Tag Archives: technology

Current trends in solar

Barak Obama talking up the solar power industry

Barak Obama talking up the solar power industry

i was reading an article recently called how solar power workswhich was quite informative, but it mentioned that some 41,000 homes in Australia had solar PVs on their rooves by the end of 2008, and this was expected to rise substantially by 2009. This sounded like a very small figure, and I wondered if there was more recent data. A quick search turned up a swag of articles charting the rise and rise of rooftop solar installations in recent years. The data in just about every article came from the Australian Clean Energy Regulator (ACER). Australia swept past 1 million domestic solar installations in March 2013 with solar advocates predicting a doubling, at minimum, within the following two years. That hasn’t happened, but still the take-up has been astonishing in the past six or seven years. This article from a month ago claims 1.3 million PVs, with another 170,000 systems going up annually, though it doesn’t quote sources. Others are saying that the industry is now ‘flagging’, due to the retreat of state-based subsidies, though the commercial sector is now getting in on the act, having recently tripled its share of the solar PV market to 15%. The current federal government seems unwilling to make any clear commitment to domestic solar, but the Clean Energy Finance Corp, which was established by the Gillard government, and which the Abbott government wants to axe, is now engaged in a deal with ET Solar, a Chinese company, to help finance the solarisation of shopping centres and other commercial energy users. Shopping centres, which operate all day virtually every day, would seem to be an ideal target for solar PV installation. Presumably these projects will go ahead as the Abbott government seems unable or unwilling to engage in Senate negotiations which will allow its policies, including those of axing the entities of previous governments, to progress.

There’s so much solar news around it’s hard to keep track of, but I’ll start locally, with South Australia. By the end of 2014 some 23% of SA homes had solar PV, a slight increase on the previous year. One effect has been to shift the peak power period from late afternoon to early evening (just after 7PM). South Australia leads the way with the highest proportion of panels, with Queensland close behind. Australia’s rapid adoption of rooftop solar is surpassed only by Japan. The Japanese are now voting decisively against nuclear energy with their panels.

SA-Bozing-day-solar

This graph  (from the Renew Economy website) shows that on Boxing Day last year (2014) rooftop solar in SA (the big yellow peak) reached one third of demand in the middle of the day, and averaged around 30% from 11.30am to 3.30pm. With our heavy reliance on wind power here, this means that these two renewable power sources accounted for some two thirds of demand during that period. Sadly, though, with the proposed reduction of the Renewable Energy Target, wind and solar (small and large scale) are being forced to compete with each other for more limited opportunities.

There are some short-term concerns. Clearly the federal government isn’t being particularly supportive of renewables, but it’s highly likely the conservatives will be out of office after the late 2016 election, after which there may be a little more investment certainty. There’s also clear evidence now that small-scale solar uptake is declining, though it’s still happening. Profit margins for solar companies are suffering in an increasingly competitive marketplace, so large-scale, more inherently profitable projects will likely be the way of the immediate future. Still, the greater affordability of solar PV over the last few years will ensure continued uptake, and a greater proportion of households taking advantage of the technology. According to a recent International Energy Association (IEA) publication:

The cost of PV modules has been divided by five in the last six years; the cost of full PV systems has been divided by almost three. The levelised cost of electricity of decentralised solar PV systems is approaching or falling below the variable portion of retail electricity prices that system owners pay in some markets, across residential and commercial segments.

The 2014 publication was a ‘technology roadmap’, updated from 2010. Based on the unexpectedly high recent uptake of solar PV, the IEA has revised upwards its share of global electricity production from 11% to 16% by 2050. But on the barriers to expansion, the IEA’s remarks in the foreword to this document read like a warning to the Australian government

Like most renewable energy sources and energy efficiency improvements, PV is very capital-intensive: almost all expenditures are made up-front. Keeping the cost of capital low is thus of primary importance for achieving this roadmap’s vision. But investment and finance are very responsive to the quality of policy making. Clear and credible signals from policy makers lower risks and inspire confidence. By contrast, where there is a record of policy incoherence, confusing signals or stop-and-go policy cycles, investors end up paying more for their finance, consumers pay more for their energy, and some projects that are needed simply will not go ahead. 

The four-year gap between each IEA roadmap may be too long, considering the substantial changes that can occur in the energy arena. There was greater growth in solar PV capacity in the 2010-2014 period than there was in the four previous decades. The possibilities of solar energy really began to catch on with the energy crisis of the seventies, and the technology has received a boost more recently due to climate change and the lack of effective leadership on the issue. The charge was led by European countries such as Germany and Italy, but since 2013 China has been leading the pack in solar PV adoption.

What, though, of the long-term future? That’s a subject best left for another post, but clearly solar is here to stay, and its energy share will continue to expand, a continued expansion that is causing problems for industries that have traditionally (though only over the past couple of centuries actually) profited from our expanding energy needs. Our future is bound up in how we can handle transitions that will be necessary if we are to maintain energy needs with a minimum of damage to our biosphere.

anti-matter as rocket fuel?

easy peasy

easy peasy

This post is in response to a request, I’m delighted to report.

I remember learning first about anti-matter back in about 1980 or 81, when I first started reading science magazines, particularly Scientific American. I learned that matter and anti-matter were created in the big bang, but more matter was created than anti-matter. If not for that I suppose we wouldn’t be here, unless we could be made from anti-matter. I’m not sure where that would leave anti-theists, but let’s not get too confused. We’re here, and so is anti-matter. Presumably there are plenty of other universes consisting mostly of anti-matter, though whether that excludes life, or anti-life, I’ve no idea. Confusion again. If you’re curious about why there’s this lack of symmetry, check out baryogenesis, which will feed without satisfying your curiosity – just what the doctor ordered.

The next time I found myself thinking about anti-matter was in reading, again in Scientific American, about positron-emission tomography (PET), a technology for scanning the brain. As the name implies, it involves the emission of positrons, which are anti-electrons, to somehow provide a map of the brain. I was quite amazed to find, from this barely comprehensible concept, that anti-matter was far from being theoretical, that it could be manipulated and put into harness. But can it be used as energy, or as a form of fuel? Due to anti-matter’s antagonism to matter, I wondered if this was feasible, to which my 12-year-old patron replied with one word – magnets.

The physicist Hans Georg Dehmelt received a Nobel Prize for his role in the development of ion traps, devices which capture particles of different kinds and charges, including antiparticles, within magnetic and electrical fields, so clearly my patron was onto something and it’s not just science-fiction (as I initially thought). It’s obvious from a glance through the physics of this field – using ion traps to analyse the properties and behaviour of charged subatomic particles – that it’s incredibly arcane and complex, but also of immense importance for our understanding of the basic stuff of the universe. I won’t be able to do more here than scratch the surface, if there is a surface.

The idea is that antimatter might be used some time in the future as rocket fuel for space travel – though considering the energy released by matter-antimatter annihilation, it could also have domestic use as a source of electricity. To make this possible we’d have to find some way of isolating and storing it. And what kind of antimatter would be best for this purpose? The sources I’m reading mostly take antiprotons and also anti-electrons (positrons) as examples. The potential is enormous because the energy density of proton-antiproton annihilation is very many times that of equivalent fission reactions. However, experts say that the enormous cost of creating antimatter for terrestrial purposes is prohibitive at the moment. Better to think of it for rocket propulsion because only a tiny amount would be required.

Three types of antimatter rocket have already been proposed: one that uses matter-antimatter annihilation directly as a form of propulsion; another that uses the annihilation to heat an intermediate material, such as a fluid, and a third that generates electricity from the annihilation, to feed an electric spacecraft propulsion system. Wikipedia puts it this way:

The propulsion concepts that employ these mechanisms generally fall into four categories: solid core, gaseous core, plasma core, and beamed core configurations. The alternatives to direct antimatter annihilation propulsion offer the possibility of feasible vehicles with, in some cases, vastly smaller amounts of antimatter but require a lot more matter propellant. Then there are hybrid solutions using antimatter to catalyze fission/fusion reactions for propulsion.

A direct or pure anti-matter rocket may use antiproton annihilation or positron annihilation. Antiproton annihilation produces charged and uncharged pions, or pi mesons – unstable particles consisting of a pair of quarks – as well as neutrinos and gamma rays (high energy photons). The ‘pion rocket’ channels this released energy by means of a magnetic nozzle, but because of the complex mix of energy products, not all of which can be harnessed, the technology currently lacks energy efficiency. Positron annihilation, on the other hand, only produces gamma rays. To use gamma rays as a form of propulsive energy has proved problematic, though it’s known that photon energy can be partially transferred to electrons under certain conditions. This is called Compton scattering, and was an early proof of the particulate nature of light. Recent research has found that intense laser beams can produce positrons when fired at high atomic number elements such as gold. This could produce energy on an ongoing basis, eliminating the need for storage.

The more indirect types are called thermal antimatter rockets. As mentioned, these are divided into solid, gaseous and plasma core systems. It would be beyond my capacity to explain these technologies, but the finding so far is that, though plasma and gas systems may have some operational advantages over a solid system, the solid core concept is much more energy efficient, due to the shorter mean free path between energy-generating impacts.

It’s fairly clear even from my minuscule research on the subject that antimatter rocketry and fuel are in their early, speculative stages, though already involving mind-numbing mathematical formulae. The major difficulties are antimatter creation and, where necessary, storage. Current estimates around the technology are that it would take 10 grams of antimatter to get to Mars in a month. So far, storage, involving freezing of antihydrogen pellets (cooled and bound antiprotons and positrons) and maintaining them in ion traps, has only been achieved at the level of single atoms. Upscaling such a system is theoretically possible, though at this stage prohibitively expensive – requiring a storage system billions of times larger than what has so far been achieved.  There are many other problems with the technology too, including high levels of waste heat and extreme radiation. There are relativistic problems too, as the products of annihilation move at relativistic velocities.

All in all, it’s clear that antimatter rockets are not going to be with us for a long time, if ever, but I suspect that the technical issues involved and the solutions that might be nutted out will fascinate physicists and mathematicians for decades to come.

nuclear power, part 2 – how it works

PressurizedWaterReactor

There are many tricky questions around nuclear power, and perhaps the most head-scratching one is, why did the most earth-quake prone country in the world embrace this technology so readily? The well-known environmental scientist Amory Lovins was just one to state the bleeding obvious with this remark: “An earthquake-and-tsunami zone crowded with 127 million people is an un-wise place for 54 reactors”. Combine this with a secretive governmental and industry approach to energy production in a cash-strapped economy, and disaster was almost inevitable. There were a number of earthquake-related shut-downs and cover-ups before the Fukushima disaster essentially blew the whistle on the whole industry, turning the majority of Japan’s population against nuclear power almost overnight. After Fukushima, the generation of nuclear power worldwide fell dramatically largely due to the shut-down of Japan’s 48 other nuclear power plants, though facilities in other countries were also affected by the publicity.

Yet it’s reasonable to ask whether other countries, such as Australia, should reject nuclear power outright because of Japan’s bad example. Australia rarely suffers serious earthquakes – South Australia almost never. And there may be safer ways to utilise nuclear fission as energy – now or in the near future – than has been employed in Japan or other countries since the sixties. So, just how do we generate nuclear power, how do we get rid of waste material, and are there any developments in the pipeline that will make generation and storage safer in the future?

How’s the energy produced?

Much of the following comes from How Stuff Works, but for my sake I’m putting it mostly into my own words. We derive energy from nuclear fission in the same way that we derive energy from coal-fired power stations – by turning water into pressurised steam, which drives a turbine generator. The difference, of course, is the source of the heat – uranium rather than carbon-emitting coal. Nuclear reactors create a chain reaction which splits uranium nuclei into radioactive elements, releasing energy in the process. A thorium fuel cycle rather than a uranium one is also possible, though with limited market potential at this point.

Uranium, in the form of isotope U-235, can undergo induced fission relatively easily. However, naturally occurring uranium is over 99% U-238, so the required uranium has to be enriched so that the U-235 content, which is naturally at around 0.7%, is increased to around 3% (weapons-grade uranium enrichment requires over 90% U-235). The enriched uranium is formed into pellets, each about 2.5 cms long and less than 2cms in diameter. These are arranged into bundles of long rods which are immersed in a pressure vessel of water. This is to prevent overheating and melting. Neutron-absorbing control rods are added to or subtracted from the uranium bundle, by raising or lowering, and these control the rate of fission. Completely lowering the control rods into the bundle will shut the reaction down.

The fissioning uranium bundle turns the water into steam, and then it’s just the technology of steam driving the turbine which drives the generator. But then there’s the matter of radio-activity…

Before we get into that, though, I should mention there are different kinds of reactors, which use different systems and different cooling agents. I’ve been rather cursorily describing a Light Water Reactor, the most common type. They use normal or regular water, and there are three varieties: pressurised water reactors, as described; boiling water reactors, and supercritical water reactors. There are also heavy water reactors which use water loaded with more of the heavier hydrogen isotope called deuterium. But whatever is used as a coolant and/or a neutron moderator (a medium that moderates the speed of neutrons, enabling them to sustain a chain reaction), the issue of radio-activity needs to be dealt with.

What are the safeguards against radioactive decay? 

What I previously termed ‘induced fission’ involves firing neutrons at U-235 nuclei. The nucleus absorbs the neutron and then becomes unstable and immediately splits, releasing a great deal of heat and gamma radiation from high energy photons. Among the products of the split are fissile neutrons, which then go on to split more nuclei, a chain reaction which can be controlled with the manipulation of control rods as described above. Uranium 235 and Plutonium 239 are among the very few fissile nuclei – those that lend themselves readily to nuclear chain reactions – that we know of.

The trouble with induced fission is that the products of the reaction are vastly more radioactive than the fissioned material, U-235, and their radioactive properties are long-lasting, leading to the obvious problems of safeguard, storage and elimination.

In standard light water reactors, the pressure vessel is housed in concrete, which is in turn housed in a steel containment vessel to protect the reactor core. Refuelling and maintenance equipment is housed within this vessel. Surrounding this we have a concrete building, a secondary containment structure to prevent leakage and to protect against earthquakes or other natural (or man-made) disasters. There was no such secondary structure at Chernobyl. The nuclear industry argues that, when these safeguards are properly maintained and monitored, a nuclear power plant releases less radioactivity into the atmosphere than a coal-fired power plant.

Even if this wins some people over, there are the really big issues of mining and transportation of uranium and nuclear fuel and storage of radioactive waste. According to the USA’s Nuclear Energy Institute, 2000 metric tons of high-level radioactive waste are produced annually by the world’s nuclear reactors, which is hazardous to all life forms and can’t be easily contained. This radioactive material takes tens of thousands of years to decay. Low-level waste, which contaminates nuclear plants and equipment, can take centuries to reach safe levels.

Storage, or possible recycling, of waste is probably the major issue for the nuclear power industry’s future, in spite of all the understandable current attention given to melt-downs. The How Stuff Works website summarises the present situation:

Currently, the nuclear industry lets waste cool for years before mixing it with glass and storing it in massive cooled, concrete structures. This waste has to be maintained, monitored and guarded to prevent the materials from falling into the wrong hands. All of these services and added materials cost money — on top of the high costs required to build a plant.

In my next, and hopefully last, post on this subject (for a while at least), I’ll focus more on this storage issue, and on other developments in nuclear fuel, such as they are. I’ll be relying particularly on the MIT interdisciplinary study ‘The Future of the Nuclear Fuel Cycle’, which came out in 2011 – just when the Fukushima-Daiichi disaster hit the headlines…  

energy solutions: nuclear power, part one – the problematic past

 

jordan-nuclear-energy-protest2    images

Here in South Australia, our Premier (the leader of the government) has recently announced a major inquiry into the viability of nuclear power for the state, and this is raising a few eyebrows and bringing on a few fevered discussions. The Greens are saying, what need for that old and dangerous technology when we have the prefect solution in renewables? Many scientists are arguing that all options should be on the table, and that our energy future should be flexible with many different technologies in the mix – solar, wind, geothermal but also perhaps clean coal (if that’s not an oxymoron), a new-look nuclear technology, and maybe even a technology of the future, such as fusion – not to mention the harnessing of anti-matter, mentioned to me recently by an enthusiastic 12-year-old.

South Australia already has a great rep for adopting new technologies. According to wind energy advocate Simon Holmes a Court, in a talk podcasted by The Science Show recently, SA gets more than 30% of its energy from wind, and some 5% from solar. If SA was a country, it would be at the top of the table for wind power use, a fact which certainly blew me away when I heard it.

Of course, South Australia also has a lot of uranium, a fact which has presumably influenced our young Premier’s thinking on nuclear energy. I recall being part of the movement against nuclear energy in the eighties, and reading at least one book about the potential hazards, the catastrophic effects of meltdowns, the impossibility of safe storage of nuclear waste and so forth, but I’ve also been aware in recent years of new safer types of fuel rods, cooling systems and the like, without having really focused on these developments. So now’s the time to do so.

But first I’m going to focus on the nuclear power industry’s troubled past, which will help to understand the passion of those opposed to it.

No doubt there have been a number of incidents and close things associated with the industry, but the general public are mostly aware of three disturbing events, Three Mile Island (1979), Chernobyl (1986), and Fukushima (2011). I won’t go into too much detail about these, as you’ll find plenty of information about them here, here and here, and in the links attached to those sites, but here’s a very brief summary.

The Three Mile Island accident was the result of a number of system and human failures, which certainly raised questions about complex systems and the possibility/inevitability of an accident occurring, but the real controversy was about the effects, or after-effects, of the partial melt-down. It’s inevitable that anti-nuclear activists would play up the impact, and nuclear proponents would play them down, but the evidence does suggest that, for all the publicity the accident garnered, the effects on the health of workers and residents of the area were minor and, where strongly claimed, largely unsubstantiated. Anti-nuclear activists have claimed widespread death and disease among animals and livestock in the region, while the local (Pennsylvania) Department of Agriculture denied any link. Research is still ongoing, but with so much heat being generated it’s hard to make sense of any light. One thing is certain, though. When an accident does happen, the costs of a clean-up, one that will satisfy everyone, including many of the nay-sayers, is astronomical.

Two reactors were built at the Three Mile Island site in 1974, and they were state-of-the art at the time. The second reactor, TMI-2, was destroyed by the accident, but TMI-1 is still functioning, and ‘remains one of the best-performing units in USA’, according to the World Nuclear Association, which, unsurprisingly, claims that ‘there were no injuries or adverse health effects from the accident’.

A much more serious accident occurred at Chernobyl in the Ukraine, then part of the Soviet Union. It has received a level 7 classification on the International Nuclear Event Scale, the highest possible classification (Fukushima is the only other accident with this classification; Three Mile Island was classified level 5). Thirty-one people died as a direct result, and long-term radiation effects are still under investigation. The figures on cancer-related deaths are enormously varied, not necessarily due to ideological thinking, but due to different methodologies employed by different agencies in different studies. The difficulties in distinguishing the thousands of cancers resulting from the radiation and the millions of cancers suffered by people in the region over the 20 years since the accident can hardly be underestimated. Most analysts agree, however that the human death toll is well into the thousands.

The Chernobyl disaster is notorious, of course, for the response of the Soviet government. No announcement was made to the general public until two days afterwards. When it came, it was as brief as possible. Workers and emergency services personnel who attempted to extinguish the fire were exposed to very high (that’s to say fatal) levels of radiation. Others involved in the massive clean-up were also heavily exposed. The cost of the clean-up, and of building a new containment structure (the largest civil engineering task in history) amounted to some 18 billion roubles. A half a million workers were involved.

The Fukushima disaster was caused by a tsunami triggered by a 9 magnitude earthquake, and the destruction caused (a meltdown of 3 of 6 of the plant’s reactors and the consequent release of radioactive material) was complicated by the damage from the tsunami itself. It was a disaster waiting to happen, for a number of reasons, the most obvious of which was the location of the reactors in the Pacific Rim, the most active seismic area on the planet. Some of the older reactors were not designed to withstand more than magnitude 7 or 8 quakes, but the most significant design failure, as it turned out, was a gross under-estimate of the height required for the sea-wall, the fundamental protection against tsunamis. To read about the levels of complacency, the unheeded warnings, the degree of ‘regulatory capture’ (where the regulators are mostly superannuated nuclear industry heavyweights with vested interests in downplaying problems and overlooking failures) and the outright corruption within and between TEPCO (the Tokyo Electric Power Company) and government, is to be alerted to a whole new perspective on human folly. It is also to be convinced that, if the industry is to have any future whatsoever, tight regulation, sensible, scientific and long-term decision-making, and complete openness to scrutiny by the residents of the area, consumers and the general public must be paramount.

Though there’s ongoing debate about the number of fatalities and injuries caused by the nuclear power industry, that number is lower than the numbers (also hotly debated of course) caused by other major energy-generating industries. Commercial nuclear power plants were first built in the early seventies and 31 countries have taken up the technology. There are now more than 400 operational reactors worldwide. The Fukushima disaster has naturally dampened enthusiasm for the technology; Germany has decided to close all its reactors by 2020, and Italy has banned nuclear power outright. However, countries such as China, whose government is rather more shielded against public opinion, are continuing apace – building almost half of the 68 reactors under construction worldwide as of 2012-13.

It’s probably fair to say that Fukushima and Chernobyl represent two outliers in terms of operating nuclear power plants, both in terms of accident prevention and crisis management, and the upside of these disasters is the many lessons learned. I presume modern reactors are built very differently from those of the seventies, So I’m interested to find out what those differences are and what ongoing innovations, if any, will make nuclear fission a safer and more viable clean energy option for the future. That’ll mean going into some technical detail, for my education’s sake, into how this energy-generating process works. So that’ll be next up, in part 2 of this series.

solutions, an intro

Whatever-you-need-the-Solution-is-Here-Help-and-Assistance-on-EVERYTHING-Mozilla-Firefox-2014-05-26-18.34.57

Today as reporters report on the repeal of Australia’s carbon tax and people I know and many I don’t know on Facebook are urging us to join forces to bring down the government because of this and many other issues, I’m inclined to think beyond local politics and policies, not because they aren’t important but because protesting endlessly and talking of revolution isn’t as interesting to me as finding solutions, short term and above all long term, for the predicaments we’re faced with and the problems we’re beset with, and which sometimes we don’t feel beset with because, well, I have a job, at least for now, and I have food in my belly, I’m in relatively good health, I’m not at war with anyone, my future housing is secure and so forth. But we’re not islands, we suffer with those that suffer, we’re arguably the most social species on the planet, so the fate of people fleeing from persecution, or simply trying to get to places of greater opportunity, as well as the fate of the under-nourished, the under-educated, the exploited and mistreated, these are fates that impact on us, as we compare and contrast, as we feel guilty, or lucky, or angry or frustrated or saddened about the world we live in.

It’s true that on the face of it, Australia currently has a government that is in denial of anthropogenic global warming and has an ideological agenda of reducing government spending in areas we associate with our health and well-being, but I find it hard to believe that senior government ministers are truly anti-science, anti-innovation or indifferent to the sufferings of the poor, of refugees and so forth. The key is to engage their potential for doing the best for us all.

I’ve also been guilty, elsewhere, of mocking, dismissing and reviling ‘enemies’ – and let’s face it, many people do make it hard to engage with them positively – but it generally makes me feel better to report positively on developments and on people, to feel inspired by innovations and solutions.

And so to solutions, not just for we humans, but for all the other life forms we’re related to, which is of course all of them. But let’s start with humans, of whom there are currently nearly seven and a quarter billion on the planet according to the world population clock, an amazing site to clock into, though I can’t vouch for its accuracy. As I’m reminded by various sources, such as The Origin of Feces and Australia’s Cosmos magazine, this growing population is also consuming more calories per capita than ever before (2830 in 2009 compared to 2189 in 1961), and therefore producing more shit with the potential to contaminate our waterways, not to mention shit from livestock, nitrous oxide from fertiliser, methane and CO2 from farming, mining, industry and transport, and so on. Yet we are surviving and thriving for the time being, and beavering away at solutions to these problems, and solutions to the problems created by our solutions.

So this blog is an attempt to promote solutions to problems, large and small, global and local, serious and trivial and everything in between. I’m neither a technophile nor a technophobe, and I’m not a science nerd or a cool arts dude, I’m just an observer struggling to make sense of the messy and ingenious lives of us. Because of my lack of general expertise I may have to over-explain things to some in order to make sense of them to myself, but anyway, we’ll see.