# U.S. Energy Mix Since 1776



## Laszlo (Aug 23, 2015)

The EIA produced an updated history of U.S. fuel usage from 1776 through 2014:













Wood was overtaken long ago by fossil fuels, but has never really gone away. When the renewables category is broken out, it looks like wood was still barely holding onto 2nd place (after hydroelectric) as a renewable fuel source for 2014. However, with the breakneck growth of wind I don't expect it to hold that position by the time the EIA issues a new report.


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## jebatty (Aug 24, 2015)

Small hydro, on a city or industrial plant scale, used to be a relatively big deal, maybe not on a total Btu basis but on number of installations. Then NG came along and provided fuel so cheap that hydro was abandoned. The small town near where I live had a hydro on the river that runs through town. That was removed many years ago. My dad was the Chief Engineer at a small state operated facility that had a coal fired, oil backup, generating plant for electricity and steam for space heating. That too was removed when NG came on the scene.


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## woodgeek (Aug 25, 2015)

Nice charts.  

I have my usual gripe that stating energy use according to input BTUs overstates the importance of less efficient fuels.  Notably, it makes renewables like hydro, wind and solar half as big as they would be if they were scored by output energy services, but that is much harder to do.

Of course, we can just note that in a future energy transition from combustion fuels to such renewables, we can anticipate a >50% input BTU demand _decrease_, on a per capita constant living standard basis.  Renewables don't need to replace all those BTUs, just half of them (and make up for population and living standard growth).


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## DBoon (Aug 25, 2015)

Does anyone know if the EIA accounts for behind the meter solar in their estimations?  

Also, it looks like the war on coal started in 1905...I hadn't realized it's been going on for so long...


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## iamlucky13 (Aug 25, 2015)

DBoon said:


> Does anyone know if the EIA accounts for behind the meter solar in their estimations?



I believe they do. I haven't looked at their method for calculating these charts, but I've spent a fair amount of time digging through their other data for my own edification, and it appears to me that they do base their solar data on estimates of production based on number of systems installed and where they are, not what the utilities record as having been net metered.

The same question would apply to wood, as while major users of wood for industrial heat may disclose their consumption via air quality permits, the consumption by residential users like us has to be estimated. If I remember right, that's largely based on the home heating data collected by the Census bureau in the long form decadal census questionnaire.



DBoon said:


> Also, it looks like the war on coal started in 1905...I hadn't realized it's been going on for so long...



If you look at the percentage share graph, it looks like coal reduction started then, but it didn't. If you look at the total energy consumption graph, you will see that petroleum usage effectively started then, followed closely by natural gas.

So those two didn't immediately displace coal, but simply made up more of the energy growth then coal did.


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## Ashful (Aug 25, 2015)

woodgeek said:


> ...we can anticipate a >50% input BTU demand _decrease_, on a per capita constant living standard basis.  Renewables don't need to replace all those BTUs, just half of them (and make up for population and living standard growth).


Not according to Jevon.  We'll just build bigger houses to heat.


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## iamlucky13 (Aug 26, 2015)

Ashful said:


> Not according to Jevon.  We'll just build bigger houses to heat.



Already being done. The median new home 40 years ago was 1560 square feet.

The median new home today is 2453 square feet (source on page 9)


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## Grisu (Aug 26, 2015)

The difference is even more pronounced when looking at sqft per occupant. According to this source (http://www.100khouse.com/2008/10/20/so-many-square-feet-so-few-people/) it essentially tripled in the last 60 years. Somehow people don't seem to like spending time with each other anymore when on average a person has now 900 sqft of housing just for him/herself. We have become a society of loners.


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## Ashful (Aug 26, 2015)

Grisu, you seem to be implying more sq ft per occupant is a bad thing, but I am not convinced it is.


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## begreen (Aug 26, 2015)

Easy to figure. What is your household energy consumption per individual vs Grisu's?


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## iamlucky13 (Aug 26, 2015)

Grisu's link actually could use some corrections - first of all, averages vs. medians. Median is a better measure of "typical" home size. Averages are skewed disproportionately upward by the extremes.

Secondly, and something I should have clarified in my own post, is that the figures given are only for a small subset of the market. The figure is only for single family homes. Condos, apartments, and attached townhomes are not included, and since the fraction of homes in those categories has gone up a lot in recent decades, that's important.

That figure also is only for the ~1.5 million homes built each year (recent max of 2.1 million in 2005, min of 0.55 million in 2010*, and current year rate of 1.2 million). It doesn't factor in the median or average of the 120 million existing homes.

Altogether, the HUD estimated that median home size of all housing units, single family detached or otherwise, and new or existing, increased from 1610 square feet in 1985 to 1774 square feet in 2005. They only started tracking home sizes in 1985, so older data isn't available.

http://www.huduser.org/datasets/ahs/ahs_taskc.pdf

So the trend is definitely larger homes and fewer occupants per home, but not quite as dramatically so as originally suggested.


* Just think how bad it was for anybody working in construction when the market plummeted almost 75% from 2.1 million homes to 0.55 million homes in only 4 years!


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## semipro (Aug 27, 2015)

I've never thought that geothermal should be included as a renewable. The supply is finite and not renewed by the sun, at least not in any practical time-frame.
Ground-source is renewable, geothermal no.


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## woodgeek (Aug 27, 2015)

Ashful said:


> Not according to Jevon.  We'll just build bigger houses to heat.



I agree.  While the size of US houses has doubled over the last 50 years, the amount of energy for heating homes has decreased somewhat due to better codes (which take a looong time to roll into housing stock).  Jevon would nod.

Is that trend done, or will we all have 2000 sq ft of passive house (and three private bathrooms) per person in 50 years?  I personally think we'll asymptote to ~1 bath and ~1000 sqft per person (on average) in a 'rich' world outcome.


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## woodgeek (Aug 27, 2015)

semipro said:


> I've never thought that geothermal should be included as a renewable. The supply is finite and not renewed by the sun, at least not in any practical time-frame.
> Ground-source is renewable, geothermal no.



I have seen calculations that at urban densities in northern US climates, ground source heat IS depletable, if it became a major source of heating.  You would probably need to pump the heat back in in the summer, at a small cost.


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## iamlucky13 (Aug 27, 2015)

In northern climates, which are almost exclusively heating dominated, that could be an issue. In climates with definite heating and cooling seasons, it shouldn't be.

Whether or not regular geothermal (not ground source) can be considered renewable or not depends, like many other renewable resources, on how fast you take energy out of the system vs. how fast it is "generated." Wood is renewable, as long as you don't consistently cut it down faster than it regrows. With geothermal, the overall heat reservoir of the earths interior is not significantly affected by geothermal power plants. The issue is how fast that heat flows to a geothermal well.

As I understand it, geothermal plants usually start off with a very high output, then settle into a new equilibrium at some lower output.


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## jharkin (Sep 22, 2015)

woodgeek said:


> I personally think we'll asymptote to ~1 bath and ~1000 sqft per person (on average) in a 'rich' world outcome.



Meaning the average family of 4 (2 kids) would live i a 4,000 square foot 4 bathroom house?  In my market that's a million plus and only affordable to the top 1-2%, even in this very high per capita income state.  I doubt it.


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## woodgeek (Sep 22, 2015)

You live in a HCOL area Jeremy.  I think people 70 years ago in the US would be astounded by the 2500 sq ft average family house of today, with 2.5 baths.  They were closer to 1500 and 1 or 1.5 baths.


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