopolies its hard to integrate a coal generating plant with a steel mill heat treatment plant and a sardine canning plant and a greenhouse all under the same roof. Maybe with infinite scaling nano-technology all industrial plants could do all things to really boost efficiency.
Carnot efficiency is 1 - Tcold/Thot. You must also remember to convert temps to an absolute scale. So from your example, that is 1 - (535/1500) or 66% efficient.
The Carnot cycle is a poor model for steam turbine electric power plants. Rankine cycle efficiency of ~40% is the more
relevant theoretical upper limit.
> Low grade process heat is surprisingly useless in practice, unfortunately.
For electricity generation, yeah. What it is that stops us from using it for residential heating? Eg, space heating and for hot water. Is it just the proximity to big power plants that makes it unfeasible?
It's hard to distribute heat...you would need steam or at least hot water pipes everywhere.
You would also need to vent the steam when it's not needed...so if you only need the heat for a few months of the year, you don't get that much efficiency increase overall.
It would be nice if we knew what constituted "rejected" when they were making the diagram. Are they taking into account Carnot efficiency, line loss, the efficiency of light bulbs to create light instead of heat, does heat loss from light bulbs count as waste in the winter time when the heat is a desirable side effect, etc..
We can guess what rejected energy meant when this was drawn (presumably, Carnot efficiency was taken into account, since that's the most probable explanation for the very low efficiency of transportation), but it's hard to interpret without knowing for sure. (I assume the LLNL has a document somewhere that breaks this all down, but it would be nice to have more details in the article.)
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.
Where energy generation is tied to some evil (ie c02 emmissions) then any energy not harvested, or lost in transit to users, is waste regardless of the financials. Even where no alternative exists, the waste lable is appropriate as a description of an area ripe for innovation and improvement.
Yes, all else being equal, cost is the only thing that matters.
But often all else is not entirely equal, and then an analysis like this may be helpful.
For instance, if you look at the transportation sector, you don't actually need to supplant all the energy there, only the actually useful part. And batteries + an electric motor is in fact much more efficient than gasoline + an internal combustion engine.
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.
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).
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.
If you don't have natural gas or want to burn wood, basically your only choice is electric resistive heating (COP = 1) or an air source heat pump (COP > 1, above 10-15F) (other options like ground/water source heat pumps are possible but expensive/need specific conditions), the heat pump option will be more efficient, even in a cold place. When it gets cold enough that the heat pump isn't performing you simply turn on the auxiliary resistive heaters instead, there will at least be some days in the shoulder season where the heatpump is beneficial from an efficiency standpoint. If it makes economic sense is another matter. I think if you are going to get central AC or a minisplit its not that much more expensive to get a heatpump.
If you have natural gas it makes sense, economically, to use that to heat most places in the USA.
> 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?
My air conditioner in Tampa has a reverser valve to run as a heat pump when it's cold out; it'll run down to 0F using only the air source condenser unit.
My understanding is the limit to the heating potential of a heat pump system is the evaporator freezing over, which is why they are more popular in areas with low humidity. I think at a certain point the heat pumps spend so much time in defrost mode with the auxiliary heater running that they aren't economical.
Wintertime humidity is rarely if ever high enough for frost buildup to be an issue--it's the humid shoulder seasons that have this problem, but your heating/cooling needs during those seasons aren't that high anyway, so defrost cycles won't lower comfort and efficiency all that much.
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.
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.
This is a case where building climate-appropriate structures helps tremendously.
Thorstein Chlupp / Riena LLC builds net-zero-energy homes in Fairbanks, AK. He has numerous very long (1-3 hour) videos describing his design methodology and process in detail. The homes are designed, from the sub-grade up, to be as efficient as possibly in a high-heating-need environment. He makes extensive use of thermal mass and insulation, as well as design features minimising heat loss, and maximising gain.
At the core of his homes is a a 5,000 gallon stratified thermal storage tank -- a repurposed fuel tank filled with water, and packed in roughly 1 meter of insulation on all sides. Sourced heat, from solar thermal panels, a wood stove, and other sources, is fed to this. It drives both space and water heat for the structure itself.
Walls have 18"+ insulation, all fittings are thermally isolated, heat exchanges are used on air and water transfers, etc. It's pretty impressive stuff.
For Wisconsin, you might not choose to apply all the concepts, but the idea of banking heat (or chill) in the summer (or winter) through some form of mass storage (ground, tank, other), might apply.
There are community thermal storage systems which have been designed and deployed in both Canada and Germany.
That's pretty sweet. My cousin in-law is actually a builder in Marquette, MI, which is on Lake Superior on the Upper Peninsula.
He talks a lot about similar building concepts. I know he takes a lot of pride in building extremely efficient homes. I think I've listened to him talk about heat exchangers for several hours straight before.
He mentioned they can't do geothermal effectively up there because the bedrock is above the frost line. They have less than a few feet of soil in a lot of places before you get down to granite. I imagine geothermal has issues with permafrost that makes installation similarly difficult.
Thanks for the links, I'll definitely check them out.
That's where some of Chlupp's concepts -- building on top of a very large sand base, for example -- might come in handy. He doesn't make use of geothermal (ground-loop) heat pumps though.
A fair bit of his technology comes from Germany, as does he ;-)
And there are some videos there that run less than an hour. Though I find the two listed to be well worth the time to watch -- information dense. You can skip through bits if necessary.
A minor nit: Burning gas for heating is not 100% efficient, unless you really want to die of carbon monoxide poisoning. Combustion gasses are exhausted to the atmosphere. Heat is transferred via a heat exchanger into the recirculated internal air of the house.
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.
Technically, they didn't oppose it, but they didn't support it either, as members had mixed feelings about the approach, which I'll paraphrase as it partly being a disguised tax cut for the wealthy rather than a revenue neutral carbon fee.
I personally support offsetting carbon taxes against other taxes, but since it would be regressive, I'd lean towards mitigating that in whatever compensatory tax cuts were introduced.
That can work too, though it's still probably regressive, as some people have more resources to adapt than others.
And if the policy is regressive then you face the danger of it blowing up in your face. For example, see what happened when the rich in America seized most of the benefits of globalisation, now we have Presidents threatening to burn it all down and being popular in doing so. If you actually want carbon reduce toon to be successful you need to factor in the politics, both getting the wealthy and powerful on board and getting the average man in the street to feel that he's not being screwed (which some people will tell him he is, even if he isn't).
Maybe, but I would kind of assume that poorer people already end up emitting a lot less carbon since most carbon emitting activities already have a significant cost involved.
I'm not so sure: poorer people often have to drive further, in clunkier cars. In any event, it's likely more 'regressive' than income: a rich person might earn 10X, but generate 2X the carbon. I bet there's data for this, though.
Because of the refund, 2X the carbon doesn't mean 2X the taxes. Someone who emits 120% of the average amount of carbon pays twice as much as someone who emits 110% of the average, but emits less than 10% more.
> 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.
Transportation waste is the inefficiency of the internal combustion engine.
The presentation isn't "hand wavy", it's just simplified. Most of the confusion in this thread is from users who don't understand relatively simple aspects of how energy is generated and used. Which is fine, but the response to that should be to look something up or ask a question, not attack the graphic.
Well actually there is an article along with the very fine graphic. I think the article could have expended a few more sentences on energy waste. That's all. This wasn't an attack.
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.
> lighter cars use less fuel even without changing the % of waste energy generated.
Yes, but they reduce the total Joules of energy wasted, and that's the important point.
And that would be reflected in the graph at hand. I know we're all talking percentages, but the graph is actually about total quantity. If everyone were in very light cars, the transportation bar would be narrower, and the total energy going to the Waste node would be smaller.
So it's accurately reflecting any efficiencies of that kind.
> I'm really at a loss to understand what the transportation waste means. Sure, you also need to propel the mass of the vehicle.
Total work done by the vehicle / total energy contained the fuel.
A small combustion engine is a very inefficient converter of energy, so it's no surprise that it's only able to use 1/4 of the available energy. The rest is lose as heat (as well as minor losses such as noise and slippage).
This boils down to well-known and well-understood behaviours of energy systems, particularly at large scale.
Much of the waste is simply Carnot efficiency of thermal systems: the amount of useful energy you can extract is proportional to the (absolute) temperatures (Kelvin) of the "hot" and "cold" ends of the cycle.
For thermal electrical generation -- coal-fired plants, gas-fired turbines, oil-fired turbines or diesel generators, biomass thermal, solar thermal, or nuclear plants -- this is in the range of 30 - 45% or so. Ironically, high-temperature thermal coal achieves some of the best thermal efficiency. This doesn't mitigate its far more compelling downsides.
Direct kinetic or photovoltaic electrical generation has no thermal losses, but is subject to the efficiency constraints of the input stream: hydroelectric, wind, or solar PV.
There are additional losses in transmission (about 6%), and in electrical conversion and switching equipment ( ~<10%). The net is about a 66% energy loss in what's delivered to the electrical customer.
For transportation, you have the same Carnot efficiency limits, but given the smaller temperature differential start with a lower initial efficiency -- about 30%. There are additional losses through parasitic systems (any powered in-car features: power steering, brakes, A/C, electrical and electronics, etc.), transmission losses, tire and wind drag.
Again, all well understood and modeled, and well-behaved in large-number populations.
The Lawrence Livermore National Lab (LLNL) has done energy modelling for the United States since the 1970s, and has a set of flow diagrams (Sankey diagrams) showing flows dating to the 1950s, through the present.
> "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."
If there's one thing libertarians love, it's redistributing money through the government.
I think the term "redistribution" adds confusion to the issue. The idea behind a carbon tax like that is that polluters owe everyone else something (they're taking from tax payers in various ways: air quality, property value, life expectancy), and the easiest way for them to pay up is through a tax. Viewed through that lens, libertarians may view a carbon tax as getting rid of free-rider pollution producers. The value of those things being given up in exchange for whatever is being produced is no longer being completely ignored. It would also have the effect of restricting the least efficient/profitable pollution producing processes.
You're assuming ignorance on the part of libertarians. However I think you'll find that many understand the problem of externalities fine and simply disagree with the common tax "solution" taught in Econ 101 classes around the country.
Having read that, I'm not finding myself enlightened or my mind opened in the least. What was the point, other than it's hard to calculate externalities?
Argument that "it's hard" is not much of an argument at all. It does make me think that there's considerable flexibility in a "libertarian" position on externalities though.
That's an article of faith, not an article of fact.
But I do agree that the best pricing schemes involve settling on price through transaction. Take, for example, cap & trade schemes. This is a widely used mechanism to manage negative externalities.
Externalities exist, whether or not the "Austrian" school has a way to deal with them. Considering the issue, deciding that one's philosophy can't deal with them, and therefore deciding to stick one's head in the sand instead is why mises.org remains fringe. It's an irrational, religious framework.
I read your comment earlier and saved it for later. I too find myself unenlightened.
Fine it's impossible to correctly calculate externalities. I don't see the line from there to: "BigCo dumped a ton of waste in my pond, but it's unfair for the government coerce BigCo to compensate me because there's a chance the I might get more than the true value of that pond."
I'm torn on environmental taxes. As an economist, I see them as a truly vital form of offsetting negative externalities. The problem is that environmental externalities can be very hard to measure, and it often becomes political, rather than emperical. Worse, is that taxes only get larger over time (and very very rarely sunset, even if legislation specifies a sunset claus). This makes me very nervous about something as nebulous as a "carbon" tax. Carbon is in nearly everything we care about on this planet, and it feels like it's opening a pandora's box.
For things like transportation I'd much rather see a "miles traveled" tax than a carbon tax (it could even be tiered for electric vehicles). It's far more specific, and thus harder to lead to crazy far reaching taxes in tangential areas.
> I'd much rather see a "miles traveled" tax than a carbon tax
Why? The harm done is relative to emissions, which is exactly proportional to the volume of fuel going in. A tax on miles traveled would unfairly punish cars with great (or infinite) gas mileage. (Unless you think the relevant externality is cars on the road...)
A few externalities do happen from cars on the road. Oil leaks are one. Aerosol pollution (black carbon type) from wearing down tires on the road. Roadkill impact on wildlife.
But they're dwarfed by non-environmental factors like road wear-and-tear, and accidents, which are covered by other taxes and insurance.
> Worse, is that taxes only get larger over time (and very very rarely sunset, even if legislation specifies a sunset claus)
The past 40 years of politics shows that this is simply not true in reality, though it is often repeated. There is significant political will to lower taxes, and taxes get lowered frequently. More frequently on the wealthy, but frequently nonetheless.
When it comes to taxing externalities and improving market function, there's often significant room to improve the market. As long as costs can be estimated within ~50% it's going to be a big win to legislate them. However, since the cost of going over is often not linear, it can be difficult to enforce in a fair way in the market without some sort of auction scheme like what goes on in cap & trade.
A miles tax is far worse than a carbon tax; it's far more of a stab in the dark. It doesn't even account for wear & tear in any way, which is dependent on an polynomial of the vehicle weight.
Large fossil fuel companies, like Exxon, are planning on an $80/ton carbon tax. There's zero reason to not phase this in along with the Paris accords. It's silly to ignore the work that those, negatively affected by the tax, have already agreed is going to happen.
If they are in favor of the government redistributing assets through force when enforcing contracts, hopefully they can understand the concept of externalities and the need for fees on externalities in order for markets to work better. Of course, that's assuming that the libertarian is also in favor of using free markets optimally.
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.
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:
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.
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.
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:
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.
Yea, I was thinking of the global level. Focusing on US policy is a fair point. There are definitely things the US can do to address deforestation internationally, but maybe it's a more difficult task than focusing on domestic transportation.
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).
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.
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).
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%).
I'm not so sure. Would it really be preferable to have the energy use per capita of, say, India?
Using energy is overall a good thing. It improves our quality of life. Energy use is not something we want to get to zero - otherwise we might as well be living in the stone age.
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:
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.
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.
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.
For a global view, projected for 2050, take a look at this tool from the UK government and others: http://tool.globalcalculator.org
Select Energy (at the top) -> Sankey (on the left) and optionally apply policy scenarios.
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.
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/
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:
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).
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[ 3.1 ms ] story [ 161 ms ] threadhttps://flowcharts.llnl.gov/content/assets/images/charts/Ene...
But I believe the blog adds useful context (starting with the quads)
https://en.m.wikipedia.org/wiki/Sankey_diagram
https://bost.ocks.org/mike/sankey/
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...
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.
More or less rejected means "lost as heat before we can do something useful with it".
Computers will turn essentially all power entering them into heat. But then by that measure we can never make an efficient computer but would have to look at something like flops/W to give us actionable information.
What is a measure we can apply consistently to computers and cars and get actionable information?
What happens "past the meter" is a consumption question.
Generally.
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
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.
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...)
Ideally, that waste heat would be put to some use...that's called co-generation [2]
[1] http://blog.schneider-electric.com/energy-management-energy-...
[2] https://en.wikipedia.org/wiki/Cogeneration
So simply running hotter is not a realistic solution to get above 30 or so percent, not at current technology levels. That's where strange staged and cogeneration schemes are applied to boost efficiency.
Low grade process heat is surprisingly useless in practice, unfortunately. Also economics and politics smack up against engineering ideals, where massive vertical integration would result in higher efficiency but short of nationalizing all industry or allowing massive monopolies its hard to integrate a coal generating plant with a steel mill heat treatment plant and a sardine canning plant and a greenhouse all under the same roof. Maybe with infinite scaling nano-technology all industrial plants could do all things to really boost efficiency.
https://en.wikipedia.org/wiki/Rankine_cycle
For electricity generation, yeah. What it is that stops us from using it for residential heating? Eg, space heating and for hot water. Is it just the proximity to big power plants that makes it unfeasible?
It's been done though.
https://en.wikipedia.org/wiki/District_heating
We can guess what rejected energy meant when this was drawn (presumably, Carnot efficiency was taken into account, since that's the most probable explanation for the very low efficiency of transportation), but it's hard to interpret without knowing for sure. (I assume the LLNL has a document somewhere that breaks this all down, but it would be nice to have more details in the article.)
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.
But often all else is not entirely equal, and then an analysis like this may be helpful.
For instance, if you look at the transportation sector, you don't actually need to supplant all the energy there, only the actually useful part. And batteries + an electric motor is in fact much more efficient than gasoline + an internal combustion engine.
(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.
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).
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.
If you have natural gas it makes sense, economically, to use that to heat most places in the USA.
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?
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.
> 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.
Thorstein Chlupp / Riena LLC builds net-zero-energy homes in Fairbanks, AK. He has numerous very long (1-3 hour) videos describing his design methodology and process in detail. The homes are designed, from the sub-grade up, to be as efficient as possibly in a high-heating-need environment. He makes extensive use of thermal mass and insulation, as well as design features minimising heat loss, and maximising gain.
At the core of his homes is a a 5,000 gallon stratified thermal storage tank -- a repurposed fuel tank filled with water, and packed in roughly 1 meter of insulation on all sides. Sourced heat, from solar thermal panels, a wood stove, and other sources, is fed to this. It drives both space and water heat for the structure itself.
Walls have 18"+ insulation, all fittings are thermally isolated, heat exchanges are used on air and water transfers, etc. It's pretty impressive stuff.
For Wisconsin, you might not choose to apply all the concepts, but the idea of banking heat (or chill) in the summer (or winter) through some form of mass storage (ground, tank, other), might apply.
There are community thermal storage systems which have been designed and deployed in both Canada and Germany.
https://en.m.wikipedia.org/wiki/Seasonal_thermal_energy_stor...
http://www.reina-llc.com/
He talks a lot about similar building concepts. I know he takes a lot of pride in building extremely efficient homes. I think I've listened to him talk about heat exchangers for several hours straight before.
He mentioned they can't do geothermal effectively up there because the bedrock is above the frost line. They have less than a few feet of soil in a lot of places before you get down to granite. I imagine geothermal has issues with permafrost that makes installation similarly difficult.
Thanks for the links, I'll definitely check them out.
Video search: https://m.youtube.com/results?search_query=thorstein+chlupp
These two in particular detail the design logic:
https://m.youtube.com/watch?v=AtHkvpRI6fc
https://m.youtube.com/watch?v=Xen_VWyDezY
A fair bit of his technology comes from Germany, as does he ;-)
And there are some videos there that run less than an hour. Though I find the two listed to be well worth the time to watch -- information dense. You can skip through bits if necessary.
[1] https://en.wikipedia.org/wiki/Central_heating
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...
I would be surprised if carbon tax payments offset some other taxes.
* Carbon tax forecast for X billion in revenue.
* Let's knock X billion off of income taxes (or whatever else you want).
This is what Washington State tried, although the measure was sadly opposed by "environmentalist" groups like the Sierra Club.
http://www.sierraclub.org/washington/sierra-club-position-ca...
I personally support offsetting carbon taxes against other taxes, but since it would be regressive, I'd lean towards mitigating that in whatever compensatory tax cuts were introduced.
And if the policy is regressive then you face the danger of it blowing up in your face. For example, see what happened when the rich in America seized most of the benefits of globalisation, now we have Presidents threatening to burn it all down and being popular in doing so. If you actually want carbon reduce toon to be successful you need to factor in the politics, both getting the wealthy and powerful on board and getting the average man in the street to feel that he's not being screwed (which some people will tell him he is, even if he isn't).
https://www.vox.com/energy-and-environment/2017/5/3/15512258...
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.
The presentation isn't "hand wavy", it's just simplified. Most of the confusion in this thread is from users who don't understand relatively simple aspects of how energy is generated and used. Which is fine, but the response to that should be to look something up or ask a question, not attack the graphic.
However, this stuff still very simplified as lighter cars use less fuel even without changing the % of waste energy generated.
Yes, but they reduce the total Joules of energy wasted, and that's the important point.
And that would be reflected in the graph at hand. I know we're all talking percentages, but the graph is actually about total quantity. If everyone were in very light cars, the transportation bar would be narrower, and the total energy going to the Waste node would be smaller.
So it's accurately reflecting any efficiencies of that kind.
Total work done by the vehicle / total energy contained the fuel.
A small combustion engine is a very inefficient converter of energy, so it's no surprise that it's only able to use 1/4 of the available energy. The rest is lose as heat (as well as minor losses such as noise and slippage).
Much of the waste is simply Carnot efficiency of thermal systems: the amount of useful energy you can extract is proportional to the (absolute) temperatures (Kelvin) of the "hot" and "cold" ends of the cycle.
For thermal electrical generation -- coal-fired plants, gas-fired turbines, oil-fired turbines or diesel generators, biomass thermal, solar thermal, or nuclear plants -- this is in the range of 30 - 45% or so. Ironically, high-temperature thermal coal achieves some of the best thermal efficiency. This doesn't mitigate its far more compelling downsides.
Direct kinetic or photovoltaic electrical generation has no thermal losses, but is subject to the efficiency constraints of the input stream: hydroelectric, wind, or solar PV.
There are additional losses in transmission (about 6%), and in electrical conversion and switching equipment ( ~<10%). The net is about a 66% energy loss in what's delivered to the electrical customer.
For transportation, you have the same Carnot efficiency limits, but given the smaller temperature differential start with a lower initial efficiency -- about 30%. There are additional losses through parasitic systems (any powered in-car features: power steering, brakes, A/C, electrical and electronics, etc.), transmission losses, tire and wind drag.
Again, all well understood and modeled, and well-behaved in large-number populations.
The Lawrence Livermore National Lab (LLNL) has done energy modelling for the United States since the 1970s, and has a set of flow diagrams (Sankey diagrams) showing flows dating to the 1950s, through the present.
If there's one thing libertarians love, it's redistributing money through the government.
Some example reading to open your mind: https://mises.org/library/externalities-argument
Argument that "it's hard" is not much of an argument at all. It does make me think that there's considerable flexibility in a "libertarian" position on externalities though.
But I do agree that the best pricing schemes involve settling on price through transaction. Take, for example, cap & trade schemes. This is a widely used mechanism to manage negative externalities.
Externalities exist, whether or not the "Austrian" school has a way to deal with them. Considering the issue, deciding that one's philosophy can't deal with them, and therefore deciding to stick one's head in the sand instead is why mises.org remains fringe. It's an irrational, religious framework.
Read Mises Human Action and you will understand.. Austrian economics is a priori (built from first principles) not a posteriori (empirically derived)
Fine it's impossible to correctly calculate externalities. I don't see the line from there to: "BigCo dumped a ton of waste in my pond, but it's unfair for the government coerce BigCo to compensate me because there's a chance the I might get more than the true value of that pond."
For things like transportation I'd much rather see a "miles traveled" tax than a carbon tax (it could even be tiered for electric vehicles). It's far more specific, and thus harder to lead to crazy far reaching taxes in tangential areas.
Why? The harm done is relative to emissions, which is exactly proportional to the volume of fuel going in. A tax on miles traveled would unfairly punish cars with great (or infinite) gas mileage. (Unless you think the relevant externality is cars on the road...)
But they're dwarfed by non-environmental factors like road wear-and-tear, and accidents, which are covered by other taxes and insurance.
The past 40 years of politics shows that this is simply not true in reality, though it is often repeated. There is significant political will to lower taxes, and taxes get lowered frequently. More frequently on the wealthy, but frequently nonetheless.
When it comes to taxing externalities and improving market function, there's often significant room to improve the market. As long as costs can be estimated within ~50% it's going to be a big win to legislate them. However, since the cost of going over is often not linear, it can be difficult to enforce in a fair way in the market without some sort of auction scheme like what goes on in cap & trade.
A miles tax is far worse than a carbon tax; it's far more of a stab in the dark. It doesn't even account for wear & tear in any way, which is dependent on an polynomial of the vehicle weight.
Large fossil fuel companies, like Exxon, are planning on an $80/ton carbon tax. There's zero reason to not phase this in along with the Paris accords. It's silly to ignore the work that those, negatively affected by the tax, have already agreed is going to happen.
Source: http://www.justfacts.com/taxes.asp (tons of footnotes there to bea.gov
I would assume that the tax rate would be based on vehicle class, but that seems too easy.
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, for example.
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
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.
https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...
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...
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.
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).
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).
They import petrol for cars at the very least.
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%).
Using energy is overall a good thing. It improves our quality of life. Energy use is not something we want to get to zero - otherwise we might as well be living in the stone age.
https://flowcharts.llnl.gov/content/assets/images/charts/Ene...
https://flowcharts.llnl.gov/content/assets/images/charts/Ene...
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.
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.
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.
All energy other than petroleum, natural gas, and biofuels, is 3%.
https://www.eia.gov/Energyexplained/?page=us_energy_transpor...
I guess it's just so efficient relative to the other sources.
GDP is notorious for this.
For similar worldwide usage patterns, see the IEA's (International Energy Associaton) Sankey chart: 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:
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...