# Air Pollution - Types, Sources, and Fixes

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 wasÂ 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.Â 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,Â 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 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

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 clearÂ 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 plantÂ More important, these areÂ 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.

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.Â 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.Â 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,Â natural gas powerplants produce predominantly NO2. They burn CH4, and convert it to CO2 and H2O.Â NO2 emissions can easily be reduced by 90% with proper controls (discussed in the next post).Â 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.

## 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.

- Jason Munster

# Adele and Hello - Math and a Carbon Footprint Analysis

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.

$24 \frac{hr}{day} \cdot 60 \frac{min}{hr} \cdot 60 \frac{sec}{min} = 86,400 \frac{sec}{day}$

And over 20 days:

$86,400 \frac{sec}{day} \cdot 20 days = 1,728,000 seconds$

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:

$6 min \cdot 60 \frac{sec}{min} \cdot 178 \frac{views}{sec} = 64,000$

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,Â on just youtube,Â 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 tooÂ frequently may drive people into depression.

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

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)

$0.5 kg-CO_2 \cdot \frac{44}{12} = 1.85 \frac{kg-CO_2}{day}$ 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.

$1.85 \frac{kg-CO_2}{day} * \frac{1}{240} = .00771 \frac{kg-CO_2}{view}$

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

$0.00771 \frac{kg-CO_2}{view} \cdot 15,000,000 \frac{views}{day} = 115625 \frac{kg-CO_2}{day}$

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 Â ðŸ™‚

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?

- Jason Munster

# Tesla's Powerwall - Not Economical

Tesla Powerwall

I'm gonna open by saying that I really like Tesla's powerpack. Technology isn't pushed past the bleeding edge without loss-leaders pioneering. That being said, the numbers, as usual, don't lie. On a per-unit-energy cost basis, these things aren't economic in most of the US. Once you consider the externalities, however, the overall benefit does make them "profitable." Likely you will see subsidies to internalize these externalities, thus making the powerpack work.

Unless the inverter costs too much. More on that later.

One major implication I haven't seen anyone talk about? Utility companies currently have to pay people with solar panels who produce excess electricity at market rates. They've been trying to get rid of this for years.Â This technology gives utilities every reason to demand they no longer pay people for their excess produced solar power. This has enormous implications. It's now indefensible to force utilities to buy at market rates the extra power produced by homes with solar. Read more near the bottom.

Tesla's Powerwall next to a car. Small-ish and sleek. 7 inches deep, weighing 220 lbs

# What is this Powerwall?

Powerwall is a power pack that you hang on your wall. It costs $3,000 for a 7kwh pack designed for a daily cycle, meaning it's charged and used once per day. This is the cost without installation. Also, this is the cost if you already have solar cells and an inverter. If you want to work with the grid alone, you have to buy an inverter*. Even if you already have solar cells and don't need an inverter, this seems like it's a product designed for the wealthy. Let's look at the math (my favorite part!) *Inverters. Batteries and solar panels produce DC current, or Direct Current. This means it doesn't change phase. What we use in our homes is Alternating Current or AC. The alternating current means that the positive and negative terminals switch sides of the power plug. In the US, they switch sides 60 times per second. DC means that the terminals do not switch sides. Hence batteries having a + and - terminal, and all your non-battery electronics not having these. The Maths! We are going to make some of the rosiest assumptions in the world. First, though, let's get some solid data lines up. Take a peak at NPR's cost of electricity infos. 1. On average, people pay 12 cents per kwh of electricity 2. In Hawaii, they pay 33 cents. We'll use this as a case study. 3. The Northeast and California, two other case studies, pay about 16 cents. 4. The average American uses 900kwh of electricity per month in their home (from eia.gov). Really rosy assumptions 1.Â The sun shines for 300 days a year and provides enough electricity to power your house during shining and to fully charge the battery 2. The electricity grid doesn't buy back your excess solar*. If they do have to buy it back, then the economics discussed here don't play out 3. You've already paid for all of your solar installation and you aren't concerned about those costs of that electricity going into this powerpack 4. These things don't degrade over time (extremely rosy assumption) Hokay! 300 days per year of 7kwh of electricity provided by this beast is: $300 \frac{days}{yr} \cdot 7 \frac{kwh}{day} \cdot = 2100 \frac{kwh}{yr}$ So 2100 kwh/year. What's that get you in most of the US? $\ 0.12 \cdot 2100 = \ 252$ So$252 per year. For a $3000 battery pack. In most of the US, if your solar panels worked perfectly for 300 days a year, it'd take you 12 years to pay back your investment. This is a 6% annualized ROI (Return On Investment). In other words, you'd make more money in the stock market, so it's a bad investment, not even accounting for installation costs and with impractically rosy assumptions, in most of the US. What about in the Northeast and California, where electricity is$0.16?

$\ 0.16 \cdot 2100 =\ 336$

Or payback in 9 years. This is an 8% ROI, making it a decent investment.

Let's be realistic, though. In the Northeast, we have storms and winter. Solar panels don't work so great here. We aren't getting 300 cycles per year out of this. We'd be lucky to get 150, making it an 18 year payback, or about a 3% ROI. What about California? They actually might get 300 days of viable sun a year. So in California, you could be break-even.

Now what's the problem here? Normal people don't look for 8% ROI on their home upgrades. They look for 15%. Pretty much they want 3-5 year payback periods. So pretty much, someone has to have a very green outlook on life to buy one of these. Or there have to be subsidies (more later)

Hawaii

Hawaii has sunshine and electricity costs 33 cents. Let's say you've paid off your solar panels in Hawaii.

$\ 0.33.2 \cdot 2100 =\ 700$

In Hawaii, with our rosy assumptions and no installation cost, the powerpack will pay for itself in 4.25 years, for a whopping 18% return on investment, without any subsidies. There is a viable business model here.

Seriously, someone go start a powerpack/solar panel installation company in Hawaii.

Anywhere else, and these things will need hefty subsidies.

Subsidies

Why would you subsidize these things? Easy. There are only two reliable power sources that can compensate for variability in solar power: hydro and natural gas. Every other power plant takes far too long to spin up to be useful. In other words, nuclear power doesn't stop producing pretty much ever. Coal power takes about a day to get to capacity, so it can't cycle well.
Hydro power is a limited resource. We are pretty much tapped out in the US, and what we have is already being used, so it can't ramp. We'd have to replace what's currently being used with coal, natural gas, or nuclear to use hydro for solar-grid reliability, so that entirely defeats the point.
Natural gas ramps quickly, and we have excess capacity in the US. Natural gas still produces CO2 that spreads globally, and NO2 that spreads locally. NO2 becomes a strong acid when you breath it in, so we have healthcare reasons to reduce it. Thus it might make sense to subsidize these powerpacks to make people more likely to buy them.
Second, this is good tech. It's pretty much where it needs to be in order to make sense to buy in many parts of the country, if you already have solar. Subsidizing it will cause further advancement in battery tech, making it that much more viable in a wider array of applications. Battery tech is one of the things holding us back from so many viable technology applications, so if there is something to subsidize that will more than pay for itself, it is battery tech that is nearly cost-even now.
Some Extra Thoughts on my Rosy Assumptions
*If Solar Companies don't need to buy back Electricity
In most places, if you produce excess electricity that you don't use, the solar company has to buy it back at market rates. So buying this powerpack and storing energy for commercial purposes is useless. All of the economic discussion above is bunk if the grid needs to buy your excess power. In other words, only greenies would buy it.
One important thing to consider.Â This product makes storing electricity from solar into a break-even cost in any sunny part of the country. Utilities have always hated paying for this. They lose money on it. They've fought legal battles to get it repealed. And now they have the ammunition they need to repeal it, because it's now no longer a burden to consumers to store their excess electricity for later use themselves.
Maybe consider buying utility stocks if you find a company that is over-exposed to paying for home-solar-produced power? I'd tell you to look towards California here.
Inverter Costs
If you don't have solar already, you have to pay for the inverter to make this thing convert DC back to AC for your home. I can't see any reason to do this. The cost differential between peak power and non-peak is about 4-6 cents in most places. Far too little to justify the expense of both an inverter and a powerpack. A gas generator is a better bet if you need reliable power.
Large Scale Efficacy
I'm betting the large-scale systems are more cost-effective. They don't need to be as small and as sleek. And you can have one large inverter for all of the daisy-chained power packs. Who would buy these? Commercial electricity buyers, like stores.
Who wouldn't buy these? Industrial complexes. They make deals directly with electricity companies and pay $0.07 to$0.10 per kwh.
Â - Jason Munster

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 SundayÂ of every month. Today's post isÂ 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 RoadwaysÂ 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 roadsÂ 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 roadsÂ 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) TheyÂ 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.

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

$1 \cdot 120 \cdot 12 = 1440 in^3$

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 $cm^3$ of water = 1 gram. There are 2.54 cm per inch, so:

$1440 in^3 * (2.54 cm/in)^3 = 23600g$

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

$23600 g \cdot 334 \frac{J}{g} = 7,880,000 J$

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

$7.8 \frac{MJ}{ft} \cdot 5280 \frac{ft}{mile} = 41184MJ/mile$ 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.Â 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 theÂ 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,Â 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 themÂ 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 REEsÂ 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 energyÂ (my link, please read it for background if you feel a bit lost, it is far briefer than this post)Â 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 powerplantsÂ (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 thatÂ (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 ðŸ™‚ *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. # China's Water Shortage and Power Plants (their power plants definitely have a drinking problem) In the previous post, I described how thermal power plants use a massive amount of water. This time we are going to explore a specific case.Â As usual, it's China. Power plant water use can be a problem in a water-stricken area. Let's look at a case-study. China is a water-stricken area, and has a lot of thermal power plants. In fact, China uses more primary energy than any other country in the world. Unfortunately, their power plants are far less efficient than they should be. So they are wasting water, and this is unsustainable. Moreover, China has 1,350 million people. The US has 314 million. First, let's look at the rainfall of China, compared to the US: Rainfall in China, in inches Rainfall in the US, in Inches Looks pretty similar, right? Now recall that the US has 1/4 the population of China. And pretty much the exact same amount of area. Keep that in mind while we look at China's powerplant locations: China's water stressed areas, compared to where power plants are planned. Source, So. The places that have the most people and need the most power are the same as the dry places. In other words, China is building the bulk of its thermal power plants in the area that can't provide sufficient water to cool the power plants. Before coming to the complete picture, let's check out the water use: Fresh Water Use in the US. source In the US, 80% of water use is to grow food and to make electricity. Finally, where is all this water coming from? Rain alone isn't enough, it comes from the ground. Fresh water from the ground is not unlimited, and we are running out of it. It's called Fossil Water, and here is what the situation looks like in the US: Water withdrawals in the US In other words, a huge chunk of our country is relying on water that will not exist in a few decades. And looking at China: China's groundwater depletion rate In the US, the scale of groundwater depletion tops out around 400 cubic kilometers. In china, it tops out at 3,000 in regions. That's not to say that the US won't run out. It just says that China is in serious trouble. Again, 80% of water use is for electricity and agriculture. And China has 4x the people of the US. There is not sufficient water. Would you rather run out of electricity, or run out of food? It's not an easy choice, but food can be imported. That being said, someone has to grow the food, and that country better have a robust water supply. Moreover, food growth is a low income industry. A country that marries itself to being a food supplier, unless it charges gouging levels of prices, is marrying itself to never being a high-income country. But charging price-gouging levels is a bad idea. While this mental exercise was fun, let's look at some examples. First, while Californians probably shouldn't have been growing water-intensive almonds in a dessert in the first place, running out of water has imperilled the world supply of all sorts of nuts and things. They are tearing up their farms because of lack of water. That's only the start. Drought in Syria helped bring about war there. Syria is a tiny country that doesn't matter on the world scheme. India, China, and Pakistan face water shortages. Combined, they have 1/3 the world population. They also happen to hate each other. As climate change progresses, and some countries face droughts, people may not want to choose between food and electricity. They may try to divert water supplies, sparking tensions and even war. So. Does your power plant have a drinking problem? If you live in China, it definitely does, and it's causing all sorts of strife. Wrapping it all together: Yes, a country can import food. But you know how much of the world relies on the middle east for oil, and we talk about energy security? That's just stuff that makes your cars move. Remember how Russia threatens to shut off natural gas to Europe if they don't get in line with Russia's plans, and so much of Europe is cowed? That stuff keeps homes warm, but it isn't as important as food. Imagine a powerful country that is mostly reliant on other countries for food to stay alive. That's a really bad situation. The country in this situation has to either take dictations from whoever feeds them (not really a problem if you are getting your food from non-powerful nations, but still irksome), or has to take over a food-producing country. One potential solution: Chinese power plants are notoriously inefficient. If you have a 25% thermodynamically efficient powerplant, it uses 30% more water than a 37.5% efficient power plant. China should either shut down inefficient plants and require new construction that is efficient, or require retrofits of old plants. It would be very expensive, but less expensive than the social and political cost of running out of water too soon. What about the US? Most of our plants are pretty efficient already. Especially our Natural Gas plants that much of the country runs on. We probably spend too much water on watering desserts to make food, but that's another story. An almost-final note. While solar power and wind power use water in construction, their water use is minimal compared to that of thermal power plants. Barring solar-thermal (it's thermal, it uses water), these renewable resources are the only answer to the reducing the choice between electricity and food. In other words, expansion of wind power and solar PV is the only cheat code we have to deal with this impending water shortage. One last thing. Why did I single out China? Only because I know a lot about China. Pakistan will have water shortage issues, but they already don't have electricity. In the summer, they have blackouts for up to 20 hours a day cause they can't produce enough electricity. This is a country of 180 million people, bordering India, and sharing a strong mutual resentment with India. More on this later, though. Thanks for reading, - Jason Munster # Your Power Plant Might Have a Drinking Problem 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, sourceÂ 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.Â 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 Â 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 # The President's State of the Union Address. Geopolitics of Oil: Expanded US (and Russian) Oil Drilling and the Middle East's Bane. An oil rig in the Bakken. This represents a massive shift of primary energy resource production power in the world. pictureÂ source What do the price of oil, the president's state of the union address, and middle eastern stability have in common? In the address, the President talked about fighting climate change, but the US is going full-tilt towards more drilling. While this sounds like hypocrisy, it actually puts the US and the world in a better position to deal with climate change. Sounds crazy? Keep reading. Here's a hint though:Â What would happen if the price of oil dropped to$40 overnight? Much of the Middle East power structure would collapse.

The Science!Â  (skip this if you only care about what oil prices do for the Middle East)

Because this is a science blog, I am writing science stuffs here.

Hokay, the background. The world consumes around 90 million barrels of oil a day. How much of this does the US produce? Check out this graph:

Historic US oil production. Source is EIA

I want to point out three things. First, in the 70s and 80s the US was one of the world's most prolific oil producing countries. A lot of this came from huge Texas fields, like Eagle Ford. And then the gigantic basins like Eagle Ford ran out of easily accessible oil, and US oil production collapsed. Now look at the ramp rate of production in the most recent years. The rate of increase in production is unprecedented. It's going up fast.

Next, lets focus on Texas and North Dakota:

North Dakota and Texas Oil Production

Notice the massive rate of increase of production. From 2008 to 2012, Texas alone increased production so much that it provided an additional 2% of the world's oil. North Dakota is producing nearly 1 million barrels a day, or slightly more than 1% of the world oil. Together, they produce 3.75 million barrels per day, 4% of the world's oil.

Let's put this in perspective. Iran produces 4 million barrels a day. North Dakota and Texas alone produce nearly this much. Look at those growth rates. Are they showing any signs of slowing down? No. In other words, the US is rapidly becoming one of the world's most prolific producers of oil.

How'd this even happen? Hydrofracking and horizontal drilling. Earlier I said that Eagle Ford and such were played out. In reality, all the easy oil in it was pulled out. The remaining oil is like the Bakken: tight oil. Let me emphasize this:

Every single major play of the 70s and 80s is about to become a new Bakken.

That means going back to the days when the US was the largest oil producer in the world. That means Russia is also going to be able to ramp up production, once they figure out how to hydrofrack.

So the price of oil is going to drop in the future.

What This Means for Politics and the Middle East;

Expansion of drilling in the US and Russia will have two major effects. The first is that we will no longer rely on oil from the Middle East to supply the world markets. In this case, the world will care less about stability in the middle east. To the point where the world would just let the Middle East burn, just like we let happen in AfricaÂ today (except for Israel, I would guess)

This would mean less military spending, which would in turn mean more domestic investment (or lower taxes, but our ailing infrastructure and gutted R&D budget really could stand to be brought back up to where it was when the US rose to become the world's only superpower).

The second implication of this glut of oil is much more far-reaching. It means is lower oil prices worldwide. If oil drops below \$75 a barrel, even Saudi Arabia struggles. It'll be hard for the Middle East to make trouble when they cannot afford to. Now let's say hypothetically that Iran funds terrorist groups (I haven't researched this and don't know whether it is true, so it's a hypothetical). If the price of oil drops to the point where they can no longer profitably produce, then suddenly our hypothetical country cannot fund terrorism. And we save moneys from no longer needing as much anti-terrorism programming.

In other words, we save money because we won't be sending military to the middle east, and because terrorism will potentially be more poorly funded. Â

Let's sum up: produce more oil, the price of oil drops, countries and companies make less money from oil (mostly countries, companies have a way of maximizing profits pretty well), since countries have less money, they can't push their state agendas as much.

Wrapping This Up

So, pretty much, drill more in the US (where we can regulate emissions), save a ton of American (and European) money by no longer having to make sure there is peace around oil resources, use that money to fix all the problems we've created with the environment. In other words, more drilling is a potential long-term solution because it will eventually free up more funds in the federal budget.

It's my guess that the president can't say, "We need to drill in the US to make it so we don't have to spend money stabilizing the Middle East. Once that is no longer a problem, we can use the extra money to address climate change."

Some criticisms: If the decrease in the price of oil results in more oil consumption, this would be bad for the environment. We need to continuously improve efficiency of vehicles and industry, and decrease our demand for oil and fossil fuels. Any money saved from military intervention happening less should be driven towards this goal.

That's all for now! Thanks for reading.

- Jason Munster