Archive for the 'Technology' Category

Jan 24 2020

Small Modular Reactors

Published by under Technology

What do you call it when you are both excited and pessimistic about something at the same time? Well whatever the word is, that’s what I feel now. Rolls-Royce has announced that it plans to build so-called small modular reactors (SMRs), which could be in operation by 2029. These are small nuclear reactors that would sit on a 10 acre space, about 1/16 the size of a standard reactor. The Rolls-Royce design is not the first one. The US has been developing SMRs of varying sizes, up to 300 MW capacity, and China and South Korea are developing SMRs.

Actually – small nuclear reactors are not new. We have been using them on nuclear submarines and other vessels for years. What is new is commercial SMRs for grid power. I could not find any in operation currently. The US company NuScale, has approval for a design and could be operational by 2026. They estimate the electricity costs at $65 per MW hour, which is not far from the current costs of solar at $60, and offshore wind at $50. Of course, wind and solar prices are dropping, but the hope is that economies of scale will also drop the cost of SMRs.

There are also potential advantages of SMRs over renewable and traditional nuclear power plants. Regarding renewables, while the prices are dropping now once we saturate the grid with renewable energy, something like 30% penetration, in order to increase the grid share of power from renewables you need some combination of two things, grid storage and overcapacity (sharing energy across the grid). The latter also requires a massive grid update. So the effective cost of renewables will start to skyrocket. The solution is to make up the rest of our energy infrastructure with on-demand energy sources. We can try to maximize hydroelectric and geothermal (which are geographically limited), but for now that means fossil fuel or nuclear.

So realistically, over the next several decades at least, the real choice we face is not between nuclear vs renewables, it’s nuclear vs fossil fuel – and I think the answer here is a no-brainer (I will return to this below).

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Jan 07 2020

Carbon Efficiency of Electric Cars

Published by under Technology

Arguments about which technology is the most energy and carbon efficient over their entire lifetime are good ones to have. This is where the conversation should be focusing, not rehashing questions that are not currently scientifically controversial. But the debate about life cycle efficiency is complex, and often gets abused or misunderstood. We face these questions from biofuels to solar, wind energy, and all-electric vehicles.

With regard to electric vehicles, for example, it is not enough that they do not emit carbon from a tailpipe. We have to consider the energy used and carbon released during the entire manufacturing process, including sourcing the raw material. We also need to consider the source of energy used to charge the vehicle, and what happens to the battery at the end of its lifetime. This is a difficult assessment to make, and every study that attempts to do so must make a number of assumptions which affect the outcome.

The result is many studies with a range of outcomes based on different techniques and assumptions used. This is a common situation in science, and what is typically done is to look at the full range of study outcomes, which should follow somewhat of a bell curve of results, and see where the peak is. It does not make sense to rely upon individual studies that are out by either tail – these are literally outliers. So bottom line – what do these studies show? They indicate that over the entire lifetime of an electric vehicle, under most driving conditions, they produce less carbon than an average gas vehicle, and hover around the efficiency of a gas-electric hybrid. The greatest individual determining variable is the source of the electricity (“fuel cycle” in the chart).

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Jan 03 2020

Golden Rice Approved in Philippines

Published by under Technology

This is a quick follow up in the golden rice story (golden rice is a GM rice with added beta carotene, a precursor to vitamin A). I have written about it here, here, and most recently here. The news is that the Philippines have just approved golden rice as safe for human and animal consumption. The US, Canada, Australia and New Zealand have already approved golden rice, but these approvals were symbolic and none of those countries would actually need to grow it. The Philippines is the first nation that both consumes large amounts of rice and suffers from large numbers of vitamin A deficiency to approve this GM crop, meaning that they intend to actually grow and eat it. There is still one more step before the rice will be grown:

“The Philippine Rice Research Institute and the International Rice Research Institute will now carry out taste tests as they seek approval for farmers to grow specific strains commercially.”

This is good news, the approval of golden rice is grinding forward despite dedicated opposition from anti-GMO groups. As I discuss in more detail in the earlier articles, both the opposition and approval are partly because golden rice breaks all the typical anti-GMO propaganda tropes. The rice was developed as a humanitarian project, it’s sole purpose is to improve nutrition for the world’s poorest children, it will be made available patent and royalty free and without restriction, and it does not involve the use of any pesticides. There is no issue here of farmer sovereignty, corporate profits, or any of the usual nonsense.

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Jan 02 2020

Update On Wind Turbines and Birds

Published by under Technology

Objective numbers are great for any debate or discussion. They have a way of cutting through all the subjectivity, confirmation bias, and nonsense. I like to say – you can’t argue with the numbers – but of course, I know that people still do. More importantly, they straight up ignore, deny, or distort the numbers, painting an alternate reality at will. But for those who still care about data and facts, here are some recently updated numbers on bird deaths from various sources.

This story is in the news again because Trump recently renewed his attack on wind turbines. Pretty much everything he said was wrong or significantly distorted, as others have pointed out. I want to focus on his previous claim that wind turbines, “kill all the birds.” He recently added:

“You want to see a bird graveyard? You just go, take a look, a bird graveyard, go under a windmill someday you will see more birds than you ever seen, ever in your life.”

This is, of course, hyperbole, but I don’t think that excuses his lack of precision and context. He is making a clear point – we should oppose wind turbines in part because they cause an unacceptable number of bird deaths. Look at the chart above – this makes it visually clear that the number of bird deaths from wind turbines does not even register when compared to other sources. It is less than the uncertainty in other sources of bird deaths. In fact, if anything the chart visually underestimates the difference because you can’t really even see how small the total from wind turbines is.

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Dec 20 2019

Commercial Spaceflight in the 2020s

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To spaceflight enthusiasts, the 2010s was a transitional decade. The shuttle program ended in 2011, and along with it America’s ability to put astronauts into space. We have been hitching rides with the Russians to get to the space station (ISS) ever since. NASA had no plans to replace the shuttle anytime soon, and instead announced that it would focus on deep space capability while relying on commercial companies to take over missions to low Earth orbit. So, after almost a decade, how is this plan working out?

Well, there have been the inevitable delays, but otherwise I think NASA’s plan was a good one. Earlier this year SpaceX successfully tested their Dragon capsule, and they are planning to launch their first astronauts in the first quarter of 2020. SpaceX has had an impressive decade. Not without failures, but the development of reusable rockets able to land vertically is a game-changer for space travel and is definitely an impressive achievement for the company.

Meanwhile, Boeing also received a contract from NASA to develop the capacity to launch people into space. They are about to launch their Starliner capsule to the ISS with supplies as a final test before being approved the take crew. The capsule will also have an “anthropomorphic test device (ATD)”, which is fancy tech speak for a test dummy. The ATD will be loaded with sensors to see what an astronaut will experience during take off and landing. The capsule is designed for a ground landing, using parachutes and airbags to land on desert sand in New Mexico. If all goes well they also plan to launch people in 2020.

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Dec 17 2019

Where is Fusion?

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The promise of commercial-scale fusion energy has been looming in the background of our collective conversations about climate change and the future of our energy infrastructure. The potential of fusion is tremendous, but we are likely still decades away from commercial power plants. Exactly how far away is a matter of debate. There are some indications, however, that the industry is progressing from proof of concept research to commercialization. No one is seriously arguing that we are close, but this may be a sign of real progress.

Fusion energy is the energy that powers the sun. It comes from fusing light elements into heavier elements, starting with fusing two hydrogen atoms into one helium atom. You can get net energy out of fusing light elements, all the way to iron. Iron requires energy to either fuse or to undergo fission, and so that is the end of the line in terms of energy production. The heavier the element, the more pressure and heat it takes to fuse. All suns start our fusing hydrogen into helium, by definition. Once the hydrogen fuel is burned, suns that are sufficiently massive will contract, increasing their temperature and pressure, until their helium core starts to burn. More and more massive stars can fuse more and more heavier elements. The most massive stars can fuse lighter elements into iron, and then, as stated, that is as far as they can go.

Here on earth researchers hope to build devices that create sufficient heat and pressure to fuse hydrogen into helium. Deuterium and tritium (isotopes of hydrogen with one and two neutrons respectively) are easier to fuse, so that is what is being used. The advantage to a successful fusion reactor is that the conversion efficiency of fuel into energy is tremendous, greater than fission. Only matter-antimatter annihilation can produce more energy for a given mass. Further, fusion produces no long-lived nuclear waste, and releases no carbon or other pollutants. The end product is helium, which is a useful element. Tritium itself is radioactive, but very short-lived. Also, the containment vessels will become bombarded with neutrons, and it remains to be seen what technologies will be used to protect the structure.

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Dec 16 2019

Smartphones, AI, and Disease Management

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As new technologies come online they often reverberate in other industries in unanticipated ways. New technologies may offer possibilities that did not previously exist. The smartphone is perhaps the best recent example of this. This was designed to be primarily a phone, including texting and video capabilities, but with access to the internet. So it is also a handheld computer. But it didn’t take long for app developers to realize that – hey, if people are carrying around an internet-connected computer at all times, that opens up a whole world of new possibilities.

Most smartphones also have three sensors in them, a microphone, a camera, and a vibration sensor. This allows for the convenient gathering of information from the user. Sure, this can be used for nefarious purposes, but also can be leveraged for things that can benefit the user. There are now, for example, apps that will monitor your sleep, or your daily exercise. Even simple things can be really useful. Patients, for example, can take pictures of themselves while having intermittent symptoms, to show their doctors later. The ability to take pictures pre-existed smartphones, but the fact that almost everyone now has a camera on them at all times, which produce digital pictures that are easily shared, is a game-changer.

This is all even without designing specific sensors optimized for medical applications. It does seem likely that the smartphone will evolve to some degree into a “tricorder” like medical sensory device, communicating information to your doctors in real time. Things like monitoring your pulse, heart sounds, breath sounds, retinal scan, and skin examination are already possible. Specialized plug-in or bluetooth devices could greatly expand this capacity, making some medical testing cheaper, more convenient, and also better in some ways. The big advantage is the ability to do long-term monitoring during normal life activities. Such applications also have the potential to expand modern medical testing into poor or developing areas that would otherwise lack it.

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Nov 05 2019

Another Artificial Leaf

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Scientists report a new process for using sunlight to convert atmospheric carbon dioxide into oxygen and fuel. Anything that does a version of this basic process has been called an “artificial leaf” because that is what photosynsthesis does, convert CO2 and water into oxygen and glucose. The balanced equation is this: 6CO2 + 6H2O ——> C6H12O6 + 6O2, and the process is driven by energy from sunlight.

Plants evolved to do this efficiently. So, if we want an efficient system to remove CO2 from the air and make useful molecules, we can use life that already does this: plants, algae, or photoplankton. This is the basic concept of biofuels. Of course, when you burn biofuels you release the CO2 back into the atmosphere, so this isn’t a way to remove CO2 permanently, but it is a potentially carbon neutral process, with the energy ultimately coming from the sun.

I say potentially carbon neutral, because it depends how you are growing the biomass. If you are using fossil fuel based fertilizer and the farming itself is energy intensive, then you may release more CO2 than you take out. This is a limiting factor for using biofuels as a strategy for decarbonizing the energy infrastructure. Also, farming is very land intensive, and we need that land to grow food. For these reasons I don’t see biofuels as a major solution to the carbon problem. At best it can be used to recycle biomass that would otherwise be wasted to replace fuels for applications (like jet fuel) that are not easily replaced with electric motors.

The “artificial leaf” approach is very similar to the biofuel approach, except we use technology instead of biology. The key is in developing catalysts that will efficiently produce the reactions we need, getting their primary energy from sunlight. The advantage over biofuels is that if we could develop a scalable, efficient, and cost effective process it may not depend at all on farmland or large amounts of water. In the end this is an energy storage solution for solar energy, and in that manner is similar to using photovoltaics and batteries. In the case of the artificial leaf, the leaf is the photovoltaic, and the end product is the “battery” or energy storage medium.

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Nov 01 2019

Musk Wants the Moon by 2022

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From SpaceX we get the following statement:

“Aspirationally, we want to get Starship to orbit within a year. We definitely want to land it on the Moon before 2022. We want to […] stage cargo there to make sure that there are resources for the folks that ultimately land on the Moon by 2024, if things go well, so that’s the aspirational time frame.”

That is quite aspirational. People have mixed feelings about Elon Musk, who tends to dream big but not always deliver. But sometimes he does, and SpaceX has perhaps been his most successful endeavor. His goal is to make commercial spaceflight practical and reduce the cost of getting into space. His primary mechanism for that is the development of the reusable rocket, which SpaceX has perfected. By now you have probably seen video of SpaceX rockets landing vertically. To me that accomplishment wins Musk an eternal place in the pantheon of awesome people.

A the very least that has earned him the right to be taken seriously when he states his next big goal for space. SpaceX has developed the Falcon 9 followed by the Falcon Heavy, both of which have been flying successfully with many recoveries of the rocket boosters, as they were designed. They have also developed the Dragon capsule, which has successfully autonomously docked with the ISS, and is able to deliver and return cargo. The first crewed mission is scheduled to go up in 2020, and that will hopefully end our dependence on Russia for lifts to the space station.

Meanwhile NASA is developing its Orion spacecraft system, with the first crewed flight of its new capsule slated for 2022. NASA originally planned to return to the Moon by 2028, but the Trump administration arbitrarily asked them to move that up to 2024. NASA is dutifully complying, but many are skeptical they will be able to achieve that accelerated timeline.

On top of all this SpaceX is developing an entirely new spacecraft, called Starship. This is a completely independent system, so it will not use any of the major components from the Falcon, Falcon Heavy, or Dragon capsule. Starship is a two-stage system – there is the Starship spacecraft and the Super heavy rocket, collectively referred to as Starship. The Super heavy rocket will get the spacecraft into Earth orbit and then return and land to be reused. The Starship spacecraft will then be able to travel into higher Earth orbit, return to Earth for fast long-distance travel, or travel to the Moon, Mars, or other deep space destinations.

The top third of Starship is for crew or cargo, with various possible configurations. The lower two-thirds are for fuel. The craft will be able to land intact on the Moon or Mars and then lift off again for return to Earth, and ultimate reuse. The Starship is what SpaceX plans to take to the Moon by 2022.

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Oct 22 2019

Prime Editing the Genome

Move over CRISPR – enter Prime Editing.

Maybe. What we can say is that the pace of technological advancement in genetic editing is advancing so quickly it’s hard to keep up. Now a new study, published in Nature, details a new method for editing called prime editing. The authors write:

Here we describe prime editing, a versatile and precise genome editing method that directly writes new genetic information into a specified DNA site using a catalytically impaired Cas9 fused to an engineered reverse transcriptase, programmed with a prime editing guide RNA (pegRNA) that both specifies the target site and encodes the desired edit.

So actually this is built off of CRISPR technology, using a Cas9 component, and then pairing it with a bit of RNA (pegRNA) that both targets the bit of the genome you want to edit and also has the new code you want to insert. Insertion is accomplished by the enzyme reverse transcriptase. How does this compare to existing methods for gene editing? The authors again:

“Prime editing offers efficiency and product purity advantages over homology-directed repair, complementary strengths and weaknesses compared to base editing, and much lower off-target editing than Cas9 nuclease at known Cas9 off-target sites. Prime editing substantially expands the scope and capabilities of genome editing, and in principle could correct about 89% of known pathogenic human genetic variants.”

It is more precise and has fewer errors, and is able to target 89% of known genetic diseases. It cannot fix errors where a gene is entirely missing, or where there are too many copies of a gene. They tested the method on two human genetic diseases in human cells, Tay Sachs and sickle cell anemia, with success.

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