Tag Archives: Coal

Air Pollution - Types, Sources, and Fixes

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I finished my PhD last week. Today I start posting again. This is a month-long series, one post each week, regarding air pollution and our health. First, we discuss types of pollution, then the health effects of different types based on where you live (US vs. China as case studies), then we move on to the health effects of each type, finally we end on how you filter it.

Hint: Two posts ago (and over a year ago) I said I was taking a break to build a better pollution filter. I did that, and the final post in the series will be telling you all about that part. In the meantime, please go to www.getblueskies.com, sign up for our upcoming release emails (which will let you know when we launch on indiegogo with a discount for the first buyers), and share our website with your friends that might be interested.

Air Pollution

I was speaking with a physician about air pollution, and about which types cause asthma, and she was stunned that there is background research indicating that different types of outdoor pollution have differing relationships with asthma. Part of the reason for this was that she didn't realize how easy it was to differentiate which types of pollution come from which sources.

Okay, then. There are several major types of pollution. And NO2 from traffic is far and away the outdoor pollutant that that is most highly associated with our increasing asthma rates in the US (more on this in a future post).

Major Pollution Types

Particulate Matter is big chunky pollution. It is called PM10, or PM2.5, for how wide it is. PM10 is 10 microns wide, PM2.5 is 2.5 microns wide. For comparison, the average human hair is on the order of 100 microns wide (thin hair is about 17 microns, thick hair is up to 180). PM can be dust, fine soot, pet dander, or pest droppings (think cockroach poop). These can be very easily filtered with HEPA-style filters (HEPA filters are physical filters that block large pollution particles using small holes).

A photo from my time in China. PM pollution is pollutiion you can see.

A photo from my time in China. PM pollution is pollution you can see.

Chemical Pollution is very defined and very small. It's specific molecules. It's about 10,000 times smaller than PM2.5. It's also about the size of the the air we breathe, so you can't physically filter it. It is things that you've heard of, like CO (carbon monoxide), SO2, and NO2 (these both become strong acids in water, which causes acid rain. Note that our lungs are about 100% humid air, so they become strong acids, like battery acid, in your airways). These are extremely difficult to filter, and tend to require chemical reactions (more on that on a later post!). We are focusing on SO2, which just comes with fossil fuels, and NO2, which comes about every time you burn something in our atmosphere (our atmosphere is 78% nitrogen, and 21% oxygen, when you burn things, it uses the oxygen to convert stuff into CO2 and other emissions, but at high heats, it also produces NO2. Higher heats means more NO2). We ignore CO for now, and we ignore CO2 because it doesn't cause immediate health threats compared to these other pollutants.

Cars emit a lot of NO2. Catalytic converters help, but they still produce NO2 in amounts that are harmful

Cars emit a lot of NO2. Catalytic converters help, but they still produce NO2 in amounts that are harmful

VOCs are complicated. They are typically things you smell, like the new car smell, new elevators, paint, permanent markers, etc. Some people are highly sensitive or allergic to these. They can typically be filtered by most activated charcoal filters, because the carbon radicals in VOCs tend to adsorb well onto charcoal (ie they bond to it). We are going to ignore this, because we're assuming you don't like to leave your child in a freshly painted room, in new cars, or on new elevators.

Pollution Sources and Types

Hokay, so, now we need to discuss which pollution sources produce each. So I've made this helpful chart. These are relative amounts of pollution within their category, with no clear scaling criteria, but it gives you an idea of how different vehicles or power sources relate in terms of pollution. In other words, a two stroke engine clearly doesn't produce as much pollution as a coal fired power plant More important, these are rough relationships. You can have a wide range in each category, with a coal plant with no controls that burns high-quality coal producing significantly less pollution than the same design coal plant that burns low quality coal, for example.

Chart with differing sources of pollution, and relative amounts of pollution produced by each.

Chart with differing sources of pollution, and relative amounts of pollution produced by each.

 

Let's go through this one-by-one.

Vehicles burn gasoline or diesel. Gasoline vehicles pretty much just produce NO2 (and CO! But we are ignoring that for now), and our catalytic converters help reduce that. Smog is a byproduct of NO2 interacting with other pollutants that are already in the air. The part of smog that we see is actually PM pollution, rather than chemical pollution. Diesel vehicles produce a lot PM, and some SO2, and relatively more NO2. Catalytic converters can reduce NO2. Using low-sulfur diesel can reduce SO2. A lot of developing countries do not use low-sulfur diesel or catalytic converters, so they produce a ton more of every type of pollution. Two Stroke Engines are common in India (and other places, but not so much in China, and almost never in developed countries, unless you count lawnmowers). These things burn oil alongside gas. They produce nasty fumes, like your weedwacker or small lawnmowers. This is part of the reason that India has a particularly nasty type of air pollution. These are being phased out over time, with bans on new models of two-stroke engines in many cities.

Power Plants are a lot more complicated. In the next post, I will be discussing pollution controls in power plants in more detail. Put simply, natural gas powerplants produce predominantly NO2. They burn CH4, and convert it to CO2 and H2O. NO2 emissions can easily be reduced by 90% with proper controls (discussed in the next post). Coal fired power plants can be nasty. With no controls and with using low-cost coal, they produce a lot of each type of pollution. PM is the result of impurities in the coal that can't be burnt, or unburnt specs of coal. Low-grade coal produces prodigious amounts of PM, and contains a lot of sulfur that burns to produce SO2. They produce a lot of NO2. All of this can be reduced greatly simply by building in controlling systems. These controlling systems are used in nearly every coal plant in developed countries and in many coal plants in advanced developing countries. They are completely ignored in nearly every coal plant in many developing countries.

smoke_stack

Which should I be concerned by?

Traffic Pollution vs. Power Plant Pollution

Which of these should you care about? That depends on where you live. Most of the pollution in developing countries comes from power plants, but if you live next to a busy street or highway, traffic pollution could be the bigger concern. If you are in a developed country, particularly the US, traffic pollution is almost always the largest concern. Why? Because you are sitting directly next to the source. Whether you're biking or walking with your infant in a stroller, you are right next to the pollution. The problem exacerbates when you are nearby to a highway or major intersection, because there is a ton of traffic.

So, in short, if you are in the US and much of Europe, you should be worrying about the invisible (but smellable) traffic pollution that you are breathing in. If you are outside the US, it varies country by country. If you are in China or India, you need to be concerned about both traffic and powerplant pollution, and there is pretty much no escaping it.

Thanks for reading!

- Jason Munster

 

Adele and Hello - Math and a Carbon Footprint Analysis

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This is my first post-startup-launch post. (If you haven't yet, check out my website and sign up for more information!)

I mentioned I wasn't going to post about the environment as much anymore, but I can't stop. I honestly started this just to show how fun math can be in looking at the number of views on Adele's Hello on youtube. It ended up with me being curious what the environmental impact was.

So today I looked at the youtube video of this song. For your convenience, here it is so you can listen to it while reading this post. Apparently it's blowing up, with an insane number of views per day.

It has 309,000,000 views and has been up for all of 20 days. Let's use some basic math to figure out how popular this song is!

Let's first see how many seconds there are in a day.

And over 20 days:

With 309,000,000 views in that time, we end up with 178 views initiated per second, on average, for 20 days, nonstop.

But, hold up, it takes 6 minutes for this song to complete. So that means, on average, there are:

Let's round that up to 65,000. On average, at any given time, there are 65,000 people watching the Adele Hello video on youtube. There are 15 million views per day. That's just one video on one source. In eight whole day, as many people listen to the song, on just youtube, as watch the superbowl.

If this clip keeps up (which is unlikely), she will surpass Gangam Style, with over 2 billion views, in less than 150 days. And medical stocks will go up, cause I worry that listening to this song too frequently may drive people into depression.

"But Jay," you say, "what about the energy and environment component?!?"

Adele, impacting your heart, and impacting the environment

Adele, impacting your heart, and impacting the environment

Let's figure out Adele's carbon footprint from youtube! Let's assume that Google's hosting emissions are negligible. Let's just focus on the energy used for a laptop. Let's say that it is 50W (this is conservative).

From a prior post, we know that a 100W lightbulb uses ~1kg of coal per day. So a laptop will use about 0.5kg per day. How much CO2 is this?

This is basic chem! Let's get really basic. Coal is mostly made up of carbon. So when it is burnt, every carbon molecule breaks off and bonds with O2. So we assume that all 0.5kg of carbon becomes CO2. You need to add that weight of the O2. C weighs 12 AMU (atomic mass units, pretty much the mass of a single molecule) and O2 weighs 32 AMU.

So we need to multiply the weight of coal, which is pure carbon, by the proportional increase of mass of CO2, cause each carbon atom gains O2 weight (12+32=44)

for a 50 watt computer running all the time.

Also this song is 6 minutes, or 1/10th an hour, and an hour is 1/24th a day, so this song takes 1/240th of a day.

Don't forget, though, that we have 15,000,000 views per day!

Or, you know, ~125 tons of CO2 per day. Just from Youtube and Adele. This is the generation rate of about 2000 Americans.

And why this analysis overestimates Youtube's and Adele's contribution to CO2 emissions

Most people are multi-tasking while listening to Adele (ie those 50 watts they are using are also going towards whatever else they do while listening to Adele, such as reaching for tissues to blot their tears), so you have to take a fraction of this number  🙂

Second, much of the power use in the US is now coming from natural gas, which is more efficient than coal, so you can cut down this number.

Third, tissues take a whole lot of energy to make. I'm betting that the raw number of tissues used while listening to Adele will increase the CO2 footprint.

How many times did you restart the song while reading this blog, BTW?

Thanks for reading!

- Jason Munster

Electricity Basics (and some advanced)

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I received my second request for a post! This time the submitter asks for information about electricity, transmission, and how intermittent renewables like wind and solar fit in.

So, the first question:

1. Electricity, for the most part needs needs to be consumed the instant it is produced?

Yes. Storage of electricity can be done in batteries, or with pumped-water energy storage, but these are all just ways of being able to make electricity at some moment later in time. In short, electricity, once produced, is either used immediately or stored. Massive storage is not practical at the moment, so it's used.

2. Wind or Solar electricity is essentially in addition or parallel to the base load, and do little to lessen the use of coal, NG, or nuclear derived electricity!

This bring up an interesting point about electricity production. In the US, we have 60hz electricity. It's made 60hz by the generator design (in the US, Europe and other places use 50Hz power). Thermal power plants, those that burn things to produce power, rely on spinning a turbine in a magnetic field to produce power. The magnetic field is part of the turbine design, and is too complicated for this post to discuss in further detail. The turbine is spun because water, turned into steam by the heat from burning things or other reactions (coal, natural gas, or even heat from fission), expands rapidly from water to steam. It creates pressure, and then pushes through the turbines to spin them. The turbines spin at the exact rate they need to in order to produce 60hz electricity.

If we produce slightly too much electricity, the turbines start spinning slightly faster. To keep the grid at the right speed, electricity production is reduced at plants. If there is too little electricity, the turbines will slow down, and we'll fall below 60hz. There is a constant dance of the power plants and the electricity users to make everything balance. It's mostly automated, and happens very quickly.

What does this have to do with solar and wind? A lot. Solar and wind power output can be predicted, but not perfectly. If we want to maintain a perfect 60hz grid, we need to be able to adjust for wind and solar output. Because, again, electricity is used when it is made, and not stored. Coal and nuclear power plants aren't great at changing how much electricity they produce in a short timescale, so if we are going to have power plants to make the balance necessary, we need hydro and natural gas to account for the variability of the solar and wind. There isn't enough hydro to do that all over the country.

In  other words, if we want to maintain a 60hz grid, we are always going to have some amount of natural gas power plants.

But beyond that little wrinkle, solar and wind power absolutely offset coal-fired power plants. The more solar and wind we have, the less nuclear and fossil fuel power we need, in general.

In practice, do renewables offset much? See the chart below.

US primary energy consumption. Source: eia.gov info

Short version: Wind was about 1.2% of primary energy (primary energy counts burning oil for cars as well), and solar is 0.16%. So wind and solar can replace coal and nuclear, but it barely does currently.

Longer version: We can let the 60hz grid go from exactly 60hz to let it slide between 58 and 62. And then we can fairly easily do away with a lot of other power plants, as long as we have enough wind and solar. Note, however, that there aren't enough good wind sites in the US for this, and solar is currently too expensive and resource-demanding to replace fossil fuels.

3. Electricity is bought and sold just like a commodity?

In some ways, yes, but not exactly! There is a complicated daily bidding process, and several factors are brought into play.

This one is a bit confusing. I'll do my best. Power plants bid on the day-ahead market. They submit their bids to what is typically called an ISO, for Independent System Operator (some places call it differently, like RTO for Regional Transmission Organization. The ISO/RTO looks at the bids, looks at their best guess for power the next day, and then figures out how many of the power plants they need to hire for the day. Those that don't get hired don't actually burn anything or produce power. Those that do get hired, get hired at the rate of the highest bidder. Let's do an example to explain better.

Note that a MWh is one hour of one MW production. So a 600MW plant produces 600MWh in one our, and 1800MWh in 3 hours.

A plant says, "I can produce this many megawatts at this many dollars per megawatt." Power Plant 1 might say, "I can produce 600MW of coal power at $80/MWh." Power Plant 2, "I can produce 1000MW of natural gas power at $100/MWh." Power plant 3, a nuclear power plant, doesn't shut down. They just keep running. They say, "I can produce 1200MW at $0/MWh." Why? Cause they have to run anyways. They are delivering that power at any price. Power plant 4 is an old coal-fired power plant that has already paid for itself, so it's really cheap, and says, "I can provide 300MW at $50/MWh"

Let's assume it is determined that all of the less expensive power plants, along with Power Plant 2, need to run in order to satisfy electricity demand. They want $100/MWh. Power plant 1, despite bidding in at $80 per MWh, gets $100/MWh, nuclear plant 3 also gets $100/MWh, and coal plant 4 also gets $100/MWh.

On another day, it is determined that only enough electricity is needed for power plant 4 (and all the ones who bid below it). So Power plants 1 and 2 do not produce electricity, power plants 3 and 4 each get $50/MWh.

Should inputs become more expensive, then the power plant has to raise its price. Natural gas, for example, became a lot less expensive in the past 5 years. So they now produce electricity for less than a new coal fired power plant would. So they bid in for less.

A bit confusing, right? It gets more complicated than that. This is a great example to show that electricity is not exactly treated like a commodity.

Now what about solar and wind? Pretty much, if solar and wind is produced in the US, it is purchased, pretty much outside the normal bidding system. What happens to the bidding system if all power becomes solar and wind? There probably will still be some version of it, changed to fit the new system!

That's all for now, thanks for reading!

- Jason Munster

Remedying air pollution, one person at a time

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One of my friends once told me, "If you are complaining about the government and aren't doing anything to solve the problem, then you are part of the problem."

I decided to do more than write about pollution associated with energy, and have started a side project to build a breathing filter (and mask that it will go with) for people living in and visiting countries with significant air pollution.

My apologies for not posting this sooner, I wanted to wait until I had finished a major milestone on my PhD that was taking literally all of my time. In other words, I didn't want to post about "working on" something that I had no time to work on. I hope to become active again in posting related articles now that I've a bit of free time again.

20,000 people die every day from air pollution. Most of them cannot afford current filters. It's time to change that.

So. China and India are not going to institute US-level air pollution controls on their power plants. So if they aren't going to filter the entire sky the way we do, the next best thing is to just filter the parts that people breath. By filtering it just before they breath

"But Jay," you say, "Aren't there other masks on the market already?"

Indeed, my friend, there are. Except most of them fail in one way or another. Nearly all of them fail to achieve a face-seal. This means that there are small leaks. Small leaks are fine when you are filtering large particles like water droplets (think viruses that travel on sneeze particles), because the leaks are often at 90 degree angles. The droplets can't make those 90 degree bends, and they get absorbed by the mask or deposited on the skin. This is why doctors masks can be fairly effective. PM2.5 and chemical pollutants, however, are small. PM2.5 is 1/30th the width of a human hair in diameter. It can easily make a 90 degree turn through a leak in a mask, and get into your lungs where it penetrates deeply, creates scar tissue, and then gives you asthma and lung cancer until it kills you. The other pollutants are literally molecules. They have no problem making any bend of any sort. If there is a leak, they are getting through.

Gas mask. The only true way to ensure there is no leak.

What's the easiest way to tell if your mask leaks? Take a deep, sharp breath. If your mask doesn't push against your face from suction until the pressure equilibrates, you don't have a good seal. So pretty much, every mask short of the one pictures above doesn't work.

So this is one part of what I will address. I've a few methods to ensure no leaks while maintaining low costs for masks. I'm not exactly going to be open on how I will do it, but this is happening.

So, if you plan on traveling in China, India, or near LA (heh) next year and need a breathing filter, be sure to talk to me.

- Jason Munster

Which Country has the Worst Air Pollution in the World?

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Before I get into anything, this is a first in a series of three articles I am going to be releasing. Instead of my monthly release rate, I am going to be releasing them one each week. If you are traveling to or live in a polluted environment, I highly suggest you subscribe to the blog or do it as an RSS feed.

Now to the article!

If you guessed China, you guessed wrong. Did you get it wrong? If you say you didn't, I am going to call you a liar. Every person I know, when asked which country in the world has the worst air pollution, answered China. This includes experts on China, experts on air pollution, and experts on countries that are more polluted than china.

Also, the number of people that die per year from air pollution is staggering, more on that after the math.

China isn't even close to being the country with the most fouled air. That distinction belongs to India, by a huge margin.

Okay, well, let's delve further into it. Of the top 20 most polluted cities in the world, how many would you guess are in China? Okay, that was a trick question. China doesn't have any of the top 20 most polluted cities in the world. And India holds the distinction of having at least 10 of them.

A gate in India that can't be seen through air pollution.

Before getting to the science grit, one more important thing. Owing entirely to city air pollution in India, at least one study shows that Indian citizens living in cities have 30% less lung capacity than Europeans living in cities. So, pretty much, pollution makes it so

Okay, let's back up and discuss air pollution a bit.

What is Air Pollution? (This is the technical part of the post)

In this above mentioned study, air pollution is strictly PM2.5. Why is that? Because PM2.5 is particulates smaller than 2.5 microns, roughly 1/30th the width of human hair. They are small enough that they penetrate deep into the lungs, where they cause permanent damage and can lead to cancer. PM2.5 is produced by powerplants (mostly coal-fired) and any combustion-based motor vehicle. The EPA has a great guideline for PM2.5 if you want to read more.

There are other pollutants that everyone seems to ignore. Back in the day, you heard a lot about acid rain. Acid rain is caused by and . Combusting anything creates NO, cause there is so much in the air (78% of the stuff we breath is ) that some of it combines with oxygen during combustion, creating NO. NO reacts with to produce NO2 and O-, the latter of which produces ground-level ozone (more on that soon). Let's look at what happens to and in air:

So that's sulphuric acid.

And that is nitrous and nitric acid. Another fun reaction is:

VOCs are Volatile Organic Carbons. It pretty much means organic matter in the air. It comes from plants. , or ozone, is bad for people and plants at ground level.

So let's review what happens here. Power plants burn fossil fuels, they produce PM2.5 which causes cancer, coal-fired powerplants produce which becomes acid in your lungs, and all combustion plants produce which also becomes acid in your lungs. PM2.5 is the worst, but the other pollutants are also bad. Burning coal causes the most of all of these pollutants. Lower grade coal, the stuff burned more often in China and India (the US has high grade coal), has less energy relative to pollutants, so it makes more pollution.

Now, exactly how bad are ozone, NOx () and SOx ()? They are all similar, so lets just look at SOx health effects according to the EPA. In short, exercising in an environment with this stuff is bad for you, and sends people to the emergency room. In the worst case scenario, it exacerbates or triggers asthma, heart attacks, and aneurysms, killing people nearly instantly. Long term exposure increases asthma and other health hazards. Now keep in mind that this stuff is considered less of a problem than PM2.5.

Back to the Qualitative

Okay, now that we know what the stuff is and what it does, let's get to some specific numbers. The World Health Organization indicates that air pollution is "single biggest environmental health risk in the world" the largest health hazard in the world, killing 7 million people per year.

What's the best way to deal with this stuff? Staying indoors helps a lot. Your house acts as a good barrier against it. Having a filter also helps. If you live in China or India, build one of these at your home. The filter will stop working eventually, so it will have replacement costs, but you can probably get clean air for around $100 per year for a single room in your house. Now keep in mind, this is a HEPA filter, which filters out only particles. Good luck with that SOx, NOx, and ozone. The guy who stapled together the filter and the fan states that it's the only thing you need for clean air in his blog. Clearly the PhD he is learning in psychology does not qualify him to know a lot about air quality. It doesn't disqualify him from knowing about it, but being completely unaware of the chemicals I described above does.

HEPA + fan. Good for PM2.5, useless vs. ozone, SOx, and NOx.

 

In other words, this filter will work inside, but you are still going to get bad chemicals living in your lungs. If you want to filter more, be prepared to shell out thousands of USD. Also, if you plan on going outside, or you want to exercise, if you work outside, you're pretty well screwed. There are a few masks that work, but all have their flaws or are expensive. More on this later, we've hit 1000 words and it's time to go.

Before we let me repeat one thing. If you are in a polluted area: Do. Not. Exercise. Anywhere. That. Isn't. Filtered. And no mask on the market filters out SOx, NOx, and Ozone.

Thanks for reading!

- Jason Munster

Solar Roadways: Full of Crap and Bad at Math

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First of all, sorry it has been over a month since I've posted. I've decided to get together a few people to start addressing some of the things I write about, and that has taken my time up til now. I'll be posting once per month from here on out, on the first Sunday of every month. Today's post is a long one, but one of the most interesting I've written by far.

This is the one time where I will say the following: if you are short of time, skip directly to the math section. It shows a serious glaring deficiency of either forethought or disclosure on the part of the founders of Solar Roadways. Moreover, it shows they can't do basic math. Never trust an engineer who can't do basic math. It's a very crackpot idea.

Here We Go!

I've heard a lot of talk about Solar Roadways recently. I'm going to use it as an example of how to analyze some "science." After you follow the very basic math below, you will see that the team at Solar Roadways does not know what numbers to run*. A much larger problem: they suggest that solar roads can replace fossil fuel power, while simultaneously and surreptitiously admitting that they need a ton of grid power to make this work. So pretty much they are either dumb or straight up liars.

First, let's talk about why these roads might be good, from their point of view. Being a by-the-numbers type of guy, the first thing I did was check the "numbers" section of their website. While their assumptions are dubious at best (more on that later) They say that their roads could provide 3x the energy that the US needs, in kilowatt hours (kWh is a useless measurement here, cause it will be intermittent power. In other words, it produces no energy at night, and will need to be supplemented by fossil fuel power. More on that later). Also, the roads look a lot cooler, with light-up sections, and ability to melt snow so that road maintenance is reduced.

So the thing is wired to the grid so that if it snows, it can use heating elements to melt the snow instead of plowing it. But doesn't snow take a lot of energy to melt? Would it take less energy just to push it with a plow? Time for the math!

Math of Melting vs Pushing Snow

Plow trucks to be replaced by Solar Roads? Not happening.

Plow trucks to be replaced by Solar Roads? Not happening.

Okay. Let's assume middle-case scenario of 8 inches of snowfall, being removed with one sweep by plow trucks, and that this is between powder and heavy snow in consistency, which means 1" of water equivalent. A DOT snowplow clears 10' width of snow, or 120 inches. In one foot of movement forward and plowing 8" of snow it moves the water-weight of 1"x120"x12" or

Now we have to figure out how much energy cost this took in fuel, so we will later relate this to the mileage efficiency of a DOT truck. First, let's figure out how much energy it takes to melt this much snow into water. Do do this we need the latent heat of fusion, or the energy it takes to transition from ice to snow. It's 334 Joules/gram. How do we convert from cubic inches of water to grams? Easy. Because the metric system makes sense, one of water = 1 gram. There are 2.54 cm per inch, so:

Okay, we have grams, now let's calculate the energy to melt as much snow as a plow moves from driving 1':

Or ~7.8MJ. Per foot. Or, for a mile:

to melt 8 inches of snow.

Okay, so, a plowtruck uses diesel. Each gallon of diesel has 136.6MJ. Very conservatively assuming a plowtruck gets ~5 miles to a gallon (I'm guessing it's more like 10, someone who has driven one, correct me and I will correct these #'s), it would take 27.3 MJ to plow one mile of snow. Compared to 41,184MJ to melt it. It literally takes 1500x as much energy to melt is as it would to move it.

This is what you would call a very very bad idea. Engineers as cofounders should know better than to let this slide as a potential solution.

End of Math Section

Okay, so now that we've completely dismantled the case of using these things to melt snow, lets move on to some other issues. We'll skip the minor issues, because that's just nitpicking, and move straight to the parts where they just don't know what they are talking about, and finish with things they clearly know about, but are purposefully misleading people with in order to get more money. Finally, we will close with me realizing that Nathan Fillion is a fool.

Okay, to the problems with this solar roadways project:

Dubious assumptions:

Things they don't understand: the supply lines of a very basic input.

REE mining in China is not a clean thing. Nor was it great in the US. Right now there is not enough world production to make enough of these solar roadway tiles. Look at this article to see more pictures of REE production in China.

They assume an 18.5% efficiency of the solar panels. These are panels that use Rare Earth Elements (REEs). On their FAQ, when someone asks if they are using REEs, they state (paraphrased), "Our electronics don't use silver or gold" (neither of which are REEs, so they are either changing the topic or don't know what question they are answering) "but we can use any solar cell." Good that they can use any solar cell, because there is not enough REE production in the world to produce solar at the scale they need to even replace one major highway with these. Bad they they use 18.5% as their assumed efficiency, because solar cells in this range of efficiency use REEs.

REEs are pretty much only produced in China, because producing them make a massive amount of pollution. Decades ago every other major country quit producing REEs because of the pollution they cause, and because China didn't care about pollution or health hazards, so the world was happy to let them pollute themselves and take their REEs. It's been so long since the US produced REEs that we literally don't know how. Solar Roadway's answer is "let's leave this to the government." They aren't addressing the problem at all. While other countries are looking to have their own production, it will take a very long time for this to come to fruition, and the production rate still won't be enough for a second-rate harvesting design (flat roads with bad optics vs. tilted panels with great optics to concentrate light perfectly).

At best, they can go with non-REE solar cells, which have about an 5-10% efficiency. That means that each of their hexagonal panels will produce half the power anticipated, and thus will make half as much money toward recuperating their costs. In other words, these non-REE solar panels need more basic raw materials (in terms of roadway) per kwh produced, and thus will cost more per unit energy, in an already material-intensive design for a solar cell. This shows that the project is lacking in any real expertise or understanding of the core problem they are trying to solve. Keep in mind that these are not dealbreakers. The team could hire an expert, or consulting, to fill in their knowledge gaps (likely the former, consultants are expensive, and they really need long-term help to bring this to fruition). Also, it doesn't negate all the other benefits of the solar roadways. Finally, non-REE solar panels are a hot topic in research. If the rest of the solar roadways tech is developed, and they are just waiting for good solar cells, it will rapidly enhance future deployment.

In short, the solar cells are a slight additional benefit to whatever holds them in this case of mass-distribution and inefficient use of cells. So if this new road itself doesn't compare favorably to asphalt, the project is sunk in the water.

Things they are just completely wrong/misleading about: melting snow, shutdown of fossil fuel, price of energy

We discussed the melting of snow. They suggest it replace snowplows. Bad idea. It's clearly not going to work, energetically speaking.

They keep talking about how 50% of US electricity use is from fossil fuels, and how these roads are going to replace it. This is so wrong that it is hard to debunk in one post. But here goes: First, only 40% of US primary energy (my link, please read it for background if you feel a bit lost, it is far briefer than this post) is for electricity. Second, only 66% electricity of this comes from fossil fuels. In other words, 26.4% of US electricity comes from fossil fuels (if we change all our transportation over to electric, these numbers will change, but that would require these roads to have induction power installed - AKA roads that provide the car with energy for driving so they don't have range issues). This is the total amount of emissions that could be replaced by solar roads in their current design.

Primary energy in the US. As detailed by the math above, only 25% of primary energy in the US can currently be replaced.

 

So, pretty much they are off to a bad/misleading start there. But this is nitpicking. The real issue comes in when they talk about replacing fossil fuels. First, they talk about heating the roads. This means they will have to put energy into the roads. Where will this energy come from? Power plants. So much for shutting down fossil fuel. But wait, there's more! Solar power is intermittent. It doesn't even work at night, so power plants also have to be on then. So pretty much, their idea of shutting down power plants is completely shot out of the water by these two things. Can solar roadways still be part of a larger energy solution? Well, not if they are heating roads to melt snow. That just takes far too much energy. If they scrap the melting snow idea and go to just producing energy? Yeah, it might help some. But let's get to one last funny part, the one that shows they know that they won't be shutting down fossil fuel power any time soon.

Energy storage. From their FAQ, they mention that there will be "virtual storage" in that during the day they will add power to the grid, and at night they will take power from the grid. This is double-speak to mean: during the day we will provide power that can offset coal and natural gas power plants. At night when we aren't producing, natural gas powerplants (again, my link) will fire up to power our roads (nuclear is not an option for power phasing like this, nuclear powerplants don't spin up or wind down on half-day timescales). In other words, they fully well understand that they aren't going to do away with the rest of the power grid, and that they aren't going to replace all those fossil fuel emissions. So pretty much, saying that these can replace our power grid is double-speak sales points.

The final problem? They don't understand energy distribution. Electricity is produced at about $0.03 to $0.08 per kwh at a power plant. By the time it arrives to us, we pay $0.13 to $0.25 (or $0.50 in Hawaii), because distribution costs a lot of money. Solar panels on our roofs produce power that costs about $0.15 to $0.20 cents per kwh, give or take. So the end-user cost of grid power is the same as that of house solar. But if you run that solar power through the distribution channels and add that price, suddenly you're talking $0.25 to $0.40 power. So, unless they are giving this power away for free, it's probably not gonna be a great solution.

Some Solutions

I've softened my usual tone quite a bit for this writeup, cause I don't want to be a complete naysayer of something who is trying to do something positive (sorry, I know how much you all know and love my biting sarcasm and scathing reviews).Outside of their false solution of trying to solve the energy/climate issue, this idea has some potential. On that note, rather than pointing out problems, I've come up with some great solutions.

My suggestions:

1: Nix the whole melting of snow concept to replace plow trucks. Energetically, it doesn't work. Plow trucks should still exist. Instead of replacing them, replace the salt and sand they need to spread. Make it so plowtrucks plow all but the last 1/8" of snow, then melt that (note, this is still a tremendous amount of energy, but stay with me). This will have a few benefits:

  • No more salt and sand on roads means less salt and sand damage to vehicles, making vehicles last longer
  • No more salt and sand on roads means that DOTs can save money buy not buying these things
  • ... no salt and sand runoff, which pollutes local waterways
  • ... animals that go to roadways in the spring to lick off accumulated salt won't do that, reducing traffic accidents from moose and deer, etc.

2: Get a bit more cognizant or REEs and their limitations. Don't use bad assumptions that are easy to poke holes in.

3: Stop selling people on false promises of doing away with fossil fuels. It makes the whole green movement look bad when prominent people are lying or severely misinformed.

4: Focus on the real potential of making these have inductive energy for electric cars. This could eliminate range anxiety (people fearing their electric cars will run out of energy and leave them stranded). Electric car sales will move a lot faster if people can drive from LA to SF, or between Boston/NYC/DC. The potential partnerships include every major car company that markets in the US. Also, this could reduce oil use, and drastically reduce air pollution from cars in these busy areas by further replacing combustion engines with electric ones (even if we power them with electricity from coal, a well-scrubbed coal plant produces fewer bad things than a car). Moreover, since people won't need fuel, they could be assessed a charge per mile driven instead. By whoever owns the roads. Here is your real money-maker for the roads, fellas. It will be far more lucrative than producing tiny amounts of electricity. Please get on this. It will lead to more electric car research, and more rapidly drive forward battery development, and it turns out that cars make a bunch of really bad pollution that causes harmful side effects like death.

This last bit, changing your startup's tack when a better model comes along, is important. And solar roadways needs to do that for a viable product, because their core solution faces a lot of headwinds (yay, sailing puns!) in break-even with their current model.

So, overall, these roads could be an excellent idea. The solar part, their main selling point, is BS because of cost, efficacy, and the need for gas-fired power plants to supplement them. The shutting down most fossil power plants is a lot of nonsense for the same reason. Making the environment better by reducing salt and sand use? Decent. Potentially by making most cars electric? Game-changer, but they are barely looking at that aspect right now. Probably cause they are too busy counting the piles of cash that indiegogo just threw at them (or, more likely, answering the insane number of emails that comes from this sort of campaign).

Hokay, that's my piece. Thanks for reading this long one.

- Jason Munster

Extra stuff!

Some background about Solar Roadways initial funding: They were funded by government SBIR. This stands for Small Business Innovative Research. It's for high-risk, high-reward research. In other words, this was considered high-risk from the start. They got a phase II, which means they did well. It's clear they still have issues and are still high-risk. But I'm glad someone is paying for research and innovation like this, especially because if it pays off, it could result in more jobs and more taxpayer base. That being said, they haven't received more funding or any grants to build this out further. Possibly cause it's a big, crazy idea. Elon Musk can pull off big, crazy ideas, because he is a brilliant manager and has a very strong personality. These guys are going to need some bigger guns on their team if they are going to make something of this project.

Second, Nathan Fillion is a bit of a fool. In touting Solar Roadways, he displays why pop culture heroes shouldn't get involved in matters outside their field of expertise (mainly, looking good in front of a camera, and pretending to be someone who they aren't in front of a camera). His adoration of something he doesn't understand falls deep within the territory of religious fervor. Nerds: just cause one of your heroes likes something doesn't mean it actually is plausible.

One final-final note: I know that this post is 3x longer than my rest. I assure you, it's far shorter than I wanted it to be. I don't believe in two-part posts very often, though. If you have read this far. please leave a comment so I can appreciate you forever 🙂

*Engineers who don't know what numbers to run are a bad investment. For my own company, all business types are skeptical of how much I know (or want to take advantage of me fully) until they find out that I used to be in finance and have a really good idea of the big picture of most things. In short, this company has a lot of potential once they take on broader experts.

Your Power Plant Might Have a Drinking Problem

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While at an energy conference (ARPA-E, 2014) I found out that power plants account for 40% of water draw in the US. Simply put, they use a lot of water. The good news is that it doesn't have to be fresh water. Brayton Point, for instance, uses grey water. In other words, it uses water that came from your toilets and sinks that has been reprocessed. Others use saline water from oceans (all water in the oceans is saline, cause it is salt water).

No math this time, just review the math from my thermal power plants post.

Why do power plans needs water? Cooling purposes. The way a turbine works is that high-pressure air has to drive through it. The way this happens is water is flashed to steam. Steam takes 1600x the space at 1 atmosphere compared to water. So it creates a massive pressure differential on one side of the turbine, turning the fans, turning the turbine, and generating electricity. The steam needs to be cooled on the other side to either create the vacuum that drives the pressure differential to turn the turbine, or, if it's a close cycle and the same water is used, to cool the steam back to water. It needs to be water again, otherwise it cannot expand and drive the turbine.

Schematic of a thermal power plant. It needs water to cool the water used to drive the turbine.

Okay. That was complicated. Let's break it down further. This section if very detailed, and most of you will want to skip this paragraph. Here goes: There are two major ways to run a thermal power plant. Combined cycle, and single cycle. Combined cycle is more efficient. How? It uses several turbines to extract energy rather than a single one. Think about it this way: when you have 300 degree celcius steam coming from the coal-burning reactor, it is all steam. There is no water-phase droplets in it. This is called dry steam. It can be directed to special high-efficiency turbines that can extract a lot of energy. The steam then loses pressure and temperature, and some water droplets begin to form. If this mix of steam and water were directed at the same turbine, it would pit and tear at the turbine blades, destroying it. Two things could be done with this steam. Either it could be directed to another turbine, or it may not be reused. The second turbine will be designed differently for steam that is lower pressure and lower temperature. Having multiple turbines like this increases efficiency. Inefficient plants use only one turbine

(everyone else should join back in now) Eventually you end up with a mix of water a steam. As I said before, this has to become water again, so it can expand to steam and drive turbines. Or, if a plant is doing a once-through cycle and expanding water from a stream, it needs to dump the water back into the environment. Dumping near-boiling water into the environment is a terrible idea. That would be a bit of a disaster. So, in either case, you need a lot of water from the environment to cool the water used for the steam cycle in the plant. An alternative scenario is using evaporative cooling towers. They evaporate water, which requires heat to go into the water, which then cools other water. No matter what, cooling a plant requires a lot of water.

So here we come back to the end point. Power plants use an insane amount of water. "Ahh, but Jason," you ask, "these are just thermal power plants. I use solar power. So my plant is water-efficient!"

Not so, I say! Solar plants also use water for cooling and cleaning. And this is from NYT, an ostensibly liberal paper that likes solar. This is because major solar plants use solar thermal, rather than solar PV. Solar PV is pretty much water-free, other than for cleaning mirrors. But that electricity is too expensive to be useful at the grid scale (recall from a prior post that it costs about 3-7 cents to produce a kwh of electricity, but we buy it for 20 cents, so it makes sense for us to put solar panels on our houses at the cost of 20 cents per kwh, while it doesn't make sense for power companies to use solar panels since they mark up prices 3x to get power to us).

How does this compare to coal? In the link above, we have solar power using 1.2 billion gallons a year to produce 500mw of power. Your average coal plant produces 600 watts of power. A once-through plant draws "between 70 and 80 billion" gallons a year. But a closed-cycle plant, the one that uses the same water in the plant and only uses other water for cooling at the end of the power cycle, uses 1.7 to 4 billion gallons a year. So the efficient ones are comparable to solar in water use.

So here we have a chart showing all this:

Water use by power plant type, source 

Note that you can find different graphs using different information sources, but the general point always remains: power plants use a lot of water.

Wind power, however, doesn't use water. Unfortunately, wind power is only available in a few places. How about hydro power? It passively uses water, so it doesn't really count. Great, right?

Not so fast. How much of the US power generation comes from thermal and solar sources? According to the EIA, 87%. I reproduce the info here:

In 2012, the United States generated about 4,054 billion kilowatthours of electricity.  About 68% of the electricity generated was from fossil fuel (coal, natural gas, and petroleum), with 37% attributed from coal.

Energy sources and percent share of  total electricity generation in 2012 were:

  • Coal 37%

  • Natural Gas 30%

  • Nuclear 19%

  • Hydropower 7%

  • Other Renewable 5%Petroleum 1%

    • Biomass 1.42%
    • Geothermal 0.41%
    • Solar 0.11%
    • Wind 3.46%

  • Other Gases < 1%

So yeah. Your power plant has a drinking problem.

thanks for reading!

- Jason Munster

Apartment Rentals and Energy Waste

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Landlords usually suck. And they probably cause some notable percent of emissions by being lazy (I would guess like 1+%) and not modernizing their apartments (modernizing by 1980s standards).

Drafty rental unit?

Background

A few months ago, I wrote my most-trafficked article about why living in the suburbs is bad for your wallet, and bad for the environment.

A lot of people had some ridiculous responses.

The ultimate point of the article was that living in a city is better for the environment than living in the suburb. Many responses mostly ignored the environmentally friendliness part. These butthurt folk only cared about the size of their house (which, as we showed in the previous article, means they probably suck in terms of energy efficiency). If they did, they would have pointed out the giant gaping hole in my argument: most landlords don't give a care about energy efficiency of your apartment. They aren't paying for utilities, they only care about your rent.

Some Sources of Energy Waste in Houses

In my last article, I pointed out that all houses need some amount of venting. So bigger houses will likely need a lot more energy to heat and cool than smaller houses. The driver of this was how many times per day the house cycled all of its air. It will surprise most people to find that the amount of ventilation that is still considered safe will dump all of your heated / cooled air 15 times per day.

Drafty windows, much? (same disclaimer as below, burrowed image from a commercial website)

In most cases, your landlord doesn't care about how drafty your place is. On other words, the old place I lived in in Somerville probably exchanged all of its heat to the atmosphere about 100 times per day (we could perceptively feel drafts through every window and door). So the place took about 4-8x as much energy to heat as a well-sealed house of the same size.

What incentive does the landlord have to fix this? Absolutely none. He doesn't pay any utilities. He gets rent no matter what. Given that a majority of people won't ask what the air-exchange rate of an apartment is, he won't have to fix it.

What about appliances? Stoves are pretty easy. Electric stoves produce heat by using electricity to heat an element. They are pretty efficient at converting electricity to heat, but newer ones can definitely be more efficient and save you money. Gas stoves, as long as they don't leak, do pretty well despite age.

Remember these fridges? (note: I just burrowed this from a random site since I couldn't find a .gov site with an old fridge)

Fridges, dish washers, clothing washers, and dryers, or really any other appliance (including hot water heaters, etc.) are a very different story.

Just go here and play around with how much you'd save in electricity annually to figure out how much you'd save by buying a new fridge.

And then remember that 1 kwh of electricity requires 1 lbs. of coal. And then let's consider that replacing an early 1990s era fridge with a new energy efficient one in MA will not only save about $200 per year, but will save nearly 1300 kwh. Or 1,300 pounds of coal, if you get all your power from coal (or about 700 lbs. of methane (recall that methane produces a lot less CO2 for the same energy production)). I am going to repeat that again. Replacing a 20 year old fridge will prevent the equivalent of burning 1300 lbs. of coal in environmental change per year.

That's right. Your landlord being lazy and cheap is making us burn 1,300 lbs. of coal per year. And the energy savings from replacing other old appliances is similar.

What about replacing windows, doors, etc., for ones that don't leak? For ones that have a lower amount of heat transfer directly through the window (double paned, triple glazed, etc.)? It's huge. You can even get tax credits to replace old windows, making the payback time less than 5 years. But many landlords don't care about this, because they don't face the costs of heating a home. They would just be paying money for replacement appliances and windows, and they would never see a return on this investment.

I don't think I need to belabor this point. Old appliances and leaky housing are things your landlord doesn't care about, but they are things that matter in terms of energy use.

So how to fix it? That's for policy people to figure out. I'm not one of them. But I would suggest a few things:

1. Require that landlords report yearly costs of heating to 65F in winter, and cooling to 75F in summer, as well as electricity bills, every time they show an apartment to a potential tenant. This way tenants can add this price in to their monthly rent, and it will force landlords to make a correction for the market.

-or-

2. Require landlords to not have appliances that are more than 15 years old, and windows and doors that are not more than 25 years old

Obviously #1 is much better with market mechanisms, paperwork, etc. I would go with that, since there is pretty much no overhead involved.

Anyone else have any ideas to address this? Leave it in the comments!

Also, if you liked this, please subscribe & share. Thanks for reading!

- Jason Munster

*Recall from an earlier article that the energy use of heat from electricity depends entirely on the "energy mix" of the grid. If enough of that electricity comes from renewables (let's conservatively say 3/4), then the amount of CO2 produced from using electric heat will be better than gas heat (even if the last 1/4 is dirty coal, hence using the 3/4 conservative #).

Natural Gas Prices 2

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Natural gas flaring (NOAA). Often it is less expensive to burn natural gas than it is to get it to market.

Since I am in the field installing science onto an airplane, this is going to be a short post. In a prior post, I showed graphs with natural gas prices being de-coupled from oil (recreated and updated with the latest numbers here). I decided it was high time to do some maths related to it. All the data is from the EIA, and all the analysis is my own. I had to interpolate average coal prices for the past two years based on its link to specific coal prices.

If you know what correlation is (I think most of you do), skip over the description of correlation and go straight to Maths, since it is very rudimentary, and you could probably make fun of me for writing it. If you want to do better statistics with the data set, let me know and we can have some fun.

One important point! These prices are well-head prices. In other words, it is roughly what the major distributors of gas will pay for the stuff. Your prices as and end-consumer won't change. In other words, they pay less when the price goes down, but they sell you to at the same price. That works out pretty well for them, doesn't it?

Description of Correlation and its Limitations

Correlation: correlation is a measure of how closely two data sets match. In other words, correlation answers the question: when one set of data goes up, does the other go up? It is important to remember that correlation does not imply causation. In the case of natural resources, this idea is very easy to understand. The price of oil and natural gas both rose together in the 90s. This does not mean that the price of oil rose on its own, causing the price of natural gas to rise. Natural gas prices rose for pretty much the same reasons as oil prices rose. In this case, demand for things that burn and produce heat caused an increase in price in both of them.

Long-term prices 1-13

Wellhead hydrocarbon prices over the past 3 decades. The price of natural gas used to follow the price of oil. In 2008 this changed thanks to hydrofracking.

A classic example of the abuse of correlation and causation is ice cream and murders. Both murder rates and ice cream purchases tend to rise in cities at the same time. One could conclude that ice cream causes murderous rampages, or that the best way to relax after murder is to eat ice cream. Both of these are silly to conclude. More likely, there is an outside factor that causes both. It could be hotter weather makes people eat more ice cream, and simultaneously makes them more irritable. Or it could be that hotter weather makes people eat more ice cream, and it also makes more people be outside, where they are more likely to get murdered than in their homes. The point is that correlation can show that two factors are tied together, but often requires more than that to show a direct causal link.

Hokay. Correlation goes from -1 to 1. 0 means no correlation, 1 means perfect positive correlation: one thing rises, the other one rises by a predictable amount. -1 means perfect negative correlation: one thing rises and the other falls by a predictable amount.

The Maths!

NG correlations

The overall correlation between oil and natural gas prices from 1986 to 2012 is .68. This is pretty good for noisy data sets (noisy meaning there are outside factors, like commodity speculation in the markets). The correlation between natural gas and coal over that period is .4. This is pretty low, and partially represents inflationary increases in prices of both of these over time (if I had used real 2005 dollars instead of nominal dollars, all of these correlations might decrease).

More important is breaking out the correlations between early and late. I mentioned in the prior price post that decoupling began to happen in 2007, and then accelerated. The 22 year correlation between gas and oil until end of 2008 was .88, very high, much higher than .68. After this, the gas:oil correlation becomes -.23. The prices have become decoupled. At the same time, the correlation between gas and coal rises to .69. Not great, but definitely more coupled than gas and oil currently are.

One thing is clear about natural gas prices and correlation. Natural gas prices in the US used to be tightly coupled to oil prices. Natural gas prices in the US are no longer coupled to oil prices. They are instead coupled to coal prices, though not as tightly as the prices used to be coupled to oil prices.

Hydrocarbon prices per million BTU after hydrofracking. Pretty easy to see that decoupling, eh?

Hydrocarbon prices per million BTU after hydrofracking. Pretty easy to see that decoupling, eh?

Now we discuss the cause. The cause in this case is definitely hydrofracking in the US. Outside the US, oil and gas prices are still more correlated. Okay, that was a short discussion.

Some caveats: the numbers I used for historic coal prices are mean annual coal spot prices weighted for what was bought. These are correlated to monthly oil and gas prices. These coal prices were not available for the last two years. They are, however, tightly coupled to coal prices in general. I looked at similar priced coal over the two years, and extrapolated the prices for my model based on these. Given the very tight link of mean coal prices to the price of specific types of coal, this is not a faulty method. If someone were to use a more consistent methodology to determine coal prices throughout the entire time period I have sampled, it would produce results that are nearly identical.

Conclusions

Oil prices and natural gas prices were historically tied. With the advent of fracking in the US, natural gas prices decoupled from oil prices, and have coupled with coal prices.

So much for a short post, eh?

Natural Gas Price Drop, and Natural Gas Electricity!

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Today’s post is about the shift in US primary energy use from coal to natural gas (AKA methane). Hydrofracking, the hydraulic fracturing of rock to subsequently produce natural gas, is a new favorite pass-time in the US. Natural gas prices used to track oil prices per unit of heat. They now roughly track coal prices per unit heat. As a result, it is now economical to produce electricity from methane rather than coal. As we discussed before, coal produces a whole bunch of dirty pollution, and methane does not. All good, right?

This is very important for both CO2 emissions reduction and for reduction of other pollutants. The math section is chemistry heavy. If you are going to skip a math section, this is the one.

The highest grades of coal have composition , and lower grade coal is All coal is tainted with mercury and other heavy metals. Lower quality coal has more pollutants per unit heat, and this produces more pollution for the same amount of electricity. From the last post, we learned burning coal has quite the array of negative health effects.

The chemical composition of natural gas is CH4. It contains almost no other pollutants. It doesn’t produce particulate matter. When it is burned to produce electricity, we do not have the direct adverse health effects associated with coal. What about the CO2 emissions? These are reduced. Cause of math.

The Math of Chemistry! This is bond enthalpy chemistry. (Feel free to skip ahead if you don’t like the math parts)

Let’s look more closely at the composition of these two things. When any substance burns, it produces heat by converting everything to H2O and CO2. The resulting H2O and CO2 have lower internal energy than the coal or methane that formed them. The difference in energy from the coal to the H2O and CO2 has to be given off as heat.

Before the math: First, what is a mol? It is short for mole. Pretty bad abbreviation, eh? A mol is the number of molecules it takes to make one g times the molecular weight of the molecule. It is molecules. This is confusing. Lets use examples to make it less confusing. Hydrogen has a molecular weight of 1. A single mole of it weighs 1 gram. CH4 has a weight of 16 (12 for the carbon, 4 for each hydrogen). A mole of it weighs 16g. CO2 has a molecular weight of 44, and a mol of it is 44g. Done.

The amount of energy used to hold atoms together to make molecules is the bond energy. Chemical reactions happen, chemical compositions are changed. If the overall energy of bonds are lower after the change, heat has to be released. This creates fire.
Bond energies: C-C bonds (aromatic, the ring-type found in coal) have 519 KJ/mol. C-H is 410. H-O is 460. C=O (double bond) is 799. O=O are 494 KJ/mol.

We simplify coal as aromatic bond chains of 4(-CH-) (this is generous in terms of calculating CO2 produced per unit coal, as all my prior calculations have been) (I stole this clever approach from my advisor, Jim Anderson, to simplify things). CH4 is pretty easy as CH4.

We can write these as:


The molecular weight of our coal is 4*(12+1) or 52. Methane: 12*1+1*4 = 16

Coal: We break four C=C aromatic bonds (only four cause we would be double counting if we did each side of (-CH-), four C-H bonds, and 5 O=O bonds. We form 8 C=O and 4 H-O bonds.
Methane: 4 C-H bonds are broken, as well as 2 O=O bonds (the two O=O bonds are from converting the 4 H bonds into H2O). 2 C=O, and 4 H-O bonds are formed.

Coal: 

Methane: 

Math done!

The changing landscape of energy production based on cheap NG

Back in the day (pre-2010 or so) natural gas was much more expensive per unit heat than coal was. If you were going to burn something to produce electricity, coal was much cheaper and so produced cheaper electricity. The fact that it was pretty dirty didn’t matter as much. Then hydrofracking happened. Natural gas got cheap. Its price once roughly tracked with but below oil. Now it tracks with coal. This makes it a viable alternative to coal in power production. This fundamentally alters the primary energy landscape in the US. Once more data is available, we will revisit this.

Hydrocarbon Prices 86-12

Historic hydrocarbon prices per million BTU. Natural gas roughly tracked with oil, until hydrofracking made a glut in the market

Hydrocarbon Prices 07-12

Zooming in on the recent few years, the divergence of oil and gas and convergence of coal and gas becomes evident

 

Let’s discuss policy and environmental implications. They are pretty huge.

The math shows that in energy per unit CO2 produced, methane is about 60% more efficient than coal. This means that if we have to burn either methane or coal, and we seek to limit CO2 production, methane is the natural choice. Historically pricing prevented this from happening.

Natural gas is now only slightly more expensive per unit heat than coal. It makes sense to make electricity from natural gas, cause it produces far less pollution per unit heat. Since 2008, the US has reduced the amount of CO2 is produces for the first time in a long time. The reduction of CO2 produced by the US is partially based on this change in natural gas price. We now produce more electricity from methane than we used to. Since methane is more efficient at producing energy per unit CO2 produced, we produce less CO2 as a country.

Many staunch environmentalists argue this is a bad thing. Natural gas is still a hydrocarbon and still produces greenhouse gases. It kills far fewer people directly than coal does. The deaths that came as a result of coal might have pushed us towards a much greener economy. Methane is the lesser of two evils. It produces energy like coal. It produces CO2. It is still a finite resource. It is much better than coal.

Coal: The great of two evils between coal and methane. A picture of anthracite coal to break up the monotony of a text well. From Wikipedia.

Barring legislation to prevent hydrofracking, this trend of cheap NG will continue for a long time in the US. We have massive reserves of natural gas in our shale, and hydrofracking can get it out. This is not limited to the US, but there are only a few countries in the world that will be able to do this.

Before closing, we have one last thing. Many of you looked at the graphs of natural gas prices, saw that they were historically not much higher than coal for many years, and wondered why we didn't have natural gas electricity plants then. There are two answers. The first is that we did. It is why we have so many right now that can instantly go online. The second answer is that the EPA really only started getting strict on coal plants in 2004. The emissions from coal plants add many costs that go beyond the price of coal. Natural gas is pretty clean, so it doesn't face these costs, making it more competitive with coal.

Summary: Hydrofracking in the US has changed the natural gas price to be much lower and has made it a basic energy feedstock rather than a premium one. The US has natural gas power plant capacity, and has started shifting to electricity from natural gas. These power plants produce less harmful emissions as a result. CO2 emissions are reduced for the same amount of electricity. Harmful pollutants that cause heart attacks, asthma, and early death are also reduced. This is pretty huge.

Thanks for reading again, and sorry for the huge length

Jason Munster

* Will pointed out that I had Avogadro's # off by a factor of 10. Fixed