Archive for the ‘Technical’ Category

Arduino: Day 1

Thursday, October 11th, 2012

Part of my Halloween costume requires an micro controller to display a pattern on a led light strip. The light strip and the Arduino Uno micro controller I got to control it arrived today. In the span of about an hour I was able to:

  1. Borrow a USB A to B cable from my room mate as apparently I don’t own one.
  2. Find and follow this guide to working Arduino on Gentoo
  3. Install 16GB more ram while I was rebooting after making the kernel changes required in that guide, for a total of 23.50 Gigabytes of ram on the development system, which is also brand new.
  4. Build the circuit for the basic blink code
  5. Build and upload the basic blink code, which did require two totally hacky symbolic links before it would work.
  6. Realize that the uno includes an led on the board so I didn’t need to build the circuit and realize that it came pre-loaded with the basic blink code so that I can’t actually tell if I did anything yet.
  7. Change the blink code to use port 12 and be faster to prove I’m actually in control.
  8. Success!

Tomorrow or this weekend I hope to learn to how to talk to the led strip. Then I need to go get a fez of some kind. Oh and a Halloween party to attend in the costume, that would be a good thing to find as well.

Surprise Upgrade

Sunday, October 7th, 2012

Much to my surprise last weekend, there was a slight rumble noise coming from something in my apartment at about 3am when I was finally done playing Diablo 3 for the night. I went back out to the living room and determined the noise was not out there. I went back to my room at turned off my computer in there. I didn’t determine the noise was coming from the computer, it was late. I just turned it off to safe so I could deal with it in the morning.

In the morning I found that it didn’t want to turn on. Some LED’s blinked and the fans spun up, but it did not beep or post. I did hear some much different strange noises from the power supply while I was trying to test out some things. They slowly got worse, but I still had to put my ear on the power supply to really hear them. I decided to get a new supply, and got a 650W one sent overnight via Amazon Prime.

The new power supply was not the problem sadly. When it arrived I went directly to trying to power on the motherboard with it. It didn’t turn on at all. The supply’s fan didn’t even turn on. I checked all my connections and tried again. Still nothing. I got out a super old single core Althon mobo/cpu/ram that I have lying around and that worked with the new supply. I also tried the suspected broke supply on that mobo, and it really made a loud sound that time. I confirmed the old mobo still worked with the new supply again, and then I tired the new supply on the motherboard in failed machine. Still nothing. I took out some ram, and then it powered on just like the failed supply had done; no beep, no post. When I put the ram back in, it still powered on with no beep and no post.

So it seemed like the thing to do was replace the machine’s internals. It has been on mostly constantly since 6/21/2007 and five years seems pretty good. Here’s what I got for the new system, which is now operational:

I also picked up 8GB more ram from a friend who bought the wrong kind. My 16GB set has not arrives yet actually, so the 8GB actually allowed me to do the build today instead of waiting for the other side of the long weekend.

I had to get the DVD drive because all of my existing DVD drives were PATA, but the new motherboard only has SATA connectors. In fact, I learned while building it today that it also lacks as floppy drive connector. That spawned a two hour hunt for the plastic piece that goes in the case to block up where the floppy drive lives. I did eventually find it. And while I was looking I reorganized all of my cables and spare hardware. I filled up two boxes of old stuff to recycle or give away, including the heart of my 500Mhz P3 and my original GPU, the Riva TNT2.

The build went smoothly; everything powered up on the first try; except that I forgot to hook up a SATA cable to the new DVD drive. I also accidental chose the “auto-overclock” option in my fancy BIOS, which then turned the machine on and off a couple times trying out different settings. That is pretty cool, as overclocking just enough used to be hard. Of course I don’t really want to waste the power to overclock, so when it was done I had to turn it all off. The Linux setup went easily. I didn’t reinstall the OS; I just rebuilt the kernel as all my drives were still perfectly fine. The one real gotcha was that I had moved my Nvidia GPU to a different slot, and so it had a different bus number, and that bus number was in the xorg configuration file… so it couldn’t find my graphics card for a while.

I can’t wait till I get the extra ram, and then to run some video compression benchmarks!

On “Reviews, Reputation, and Revenue: The Case of”

Tuesday, October 4th, 2011

I, perhaps famously, introduced my parents to Yelp this summer on the way back from our annual North Carolina beach trip by suggesting we have lunch at The Ten Top in Norfolk, VA before heading to the airport to return home. The review instructing me to get the Turkey Apple Club on cinnamon bread and suggesting that the pasta salad was especially good sold me enough to sell my parents. It worked out wonderfully, and is actually my favorite part of the whole trip. That may be because I was raised on going out to eat, and it was one of two restaurants featured on the trip, and certainly it was the better one. A fond memory thanks to strangers on the internet, organized by Yelp.

I use Yelp frequently. In my Wednesday Night Dinner group, where we try a new restaurant most every week, picking a restaurant and sending it out to the group often is done via a one line email with a yelp URL and a time. I don’t know why we still include the time, its always 7:30; the only important information in the email is the Yelp URL. Every member has their own method of picking places, some uses sources other than yelp, as do I. I often use local reviews like this one for last week’s delicious pick, L’Impasto, but I always check the Yelp reviews as well. In fact, the reviews for L’Impasto were so good, and so few in number that I considered the possibility that they were fake. If they were fake, they were at least correct in this case.

Yelp might review Hotels, they do review places that are not restaurants, but I certainly have never looked at those reviews other than as indication that I didn’t hit the restaurants filter button yet. Although, certainly restaurant menu prices are a lot more sticky than nightly hotel rates, there is no reason this tactic could not be attempted with restaurants. The real question raised by this comic, however, is if the erroneous signal sent by enough people operating in dick mode could be enough to cause the place to close, negating the benefit received by the dicks. There isn’t an answer to that yet, but I came across an academic paper today where “in ongoing work, [the author is] estimating the relationship between Yelp and exit decisions” of restaurants. Such information is crucial to answer the question of if the dicks are going to end up screwing themselves.

“Reviews, Reputation, and Revenue: The Case of” by Michael Luca of Harvard Bushiness School, actually finds that there is a correlation between the average Yelp review and restaurant revenue from 2003 to 2009 in Seattle. Actually, “A one-star increase [on Yelp] is associated with a 5.4% increase in revenue.” Yelp was introduced in 2005, so his data set can provide details about the impact of Yelp as it grew to become the dominant resource that it is today. He uses a couple randomization techniques allowed by the way the data is collected and presented to control for correlations between average Yelp review and other factors that may increase restaurant revenues, like having better food, to bolster his argument to the level of causation. The statistics are over my head, but it the theory seems solid, and certainly a lot of his assumptions ring true to my use of Yelp.

The paper brings up another interesting point that rings especially true. It finds that while overall, Yelp reviews correlate with revenues, that “chains already have relatively little uncertainty about quality, their demand does not respond to consumer reviews.” That is, reviews don’t matter for chains, maybe people don’t even read them. I said I was raised going out to eat. I was a picky eater and only child so going somewhere I would not fight about was probably my parent’s primary concern. That means that I was raised eating at chain restaurants, most notably Olive Garden. I believe that from when I turned five until I went to college I was at an Olive Garden at least once a month. If you include college, it might have to grow to once every three months. I still love Olive Garden thanks to all that conditioning, and when I go home to Ohio, I think I eat there within the first 36 hours, without fail. I have not once read a yelp review about the Olive Garden.

My dinner group essentially bans chain restaurants, with a couple of minor exceptions. That is likely one of a number of cultural reasons why, since moving to Boston, I’ve broken my Olive Garden streak. However, apart of my pilgrimage to Olive Garden upon setting foot in the state of Ohio, I seek out independent restaurants there as well. The paper also finds this is a trend much larger than my group. Specifically “chains experienced a decline in revenue relative to independent restaurants in the post-Yelp period.” Since ratings don’t matter for chain restaurants, but they do provide useful information on independent restaurants, there is a pretty good rational “that increased information about independent restaurants leads to a higher expected utility conditional on going to an independent, restaurant. Hence Yelp should … increase the value of going to an independent restaurant relative to a chain.”

With the power that Yelp has amassed of the past 6 years, comes skepticism, the specter of fake reviews, which I feared, and also the specter of intentionally false reviews as evidenced by xkcd. There is still another aspect of power that people take issue with, corruption or extortion of independent restaurants. Clearly, with the power to increase revenues drastically with a small shift in rating, there is an opportunity for yelp to offer to artificially increase rating at a cost to the restaurant, or extort from them with a threat of a lower rating. Enter this Davis Square Livejournal post:

I went to Paddock Pizza in Somerville on Sunday (not usually open Sundays, but there was an event) and I loved the pizza (plain). When I told one of the owners, she said she enjoyed it, too, but the first pizza chef, no longer there, got some bad reviews on Yelp and asked if I might be willing to put in a good one. I would in theory, but I’m not always much with the food review writing. Since I like their pizza and want them to stick around and keep serving it, I am willing to take someone who likes writing such things. (Their pizza is also pretty inexpensive, more so from 4 to 6pm (early bird specials), though they are only open Wed-Sat, 4-10pm). Message me if you are interested and are flexible-ish time-wise.

The text presented has been edited since my original reading. It originally included a line about “detesting” yelp, which was responded to in the comments, and caused a thread about Yelp’s abuse of its power, or at least perceptions of abuse, as no actual abuse has been proven. Here we have a restaurant which is aware of the power of Yelp to affect their bottom line, asking a patron who has expressed a positive experience to help them increase their rating. It seems the restaurant is acting fair in this transaction, they aren’t faking a review, they are merely attempting to turn a positive dining experience they provided into a positive review. Unfortunately for them, their pizza loving patron is not a writer it seems and is unwilling to jump through the hoops to become one because of perceived, unnamed abuses by Yelp. However, the crux of the post is that he is looking to hire someone to write a good review for this place for the price of dinner, presumably half a pizza. That must be some damn good pizza, maybe I should go check the Yelp reviews though. Every review since 2008, when the first review appeared has been >= 3 stars, arriving at a current rating of 3.5/5 stars. True, recent rating seem higher, but haven’t caused a upward trend in the overall rating yet. Verdict? Well no one has picked anywhere for Wednesday yet.

MIT Mystery Hunt 2011

Wednesday, January 19th, 2011

Mystery Hunt 2011 Coin - Megaman, Prince and ? Block

This year my friend Sparky finally convinced me to join his MIT Mystery Hunt team. Mystery Hunt is a large, difficult puzzle competition at MIT, the prize of which is pictured above. We did not win the prize, but the team, the Manic Sages, did manage to come in second. We finished about 2.5 hours after the winning team and it was awesome!!!!!111 It was seriously one of the best things I’ve ever done. It ranks right up there with redesigning and rebuilding the team 677 First Robotics robot in 2005.

Like the 2005 robot, this competition occurred over about 3 days, and was a race to the finish that necessitated staying up all night and coming up with clever solutions, the faster the better. The video game themed Mystery Hunt culminated in a Portal like run around MIT, during which I got totally lost. FYI: Portal is way easier with a Portal gun than with 2 sub-teams and spotty cell phone coverage. I think, overall, Mystery Hunt was even more fun than the 2005 robot because all of this was intended, not the result of 5 weeks of work with a faulty premise.

I contributed to solutions of 7 puzzles that we eventually solved without working backwards from known solutions to other puzzles. I came up with a key insight that eventually proved to be correct on 1 more puzzles that we did not actually solve, and there are 3 more puzzles that I had a hand in/made and attempt. All of the puzzles are up at (or eventually at but suffice to say that 11 is a very small percentage of the puzzles, and I could have solved zero of them on my own. The 7 that I helped solve are:

  1. You Shall Understand What Hath Befallen
  2. Drafting Table
  3. Soooo Cute!
  4. Sufficiently Advanced Technology
  5. Plotlines
  6. A Representative Sampling
  7. The Path More Stumbled

The unsuccessful, but correct key contribution was to Where’ s Antoinette, and the other three are:

Dear Comcast

Monday, November 29th, 2010

I do not care if the entire city of Boston, New England, East Coast of the US, the entire country, or the entire world is having internet connectivity problems! When I call you because my service is not working I expect to either:

  • Talk to a person, to whom I can explain my service problem and receive help or direction
  • Be able to loge a service out notice with a computer
  • Be told of known service problem in my area and be provided with a estimated time of service restoration

Any of those is acceptable. Just to be clear and ensure that I am not being unreasonable in my request, when my power goes out, my power company offers all 3 of those options depending on the circumstances. Now, the ETA I am told by the power company is not always correct. However, it is updated from time to time, and they will call me back if and when they update the ETA. Also, they call me back after they expect the power has been restored to confirm that my reported outage has been resolved. That is how a service outage should be handled, if you ask me. Excellent job government sponsored monopoly, nStar.

Being told to go online for help when the internet is not working is not acceptable! At the very least your system should detect that there is an internet problem and not play that recording. With the power company, most of those options are handled automatically by a computer, which is fine. No one expects a service provided to have enough people answering calls to deal with the flood of complaints during a service outage. However, we should be informed of the problem, when we call; not disconnected because too many people are calling. If I have to turn to twitter to find out that this is a larger problem and not just me, as well as find the solution (use google’s dns servers), then you as a service provider have failed miserably. I don’t know why I expected that you would not fail in this case, you fail every day all of the time. I really don’t understand why the government monopoly power company provides an entirely different level of customer service than you; you technically do at least have some minor form of competition.

Cotton, the WTO, and You Tube

Friday, November 19th, 2010

I want to share 3 links I uncovered over the past 6 months, 2 of them this week, one thanks to Kara, about the World Trade Organization, how it works, and what Google wants to do with it.

First, an NPR Planet Money podcast about Cotton. The Planet Money team is trying to buy cotton from a cotton farmer, and they get caught up a whirlwind of intentional politics, economics, and enforcement.

Second, if you think cotton is the only industry where this has happens, this re-cap peice from Arstechnica last March sets the record straight about the myriad of WTO claims against the US, which we have ignored or paid off.

Some commentary before we move on. Farm subsidy are awful, economically, you shouldn’t need me to explain that. So we should comply with the WTO decision on cotton. The Antigua ruling about on-line gambling is likewise an easy choice, we should repeal the law and come into compliance. On-line gambling remains legal in Nevada even under the current law, and horse racing exemption make the current policy inconsistent at best. Cuban sanctions should have been lifted long ago, along with all their associated cruft. Now, the music issue, its strange. I think its the Europeans who are wrong on this count, but our radio payment system also needs an overhaul for other reasons. But the real reason why we want a better record for complying with the WTO is because of China, Turkey, and Pakistan.

All of those countries engage in internet censorship. Specifically they have blocked in the past. This Arstechnica piece describes how Google, owner of You Tube, sees that as a very specific trade embargo. If I were the WTO, and based on the Antigua case I would accept that argument and rule against those countries for censorship as it ruled against us. That, if the WTO rulings were enforceable, would be a really great way to force China and the Islamic world to stop censorship, something that sweet talking about human rights has not accomplished in the least.

It all comes down to the Rodrik Hypothesis, which I increasingly see reason to beleive may be accurate. It states roughly that:

Economic globalization, political democracy, and the nation-state are mutually irreconcilable. We can have at most two at one time. Democracy is compatible with national sovereignty only if we restrict globalization. If we push for globalization while retaining the nation-state, we must jettison democracy. And if we want democracy along with globalization, we must shove the nation-state aside and strive for greater international governance.

In this case, as with most that I am prone to like, we are going the globalization + democray route by getting rid of the nation-state. Making the WTO rules enforceable over the sovereignty of the nation-state has the essential action of eliminating what makes a nation-state a nation-state.

Lincoln Memorial

Tuesday, June 1st, 2010

I just love that shot of the Lincoln Memorial I posted recently. The snow scape, imposing angle, and most importantly the diffuse sunlight just make it seem so post apocalyptic. Well, if you ask people from D.C. maybe it was. But the sense is ruined by the multitude of people in the shot. So I removed them with the gimp, except for Emma, the fur hooded figure in the far foreground. I think it’s certainly an improvement.

I could have really used content aware fill, but sadly that feature isn’t in the gimp yet (actually looks like maybe it is, but plug-ins are way too much work). Lucky for me snow is very organic and the smudge brush emulates it well enough. It is also pretty good at background plant matter. Anyways, it in fact looks nothing like the Logan’s Run Lincoln Memorial, at least from the movie, but oh well.

Travel as a Graph

Sunday, April 4th, 2010

I have been averaging more than one trip a month since July of 2009, and it feels like a lot of travel, so I want to record some numbers about it in case I want to compare at some point. For the purposes of this accounting, a trip requires that I got on an airplane or stayed in a hotel while not in the Greater Boston Area. For the record I have not stayed in a hotel in the Greater Boston Area during the time period. Lets start with a graph:

The blue line is 1 if I was not home (away) and 0 if I was home on a given date. If i was traveling home on a day the line is a 1. The red line is 0 when I am home, 1 when I am traveling for work, and 0.5 when I am traveling for pleasure. Since the red line is on top of the blue, you can really just think of the blue as personal trips.

This tells us that I spent all of October in Boston, a fact I had forgotten. I have been averaging 1.3 trips per month divided between 0.5 personal trips per month and 0.8 work trips per month.

This has lead to a total traveling percentage of almost 32% of days. That is on any given day there is a 32% chance I’m not in Boston. I would have expected that number to be much higher, but the graph seems to agree with it. If we look only at 2010 only I’ve been gone for a slightly higher 36%, but I really feel like it’s been 50%. That’s the point of the analysis. I now know that 32% is way too high.

Renwable Biofules Law in MA

Saturday, February 20th, 2010

A couple of weeks ago my Dad sent me an interesting article via e-mail about a law that we will apparently get to vote on in Massachusetts. It caused me to do a lot of thinking about if the law is good or not, and who would be in favor of such a law. Here’s the article, I can not find it on the net to attribute it:

Massachusetts Evaluates Carbon Neutrality of Biomass

WASHINGTON – The carbon-neutrality of biomass is up for debate in Massachusetts at both the regulatory and legislative level, with a study, ballot initiative and legislation in the spotlight. For [company] and the forest products industry, it is critical for biomass to be considered carbon-neutral because our facilities use an average of 60 percent biomass to power our operations. [company] is a leader by using 73 percent biomass to run our U.S. mills, and we support the science that when biomass, such as wood, is combusted for energy, it releases back into the atmosphere carbon dioxide that it absorbed from the atmosphere during growth. When harvested biomass is replanted, the cycle repeats. In contrast, fossil fuel is not carbon neutral. The combustion of natural gas, coal and petroleum fuels results in a net increase of carbon dioxide in the atmosphere since this carbon dioxide was never originally absorbed from the atmosphere and there is no balancing cycle to remove it. Failure to recognize the carbon neutrality of biomass could lead to unintended negative consequences such as increasing fossil fuel use and greenhouse gas emissions, reducing forest land, creating substantial uncertainty and deterring growth of renewable energy, as well as driving jobs away from the U.S. and toward jurisdictions that recognize biomass carbon neutrality.

Biomass Study
The Massachusetts Division of Energy Resources (DOER) has begun a six-month study to examine the carbon neutrality of biomass and biomass sustainability. The Commonwealth has suspended consideration of all applications for biomass facilities under the state’s Renewable Portfolio Standard pending the outcome of the study. It is expected that the study results will be used to inform new regulations addressing biomass facilities and may be precedent-setting elsewhere. The American Forest & Paper Association (AF&PA) attended the public meeting on the study last month and submitted written comments. [company] and AF&PA will continue to be engaged moving forward.

Ballot Initiative
The “Stop Spewing Carbon Campaign” has gathered the required amount of signatures necessary to move forward with a proposed ballot law that would require biomass energy sources to emit no more than 250 pounds of carbon dioxide per megawatt hour to be considered renewable. The proposal would not take offsets into account and would rely solely on smokestack emissions. The initiative, which must be approved by the legislature by the first Wednesday in May, is expected to appear on the November 2010 ballot. AF&PA is working with other organizations that are also opposed to the initiative to discuss formation of a formal opposition campaign.

Related Legislation
Legislation that would prohibit the burning of construction and demolition waste and treated wood in biomass facilities has been pending in the Massachusetts legislature for approximately one year and had previously received minimal attention. After the political and media attention given to the study and ballot initiative, interest in the legislation grew. At a December hearing, a number of environmental groups testified and expanded the conversation to biomass facilities in general. AF&PA is closely monitoring the bill to ensure it is not expanded to an outright ban

These are my Dad’s comments that accompanied the article:

It is an interesting political debate, but I would think the science is well known. I would think that if you burn it, you make CO2. Of course, the paper itself ties up carbon, as long as it is not eventually burned. Fossil fuels are just as carbon neutral as wood – They just took a lot
longer to “repeat” the cycle.

In any event, in Massachusetts, they will actually ask the voters to decide…. Weird !!

Here is my analytical response about the nature of the law and possible laws in this area:

Certainly, in the long run, the amount of carbon and oxygen on the planet remains the same with the exception of fusion, fission, meteors, and material carried by the solar wind. In this sense, we are always carbon neutral. This is the same sense by which it is easy to say fossil fuels are as carbon neutral as wood because they are produced via a cycle.

Now, the carbon neutral everyone else is talking about has to do with where the carbon is stored and in what molecules. Specifically the ratio of C02 (and CH4) in the atmosphere to the carbon stored in biomass, fossil fuels, and other stored resources. In this arena carbon neutrality is all about rates. The rate at which we release carbon from stored resources into the air, and the rate at which stored resources take up carbon from the air.

Fossil fuels take carbon from the air at an incredibly slow rate. First requiring that animals or plants bleed it from the air and then requiring they decompose for a long time. It is because of this slow rate that almost any fossil fuel burning is considered non-neutral. Trees, of course, take up carbon from the air at some, much larger rate, and so stand a much easier chance of being carbon neutral. It appears that ballot initiatives is targeting this exact sort of definition of carbon neutral. Specifically it requires “biomass energy sources to emit no more than 250 pounds of carbon dioxide per megawatt hour to be considered renewable.” This defines a rate at which carbon may be burned for it to be considered renewable. It is a convoluted rate calculation, one that is not expressed in units comparable to carbon intake by trees per unit, but one that fundamentally can be converted and compared.

There does exist a scientific question, the answer to which is also the answer to whether or not this is a good law. That question is, at what rate does biomass pull carbon from the atmosphere, and is that higher or lower than the purposed rate in the law? The law should stipulate a burning limit rate that is exactly equal to the rate at which biomass removes carbon from the atmosphere. To set a rate too high or too low would injure some party without cause. This rate may very based on the type or source of the biomass, perhaps widely, perhaps not. If it varies wildly by type then the law should take different sources and their rates into account, breaking out burning limits by source type. Such a law would correctly include the fundamental scientific nature of atmospheric carbon neutrality, which seems like a reasonable thing to do. Its already a scientific law anyways.

Of course, if the burn limit lower than what [company] burns, then [company] will have to substitute another energy source to make up the difference or it can pay the fines that I’m sure will be the penalty in the law. This is an economic choice, but not one that should be avoided. It would be up to [company] and its competitors to individually choose alternatives that minimized cost. Now, if the proper carbon externality cost is not applied to all sources of carbon, this can create perverse incentives that actually increase pollution. That is why all non-neutral carbon should be taxed at the same rate. Externality taxes (and their functional equivalents) to counteract pollution must treat all sources of pollution in the same way in order to avoid costly perverse incentives.

The fines this law would impose on non-neutral biomass combustion constitute a tax and would need to be set at the same levels as equivalent carbon taxes on other carbon sources. Therefore, this is also a requirement that must be satisfied for this to be a good law. Given that fossil fuels are not carbon taxed in Massachusetts it seems unlikely that this law will meet this standard, unless they also pass fossil fuel carbon tax equivalents at the same time.

As to the paper containing carbon, it is the person who choses to burn it that should pay the tax on the carbon produced by doing so. As stated, the only neutrality we care about is in the atmosphere vs. not. [company] putting carbon in paper should not result in a tax payment. It should result in a carbon tax credit if that carbon (the whole process in general) were to, in some way, result in a net drop of carbon from the atmosphere.

If fact, if one were to credit trees owned by a person for reducing carbon, and tax all carbon put into the atmosphere it should be equivalent to the properly calibrated law that induces taxes only above
the limit at which burning becomes non-neutral. That is, it is equivalent to the government in terms of net tax collected. It may change who pays the tax and who gets the credit. But [company], owning lots of trees, would surly fair the similarly under both systems.

However, I failed to understand until my father responded that his company would be in favor of the law. I had clearly assumed above that they were opposed due to the taxes they may incur if they burned too much. Here is his response:

I would go with your definition, but suspect that is not the one that will be used.

I’m not sure what it takes for “biomass energy sources to emit no more than 250 pounds of carbon dioxide per megawatt hour to be considered renewable” but it takes at least 15 years to grow a tree, and only a few minutes to burn it, so I cannot see how that can be carbon-neutral.

Certainly [company] would benefit greatly from defining biomass as carbon-neutral. We currently generate over 75% of our energy from biomass. I’m sure we could easily move that to 100%. If the price were right, we could exceed 100% [& sell power to the grid]. The problem I have with this is the definition of biomass as carbon-neutral. Burning wood &/or other biomass &/or ethanol or other petro-like products created from biomass actually contribute to exactly the same problem. We need to find cleaner solutions.

I had failed to understand the scope of the badness of the law. I had assumed above that the units did actually work out properly. This time I set out to discover if that was indeed the case:

Lets look at the “biomass energy sources to emit no more than 250 pounds of carbon dioxide per megawatt hour to be considered renewable” part. Lets consider only one adult tree of mass 850kg (when burned) that will be burned under this regime, and we want the burning to result in zero net co2 creation after considering the absorbed co2 during the life of the tree.

250 lb co2/megawatt hour = 0.315×10-7 kg co2/Joule

( wood provides 15 GJ/1000kg = 15×10^6J/kg wood (ignoring energy spent in drying, lets say solar does this for us)

Combining we get: .4724920521 kg co2/kg wood

therefore any wood that we burn will have to produce co2 at a rate equal to or less than that per kg to be renewable. Now, how long will it take a tree to absorb that much co2 per kilogram.

a tree absorbs co2 at a rate of 48lb co2/year ( which is 6.899×10-7 kg/s

it will therefore take a tree 684870 seconds (190.2 hours, 7.9 days) to absorb the co2 that is released by burning 1 kg of it. Therefore out 850kg tree would need to live for 6737.7 days (or about 18.459 years) before it was burned in order for burning it to be renewable.

A more complex calculation can clearly be done involving a varying rate of co2 absorption based on growth, and more exact figures for specific kinds of trees. This type of calculation could produce a graph showing when it would be renewable to burn the tree.

Anyways, that is how the rate comparison pans out I think. I expected that [company] would be opposed to this law. Since they use so much biomass to generate so much power it would be quite bad for them if it turned out that they burned at a non-renewable rate, as defined by the 250 lb co2/megawatt hour.

But yes, I think I see your point. As shown by that rate calculation above this 250 number implies a certain amount of time that our tree needed to be alive, in order for it to be neutral. The law as described imposes no such restrictions on the age of the tree burned, and therefore it has zero bearing on if the burning that takes place is actually neutral or not.

I now understand why [company] would favor this law. When I first responded I assumed [company] would not favor the law, because as we both agree, the burning that they do could easily be non-neural in reality, and clearly I fixated on encoding reality in to law. This law, as described, since it does not include a time factor, violates an assumption I made in my 4th paragraph above. I had assumed that the rates were comparable, equivalent in units, but they are not.

So, fundamentally flawed law has no basis in reality really. Except that as my dad says ~15 years is about how long they usually let the trees grow for other reasons and so as he says:

That is actually a lot closer to carbon-neutral than I had imagined it would be. I wonder who figured out the 250 lb co2 / megawatt hour limit? Maybe they knew something.

Econ Quiz

Wednesday, May 6th, 2009

This was on Greg Mankiw’s Blog a while back, but I just got around to taking it. It’s a little flash based econ AP testlet, consisting of 18 questions. With no preprtion of any kind I managed to get 13 of 18 correct. And, darn it if I wan’t so close on two more.