Short Change: The Vampire in your Living Room

Printers, microwaves, chargers, DVD players, desktop computers and many other devices all drain energy when turned off or not in use. This drain is known as ‘vampire’ or ‘standby’ power and is responsible for a huge amount of energy loss each year. Since that energy is largely generated by burning fossil fuels, vampire power accelerates the rate of global warming as well as raising your electricity bill.

TVs, Printers, microwaves, chargers, DVD players, desktop computers and many other devices all drain energy when turned off or not in use. This drain is known as ‘vampire’ or ‘standby’ power and is responsible for a huge amount of energy loss each year. Since that energy is largely generated by burning fossil fuels, vampire power accelerates the rate of global warming as well as raising your electricity bill.

According to UC Berkeley, Americans lose 200-400 terawatt hours per year to vampire power; that’s enough electricity to power all of Italy! That is quite something, given that the US population is only about 5 times larger than that of Italy. Some investigations into vampire power have found that many appliances actually use more energy during the time when they are idle than they do when they are in use. One survey of office buildings in Thailand found that 90% of the electricity used by printers, copiers and fax machines was vampire power. In other words, it would cost 10 times less money and emissions to run these devices if they were simply unplugged when not in use. Another study found that 80% of electricity used by video recorders in Australia was used in standby mode.

So how can you identify an energy vampire? Unfortunately it is not as simple as throwing holy water at your devices. There are, however, some good rules of thumb. Anything that can be turned on with a remote control is likely an energy vampire, since the sensor which picks up the signal must remain on 24/7. Another likely culprit is any device, like microwaves or radios, which constantly displays the time on a screen. There are, however, many other devices which consume power when not in use but show no external signs of doing so.

This issue negatively affects both the bank accounts of the average consumer and the global effort to combat climate change. Compared to dismantling the fossil fuel industry or convincing everyone to stop eating meat, this is a relatively easy fix. One way to slay vampire power is on the side of the consumer. If you buy a couple of extension cords with on/off switches, you can easily cut power to things like TVs and printers when they are not in use. Try keeping your remote control beside the extension cord so that you can flip the switch when you go to pick it up. There is, however, only so much we can do.

The more promising solution to vampire power is technical and is the responsibility of electronics manufacturers. For example, energy-saving devices can be built which automatically cut power when not in use for a certain amount of time. Another example would be phone or laptop chargers which cut the power when the device is fully charged or unplugged. It is estimated that changes to the power circuits of devices could reduce vampire power by as much as 90%, so manufacturers have the power to largely fix this issue all by themselves. One problem with this is that consumers are more likely to buy, for example, a TV which can be turned on remotely, so manufacturers have an incentive to keep producing goods which drain power when not in use.

Cutting vampire power would allow us to supply many more people with electricity without a corresponding increase in CO2 emissions. Improvements in efficiency such as this will be necessary to fight climate change, but must occur in tandem with a number of other tactics, including a conscious effort to reduce energy consumption across the board. It is the responsibility of manufacturers and consumers alike (but mainly manufacturers) to be careful about how much power is being used, and to identify and eliminate any power drain which is not absolutely necessary.

A Salt and Battery: How to Store Sunlight

It has become common knowledge that humanity needs to change the sources of our energy at an unprecedented rate if we are to avoid the worst effects of climate change. Renewable energy systems are the most promising means available to reduce our impact on the earth without giving up the comforts of readily available electricity. However, an issue with some renewables like wind and solar is that the energy is only available sometimes. There is no solar power without sunlight and no wind power without wind. In this article I’ll be looking at a type of solar power plant which avoids this problem in a most ingenious way.

It has become common knowledge that humanity needs to change the sources of our energy at an unprecedented rate if we are to avoid the worst effects of climate change. Renewable energy systems are the most promising means available to reduce our impact on the earth without giving up the comforts of readily available electricity. However, an issue with some renewables like wind and solar is that the energy is only available sometimes. There is no solar power without sunlight and no wind power without wind. In this article I’ll be looking at a type of solar power plant which avoids this problem in a most ingenious way.

One way to solve the storage problem might be to connect all our renewable energy infrastructure to a massive international grid. What this would achieve is that excess solar power from a hot day in San Francisco could be used to power Beijing in the middle of the night, or excess wind power from blustery Ireland could be used to power gustless Brazil. This is a very good idea in theory but it has its drawbacks. Consider the sheer quantities of copper and rubber required to connect every solar and wind farm in the world to every home or business which requires their energy. And what about the time it would take for such an ambitious project to reach completion? Climate change is already here and will soon become entirely irreversible without swift and decisive action.  

So how else can we store and distribute renewable energy? The answer seems very simple; build a battery. If you need solar power at night, why not store the electricity generated during the day rather than transporting it to the other side of the world? This, however, is far easier said than done. The current generation of lead-acid (car) and lithium-ion (phone) batteries are remarkable works of engineering. They are not, however, up to the task of storing the amount of energy we need them to store without seriously depleting natural resources like rare-earth metals. We are badly in need of a breakthrough. Lead-acid batteries have been working on the same basic principle since their invention by Gaston Plante in 1859 and are still one of the most widely used rechargeable batteries on the market. In this article, I’ll be looking at a new way of storing solar power that may revolutionise the energy grid of the future.

‘Concentrating solar power’ (CSP) plants have been providing more and more people with electricity ever since they were first built on an industrial scale back in the 1980s. The difference between these solar plants and standard photovoltaic (PV) plants is the way in which the electricity is generated. In PV panels, solar energy is converted directly into electricity. In CSP, the heat energy from the sun is used to make steam which spins a turbine and this is what generates the electricity. This is roughly the same process used to generate power from coal, oil, natural gas, nuclear fission, incineration, plasma gasification and thermal wave power so the proof of concept is definitely there. The major advantage of CSP over PV is storage. If your plant is generating electricity directly from the sun, you need somewhere to store the electricity when it is not needed; a battery. If you are generating electricity from heat, on the other hand, you can store the sun’s energy in something called a heat transfer fluid (HTF). This is any fluid, like mineral oil, which retains heat well over time.

The most basic and widely used form of CSP is known as a ‘parabolic trough power plant’ (PTPP). The first documented use of this technology was Auguste Mouchout’s ‘solar steam engine’ in 1866. In PTPPs, mirrors focus sunlight onto tubes which contain a HTF. The mirrors are curved like those you might see in a house of fun and are arranged in troughs with the tubes of HTF running down the centre. Picture a hot dog but with mirrors rather than bread and tubes rather than a highly questionable meat-like substance. The hot HTF is transported through the tubes to a series of heat exchangers where it evaporates water to spin a steam turbine. If electricity is not needed at that moment, the hot HTF can instead be transported to a storage chamber from which it can be removed when the need arises for electricity. Once the heat has been converted into electricity, the HTF returns to the troughs to begin the process again. 97% of the CSP plants currently producing energy are PTPPs.

Parabolic mirror with tubes of HTF

PTPPs, however, are not the only type of CSP available. Back in 2011, a company called Solar Reserve received a loan of $737 million for a project called ‘Crescent Dunes’; a massive solar plant in the Nevada desert which can provide electricity to 75,000 homes, night and day. Crescent Dunes is what is known as a ‘power tower’ CSP plant. Power towers operate on the same basic principle as PTPPs, but rather than each mirror focusing sunlight onto a different section of tubing, all the sunlight is concentrated on one central tower. Focusing all the sunlight on one place means that the plant operates at much higher temperatures, greatly increasing efficiency. This design also does not require expensive curved mirrors like PTPPs. The plant instead uses ‘heliostats’, flat mirrors which track the sun and change their position to maximise the amount of sunlight hitting the tower.

The real genius of the project is what is contained within the tower. Inside the tower is a mixture of potassium nitrate and sodium nitrate; also known as salt! More specifically, saltpeter. Sodium nitrate is currently used to preserve certain foods and is the reason bacon goes green if left uneaten for too long. In power towers, the salt is heated by the sunlight reflected off the mirrors until it is molten and packed to the brim with energy. The salt is cheap and extremely good at retaining heat, acting as a kind of thermal battery. This means that power towers can continue to provide energy long after the sun has stopped shining. What’s more, salt can be used at much higher temperatures than any of its competitors. One issue with using molten salt is that it can freeze in the pipes. For this reason, new types of solar salt are being developed which have much lower melting points.

One apparent issue with this design is the effect on birds. If you have thousands of mirrors concentrating the blazing sunlight of the desert into one spot, any bird that is unfortunate enough to fly through the firing line could be killed by direct heat. There have even been reports of birds bursting into flames mid-air then crashing down to earth like meteorites. We have decimated insect populations around the world, depriving many birds of their food source, and scientists estimate that between 100 million and 1 billion birds die each year by flying into buildings in the US alone. Given these facts, it could be argued that bird deaths are an unacceptable side-effect of power towers However, recent studies of bird deaths in a number of power towers have shown that initial estimates may have been wildly exaggerated.

Back in 2014, a conservationist by the name of Shawn Smallwood very roughly estimated that Ivanpah, the world’s largest CSP plant, could be killing 28,380 birds per year. That number or anything close to it would indeed be unacceptable. However, at the same time that Smallwood made his estimate, a large-scale study was being carried out at the Ivanpah plant to see just how many birds were actually dying. After 8,935 person hours and 281 dog-hours of searching, the team found just 695 dead birds and 35 dead bats. Adjusting for the bodies that weren’t found or were carried off by scavengers, the team estimated that around 3,500 birds had died in the plant’s grounds over the course of the year. They estimated that only around 1,500 of those deaths were caused by birds flying into the tower or being burned by the mirrors. That’s nearly twenty times fewer deaths than the number predicted by Smallwood which tarnished the plant’s name in the media. The other 2,000 deaths were listed as ‘unknown causes’ which could have nothing to do with the power plant at all. To put these numbers in context, it is estimated that in the US alone, domestic cats kill 1.3 to 4 billion birds per year.

Another consideration is that the negative effects suffered by birds if climate change goes unchecked greatly outweigh the effects they will suffer from concentrated solar, particularly given the recent assessments which show that the damage to bird populations from CSP is far less severe than was previously thought. There is certainly merit to this argument. We need to develop and roll out effective energy alternatives very soon or else birds, mammals, fish and insects alike will all suffer the worst effects of climate change.

It seems that CSP plants are getting better and better at mitigating the risk to bird populations. Each year the number of deaths goes down as adjustments are made to what is still a very new technology. It may seem cold and calculated to talk of flaming birds like mere teething pains, but we need to make these kinds of hard decisions if we are to ensure that we leave a habitable planet to future generations of people and birds alike.  

In PTPPs, the sunlight is concentrated on a massive number of different points which are at ground level, meaning that the threat to birds is greatly reduced. However, there are a number of drawbacks. First and perhaps most important is that power towers are far more efficient at converting heat into electricity. This is partly due to the higher operating temperatures but is also affected by the surface area on which heat-loss can occur. If you concentrate all the sunlight onto one point, there is a much smaller area in which heat can radiate out into the atmosphere. Another major factor is how much of resources like oil, metal, water or salt are required for the process. In power towers, you only need enough HTF at any given moment to fill the relatively small space at the top of the tower. If you are constantly heating several kilometres of pipes, on the other hand, you will lose a lot more heat to radiation and use a lot more resources in the process.

Like many sustainable technologies, there are a number of advantages and disadvantages to CSP. When it comes to large-scale energy production, CSP seems to have PV beat, but If you are just looking to power your own house, PV rooftop solar panels are far easier to install and provide you with a personal energy supply. In the US, you can also make money from producing excess energy for the grid, with the UK set to follow suit in January of 2020 after much controversy and tomfoolery on the part of the government. Right now, good PV panels convert roughly 20% of sunlight into electricity but researchers think that number could theoretically be brought as high as 80% with a few breakthroughs. When it comes to deciding which type of CSP is best, I will leave that up to you.

Power towers are far more efficient and require far fewer resources to generate the same amount of energy. Despite initial exaggerations, however, power towers do pose a threat to birds, particularly if new plants keep being built. What’s more, they do not have a proven track record as long as their rival. What is certain is that if we do not transition to cleaner forms of energy ASAP, the consequences will be far more severe than most people think.

We will see an acceleration of biodiversity loss and an increase in the frequency and severity of natural disasters like hurricanes and floods. Large areas of land will become inarable, greatly reducing our food supply, and hundreds of millions of people will be exposed to extended periods of drought. Depending on which predictions are correct, the emissions reductions brought about by technologies like CSP could easily end up saving more lives than were lost to the holocaust. If that is not worth investing in, then I truly don’t know what is.

Gas in the Tank: How Methane could be the Future of Fuel

New research has shown that it may be possible for us to convert methane into fuel cheaply, quickly and on a large scale. The key to this energy revolution will be exploiting a type of bacteria known as methanotrophs. Methanotrophs are incredibly abundant in nature. They account for 8% of all heterotrophs on earth (organisms like us that have to ‘eat’ rather than photosynthesising their food). These incredible bacteria are capable of converting methane into methanol very easily, a process that has been referred to as the holy grail of modern chemistry. If we could perform this conversion as easily as methanotrophs, we could seriously cut down our GHG emissions.

Almost all the talk of climate change in the media focuses on CO2, as it is the most abundant greenhouse gas (GHG) on earth. It is not, however, the most potent. Not by a long shot. Over a 20-year period, methane is around 86 times more effective at trapping heat than CO2. This is worrying since humans have caused, in just 300 years, an increase in global methane from 715 parts per billion to 1774 parts per billion, the highest level in 650,000 years. That works out to about a fifth of all global warming, making methane the second most significant GHG on earth. Roughly 60% of all atmospheric methane is the result of human practices like large-scale animal agriculture and poorly-managed landfills.

Before I get going, I would like to acknowledge the paper “Biotechnological conversion of methane to methanol: evaluation of progress and potential” as it proved to be an extremely useful research source on this topic.

New research has shown that it may be possible for us to convert methane into fuel cheaply, quickly and on a large scale. The key to this energy revolution will be exploiting a type of bacteria known as methanotrophs. Methanotrophs are incredibly abundant in nature. They account for 8% of all heterotrophs on earth (organisms like us that have to ‘eat’ rather than photosynthesising their food). Methanotrophs were first identified way back in 1906 but in the 1970s, 100 types were isolated, characterised and compared in a landmark study. These incredible bacteria are capable of converting methane into methanol very easily, a process that has been referred to as the holy grail of modern chemistry. If we could perform this conversion as easily as methanotrophs, we could seriously cut down our GHG emissions.

In May of 2019, researchers at Northwestern University identified the cofactor involved in catalysing the conversion of methane to methanol, providing a huge step forward in our understanding of how methanotrophs carry out this incredible process. Methanotrophs are known to carry out the conversion using an enzyme called methane monooxygenase (MMO), but the researchers have now identified the copper ion which accelerates this process and the site at which that copper ion is bound.

Methanol is an energy-rich fuel that can be used for everything from automobiles to electricity generation. In fact, methanol can be put straight into a standard internal combustion engine, meaning that we would not need to design new types of engines in order to make the switch. Burning methanol in an engine produces 20-25% less GHGs than burning petrol, but even these emissions are cancelled out by the fact that methane is removed from the atmosphere to produce the fuel. In other words, it’s already better than burning petrol, and the fact that it removes methane makes it better still. Remember, methane is far more potent than CO2 as a GHG. By converting methane to methanol then using the methanol as fuel, you are essentially converting methane to CO2, which causes much less global warming. The conversion happens at a ratio of 1:1, meaning that simply converting methane to CO2 would result in a serious decline in GHGs in the short term. In addition, the energy you get from burning the methanol means that you don’t have to burn as many fossil fuels, further lowering the carbon footprint of the process.

Right now, we are able to convert methane to methanol. In fact, we have been doing this on a relatively large scale for quite some time now. In 2015, the global demand for methanol was 70 megatons. The difference between current methods of converting methane to methanol and using methanotrophs instead is the temperature and pressure under which the reaction can be carried out. Current methods require temperatures of 900 degrees Celsius and pressures of 3 megapascals. In other words, that is roughly the same temperature as lava and roughly the same pressure that is exerted on a submarine 1,000 feet below the sea. Methanotrophs can perform the same conversion at room temperature and atmospheric pressure (the normal pressure at sea-level). This is known as ‘ambient conditions’ and describes the temperature and pressure wherever you are reading this article (provided you are not reading this in a volcano or a submarine).

The problem with needing extremely high temperature and pressure to perform the reaction is that it requires a lot of energy, cancelling out many of the gains made with respect to GHG emissions. That energy needs to come from somewhere and 9 times out of 10 that somewhere is fossil fuels. In addition to this, the process is currently too expensive to be economically viable, a factor that hugely influences whether or not a technology enters the mainstream. If we can harness methanotrophs’ ability to convert methane to methanol at ambient temperature and pressure, the process will become far cheaper, far quicker and far more environmentally friendly.

There is an important distinction to be made between low affinity and high affinity methanotrophs. Low affinity methanotrophs are found only where there are high concentrations of methane (more than 40 parts per million). So far, every strain of methanotroph we have isolated has been low affinity. High affinity methanotrophs, on the other hand, can perform the conversion at ambient levels of methane (less than 2 parts per million). Isolating and exploiting high affinity methanotrophs is the real holy grail, since this would allow us to convert the methane in the air all around us into fuel rather than just being able to perform the conversion in places where concentrations of methane are high.

Another way this process might reduce GHGs is by creating an incentive for oil companies to stop ‘flaring’ natural gas when exploring for oil. As you bring the oil to the surface, natural gas comes with it. To prevent pressure building up in the pipes, the gas is burned (which is why you sometimes see oil wells with flames shooting out the top). 4% of all natural gas which is extracted worldwide is flared. Using 2017 figures, that works out to 139 billion cubic meters of gas wasted every year (nearly 1 and a half trillion Kwh). That is slightly more energy than is used each year in India, a country with nearly one and a half billion people. Since natural gas is around 85% methane, development of cheap methane-methanol conversion techniques would provide an incentive to capture and store the gas rather than burning it unnecessarily and releasing huge amounts of GHGs into the atmosphere in the process. This is an example of how we can use our current knowledge of low-affinity methanotrophs to begin cutting down on emissions.

Transporting methane is currently very difficult, since it is a gas under ambient conditions. Liquids take up far less space than gases and are also far more energy-dense. By converting methane to methanol, we seriously boost how much potential energy can be carried by a single truck. By cutting down on how many trips are required to transport the same amount of energy, we also cut down on the fuel required for transportation. Efficiency gains such as this will be vital in our transition to a sustainable society if we wish to retain our current levels of comfort.

Burning methanol is also far cleaner than burning petrol, releasing half the carbon monoxide and just 1 eighth of the nitrous oxide. Over a 100-year period, nitrous oxide has a global warming potential 265-298 times greater than CO2. The reason you don’t hear as much about it in the media is that we release far less nitrous oxide into the atmosphere than we do CO2 or methane. The problem of climate change is so huge and so urgent, however, that we need to look at ways to reduce every GHG all at once by whatever means possible. An eightfold reduction in nitrous oxide from transport would go a long way.

One possible issue with this technology is that methane is only more potent than CO2 in the short term (a century or two). It could be argued that since CO2 stays in the atmosphere for thousands of years, we are simply pushing the problem back without solving it. To this I would reply that we are dangerously close right now to setting off feedback loops which would take climate change out of our hands and make the problem unsolvable. By procrastinating on this massive issue, we give ourselves time to develop technologies that can capture CO2 on a large scale as well as technologies that can provide us with clean energy. In other words, we are in desperate need of a band-aid.

Another objection might be that the process provides a financial incentive to keep fracking for natural gas when really we need to be leaving it in the ground. This objection, I think, holds more water. While burning methanol is more environmentally friendly than simply burning the natural gas, it is less environmentally friendly than not burning it at all. One way to respond to this is by arguing that it is naïve to think that we will stop extracting natural gas and oil any time soon. Global energy demand is huge and rising and these needs must be met somehow. It is better to meet them using efficient new technologies than to continue the practices that got us into this mess in the first place. In addition, if we can develop this technology to the point where we can remove atmospheric methane rather than just converting natural gas to liquid, it could actually result in negative emissions, meaning that we would be simultaneously meeting our energy needs and reducing our impact on the environment. The potential for this technology is massive.

Conversion of methane to methanol under ambient conditions and on a large scale would be a huge step forward in developing the green energy infrastructure that is required if we are to transition to a low-carbon world. I’ve said it so many times before, but it bears repeating that if we don’t make this transition very soon, the consequences will be extremely severe for humans and other animals around the globe. We are talking about a worldwide shortage of food and water, an increase in the frequency and severity of natural disasters, rising sea-levels and much more.

Climate change is happening right now all around us, from the wildfires of California to the hurricanes of Puerto Rico. How we respond in the coming years determines whether this will be a difficult century on one hand, or a complete transformation of the Earth that could last for hundreds of thousands of years on the other. So long as we can limit warming to below the levels required to trigger feedback loops, I have faith that humans can ride out the storm relatively unscathed. It is worth remembering, however, that this is the greatest challenge our species has ever undertaken. This is why the development of technologies like methane to methanol conversion is so critical and so time-sensitive. This tech will not solve the problem all by itself, but it will give us some time and breathing room to overcome the larger issue.

Shock Wave: Electricity From The Ocean

Some renewable technologies harness the vast mechanical power available from a planet that is in constant motion. Wave power generators (WPGs) are a possible energy source of the future, but how do they compare with their rivals?

First published in UCD College Tribune

Even in this futuristic world of ours, all our electricity is generated by simply spinning a turbine. The fossil fuels which are bringing us ever closer to a complete climate catastrophe are not just used to power our cars, but also to create steam which generates the electricity needed for everything from phones to lightbulbs. This is exactly the same principle employed by nuclear power plants. In both cases, fuel is used to create heat, which is used to generate electricity. There are ways, however, to generate electricity which do not require heat at all. Some renewable technologies harness the vast mechanical power available from a planet that is in constant motion. Wave power generators (WPGs) are a possible energy source of the future, but how do they compare with their rivals?

It is worth quickly comparing ocean energy and wind energy since the two are similar in a number of ways. This is why underwater turbines closely resemble those of wind farms. A major difference between the two is the potential energy contained within. Water is nearly 800 times denser than air, meaning that the same volume, travelling at the same speed, contains much more power. What this means on the practical side is that much smaller devices can produce the same yield of energy.

A major difference between WPGs and tidal power is the source of energy. Tides result from the gravitational pull of the moon dragging water up and down our shores as it passes by above us. WPGs, alternatively, find their energy source in the sun. Solar radiation does not heat the earth evenly. The air in places which receive more heat rises upwards, allowing colder air to rush in to take its place. That rushing of air is what we call wind. Since wind is the driving force behind waves, any energy that we harvest from waves comes indirectly from the heat of the sun. It is for this reason that WPGs are considered a renewable technology.

Tidal power is perhaps the most reliable source of energy on earth. Twice a day like clockwork, unimaginably vast quantities of water rush in and out of our coasts. Globally, there is as much power available from tides alone as there would be from nearly 5 and a half billion coal-burning plants. One of the problems, however, is that only a very small fraction of this energy could actually be harvested. There are only 40 or so places in the world where the difference between low and high tide is great enough to produce a worthwhile amount of power. One way that the power of the tides can be harnessed in such places is by building tidal ‘barrages’. These consist of huge dams which trap water from the rising tide, then release it slowly when the tide is low. As the water passes through the dam back into the sea, it spins a series of turbines to generate electricity.

WPGs come in a variety of forms. One very cool design that was deployed in the ocean as far back as 2004 resembles a giant sea-snake. Each segment of the snake is attached to the next by hinge joints which are connected to hydraulic rams. As the sections of the snake move back and forth over the waves, the hydraulic rams drive a series of electrical generators.

Another simple yet ingenious way of harnessing the power of waves is by using a device known as an oscillating water column (OWC). These machines consist of a hollow cylinder containing a turbine which is attached to a buoy. As the waves pass by underneath, air is forced up through the cylinder, spinning a turbine. What makes these devices truly remarkable is the special kind of turbine contained within. The so-called ‘Well’s Turbine’ is shaped in such a way that it can generate electricity regardless of which way the air is flowing. This means that power can be harnessed when the device is rising to the crest of a wave and also when it is falling to a trough, doubling the overall efficiency.

The final method for generating electricity from the ocean is called ocean thermal energy conversion (OTEC). This is another way we can indirectly generate solar energy using the ocean as a middle man. The way OTEC works is that a liquid with a low boiling point (like ammonia) is evaporated by the warm surface water of the ocean and expands, spinning a turbine. The ammonia vapour is then condensed using cold seawater and returned to the evaporation chamber to start the process over again.  The technology required for this method is simple and rapidly improving, meaning that OTEC is very much one to watch out for in the coming years.

So, which is better, WPGs or tidal barrages? WPGs hold greater promise in my view, largely because tidal barrages can be devastating to already strained marine ecosystems. Think about it; much of the ocean’s life is concentrated close to the shore. As the tide rises, both water and marine life can pass freely through the dam. Once that waterway is shut, however, the only way back to the sea is through a series of rotating blades. Many barrages are built on estuaries where rivers meet the sea. By preventing free movement through these estuaries, barrages can also seriously disrupt the spawning patterns of fish like salmon. WPGs, floating on the surface in open water, are much easier to build in a way that’s hospitable to marine life.

This is of vital importance; through plastic pollution, overfishing and ghost fishing, we have already utterly decimated almost all marine life. With plastic pollution and ocean acidification set to get much worse, we simply cannot afford to do any more harm to the beautiful animals that reside beneath the waves. If a plan is to be truly environmentally friendly, it must consider not only the CO2 it will emit, but also the effects it will have on our fellow animals. It is this major issue, coupled with the location problem mentioned earlier, which means that WPGs hold more promise than tidal barrages. In any case, it is clear that as both the financial and environmental costs of fossil fuels rise in the coming decades, blue power will assume an increasingly important position in the global energy industry.

Getting High on Grass – Can Plants Really Fuel a Plane?

Humans have been using biofuels for as long as we’ve been using wood to fuel our fires. In the last hundred or so years, however, we’ve begun to understand how plant matter can be converted into liquid fuels that could soon power a plane. In this piece, I’ll be looking at where biofuels are now and where they need to be if they are to significantly reduce CO2 emissions.

Updated 11/09/2019

In the wake of recent studies showing how dangerously close to the brink we are when it comes to climate change, it is more important now than ever to seriously consider every possible alternative to environmentally damaging fossil fuels. One such alternative comes in the form of biofuels. Humans have been using biofuels for as long as we’ve been using wood to fuel our fires. In the last hundred or so years, however, we’ve begun to understand how plant matter can be converted into liquid fuels that could soon power a plane. In this piece, I’ll be looking at where biofuels are now and where they need to be if they are to significantly reduce CO2 emissions. I’ll be concentrating my efforts on recent attempts by the scientific community to make grass a viable fuel for transportation.

Grass is the most abundant plant on the planet. In my home country of Ireland, more than two thirds of all land is covered in naturally growing grass. If we could refine and perfect the process of turning grasses into fuel (grassoline), this could be a real contribution towards slowing the march of climate change. The problem right now is that it is expensive and inefficient. Many scientists in the field, however, think that given time and money, we could tap into this huge source of unharnessed power and perhaps help to save the planet in the process.

The reason grass in particular is being considered as a biofuel is not because it is necessarily the most efficient plant to use, but rather because of its abundance and willingness to grow in fields that are inhospitable to food crops, known as marginal lands. Another reason that grass is attractive as a biofuel is that it is not really needed for anything else. Other candidates for biofuels (like wood, sugarcane and soybeans) have the disadvantage of being useful for things like furniture, rum and tofu.

But why aviation fuel? One reason is that while cars are slowly turning electric, it is unlikely that planes will follow suit any time soon. This means that in the near future, cars could be powered by renewable sources whereas planes will continue to require liquid fuel. The other more pressing reason is that travelling by plane is far worse for the environment than any other mode of transport. This is down to two factors; first, planes are less efficient than other modes of transport in terms of emissions per passenger mile. Second, planes allow us to travel a far greater number of miles than we would otherwise be able to travel. The carbon footprint of flying from London to Hong Kong and back again is about a quarter of the average UK person’s annual carbon footprint.

The idea that we could use grass, algae and other plants to produce aviation fuel is not nearly as crazy as it sounds. The fossil fuels which we currently use are themselves made of organic matter that has, over a very long time, undergone a natural process called pyrolysis. Human beings have been using the process of pyrolysis for our own gain for thousands of years in the form of charcoal burning. Pyrolysis involves separating materials into their constituent molecules in the absence of oxygen. This means, very roughly, heating up the material to a specified temperature, covering it, and allowing it to separate into liquid, solid and gas. These products can then be refined into fuels. Recently, it has been found that microwave heating produces a higher pyrolysis yield than traditional methods since it can be done entirely in the absence of oxygen and at a very precise temperature. Another benefit is that the characteristic ‘hot spots’ of microwave heating aid in pyrolysis.

You might be thinking that grass is an important source of food for livestock. The beauty of using grass as a biofuel is that this resource would not be lost. The solid by-product of grass pyrolysis can still be fed to livestock. What’s more, by removing the liquid constituents, the feed can be preserved much longer than fresh grass cuttings. In the UK, biofuels already account for nearly 3% of all road and non-road mobile machinery fuel, but with the predicted change in efficiency given a few years, they could eventually account for a lot more than that.

Right now, scientists can only produce a few drops of biofuel from grass in the laboratory. Tests carried out at Ghent University in Belgium show, however, that there is a potentially very efficient energy source in grass if we can learn to harness it correctly. In April 2017, the researchers at Ghent found that a certain type of bacteria (clostridium) can be used to metabolize certain grasses into decane, a key ingredient in both petrol and aviation fuel. While this breakthrough cannot yet be used effectively, it is key knowledge that will inform future research into better biofuel technologies.

Hang on, you might say, if refining plant matter gives us the same fuel as we are already using, then why is it better for the environment? Surely biofuels release the same amount of CO2 as fossil fuels? This is indeed true. The difference is that the CO2 in living plants has only recently been absorbed from the air by the plant and is simply being released again. As the grass grows, it sequesters CO2 from the air. When it burns, that recently absorbed CO2 returns to the atmosphere to be trapped by the next batch of grassoline. Because of this, biofuels are said to be ‘carbon neutral’. With fossil fuels, the CO2 has been absent from the environment for a very long time, trapped underground. By burning it, we are releasing extra CO2 rather than what was already there.

A major obstacle to biofuel efficiency growth is that governments and companies are not willing to invest heavily in something that may not yield solid results for years to come. This is simply short-sightedness. The science will continue to improve. Lack of investment only slows down the process. The people who invest heavily now will surely see a huge return in a matter of years. Another well-known obstacle in the way of all renewable energies is the huge sums of money tied up in the fossil fuel industry. The industry is worth about 7 trillion USD globally. No wonder, then, that lobby groups are able so easily to sway policy-makers.

Biofuels are controversial among environmentalists, since they come with a number of downsides. Perhaps the most worrying is that every square foot of land which is used to produce the fuel is land that could instead be used to nurture biodiversity. Species are currently being lost so quickly as to constitute the sixth mass extinction in earth’s history. For me, using food crops like corn as feedstock is entirely off the table, since it opens the door to a future in which rich elites use corn-fed biofuel to fly away on their holidays while depriving poor people of food which is vital to their survival.

Another drawback is that biofuels are not very efficient when it comes to land use. According to Mike Berners-Lee, using solar panels instead to generate the power for flying would require 270 times less land than growing wheat for biofuel. The problem, however, is building a good enough battery. Right now, 1 kilo of jet fuel carries about the same energy as 20 kilos of premium lithion-ion batteries. One ray of hope came in March of 2015; ‘Solar Impulse 2’ began its attempt to become the first entirely solar powered plane to fly around the world. The journey was arduous and long for the two pilots. One of the pilots was named Bertrand Picard, a Swiss medical doctor who who was already the first person to fly around the world non-stop in a hot air balloon. Captain Picard of the USS Solar Impulse finally landed the plane in Abu Dhabi on July 26th 2016, from the spot where it had departed 505 days earlier.

Regardless of what figures like the US president may say, climate change is a very real and very serious danger. Biofuels are just one example of the many ways in which we can combat this danger, but they are one which will continue to grow in importance for years to come. The question is whether our money would be better spent developing renewable energies like solar and wind which require far less land and are thus better for wildlife conservation. When it comes to planes, however, grassoline may help to ease the transition to a low-carbon world. Every little helps in the fight against the huge and menacing entity that is climate change.

Some Further Reading and Research Sources