Sunspots, Climate Change, and Solar Hibernation

So. Today's topic is sunspots. Specifically, the upcoming solar hibernation and how sunspots relate to climate change.

Synopsis: Sunspots, solar hibernation, and such have a negligible impact on climate change in the long term, and cannot explain the warming we have seen over the Earth. Regular readers of my blog know that I don't shy away from the truth, such as the time that I wrote about how eating cow produces a lot of greenhouse gases (I am a 210 lbs. rugby player, and lean at that, eating meat is necessary for me to maintain my muscle mass, so I obviously want to keep eating it, but I also have to admit that beef has a deleterious effect on the environment). The primary driver of climate change is not short-term or medium-term solar output changes (defined as years to 100s of years scales), but is instead us.

First, what is a sunspot?

Sunspots.

The Science (as always, skip this section if you don't like science)

Hokay, so. Sunspots are places where the magnetic field of the sun strengthens locally. As a result, convection is inhibited. How, exactly? This is a subject for debate, but hydrogen interacts with magnetic fields, and the sun is comprised almost entirely of hydrogen. If you have trouble with the idea that hydrogen interacts with magnetic fields, just think to how an MRI works. The strong magnetic field in an MRI excites hydrogen atoms. Hydrogen atoms are present in water. If your body is injured, be it a bone or other tissue, or you have had a stroke and are bleeding out somewhere, there will be more hydrogen present in an area. The MRI images this extra water, and highlights where damage is. So, now we know that hydrogen interacts with magnetic fields, and something we use all the time makes use of this principle.

Yes, one of these big scary things.

So, we have super strong magnetic fields in small spots on the sun, a sun made of hydrogen, and hydrogen interacting with magnetic fields. The next step is how the sun works. It is made of hydrogen. The mass of the sun is so great that the hydrogen atoms are pushed close enough so that they merge. This is nuclear fusion, cause the nuclei are fusing to create helium. A ton of energy is released in this process.

Let's take a closer look at this idea of the atoms being pushed so closely together, because it is a pretty fundamental part of how the universe works, and your middle/high school teachers taught you lies here. We have all learned that gases are compressible, hence being able to inflate your tire, and that liquids and solids are incompressible, hence you not being able to squish them, and also the incompressibility of fluids making hydraulics work.

So this is wrong. You need immense pressures to compress a solid or a liquid, but it is possible. This is based on how atoms combine together. Atoms living in the same place like to keep their distance, because the electrons floating around the outside of the atoms push each other away. If you have enough stuff stacked on top of these atoms, say about 90% of the mass of the solar system, like we see in the sun, the mass of the stuff stacked on top of the atoms wins out over the electrons trying to keep them apart. The density of anything, including liquids and solids, can thus increase. Right up to the point where the nuclei of the atom are shoved together so closely that they bond, and then the atoms fuse to change the type of element they are. This releases a ton of energy.

nuclear- sidetracked

So, nuclear fission, the splitting of atoms, releases energy, and nuclear fusion, the combinations of atoms, releases energy. What gives? Iron is the magic element. at 26 protons (that is how many iron has), you get no extra energy from fusion or fission. So pretty much, fusion releases energy up until the atoms have fused to make iron, and fission would do the same.

Back on track with the sun

So. The nuclear fusion happens in the place of most pressure in the sun. Which is at the bottom, nearer the core. So the core of the sun is much much warmer than the outermost layer of the sun. Convection, or updrafts, from the core to the outermost layer of the sun is what heats the outermost layer.

Remember those magnetic fields that locally get very strong? They stop convection in the places where they are strongest. So the temperature at sunspots is 2000 degrees C or so less warm on sunspots.

How this relates to climate

Times of high sunspot activity are associated with a very very small decrease in average surface temperature, which means slightly less energy, and also slightly more ultraviolet radiation from the sun, which means slightly more energy. Overall, it's a difference of at most 0.04%. But remember, this is raised to the 4th power, so we have:

 or a 0.16% change in total energy output of the sun. And remember, this is at max. See this article.

In other words, it doesn't do anything. In fact, the article I just referenced indicates that there were probably other factors at play.

Sunspots are pretty in false color.

Let's get down to some real numbers. The total measured change in surface forcing of the sun during a complete solar cycle, max to min, is about 1.3 watts/m^2. According to the best measurements that science can offer, the total forcing of man-made greenhouse gases is 2.3 watts/m^2 (see section C). While sunspot cycles do move significantly, they go up and down around an average. Man-made greenhouse gas forcing is only going up. And we've dumped enough stuff in the atmosphere so that man-made forcing has dwarfed solar cycles.

Many climate skeptics have argued that sunspots account for changes in the Earth's climate. While the increase in UV radiation can have an effect on the formation of ozone in the stratosphere, the difference in radiative forcing is too small from this to matter.

Unfortunately, several of the links posted in my feedback section are from crank organizations that literally make up data or go and find "scientists" to quote (read: scientists that don't understand science, whose theories don't match observations [note: when someone's theories don't match observations, they are literally lying out of stupidity]). In short, these organizations intentionally seek to obfuscate the science of climate change by confusing the general public about which scientists are authorities, and which are crackpots.

And this is pretty much how this always goes with climate change skepticism. Next week, I will talk about a recent article that shows that over $1 billion is spent annually to intentionally confuse the science of climate change. Not to disprove climate change, mind you, but to intentionally screw with voters. It's exciting. This has nothing to do with crackpots, I just wanted to post another with sunspots from NASA cause these are cool pictures. Thanks for reading! If you are a skeptic and have more questions, or you are not a skeptic and have more questions, leave them in the comments. - Jason Munster Apartment Rentals and Energy Waste 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 #).

Why Giant Houses Always Use More Energy

Big houses use more energy to heat and cool, for reasons you might not suspect. Houses lose heat to the outside. Nearly all houses are drafty in some form or another, and they need to be somewhat drafty, as we will soon find out.

When energy prices skyrocketed in the 70s due to price gouging and market manipulation of oil (thanks, OPEC), there was a big movement to make it so houses didn't leak air (and leak their heat energy in the process). The idea is that for every bit of air you heat and then let out into the environment, you have just wasted energy. So the process of sealing houses began.

OPEC oil embargoes of '73 and '79. The prices of energy spiked worldwide.

Some groups bragged that they could build houses that only exchanged 1% of their air per hour with the outside. In other words, it would take 4 full days to lose all the heat or AC energy of a house to the outdoors. Excellent, right?

It was excellent in terms of energy savings. But anyone with a flatulent spouse/significant other can tell you that being stuck in a place that is producing unhealthy fumes is dangerous if you don't vent it. It turns out that a lot of basic human activity, like cooking and heating, produce things that are bad for humans and need to be vented.

Much more importantly for advanced cultures*, cooking (it boils water, yo) and breathing and sweating make the air inside a house humid. Humidity in a house causes mold that can make you ill or, in extreme cases, kill you. One of the most effective ways to remove all this humidity is to let the air exchange with the outside.

So here we have a problem. We need to seal our houses well in order to save energy on heating and cooling, yet we also need to allow loss of all this heated and cooled air so we don't sweat ourselves out and cause bad mold to grow.

And we arrive to the crux of the matter. A good exchange rate is .6, or that 60% of a houses air is exchanges per hour. Sounds like a lot? It kind of is. But it's what is healthy for normal technology (we aren't all going to install CO and CO2 scrubbers and dehumidifiers in our houses). So in 24 hours, we have

 hours  exchanges per day. Of your entire house volume.

So. You have to exchange air in your house. About 15 times per day. Otherwise you might start falling ill. If you have a gigantic house that is 2x larger than you need, then you will use 2x as much energy to keep the place heated and cooled as you need to. So, in short, living in a giant house is a bad thing for energy conservation (take notice, Al Gore**)

Next week we will suspend our assumption that all houses have decent exchange rates, and discuss why this is a huuuuge policy gap.

You don't really need to live in a place like this, do you?

- Jason Munster

*Developing countries still use coal. By 2020 there will be up to an estimated 400,000 deaths per year in China from indoor air pollution associated with burning coal for heat and cooking in poor rural homes (160,000 median estimate). Obviously this is more pressing than mold.

**I was going to rip Al Gore a new one for having had a huge electricity bill just after making An Inconvenient Truth, but it turns out that in 2007, before it was cheaper or easier, he elected to power his home, in TN, with solar and wind power almost exclusively, jacking up the price to a level higher than most Americans pay. So yeah, he did have a much higher electricity bill than the average American, but he only used about 4x the electricity, apparently. Which is still a lot. Except that he and Tipper both also work out of their houses. And now they have solar panels all over it. So it's not that bad. Though it is still huge.

Is Nuclear Power Really the Most Expensive Technology?

No. It isn't.

Let's explore this more. In a country that already has a well-developed electrical grid / electricity distribution system (sorry, much of Africa), doesn't have ideas based on fear about how dangerous nuclear power is (European and North American countries, +Japan), and doesn't have a terrorism issue (proliferation), nuclear power is the cheapest and least polluting type.

Okay, so where can we find a country that meets this description? How bout Croatia, where some scientists did some probabilistic modeling on this?

From the results of the simulations it can be concluded that the distribution of levelized bus bar costs for the combined cycle gas plant is in the range 4.5–8 US cents/kWh, with a most probable value of about 5.8 US cents/kWh; for coal-fired plants the corresponding values are 4.5–6.3 US cents/kWh and 5.2 US cents/kWh and for the nuclear power plant the corresponding values are in the range 4.2–5.8 US cents/kWh and a most probable value of about 4.8 US cents/kWh.

Let me sum this up. In Croatia, nuclear power is likely going to be the cheapest source. Plus is doesn't pollute and kill people like gas or coal.

Why do we face a different situation in the US and Europe? Easy. I've mentioned it before. There is so much concern about the safety of nuclear power that each construction gets mired in legal battles. The legal battles themselves don't cost much. What costs a ton is that these power plants took out $8 billion in loans, meant to be paid back over 10 years. Those loans accrue interest. If legal hurtles slow the construction of the plant down and it takes 15 years instead, those extra 5 years of loans are gonna have several extra billions in interest to pay. Suddenly the cost of power produced goes up. These costs need to be paid back. The only way to pay back higher than anticipated costs would be to charge more for nuclear power. So it's safe to say that stalling the construction of a nuclear power plant can effectively prevent it from ever getting built. Now we are in a situation where no one wants to fund a power plant, because the chance of it being slowed and made unprofitable is a bit higher. Sometimes there are just plain time overruns. The US hasn't build nuclear power plants in years. Our companies barely know how to do it. Our people haven't been trained in colleges and universities to build nuclear power plants. We just don't have the nuclear engineers we would need to make a nuclear renaissance happen, and we'd need several nuclear power plants built before we finally get the hang of it. So there will be a learning curve. Would you want to fund that learning curve? Probably not when natural gas is so cheap in the US. Are we gonna get there any time soon? Not without a major policy shift. Let's look at planned nuclear power plants worldwide: Planned nuclear power plants. Image mine, constructed from data available here So um... Good job, China. US? Not so much. 32 of the 72 nuclear power plants scheduled to come on-line in the next 5 years are in China. 4 are in the US. Nuclear power will be more expensive than gas (and coal) power in the US unless 3 things happen: 1. We account for the annual loss of life and increase in asthma and heart disease associated with gas power plants. 2. We start building nuclear power plants now, training a cadre of engineers and speciality construction personnel to finish power plants quickly, safely, properly, and on time (the first few will be finished slowly, behind schedule, but still safe and properly complete, cause lots of eyes will be on them) 3. We continue to build enough of them so that the future ones are build on time and for less expense, driving down the cost of nuclear power to competitive levels (especially when accounting for the external costs of pollution and CO2 from gas and coal). Thanks for reading! - Jason Munster Nuclear Power: Savings lives Nuclear power has saved over 1.8 million lives by replacing fossil fuel power sources. A nuclear power plant! I've mentioned that fossil fuel power plants kill people and shorten lives by emitting not only particulate matter and smog normally associated with pollution, but also NOx (natural gas power plants produce almost no particulate matter, but any time anything is combusted, the combustion process in a nitrogen rich atmosphere (78% on Earth) produces NOx, so natural gas power plants do produce NOx). Coal fired power plants, even clean ones, belch yuckies into the air. Shortly after harping on exactly this for several posts, a journal article came out that exonerated my aggressive stance on how nuclear power saves lives rather than ending them through nuclear disasters. Nuclear power has saved over 1.8 million lives, according to this peer-reviewed research. The authors didn't include long-term health ailments and non-death causing heart attacks related to climate change. Only death: full stop. They go on to say that replacing nuclear power with natural gas would cause 400,000 deaths by 2050. Replacing them with coal would cause 7 million. Meanwhile, the best estimates of long-term deaths caused by radiation exposure from the Chernobyl meltdown, mining uranium, and building nuclear power plants stands at about 5,000 No deaths arose from Three Mile Island or Fukushima. What about the radiation that Fukushima is spilling out into the ocean? It's less than 1/20th the radiation levels found in a banana. I am a banana. Eating one of me makes you ingest more radiation than Fukushima ever will. Critics are quick to point out that renewables like wind are cheaper and more effective at reducing CO2 emissions than nuclear. Great. Let's build more wind power. Except that there are not sufficiently good places to make wind effectively and cheaply. In an exhaustive (and depressing) article on the state of nuclear energy construction, it is pointed out that Germany has an installed capacity (recall, installed capacity is simply the name-plate power generation of a plant/turbine at best-case scenario) of 76GW of renewable energy. They then compared this to all of France's installed capacity of Nuclear at 63.1 GW. But, as we have talked about, renewables don't always work. While France's nuclear generators put out 407 TWh in 2012, Germany's renewables generated 136 TWh despite their larger capacity. "Except like Jason's former manager at JPMorgan, I only work under ideal conditions!" Moreover, Germany pledged to phase out nuclear power after Fukushima. What did they replace it with? Not renewables. Coal fired power plants. Meanwhile, as the US expands power generation from natural gas and ceased buying coal from the US, US coal producers are finding a new market for coal in Germany. So let's look at Fukushima a bit more. Several things are bad about fukushima. First, it melted down when a tsunami overtopped its protective walls. The US Nuclear Regulatory Commission (NRC) had told Japan 20 years ago that their Fukushima walls were too low and they could be overtopped by a very realistic earthquake scenario. And now after the disaster, groundwater contamination with (less than 1/20th of a banana's levels) radiation is all a concern. Guess what? The NRC warned Fukushima to get their groundwater issue under control three years before the Fukushima meltdown. That's right. The US NRC predicted that Fukushima was going to happen, and told Japan to get their house in order. NRC: Telling Japan what to do since 1980. "We don't have much of a job to do in the US anymore since we haven't built a power plant in decades" The US has a nuclear meltdown, too. You know what the consequences were? Pretty much nothing. It cost a billion dollar to clean up. That is a huge sum. But the meltdown was well-handled. And a lot was learned from the meltdown. My point is, the US has it's matters sorted out when it comes to nuclear safety. And we are good at identifying risks in other parts of the world. Finally, here's the big one, new reactor designs wouldn't allow for either three mile island or Fukushima to happen. With these new reactors, in the event of mechanical failure of the passive systems, the worst case scenario of the new designs is that it would take 3 full days before even needing to worry about meltdown beginning, leaving plenty of time to deal with the situation. So yes. There are risks with nuclear. But there are guaranteed deaths with coal and natural gas. The best solution by far is avoiding building new power plants and to massively increase efficiency and conservation. But people are slow at changing, and we aren't gonna change our lifestyles fast enough in the western world to avoid expansion of power use, and the developing world needs to build a ton of power capacity. So let's stop being scared of nuclear power, cause it's saving lives rather than costing them. Thanks for reading, - Jason Munster Appendix Oh, but what is this section? Just a bunch of extra information. Check out how long it takes for various countries to build nuclear reactors: Average, min, and max times of nuclear plant construction for countries that have built them. Source Hokay, so. I need to acknowledge the bad parts of nuclear power. The real ones, not the fear-mongering that happens. First, nuclear power is more expensive than on-shore wind (which is a limited resource, there are not infinite good places to put wind farms), coal, and natural gas. There is no doubt about that. If we switched everything to nuclear, many parts of the US that don't have high electricity prices will experience a rate shock. That is, their electricity bills will rise. But hey, remember what we said earlier about efficiency and conservation being the best way to save lives and to arrest climate change? Slightly higher electricity prices would promote this conservation. The initial rate shock would be a bit of an issue, but I am betting that nuclear power's opponents overstate it. Second, there is an alternative to nuclear that I want to acknowledge, with a caveat. Renewables can't provide baseload power. But renewables paired with load-following natural-gas fired plants can (recall from a prior article that gas turbine based power plants can spin up very fast, and no other major power plant type can) (we don't count hydro as a major power type because we can't build more hydro in the US, we are tapped [punny]). This is by far better than coal, and better than gas alone. But it still burns gas, which produces CO2 and kills people and causes asthma. Solving the Climate Problem I started this site to get practice in writing science for the general populace. I've slacked off because I am a bit bored of reaching for topics. More importantly, I've been playing rugby with HBSRFC. So here it is. A generalized and very incomplete version of my view on climate change, who it will affect most, and what we can do about it. CO2, The Ugly One That Won't Leave You Alone CO2 stays in the environment for more than 40,000 years. That is longer than nuclear waste lasts. Moreover, its effects are experiences by every person on the planet. What we do now has an effect on the entire planet. Luckily, technology will probably be able to fix this eventually. We can't count on this now, though. Energy and Climate Change, How They Relate Climate change is caused by emissions of CO2 by energy use, methane by agriculture and other things, and a host of other very powerful chemicals that are emitted from industry. How do we solve climate change? The answer is straightforward, but far from simple: use much less energy from sources that produce CO2. Either switch to "green" tech, or conserve. Buy less things that require all the energy to produce. Travel less, or travel in ways that produce less greenhouse gases. Make fewer babies. None of these are easily accomplished, unless you are poor and can't afford any of them. Even then, everyone is striving for a wealthier, more CO2-heavy lifestyle. So let's assume for a second that people aren't going to change their lifestyles and conserve. We need ways to get energy without belching CO2 everywhere. Live in Smaller Houses, Buy Less Stuff You can't convince Americans to live in houses that are the size that Europeans live in and you can't convince them to give up their cars to take public transportation and live in cities (at least in the short term). Houses require energy to heat and cool. Smaller houses mean fewer drafts, leading to less heating and cooling needs. How about green energy? We have reviewed those technologies. There isn't enough wind to provide sufficient wind power, and the wind isn't always blowing, so sometimes we won't have power when we want it. Hydro power is pretty much fully tapped. Tidal power is a joke in the big scheme. Solar could be an option, but it is currently far too expensive. It is not "deployable" in that with solar, you only get what the sun decides, so we will always need some backup power that can be turned on when we want. Solar doesn't work well at night, for instance. Moreover, the best places for solar are far from cities, so figuring out how to get the electricity from the countryside to the cities is a monumental task, especially in the US (even with eminent domain, getting the land to be the transmission lines through several states would be nearly impossible). So here we stand with three good reasons that solar won't solve our problem in the near future, and with the other resources insufficient. Pretty much, even if we do use solar to solve a lot of our problems, we still need some other energy source to provide baseline power. Too small! Turn back! What about buying less stuff? The amount of CO2 that goes into making cars, laptops, etc., is pretty big. How much stuff do you buy that you never use afterwards? Or you maybe use once a year or two? All of that, you could have rented, saved money, and saved space. Even better? The things that go into making electronics like cellphones are not easy to pull out of the ground. Tantalum in your cell phone is pretty much produced by indentured servitude in Africa. The other stuff that goes into electronics, the rare earth metals, these are not so rare. It just turns out that it is difficult to produce it without destroying the environment. The US has plenty of rare earth's the reason it is done in China is that they don't mind wrecking the environment and their workers (see bottom of that post). Yeah, we need electronics to communicate and keep things moving. We don't need a new iphone every 6 months. Those things last at least 2 years. Energy for Transportation This is a much larger hurtle. 35% of US energy consumption is in transportation. Transportation requires that the energy source be within the vehicle (unless you are in South Korea, where the energy source is induction and is beneath the road. Pretty badass, if you ask me). Batteries currently weigh a lot, don't have nearly as much energy per pound as gasoline, and require a long time to charge. The problem is not as bleak as it seems, however. Most driving in the US could easily be done with all-electric cars. Your bus is ugly, but it charges while driving without producing its own CO2. Well done, South Korea. Cars I've also written about Electric Cars. This is an area with a lot of potential. 120 million Americans commute to work by car. The average person lives fewer than 20 miles from work. Substantially all of them commute alone. The Nissan Leaf gets 75 miles before it needs to be recharged. The Tesla model S goes about 275 miles. No matter what the source of energy for an electric car, it produces less CO2 than a normal car. Going by the numbers available on these cars, we see that with the standard US energy mix (some renewables, lots of nuclear, a whole lot of natural gas), they produce between 33% and 50% the CO2 as a combustion engine. Bicycles I've written about bicycling. It's good for you, and saves the environment. Unless you eat only beef. Then you have other problems. Power Generation: What Works Wind power makes sense everywhere that there is a lot of wind, as long as it is onshore. Wind is pretty much going up everywhere that makes sense. It costs less than a new coal power plant, and is far cleaner. Solar power is expensive. Is there anywhere it works well? Sure, just take a look at the electricity rates paid by different types of consumers. Commercial real-estate (stores, offices) and residential places (our homes) pay a huge premium on electricity. In most states, residents and commercial consumers pay nearly 15 cents per kwh, while industrial consumers pay closer to 7 center for a kwh. How does this stack up to costs to produce? Let's return to my favorite chart: Table 1. Estimated levelized cost of new generation resources, 2018 U.S. average levelized costs (2011$/megawatthour) for plants entering service in 2018
Plant type Capacity factor (%) Levelized capital cost Fixed O&M Variable O&M (including fuel) Transmission investment Total system levelized cost
Dispatchable Technologies
Conventional Coal 85 65.7 4.1 29.2 1.2 100.1
Advanced Coal 85 84.4 6.8 30.7 1.2 123.0
Advanced Coal with CCS 85 88.4 8.8 37.2 1.2 135.5
Natural Gas-fired
Conventional Combined Cycle 87 15.8 1.7 48.4 1.2 67.1
Advanced Combined Cycle 87 17.4 2.0 45.0 1.2 65.6
Advanced CC with CCS 87 34.0 4.1 54.1 1.2 93.4
Conventional Combustion Turbine 30 44.2 2.7 80.0 3.4 130.3
Advanced Combustion Turbine 30 30.4 2.6 68.2 3.4 104.6
Advanced Nuclear 90 83.4 11.6 12.3 1.1 108.4
Geothermal 92 76.2 12.0 0.0 1.4 89.6
Biomass 83 53.2 14.3 42.3 1.2 111.0
Non-Dispatchable Technologies
Wind 34 70.3 13.1 0.0 3.2 86.6
Wind-Offshore 37 193.4 22.4 0.0 5.7 221.5
Solar PV1 25 130.4 9.9 0.0 4.0 144.3
Solar Thermal 20 214.2 41.4 0.0 5.9 261.5
Hydro2 52 78.1 4.1 6.1 2.0 90.3

Solar PV costs less in sunny areas than buying from the grid, as long as you are residential or commercial. A big industrial complex gets really cheap power, so they will never use something as expensive as PV.

The Future of Solar

Even if solar power is widely deployed in the future, it doesn't work at night. A lot of people in Houston, and other places that are unlivable without modern tech, would be unhappy if they couldn't sleep in AC. We don't have massive-scale battery tech  to compensate, so we will still need baseload.

There are two viable places to get baseload power. The first is nuclear power. The second is burning fossil fuels and then catching their CO2 and putting it underground.

Carbon Capture and Storage

This is a very unproven technology. We don't know if we can hold the CO2 underground forever (which is what would be necessary) or whether we can find a place for it. And there are only a few test cases for it. The numbers above are completely unreliable in terms of cost. This might be better in the future, but I would guess that it isn't viable for at least 15 years.

Another issue? You can't just start capturing CO2 emissions from any old power plant. Retrofitting the plant is expensive or impossible. Power plants are built to last 50 years. Even when we figure out carbon capture and storage, we can't easily retrofit old plants to make them work well.

So we need baseload. There are no green baseload sources. Making coal based powerplants green is not currently viable. Nuclear power doesn't produce much CO2, but it has nuclear waste. Nuclear waste lasts a long time. But it is the only power source that contains all its waste. It's manageable. And it decays faster than the Earth will take down CO2.

nuclear power plants are my favorite

What's the biggest problem with nuclear? I'll describe this in more detail later. The long version: it can't get financed. Short version: people are afraid of Nuclear. Cause three powerplants have blown up. Fukushima was completely preventable. The US literally told Japan twice to get their house in order, cause there was trouble.The USGS warned that the walls of Fukushima were not high enough to prevent tsunami flooding years ago. Had they followed through with the USGS recommendations, Japan would not be spewing radioactive waste into their groundwater. Moreover, the US Nuclear Regulatory Commission told Fukushima and Japan that they had a groundwater problem, and that a breach would cause widespread contamination; that if it ever melted down, it would dump nuclear waste into the ground through the water. They indicated Japan should divert the flow of the groundwater to prevent this. Still, no one died in this meltdown.

When Russia melted down a nuclear plant, it was a big mess.

When the US melted down a nuclear plant, no one was harmed and not much was released. It was just expensive to clean it.

Short version? The US is good at nuclear. Korea seems to be good at it. People shouldn't be afraid of it.

But they are. So the plants don't get financed, they don't get built, they aren't allowed to go forward.

As a result, if someone did want to finance them in the US, they would have to pay such massive interest rates that it would never pull a profit.

You know who is building them? Korea. China. Korea is also building power plants in the middle east. Other countries will follow suit. We need to get our house sorted out so our country can build power plants here and elsewhere, too.

Summing it Up

Live in smaller houses, it won't make you less happy. Buy less stuff, it also won't make you less happy. You also don't need to drive an SUV. Or drive as much as you do. Commuting sucks anyways.

Until all that happens, we still need a ton of electricity. Nuclear is probably the best way to do it for now.

That's my rant

Seriously. I'm pretty much done.

- Jason Munster

Urban vs Suburban

When I say suburbia vs. urban in this article, I am referring to people who live in the suburbs and work in the city. If you live in the suburbs and live a mile from your work, you are halfway to not being a part of the problem. The other half is not living in an oversized house.

traffic!

If you are living in a suburb and commuting to the city, you probably are being both financially stupid and a bit of a jerk to the environment. Moreover, you are probably short-changing your kids on family time. Most of this article can be read as "Don't live far away from your place of work."

Since most of my readers don't yet have kids or homes, read on to find out why you shouldn't ever leave the city.

The Financial Cost of Commuting from Suburbia (or Rural)

If your wage is $50,000 a year, living in suburbia costs up to an extra$15,700 extra over 10 years in driving time/expenses per mile you live from work. In other words, if you choose to live 10 miles closer to work, you could afford a house that is $150k more expensive. Moreover, the average suburbanite produces about 40% more emissions than a person living in a part of a city with access to public transportation. Read the real maths from the original post by MrMoneyMustache. "But Jason," you lament, "Surely you recognize that if you live in the city, you need to take public transportation, and that also costs time." To which I have to say two things: 1. No I don't. I ride my bicycle everywhere. I'm getting fit and sexy while getting around the city. 2. The only time I don't bicycle is when I have a massive amount of work to do. Then I take the subway and use my commute time to catch up on work. And the entire time I am wishing I was getting exercise on my bike. "But Jason," you say, "I live in the suburbs and I bicycle to work in the city." To you, sir, I say, "You are badass and a shining example of someone who cares about their fitness and the health of their fellow man. But if your house in the suburbs is huge, you probably still use more energy than the average city resident." urban cycling can be safe if you learn how "But Jason," you say, "bicycling is dangerous! It will shorten my life or cause injury!" Three things. 1. Take a bike safety class and wear a helmet. I am what is known as "reckless" and have yet to be in a maiming bicycle accident. It's safer than you think. 2. If you live in a city, you live just a few miles from work and will bike 1/10th the amount a commuter will drive. Based on the fact that per mile, a bicycle is 4x-10x as dangerous as being in a car, at worst your safety is break-even on a bicycle commute, and at best is 2.5x safer. 3. As MrMoneyMustache points out, bicycling makes you healthier to the point that even when accounting for the chance of dying younger from an accident, bicycling increases your life expectancy. Whereas being in a car only decreases your life expectancy while making you fatter and uglier. One last thing on bikes: In a prior post, I mentioned that if you are in shape, biking is the fastest way to get around in a city. You will save time if you live in a city and bicycle. Suburbia Home Energy Use In his paper on construction trends and CO2 per capita, Edward Glaeser shows that some cities have massively higher CO2 emissions per capita than others. This is primarily because in some cities, people live in houses and apartments that are far bigger than their needs. These houses have heating and cooling needs. Bigger houses not only have more volume to heat and cool, they also have more places they leak from. So they take a lot more energy to cool. This is why people who live in shoebox sized apartments in NYC emit only the equivalent of only 8 tons of CO2 per year in their lifestyle, and Houston residents emit 30. Also cause AC is very energy intensive. That's for a future post though. The Health Cost of Commuting from Suburbia Sitting on the highway in slow-moving traffic and breathing in exhaust fumes is not good for you. MIT says that 53,000 people die per year from the emissions of autos. So maybe stop sitting in traffic and breathing all that in, eh? Many people get stressed and upset sitting in traffic. This is obviously not good for you. I Don't Care About This, I Moved Out to Suburbs So My Family Would Have a Better Life Well aren't you the martyr? Sacrificing your time, health, and happiness for your kids. Very kind of you. That 1-2 hour commute you are doing would take 30 minutes if you lived close to work. Spending an extra 1 or 2 hours with your kid every day will be much better for them than putting them in a supposedly better school. Unless, that is, you are convinced that you are a truly shitty parent and that you damage them every time you interact with them. Summing It Up Living near the place you work and biking or public commuting there will save you time, money, promote your health, remove a need for auto repair. Most importantly, it'll give you more time with your kids. That'll mean more than a marginally better school system or a yard for them to play alone in. Thanks for reading! - Jason Munster My Research - Climate Change and the Arctic I am in Deadhorse, AK. It is as lovely as it sounds. The area of Prudhoe Bay is here because there is oil on the North Slope. Everything looks like a huge, permanent construction site with the sole goal of pulling oil out of the ground. But that isn't why I am here. Before that, some housekeeping. I have been awful at keeping up with my posting. While I am finding it difficult to write interesting posts on the same topic iteratively, the more pressing reason for my consistent delays is this trip to the Arctic Circle for all of August to do research. My team has been working their asses off in Cambridge and in Manassas, VA, to get our instrument and our plane ready. You are going to see a lot of posts about how things are going up here. Soon, my random rantings and musings will take over this blog, and the energy topics will be fewer and far between. Back to Prudhoe Bay. My research. Prudhoe Bay and the Melting Arctic I stand now in eternal sunshine. That isn't some deep metaphor. The sun doesn't go down during the summer when we are this far north. I am here to measure CO2 and methane emissions from the melting Arctic. This has nothing to do with sunlight, and has everything to do with global warming. The Arctic is Melting Ice volume in the Arctic is dropping. I have covered this in a prior post. We also mentioned that the Arctic will experience more amplification of heating than most other parts of the world. The direct response of the Arctic is to melt deeper every year into the permafrost that underlies the topsoil, where all the remnant CO2 from millenia of photosynthesis is kept. How did Millenia of Carbon get Stored in Arctic Soil? Let's start by thinking about a tree. Trees grow leaves. The leaves store CO2. They pull it out of the atmosphere and store it as mass in the leaves. In the fall the leaves fall from the trees. Bacteria consume the leaves, turning it back into CO2 (or maybe a rabbit eats the leaf and turns it into CO2). What happens when the leaf falls but doesn't get eaten? Most of the time it gets buried by snow or a bit of dirt and that CO2 is out of the atmosphere til Spring, when it warms up and the bacteria/rabbits get active again. (This paragraph is skippable. Let's replace "leaves" here with all types of organic matter. Sometimes those "leaves" end up in anoxic environments, like the bottom of marshes, and there is nothing that can efficiently eat them. Or they get buried really deep really quickly by something, and get stores for a long long time. Then that CO2 is permanently removed from the atmosphere. Unless epochs later we dig it up and burn it as fossil fuel). In the Arctic Circle, there are no trees. At some depth, maybe about 6 feet, the ground is permanently frozen. So tree roots can't go here. Moss and leaves grow here. But it is too cold for it to all get digested and eaten. Some of it pretty much sticks around forever. There are 300,000 years of undigested carbon in the first few meters of soil. Now it is warming up, and they that carbon might be ready to go. Thermokarsting. IE giant chucks of Earth falling and collapsing. Hastening this is a process called thermokarsting. In short, the ice in the soil (sometimes as much as 75% of the mass of the soil) melts. This ice held the soil together. Without it, the soil starts folding and collapsing, much like a riverbank does during a flood. Except it happens constantly in the warm days. This churning exposes tons of soil to the atmosphere. And this soil has carbon in it that can be eaten and turned into CO2 (This is a gross oversimplication, but the real details will only interest a few readers. Email me if you actually want more detail). In a bit of a slower process, underground bacteria can just eat the carbon at depth. In a more nefarious process, in anoxic environments the carbon can be converted to methane. Which is 23x stronger than CO2 on a 100 year timescale. The video below shows that these things produce enough methane so that the lakes can be lit on fire. There are millions of lakes in Northern Alaska. If they convert even .05% of the carbon in the soil to methane, it will be more GHGs than all of mankind currently produces in a year. Same thing if 1% of the carbon in the soil is converted to just CO2. This is unlikely to happen in a short time period. It is quite possible in a long time period. And the scientific community doesn't have any data on it. My team is measuring this. We are developing brand new technology to do this, and later teams will use similar or improved technology to continue the measurements. We are here to prove that it can be measured and that the technology works. Others will monitor the situation once we have proven that it can be monitored. What we are doing is pretty neat. Direct from our webpage: [Our system] has the capability to deliver to the Arctic research community a first-ever carbon isotopologue flux system that combines state-of-the art technologies in spectroscopy, infrared lasers, electronics and computing, advanced global navigation systems, high-performance airborne vertical wind speed measurements, and a state-of-the-art, high efficiency aircraft that provides regional coverage with disciplined costs. The airplane with instruments in it plus some of my team That's all for now. Look forward to more pictures from Deadhorse and Prudhoe Bay, alongside what we are doing here. Thanks for reading. -Jason Munster Bicycles The DOT says that bicycling is awesome, and has a happy dude in a suit to prove it. see site. Make sure you make it all the way to the bottom for the funny comic! What's the big deal about bicycles? Everything! You get exercise and you get around. MrMoneyMustache has a great post on bicycles that you should check out if you have time. So what's this doing on a climate change website? This one is easy. Unless you eat only beef all the time, a bike produces less CO2 per mile than a car. Maths! Good news! The maths this time are super easy! Also, great news! You can eat bacon and then bicycle and it is better for the environment than driving a car! Burning a gallon of gas gets you about 20 miles and produces 8kg of CO2. Let's assume you weigh 175 lbs and bicycle 20 miles. Most calculators show you burning about 1000 calories to do this. Let's further assume you eat potatoes to get that energy. Potatoes are about .2kg CO2 per kg potato, and a kilogram of potato has about 500 calories that we can use (it has many more, but we can't consume them all perfectly). So you need to eat 2kg of potatoes in order to gain 1000 calories and then bicycle a mile. This equates to .4kg of CO2, or literally only 5% the emissions of a car. Let's go to worst-case scenario. You eat only beef (note that you will likely die young) which makes way more CO2 in its production than potato (just picture how much cows fart, and that they produce a very strong greenhouse gas). Luckily cow is very energy dense, and you only need to eat .6kg to get 1000 calories. Unfortunately, a cow makes 29kg of CO2 equivalent per kg of meat, and 1000 calories produces 20kg of CO2 equivalent. So you are pumping the equivalent 20kg of cow farts into the air to get those 20 miles (more seriously, it is probably like .5kg of cow farts, plus some CO2, cause them cow farts really are strong greenhouse gases). So good, but not worth it for the environment Okay, so I have good news! before you go all vegan on me, Pigs are much more efficient! You only need to eat .3kg of these bad boys to get 1000 calories, and they only produce 8kg of CO2 per pound (pigs don't fart as much methane, I guess? Actually they require less feed and less water to make meat). So you produce about 3kg of CO2 if you eat bacon and bike 20 miles, which is still better than a car. Moral of the story: eat bacon and buy a bicycle. Or you could eat potatoes and veggies and be really good for the environment, but let's be realistic, Americans aren't gonna eat much less meat, so at least they can substitute pig in there. Eating bacon and then bicycling is still better for the environment than driving. Other important stuffs (like getting fit and sexy) I bike in Boston and Cambridge. I bike to work every single day. I never have to worry about finding parking. Better yet, I get to go straight from my door to the door of work. I go shopping with my bike, and that's even better. Nearly all stores have a place to park my bike right at the door, and I can usually fit all the foot I need into a large backpack. I bike to bars at night, I bike home from the same bars. When I go to a friend's party, I always bike. I pretty much never drive anywhere, and usually don't take the subway. It turns out that biking takes less time than nearly any form of transportation. One great example: my friend Erik and I were walking home from a party (I was walking my bike). He hailed a cab, I jumped on my bike as soon as he was in the cab. Erik lives next door to me. Going at my usual after-party biking pace I beat him home. And then I waited for the cab to arrive, arrogantly leaning my bike against his apartment complex like it wasn't an effort. I had just saved a$10 cab ride and a few minutes.

This is not rare. If traffic is heavy, I beat friends in a cross-town trip by about 20 minutes. I live a mere mile from work, but I can get there faster than any other form of transportation. It's faster than driving cause I don't need to go pick up my motorcycle from the garage and then find parking at work.

Biking is faster than the subway in nearly all cases, and more convenient in Boston cause my bike doesn't shut down at midnight (nor has it been stolen). Also, every time I take my bike instead of the subway, I save at least $4 round trip. Usually it is more like$20, cause I don't have to take an expensive Boston cab back home after a night out. So let's say I go out twice per week and save an average of $10 every time. That is$20 per week, for 50 weeks, or \$1000 per year. Just paid for several of my bikes, yo. Or like 3 beers a week.

What's the best part about bicycling everywhere? Being fit. Your clothes will fit better, you will have more energy, and people find you sexier. Including your spouse or significant other. Yes, yes, they do say that they love you as you are. They are lying. Get on a bike.

So wait. I just said you could do something that saves time, saves money, saves the environment, makes you more attractive, and will get you the ladies/men and/or make your relationship spicier? Why isn't everyone biking right now?!?

More seriously, people might have three reasons: you work too far away (this is a bad idea to start with, both environmentally and from a money perspective), up front cost, and safety concerns.

The first: future post. Too big to include in this one. Suffice it to say, if you don't live close enough to work to bicycle there, you live too far from work. If your job is in an area where you don't want to raise your family, you are probably either in a rough place financially or maybe you are financially well-off financially and are still making poor life decisions (more on this later, too).

The second: A bike costs a lot less than a car. Buy a cheaper car and then buy a bike. More legitimate: you have enough money to afford monthly subway fare, but not a bike. And/or you live in an area where your bike gets stolen. I got nothin' for you here. Try to take public transportation or walk, cause driving is still bad for the environment. If you can afford a car, you can afford a bike and a lock.

The third: Safety! Wear a helmet. Everyone on a bike should wear a helmet. I know helmets make you sweat and mess up your hair. You know what is worse than having bad hair from a helmet? Becoming a vegetable from getting smeared on the road.

Back to accidents. Bicycles do have a slightly higher accident rate per mile. But if you live near work and bicycle, you drive few miles. If you then consider that you cover 6x as many miles on your average car commute as your average bike commute, your death rate per minute is actually equal to that of a car. Mr Money Mustache does a great job of describing this, so I won't go farther. Moreover, If you factor in the health benefits of bicycling, you gain health and actually increases your chances of living longer (same link describes this).

Okay, this is getting long. Time to Summarize!

Bicycling will save the environment, save you time, prolong your life, make you sexier, and save you money. It's a damn miracle drug, and if you aren't on it, you are doing something wrong with your life.

-Jason Munster

Other Alternatives

Here we will cover a few more electricity producing alternatives, specifically geothermal in its different flavors, and the waste of money that is tidal power. Before that, let's make a quick roadmap of what we have covered, where that is going, and what we haven't yet covered.

Pretty much, we have talked about electricity producing resources. We have only briefly touched on energy as a whole. In the US, for example, 35% of all energy use is petroleum for transportation. None of the stuff we have discussed is useful to replace that without better battery technology. Nonetheless, it is likely that at some point in the next century, much of our domestic energy needs, including transport, will be covered by electricity. And we will require a lot more of it. An upcoming post will assess all the different tech for producing energy we have discussed, and which ones can be potential solutions.

Geothermal

Geothermal energy exists because it gets hot underground. In general, the temperature of the Earth rises by 30 degrees C for every km you go underground. This temperature increase in depth is called the geothermal gradient. If you go 7km underground, you are pretty much guaranteed temperatures of higher than 200 degrees C. Which, as we all know, is hot enough to boil water. 7km underground is pretty deep, however. In some places, the underground is much hotter. The temperature rises much more rapidly. It could be due to volcanic activity in the area, or radioactive decay underground. Either way, when hot temperatures are closer to the surface, that heat can be harnessed to drive a turbine.

Map of the geothermal resources available in the US. In general, this represents areas of higher temperature gradients.

Geothermal comes in two main flavors. One directly harnesses the steam from the ground to produce electricity (called flash steam, cause the pressurized hot water comes out, flashes to steam at atmospheric pressure, and drives a turbine), the other uses a heat-transfer mechanism where pressurized hot water from the subsurface (it needs to be pressurized, because it is above the boiling point of water at atmospheric pressure) is run through a set of heat-exchanging pipes before being put back underground. There is a third type discussed later in the article called hot dry rock.

Surprisingly, the first mechanism of directly using steam, in practice, is unsustainable and produces pollution. This is because the used steam is often vented to the atmosphere. The steam produced underground has pollutants. Like CO2 and sulfur, amongst other things. If the steam is used directly in a turbine and then expelled to the atmosphere, these pollutants come with it. If the used steam is instead re-injected into the formation, this problem is avoided.

Reinjecting the steam is easier and more common in the heat-exchange mechanism. The super heated stream of steam from underground is already isolated, and re-injection is pretty simple.

And here comes the fun part. If the steam is used and then vented rather than reinjected, the formation will run out of water. Instead of being a renewable resource, the geothermal will be a depletable resource that will only last for 10 or 20 years. This is because the pressure of the formation will drop, and the steam will no longer be able to rise. Does this sound familiar? Oil and gas production need to do this all the time to get maximum recovery rates. Reinjection of fluids is rather easy, and has been pretty well developed by the oil and gas industry.

Hot Dry Rock

The next major innovation takes a cue from the oil and gas industry. Hot dry rock is exactly what it sounds like. The rock starts off hot and dry. It has plenty of heat in it, but there is no steam or water to produce and then make energy from. How is this dealt with? Hydrofracking and injection. A well is drilled, the drill hole goes horizontal, it is fracked to drastically increase the surface area that the well hole can be exposed to, and water is injected into the rock. The water heats up a lot, then it is produced via a separate well to make steam. It is fairly complicated, and costs a lot more.

EGS

EGS stands for enhanced geothermal systems. You will run across this term a lot these days. It more or less means that the heat in the field is managed by either fracking beforehand, injecting water afterwards to maintain pressure in the field and extend the life of the geothermal power plant, or a combination of both. It drastically increases the lifetime and viability of a geothermal site.

Cost

The capital costs of geothermal pretty much will dictate the average cost of electricity produced. It looks like flashed steam will cost the least. In reality, unless the steam is reinjected afterwards, the field won't last as long, and the capital investment costs will have to be paid out over a shorter period of time, resulting in higher costs. Hot dry rock will undoubtedly always remain more expensive because of the costs associated with fracking and reinjection.

Footprint and other

Most of our power plants produce heat above ground, and need storage for either spent nuclear fuel or a coal pile (except for gas plants. They just need pipelines). So geothermal power plants don't take up a ton of space

fun uses of geothermal: geothermal heat is produced and used in Iceland to melt snow on the roads and such.

Tidal

I tend to think that tidal power sucks. In part because it is very expensive, and in part because at best it could provide all of 1% of world electricity.

Tidal power has two main problems: it uses salt water and it has only a few areas that it will work. There needs to be tides of sufficient strength that it can produce electricity, and even then, salt water is corrosive, limiting the lifetime of these power plants and making the levelized capital cost very high.

Tidal power also comes in two main flavors. One is tidal impoundment. Think of it as creating a hydroelectric dam every time the tide goes out. The tide comes in, fills up the area behind the impoundment dam, and then as the tide goes out, the area behind the impoundment dam is filled, and as it flows out, it generates electricity. As you recall from the hydropower article, the energy produced from a hydro dam directly relates to its height. The height of a tidal impoundment dam is limited by the height of the tide. In most parts of the world, this is not very high, so it is not very efficient. Moreover, it kinda messes with natural habitats.

The other type of tidal power is more or less an underwater wind turbine. The problem is that all the moving parts are underwater in the ocean. Where decay and breakdown happens quickly. Moreover, looking at the equation of energy produced via such a turbine:



where A is area, and v is velocity,

we quickly realize that the area of the rotor for a tidal turbine is small (wind turbines have 40m blades, and we aren't gonna have 80m of water depth in most places to replicate that scale in tidal areas), and the speed is slower (water doesn't flow at 6-8m/s very often). Tidal power can't scale and produce as much energy as wind. And the environment is unfavorable. In short, this is not a viable resource for large-scale energy production. And it costs a lot.

Hokay, that is all for today! Thanks for reading!

-Jason Munster