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Welcome. I am the author of Universal Time, a sci-fi urban comedy;
Beaufort 1849, an historical novel set in antebellum South Carolina;
and Pearl City Control Theory, a comedy of manners set in present-day San Francisco.

Thursday, March 31, 2016

An Energy Diet for a Healthy Planet--Part I

Part I: Envisioning 100 Kilowatt-hours/Person/Day

Biodiverse farm of the future (Singing Frogs Farm)
Nearly every human being on the planet consumes energy beyond the amount they derive from food, some more than others. In 2014, Americans, on average, consumed a total of 230 kilowatt-hours of energy per person per day. (See note at bottom for data sources and types of energy this includes.)

Is 230 kwh/person/day a lot or a little? How do we compare to other countries? As you can see, we use nearly double the amount of per capita energy as Germany and France, and nearly 2 ½ times the energy per capita of the UK. How can this be? Those of us who have visited Germany, France and the UK can testify that they have cold winters, warm summers, and that their citizens seem to enjoy a high standard of living. For comparison, I’ve included a few of the most energy-sipping US states.

Let’s compare the US to some other countries. Ones that have snow. These countries on most measures offer their citizens a higher standard of living while using 3/4ths to 1/2 the energy per person that we use. I've compared them to our most energy efficient snowy-land states. Rhode Island manages to beat Sweden, anyway.


Here we compare the US to key Asian countries (plus Australia).







And here are the big kahuna per capita energy gluttons of the world. Though the US might not tower over these guzzlers, we still hold our own. I've include some of our domestic guzzling states for comparison, all home to energy-intensive oil drilling, oil refining, or coal mining. (Texas would be on this chart if not for its huge population.) 

A number of other states, while not energy sumo wrestles, are still obese when it comes to kwh/person/day and some outdo even Kuwait, as you can see in the chart below.


It’s interesting to note that even countries that are highly energy efficient have room to improve because they all still use substantial fossil fuels for transportation and/or space heating. While electricity at present provides only 16% of US total energy consumption, even the most electrified countries in the world don’t break 30%. The reason electrification is important is that in terms of wringing the most benefit from every kilowatt-hour expended, electricity is the way to go. Electric motors turn 60% of the energy fed to them into power at the wheels whereas gasoline engines convert only 20%. (Diesel motors convert 35 – 40%.) An air source heat pump is three times as efficient as the most efficient natural gas furnace; a ground source heat pump is six times as efficient. A heat pump hot water heater is generally four times as efficient as a gas one. And a desuperheater connected to a ground source heat pump will turn waste heat into hot water all summer with almost no additional energy at all.

In the US, our current energy per person/day energy budget is this: 
51 kwh residential, 44 kwh commercial, 73 kwh industrial and 62 kwh transportation.   (This includes losses incurred in thermal generation of electricity. More on this in Part II.)
To get to 100 kwh/person/day, we’ll need the split to be more like this:
23 kwh residential, 20 kwh commercial, 35 kwh industrial and 22 kwh transportation. 

Right now 30 out of 51 kwh/person/day of residential energy is used towards space and water heating. With a combination of heat pumps, better sealing and insulation, solar hot water, energy exchange ventilators, and ceiling fans, we can drop total residential energy down to 26 kwh/person/day. Put in all LED lightbulbs and efficient appliances (and a few other items I'll mention in Part II) and we can drop it down to 21 kwh/person/day, below our future energy budget.  

For transportation, less than 1 kwh/person/day comes from electricity, making it a key area in need of change. As you can see below electric forms of transportation are substantially more energy efficient than those powered by internal combustion engines.  

Type of Transport

KWH to go 100 miles
(For transit, per 100
passenger miles)
Gasoline car (22 mpg)
155
International air travel
99
Domestic air travel
69
Gasoline motorcycle
68
Gasoline car (50 mpg)
67
Amtrak (current load)
47
Transit bus (diesel)
36
Electric car (Leaf)
34
US light rail (mostly electric)
31
US heavy rail (mostly electric)
31
US commuter Rail (mixed)
26
Amtrak (ideal 80% load)
24
Gasoline scooter
18
Calif. High Speed Rail (projected)
16.4
Electric motorcycle
12
French High Speed Rail
7 - 8
Electric Scooter
7.5
5.3
Around town walking
5.2
Japanese HS Rail
4.2
Siemens electric train
4.2
Around town biking
2.8
Electric Biking
2

Note: Around town bicycling and walking kwh/mile rates are calculated based on calories burned above baseline human metabolism (45 additional calories/mile walking and 32 additional calories per mile biking.) Transit, train and air travel calculated with 80% passenger load. Electric bike rate includes relaxed pedaling. Amtrak is a combination of diesel trains and all-electric.

Has a 180 mile range between charges
On average Americans travel 13,183 miles per person in a year. By private car (with average MPG and average occupancy) this amount of travel works out to 37 kwh/day. Way over the transport budget. If we drop travel miles by a fourth to 9900 miles/year (by a larger portion of us telecommuting and by most of us living closer to work, goods and services), that gets us to 27 kwh/person/day. This is still over the transport budget, and it doesn't include freight miles traveled. But if 2000 of those miles were by high speed rail, 3000 by transit, 2000 by air, 1900 by electric car (or rideshare) and 1000 by walking and biking, that squeezes down to 9 kwh/person/day.

Seriously efficient
Now let's look at freight. For each person in the US, 55 tons of domestic freight are moved an average of 325 mi. By diesel truck that comes to 58 kwh/day (and that doesn't include ocean shipping if it's an import.) Say we could cut this in half by buying local, by not buying stuff we don't need, by drinking filtered tap water instead of bottled water or soda, and by ending coal and oil shipments. That puts us at 29 kwh/day, still way above the travel budget. However, if we use diesel electric trains, each person's freight movement only comes to 2.5 kwh/day. If we use electric trains it gets down to .75-1.5 kwh/day, leaving a lot more room in the energy budget for passenger travel. No doubt with trains we'd have to add on a couple kwhs for the last 1 - 20 miles of delivery by electric truck, and international freight and water transport have to folded in here somehow, but all of the sudden 20 kwh/person/day for total transportation looks a lot more manageable.

Freight transport
KWH per ton per mile
18-wheeler truck
1.19
Cargo ship
.16
Diesel-electric rail
.10
Electric rail
.03--.06

As far as industry goes, Part II goes into this further, but for now I'll just point out that oil refining in the US uses 15 kwh/person/day. Get transportation off oil, and industrial energy use instantly drops from 73 to 58 kwh/person/day from refining alone.

Add in horses: 50% of energy (1850); 10% (1900)
Still, wouldn't a 100 kwh/person/day energy diet be like going back to the Stone Age? Well, up to 1900, Americans lived on less than that. (Note: chart at right is in BTUs, not kwhs.) Aside from horsepower, most nineteenth century energy came from wood and coal, much of which they burned to power wildly  inefficient steam engines and to heat drafty, poorly insulated houses. Today, all of South America, Africa and most of Asia manage to exist with less than 100 kwh/person/day, admittedly with a lower standard of living for the average person. (India survives on just 16 kwh/person/day!) But there are quite a few countries that achieve this energy diet with a comparable standard of living to the present day United States, including Italy (78), Ireland (93), Spain (90), and the United Kingdom (94). And then there’s Denmark with a higher standard of living than the US while using only 98 kwh/person/day. (Denmark, not resting on its laurels, has plans to drop to 95 kwh/person/day by 2020.)

Why should we care about a 100 kwh/person/day energy diet? We should care deeply because if we want to avoid climate catastrophe, we need to stop spewing carbon and methane into the atmosphere. Now it's true that 56 kwh out of the 230 we slurp up are completely wasted as unused heat in electricity generation, so if we  switched to all renewables and hydro, we'd only need to build out 174 kwh/person/day. Still, it’s much, much easier to produce 100 kwh/person/day of carbon-free energy than it is 174. Climate change is accelerating faster than anticipated. If we let the permafrost in the Arctic melt, the methane released will produce a self-reinforcing methane timebomb that cannot be reversed. The result will be a planet largely uninhabitable by humans. (On the plus side, pine beetles, mosquitos, zebrafish, snakes, yellow-bellied marmots, and jellyfish will likely do quite well. So, hey, it could be worse.)

If we insist on slurping up energy at current levels, even with extraordinary measures it might take us fifty years to stop spewing emissions, and that will be too late to prevent permafrost detonation. But if we can get by comfortably with 100 kwh/person/day, that’s a much easier target to meet, one we can probably achieve in 20 years. Not only is this a target we can achieve faster, it’s a target we can achieve more cheaply. That’s because energy efficiency is absolutely the most economical form of energy production available to us.
(Click for larger image)

While the cost of solar and wind will no doubt drop even more over time, in 2015 the US produced only 5 kwh/person/day of electricity from renewables (including rooftop solar) + hydro. Which means to get carbon-free we have a long ways to go. Even if we start building out solar PV and wind at 20 times the rate of 2012 (our best year ever), we won't be able to produce enough carbon-free energy fast enough to prevent catastrophe. But if we combine a rapid build out of renewables with a rapid lowering of demand through common sense behaviors and technology that already exists, we have a fighting chance. Find out how to do this and more in Part II!

Note: Most data in this post is from the 2015 BP Statistical Review of World Energy, probably the best compendium of world energy available, and from the US Energy Information Agency, the best source for state-level data. The per person per day energy figures include all large-scale sources of energy such as oil, natural gas, coal, nuclear power, hydro and renewables, their equivalent energy content turned into kilowatt-hours. They do not include rooftop PV or wood for heating or cooking, or energy expended to walk or bike for transportation. They do include all uses—residential, commercial, industrial, and transportation. Because our future will be mostly all electric, I’ve used kilowatt-hours as the energy unit of choice, better, in my opinion, than Tons of Oil Equivalent or BTU’s, although I acknowledge there’s a good case to be made for joules.


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