Showing posts with label Energy. Show all posts
Showing posts with label Energy. Show all posts

Sunday, February 26, 2017

Deepwater Horizon: Movie not-a-review



Even though this is not a review, but rather a description of how to enjoy a movie through advanced nerditude knowledge, there are some noteworthy points:

- The beginning gives an idea of how much infrastructure supports offshore exploration and the number of different companies and support industries involved. Maybe this will reduce the "nuclear energy needs a lot of additional infrastructure" comments; I'm not optimistic, though, because those comments are born of ignorance and fear.

- Casting is phenomenal and the actors portray accurately the type of worker one finds in dangerous, rough, hard jobs. Props to John Malkovich who plays the quintessential John Malkovich villain, with additional villainy and a southern accent.

- A scene I thought was "too Hollywood," when Wahlberg runs across a burning rig to start the emergency generators and save the day (well, within possible), is actually true. It actually happened, pretty much the way they showed in the movie.

- Kudos for the minimal "character development," a disease that has made many other movies unwatchable. There was some, obviously, but the movie kept to the story and focussed on the main action (first the decisions leading up to the accident, then the evacuation of the rig).

- Instead of "you should really care about this person because they have a family and lost their dog when they were little"-type "character development," we get credible interactions among human beings (which humanize them a lot more than that usual pap) and an accurate depiction of the culture in heavy industry, epitomized by: Wahlberg (about the skipped cement test): "Is that stupid?" Roughneck: "I don't know if that's stupid... but it ain't smart."

- The class demonstration that Wahlberg's daughter is preparing in the kitchen foreshadows the blowout, but it's a bit Hollywood: the complexity of what happened is beyond the movie and in fact the movie has a lot of situations where it's clear the writers decided to move forward without trying to explain what was happening (it's a movie, after all, not a training film for petroleum engineers).

- For all the entertainment value of the movie, and the educational points one may take away from it, there were 11 fatalities, a large number of injuries, and an ecological disaster involved. So, it was nice of the producers to include the final vignettes commemorating the losses.

Now, to the hard nerditude.

I heard of the incident at the Macondo well (that's the correct name for the location, the Deepwater Horizon is the drilling rig) when it happened and for a while the news were, as usual, full of uninformed speculation, name-calling, mentions of Halliburton (always a good villain for certain parts of the population) and greed, and attacks on fossil fuels.

Not being a petroleum engineer, I assumed that (a) everything the media said was either wrong or very wrong; (b) at some point there would be smart and knowledgeable people looking at this; and (c) reports from these smart and knowledgeable people would be put online, as a prelude to the many many many lawsuits to come.

So, when a friend bought the movie (friends with kids are great: they buy movies that I can borrow), I borrowed it and in a moment of extra nerdiness decided to learn something about the Macondo/Deepwater Horizon incident before watching the movie.

I struck gold with Stanford University:


I had a general idea about how drilling works, but the details are quite important. This video was very helpful:


Being an engineer, I went to the reports too. The easiest to read is the report to the President. Having read the report helped situate the movie, since a few of the important events are not in it (some are referred to in passing):

Halliburton simulated a specific cementing plan for the well, but the actual cementing did not follow that plan. In particular, because of the tight window of usable pressures for the cementing, the cementing pipe had to be centered accurately in the hole using more spacers than were actually used. Halliburton isn't mentioned in the movie because (a) they are scary and have lots of lawyers; or (b) they didn't do what they had simulated, on orders from BP, which makes it BP's responsibility.

Schlumberger (Sch-loom-bear-g-heh, which a roustabout calls Schlam-burger to mock Wahlberg's correct pronunciation) was on site to conduct a test of the cement and see if it had set, but as the action on the movie arrives on the rig, the testing team is leaving without running the test (what happened in reality). There's no doubt that the cementing failed, since that's where the oil and gas got into the pipe and eventually the riser to the surface, so in retrospect that test would have saved the rig and well.

Unmentioned in the movie is the large quantity of highly viscous plugging fluid used as a spacer between the cement and the drilling mud, which might have blocked the narrow pipes of the kill line and shown the zero pressure when there was in fact pressure. This is the part in the movie when the writers gave up, decided that giving an impromptu course in deep-water drilling to the audience was not their job, and moved forward into the actual action.

The most unbelievable scene in the movie, when Wahlberg runs across essentially a field of giant exploding flamethrowers (the burning rig) to start the backup diesel generators, is actually true. The rig was all electrically-operated, including the thrusters; without electricity they had no lights, no PA, and lost control of the rig (it moved off-station enough that it pulled the drill string through the blowout preventer and possibly disabled parts of the blowout preventer that would have cut the pipe and sealed the well).

Watching the movie, I found it difficult to believe that Transocean management, especially HR, was okay with 1 woman and 125 men on a 21-day rotation on a drilling rig, but that is apparently accurate (maybe a few more women, but overwhelming majority of people on the rig were men). The potential for lawsuit-inducing behavior just seemed too high.

All in all, I think that the movie was much more fun to watch having read the report and watched the videos beforehand than it would have been otherwise. I would have been thinking about the discrepancy between the drill pipe and kill line pressure and the blowout preventer failure till the end of the movie, so I would have missed the emotional and action-loaded last thirty minutes.

The Wahlberg/Rodriguez jump was all Hollywood, though.



Update April 5, 2017: the problems in the blowout preventer.


Sunday, October 23, 2016

Gravity "batteries"

When there's too little demand for electricity, certain grid operators (like the Portuguese one) use excess capacity to pump water from downstream of dams to the dam reservoir. This is a way to store energy for peak demand.

I understand that some mountainous region is studying the possibility of replicating this with a funicular that would operate as the water in the dam. The losses involved in moving the funicular imply low roundtrip efficiency (the ratio of the energy recovered to the energy entered into the "battery"). And, of course, the funicular can't be used for passengers, unless there's some special discount for unpredictable schedules.

At least two people have told me about a start-up (I forgot its name) that wants to solve the battery problem by using the same approach, only with dedicated masses on vertical tracks.

The tragedy of engineering is the murder of beautiful illusions by ugly numbers.

Let's say this company can use $100\%$ roundtrip-efficient motor/generators, that is, all the electrical energy that is converted into potential energy of the moved mass can be recovered as electrical energy with zero losses in the whole process. (Yes, this is a ridiculously generous assumption, but it won't matter.)

Say this company has a 1000 metric ton mass that can be raised up to 10 meters. It can therefore accumulate $98$ megajoule (MJ) or $27.44$ kWh. Sounds ok-ish for a battery, except:

1. If that mass is made of lead (density = $11.34$ kg/l), a cheap-ish dense material, its volume is 88.2 cubic meters. That's large for a battery: it's a cube almost 4.5 meters on the side. Remember that this assumes $100\%$ roundtrip efficiency motor/generators.

2. Gasoline has an energy density of $32$ MJ/l and jet fuel has an energy density of around $30$ MJ/l; using a readily available commercial-grade combined-cycle generator with around $65\%$ total efficiency, 98 MJ can be generated with less than 4 liters of jet fuel or gasoline.

Okay, the combined cycle generator takes some space, but so do the motor/generators and the support frame for the 1000 ton mass. And the space for the vertical track, of course.

Numbers. Killing illusions. No wonder so many people avoid them.

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To make up for the bursted bubble of delusion, here's the feel-good video of this week:



Saturday, September 24, 2016

Carbon capture, perpetual motion machines, and IGORs

There's one quick rule to evaluate energy-related technologies: if you can turn them into perpetual motion machines, they aren't real.

In conversation with an IGOR (Ignorant Grandstanding Oblivious Rabble-rouser), I pointed out that the idea of using atmospheric carbon dioxide to make fuel isn't entirely new (Nature did it first), but the technologies being proposed aren't realistic, for the reason above.

IGOR countered that these processes could, in his view, be the solution to our energy crisis (do we have one?), because the fuel produced by carbon-capture will provide the energy to keep the process going.

Ahem. Let's think about this, with a diagram:



What reasonable people say is that the energy extracted from the fuel will partially cover the energy needs of the capture and conversion process (that is $x > y$ but not by much); what IGORs say is that $y>x$. But if that were so, we could feed the exhaust from the energy production system into the input for the capture system, and get a perpetual motion machine that generates free energy.

Some of the more reasonable proponents of this carbon-capture and conversion idea suggest that the energy coming in can itself be green energy, like solar, and therefore there's a net "carbon-based" energy coming out of the system. Two points:
First, that's fine, but then why use part of that solar energy to create carbon-based fuels, instead of using the solar energy to replace the carbon-based fuels? Note that any $\mathrm{CO}_2$ that gets turned into fuel will yield another $\mathrm{CO}_2$ after the energy generation (conservation of the carbon), so no advantage there.
Second, the designs proposed look extremely wasteful of energy: capturing $\mathrm{CO}_2$ after it has diffused into the atmosphere is bound to require a lot of energy to flow non-$\mathrm{CO}_2$ gases in the atmosphere through the carbon-capture process. Better to stop $\mathrm{CO}_2$ at the source, if that's what you're after.
Of course, as I mentioned, Nature does provide us with a technology to use solar power to capture $\mathrm{CO}_2$ and turn it into fuel:



It also has the advantage of being pretty, giving shade, operating in silence, and bearing fruit. Trees. It's trees. Let's plant more trees. I like trees.

One particularly oblivious IGOR insinuated I was anti-environment because I prefer trees to useless noisy subsidy-harvesting machines.

With friends like that, the environment is doomed.

Monday, July 25, 2016

A rational case for Solar Roadways projects in organizations


The first time I heard of Solar Roadways my response was "so they are putting solar panels flat on the ground and shaded by cars?" My interlocutor correctly interpreted that as "What a thoroughly stupid idea; no point wasting more time on it." *

There are, however, some good reasons to start a Solar Roadways project in some organizations. Really: good, rational reasons, that you can convince an engineer with. Well, some engineers.

Because of the buzz surrounding Solar Roadways, the project might be funded. And a project funded means a number of ways to fund other projects that would not be funded. For example:

1. An overhead charge is applied to all outside grants and funding. For example, an organization might add a fifty-percent surcharge to any expenditure: spend 1000 on your Solar Roadways funded project, contribute an additional 500 to a general fund (from which the projects that aren't sexy or buzz-worthy can be funded).

2. Fund as much personnel as you can get away with from the Solar Roadways money; of course, funding them doesn't mean that they can't work on other things, and in many organizations it's difficult to tell which project a worker is working on without expending a lot of effort. Given its own problems, it's unlikely that Solar Roadways project funders will be too eager to get a serious audit of expenditures.

3. Fund as much infrastructure, capital investment, and current expenses with Solar Roadways project money. Basically same argument as personnel.

4. Use the buzz of having a Solar Roadways project to attract attention and more funding, to get potential donors to come to fund-raisers, to impress upon the alumni (for universities) how "with it" your institution is. Also, you can play the "Solar Freaking Roadways" clip with the Serenity captain over and over again for the nerdiest of your audience, thus distracting them from any inconvenient engineering professor whose pet project isn't being funded.

Obviously these aren't arguments for Solar Roadways as an energy source, but rather examples of why smart and knowledgeable people go along with nonsense like that.

Great video by Crazy Aussie Dave Jones (EEVBlog) on Solar Roadways:


- - - -

* Some people start going over the details and quibble over the durability of the panels and the visibility of the lights in them or whether they could really melt snow (hint: no, they can't).

That's like arguing about whether the container cross-bracing ties in a Maersk Triple-E would hold if instead of sailing it over water we attached rocket motors to the hull and sent it to orbit and then deorbited it towards the destination port.

(Yes, get it to orbital speed then deorbit, to make it even stupider than a simple --- though also highly unrealistic --- ballistic trajectory.)

The cross-bracing isn't the problem, the concept itself is demented.