One thing we have learnt this week- radiation danger Chernobyl 30 years on

In the first post I started giving some background information on radiation danger on the event of the 30th anniversary of Chernobyl.  Most people accept the dangers of high doses of radiation.  The disagreement is over whether constant small doses of radiation are bad for you.  This area is confusing with lots of polemical websites putting opposite points of view.  To add to the murk even for someone who has worked with radiation in the lab the units used are confusing.  A couple more background points (no pun intended) I need to made before we move on.  The first is that we are constantly exposed to radiation all the time.  The sources are from space (cosmic rays) and from naturally occurring radioisotopes in our bodies and environment.  Even this background dose seems to be disputed with some people saying its about 6millisieverts/year, others putting it lower at 1-3.  It is said to have risen due to bomb tests and civil nuclear power.  The second point is that radiation damage occurs by what is regarded as ionising radiation (that mentioned in the first post) forming free radicals.  These are shortlived atom(s) with unusual and unstable number of unpaired electrons.  They interact rapidly with chemicals in our body such as DNA damaging them.  This can lead to cancers but also other effects such cardiovascular disease.

There are several areas of uncertainty when it comes to low doses.  The first as was made plain in the letter given in the link above is where and how the dose is received.  The unit dose for gamma rays and alpha particles could be the same but the alpha emitter must be swallowed or on the skin.  Hence the dose could be delivered in a concentrated manner to one particular organ.  The same dose of gamma over the whole body would likely not be as damaging.  As an example of this I went to dentist today.  He would not give me an X-ray since it was too soon after the last one.  The dose would have been 0.1millisieverts which is not much in whole body terms, but of course I would be getting it on one small part of jaw.

The second area of uncertainty arises from if you were living close to Chernobyl what particular isotope you ingested.  I worked with Iodine-125 (the number refers to its atomic mass).  This is a potent gamma emitter and is produced in nuclear reactors.  Its leaked from reactors such as Calder Hall in the past.  However the turnover of iodine in the thyroid gland is very high.  We had a stock of iodine tablets, if you were irradiated you take some some of these and pee the radiation out.  Radioactive sodium or elements chemically similar to it would be the same.  The problem arises where the turnover is slow or almost non-existent.  Radioactive carbon is one example and strontium which is similar enough to calcium to end up in the bone marrow is another.

Another area of uncertainty is that the idea of a cumulative dose is hard to measure at low levels and hard to work with scientifically.

The last problem is due to the ethics of exposing people to low levels of radiation.  This tends to automatically limit the studies.  Theses (such as they are) have used Japanese bomb survivors, Chernobyl cleanup workers, people living around nuclear plants and astronauts (the dose they receive cannot really be described as low though).

The evidence stacks up as follows.  There do seem to be more cancers in Nagasaki survivors who received low doses (see  There has been one very large study on Chernobyl clean up workers which claims a significant increase in Leukaemia rates.  There have been some studies that have found Leukaemia rate increases around nuclear power plants.  To the best of my knowledge there have been no major increases in cancer rates in astronauts.

I would ask the following questions about the above.  How did scientists determine the Nagasaki survivors dose retrospectively and know it was low?   On the Chernobyl workers as we wrote in our book its hard in the ex-Soviet Union to determine whether someone has died of other causes due to the low life expectancy and very unhealthy lifestyles (its also difficult to get hold of such data in Russia).  On the childhood Leukaemia rates the data does not always prove a link (in fact in this table only one study does show a significant rate).  The problem with these latter studies as you will see is that the numbers are so small.  A small number of outliers can skew the stats.

Looking into this from what I have found I don’t think the low level radiation dose theory is proven.  However that does not mean I would want to live in the Chernobyl exclusion zone or think the scientific logic is flawed.  Essentially at an individual level you are looking a random event.  It takes changes to 3 or 4 genes to trigger cancer.  Radiation could be the trigger for all or none of these, it depends where you are are and what you are in contact with.  There is though a precautionary principle and many effects in biology are exponential i.e.  a small trigger has a huge effect.  There is no good reason to build more nuclear power stations for a variety of reasons -this is just another one. We may have to rely on space research to look for an answer here.


PS Incidentally I heard a epidemiologist on the 5pm news last night who confirmed my points on the Chernobyl workers it looks like there was an effect buts its hard to prove.

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Chernobyl 30 years on – is radiation all that dangerous?

The anniversary of the Chernobyl disaster is exactly 30 years ago this week.  There have been 3 major nuclear disasters (and countless near misses arguably).  The first was Three Mile Island in 1979.  This put some people off but the alternatives weren’t great.  The second was Chernobyl which changed my mind about nuclear power.  The third was of course at Fukishima which has confirmed many of our fears.  Now of course there are many and an increasing number of alternatives (which are also cheaper).  In all three disasters a total core meltdown was narrowly avoided.  Chernobyl was the worst since of the three since there was no proper containment.  The fear many of have is that the nuclear industry have little idea once a core meltdown is underway how to stop it and so far doing so has relied on a degree of luck.

Each disaster has cranked up Nuclear costs as more safety features are built in by regulators.  In the Western world this has led to a mere handful of reactors being started since Chernobyl and now an increasing number of pro-nuclear academics are questioning the existing safety regime in a bid to lower these costs.  Part of their argument is that radiation is not as dangerous as all that, so if there was another disaster things would not be that bad.  (I’ve actually heard this said on the radio over the last few months.)   Just what is radiation and just how dangerous is it?

First a bit of physics.  An atom is composed of a nucleus with elections orbiting around it (in simple terms).  The nucleus consists of protons (positively charged) and neutrons (as the name implies no charge).   These are added together and called the atomic mass (electrons being smaller are ignored).  The atomic mass is shown as a superscript in front of the element symbol (see below).  The atomic number (the number of protons is shown as a subscript).  The atomic number tells us which element it is.  The neutrons have no effect on the chemistry of the atom (slight exaggeration) and their number can vary for the same element.  Its the ratio of neutrons to protons that decides whether the element is stable.  A high number of extra neutrons (generally in heavier elements) makes it less likely.  Atoms that are not stable (and most are stable) undergo radioactive decay and produce sub-atomic bits we call radiation. There are four main types of radiation all of whose sources are a bit weird on the face of it and a full understanding probably depends on a deep knowledge of sub-atomic physics.  In releasing radiation the element changes into another.  As a final point these elements can be present in chemical compounds and that makes no difference to their decay.

The first type of radiation is when a neutron converts to proton and in doing so emits an electron (told you its weird).  This form of radiation is not too dangerous unless you ingest the source.  Electrons travel only very short distances through any matter including air.  In this example radioactive carbon 14 decays to nitrogen 14 (the normal form not radioactive).

beta decayThe next form produces anti-matter (yes it does exist) when a proton converts to a neutron.  This produces a positive electron.  When is this meets a normal electron its annihilated producing gamma rays (see below).  Little danger here unless the source is inside you are very close contact. In this example sodium decays to neon, beta is positively charged.

positron decayThe third form is alpha particle radiation.  This is a helium nuclei and is made up of protons and neutrons.  Again air and materials stop it, but if swallowed this is much more of a danger since the particles are bigger.  Here in this example the element radon decays to the radioactive gas radon.

alpha decayThe last form is gamma rays these are formed of electromagnetic radiation like light (except a much shorter wavelength).  These will travel large distances in air and through matter.  They are formed from the decay of alpha and beta emitters.  These can do great damage.

When a particular individual atom decays is a random unpredictable event.  How fast a group of atoms decays is predictable and the rate depends on the starting radioactive element.  These rates we call half lives.  This is simply the time that its takes mass x to decay to half its radioactivity.  The half life can vary from microseconds to 1019 years with everything in between.  Atoms that decay will end up as a stable non-radioactive elements.  Many atoms decay through a series of radioactive steps, the decay of radium shown above is part of the decay of uranium which ends up as lead.  In the next post I will look at the biological effects and the controversy.




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One thing we have learnt this week -ode to meters

metersCarol Ann Duffy the poet laureate is write an ode to gas meters.  As poet laureate her job is to comment on and to celebrate national life.  With conventional meters being phased out she wants to celebrate the demise of the whirring meter which apparently has been with us for 100 years.  The article mentions just gas meters but of course electricity meters are going as well.  All the old meters are supposed to go by 2020 to be replaced by smart-meters (not very long).

Whilst in a way this is a silly story there is a serious point to it.  This blog has written about smart meters a number of times.  It sees them as vital to managing our grid with a increasing amounts of renewable electricity.  It could save grid reinforcement and will certainly make billing easier for the energy companies (whether that will help the customers is a moot point).  My concerns are over the type of communication used to connect to the utilities and remote cut-off with the dangers of hacking which this entails.  There could also be crime issue with hacking as well.

I have a whole heap of different meters having multiple PV systems as well as gas.  Recently I had to have the electricity ones inspected by my energy company.  There were problems with this caused by my energy company which led to discussions on the phone.  They didn’t know that the government has prioritised smart meters for people with PV systems.  When I mentioned this they told something I did know, that current smart meters are not compatible with PV systems!  I’m not sure how many houses in the UK have PV systems fitted, you read different figures, but its certainly greater than 200,000 and even after the cuts increasing all the time.  Two issues arise from this problem.  First what happens if you try to fit a PV system to a house with a smart meter (relatively unlikely) and what happens if you already have a PV system (increasingly likely) and your utility turns up to fit one.  This whole business looks like running and running like a whirring old meter.  Maybe our poet laureate should write a poem about the whole saga.


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David MacKay an appreciation of his life

51YM3I8C0ML._SX434_BO1,204,203,200_On a visit to my parents I was surprised to see a copy of “Sustainable Energy – Without the Hot Air” by David MacKay lying around.  My father told me my brother had given him a copy since he had been at Cambridge at the same time as David MacKay.  I had heard of the book and read as much as I could whilst I was there.

Dr David McKay was born in 1967 and studied Natural Sciences and Physics  at Cambridge University.  After carrying out doctoral studies in the States on machine learning he continued his research at Cambridge.  This might have be have been it, a good but obscure career in Science if he had not written “Sustainable Energy – Without the Hot Air”.

In this he had a number of brilliant ideas.  The first was so simple (but like many innovations you wonder why you have not thought of it yourself).  This was to put all our energy use in kWh/day per person (for UK and USA), rather than barrels of oil, or millions of tonnes of oil equivalent etc.  The kWh is a unit that even we cannot define is something we are familiar with in our daily lives.  The second idea was to consider all our energy use for all we do in kWh.  Many books (and I’ve read some of them) simply say we can move over to renewables and that’s it.  The problem is as we tried to express in our book its not as simple as that.  At the moment carbon fuels and to a certain extent nuclear give us an excess of energy which means we do not have to worry about our energy use for material things which make up our total (hidden) energy demand.  Some of the examples he gives are shocking such as newspapers and magazines and aluminium cans (cans need 500W each to make).  He produced overall graphs of energy demand and supply in kWh/day per person.  When we can to write “No oil in the Lamp” he very kindly gave us permission to reproduce one of these without paying royalties.

In 2009 he was appointed as Chief Scientific officer at the Department of Energy and climate change.   Here David McKay came up with another innovation which was an on-line 2050 calculator, free for anyone to use.  In it you could come up with your own electricity system and see if you meet the UK climate targets (mandated under the climate change act).  You could choose all nuclear/solar etc or any combination thereof and see how far it got you.  This was an open source effort written in Ruby that anyone could join in.

Whilst I think David MacKay’s analysis of the problems was spot on, I did not always agree with his solutions.  He did not seem to recognise resource limitations which when you are planning longterm you must do.  He was very pro nuclear and given all that has happened since with Fukishima and the Hinkley C only confirms my anti-nuclear stance.  Indeed in some ways his energy calculator undermined his own arguments.  I had several goes with the 2050 calculator and could meet the 2050 climate target using only renewables*.   He did seem to recognise Uranium resource limitations, but his way round this was to extract it from seawater.  I got hold of one of the papers he cited and in my view he made a mistake in his calculations by a factor of 1000.  Uranium has been extracted from seawater on a minute scale but as the concentrations are in the order of parts per billion its simply impracticable.  Interestingly he was far more cautious about extracting lithium from seawater and this is a 1000 times more concentrated than uranium.

He also underestimated the speed and the fall in cost of solar or batteries (but has every excuse there), but more worryingly the contribution solar could make to the nations electricity supply.   We are now producing whilst not anything like the potential maximum he comes up with but at the same time disproportionately more than we should be in his terms, having barely scratched the surface of our roof and field space.  Partly this his caution in considering only the best south facing roofs when in actual fact roofs that face East or West give a reasonable power output.  Partly its that he considers fields and the domestic scale and not large commercial roofs (and we have barely started on these).

David McKay came from a strongly Christian background but lost his faith.  This background made him strongly aesthetic in his personal life according to some.  My last criticism of the his book was that it attempted to keep everything humming along as it is now.  What his book confirmed to me was this is not possible and its this that will be the difficult sell.  Its sad and shocking when someone dies so young.   His contribution to our future energy debate was immeasurable and he will be missed.


* closing the existing nuclear was not an option.

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One thing we have learnt this week – domestic energy prices

DSC_1715Over the last year or so as everyone knows oil and gas prices have fallen dramatically, why not domestic energy prices?  This is the question raised this week on the news.  This is particularly true of the “big six”.  But my experience of domestic energy prices with one of the 30 odd small suppliers the price of natural gas I pay has dropped a bit but not electricity.  This is very odd since the wholesale prices of energy have dropped if not to record levels certainly to the lowest levels for 2 years.

Its hard to think of any other reason for a lack of fall in domestic energy prices other than the big six are taking the opportunity to make excessive profits.  The best thing to do is to shop around.  Some of the domestic energy prices of the small suppliers are £300/year cheaper for both gas and electricity combined.


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Electricity prices and PV grid parity

776px-2013_Electricity PricesI found an interesting post that looks at the relationship between PV grid parity and electricity prices in the US.  The first thing to say is its complicated.   Whether a domestic PV system is grid parity with what comes up the garden path depends on a number of factors.  These include;

  • Orientation.
  • Solar insolation (how much light the place gets in a year).
  • Tax incentives/Feed in tariff.
  • How the user uses their solar electricity and how much they get paid if it goes to the grid.
  • Increasingly it will depend on energy storage, storing it and using it at night.  This is going to make increasing sense as the price of batteries falls.
  • Electricity prices.

The above post bases its economics on an installed cost of $3.50/W with the price installed falling towards $1.50 at some unspecified point.  The good news is that in crude terms quite a few places in the US are at grid parity now.  There is an overlap between the price per watt you would have bought your power in advance over the lifetime of your PV system (25 years) and the local electricity prices.  In some places the cost of power is more expensive than the PV power for 25 years.  However this relies on either getting a good export rate or using most of it yourself (difficult).  Lowering the costs gradually to $1.50/W installed cost is shown at the bottom of the post given in the link above.  At this price the whole of the US pretty much is at grid parity and for most people it will be far cheaper to buy the electricity upfront as a PV system on their roof.  (Its better than this now since the data is 2013 data).

What struck me though was the enormous range of electricity prices across the US.  Far more than here in the UK.  The map above shows its more than 5 fold.  Some lucky people are paying as little as 3 cents a watt in a limited part of Washington state.  In places such as California/Vermont/New Hampshire/Alaska  more than 25 cents a watt.  California I can understand with long running power supply problems.  Some of the other differences I cannot.  Its not based on competition.  The link above gives another link to the website where the above map came from.  This has a state by state guide to the number of utilities.  Washington has quite a low number whereas the others mentioned have quite a high number.  This regional variation is far higher than the UK which although the figures are not easy to get is about 20% max.  Any Americans got any ideas why the big difference I would be interested to know.  Meanwhile in some of these states it gives PV a huge opening.


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One thing we have learnt this week – Water power but not as we know it

DSCN1669When you hear or read the words water power like me you probably think of hydro but this week I learnt that Scottish Water are putting in a large PV array to power the water treatment works that provides my water.  In fact part of this story does involve more conventional water power in that I believe they are putting a hydropower scheme nearby as well for the same purpose.  You may also have heard of the floating PV array being put in at a water treatment works near London.  This is also going to be used to power some of the water treatment there.   Water companies are also putting in anaerobic digestion plants and wind turbines to power sewage treatment plants.

There is an important point here.  The array (ground mounted) in Edinburgh is going to be 250kWp, the floating array at the Queen Elizabeth II (QEII) reservoir near London will be 6.5Mwp.  Neither is meeting the entire energy needs at their respective sites.  The water we use at a domestic scale uses a lot of energy.  This falls into two parts, treatment and getting it to us.  The treatment (by which I also mean sewage treatment) takes a lot of energy but any pumping probably takes even more.  My understanding is that Edinburgh’s water supply from the reservoirs is entirely gravity fed.  However sewage and water treatment obviously still takes a lot of energy.  It really is worth conserving water for its energy use alone and switching that tap off when you clean your teeth.


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End of the oil age?

Rub_al_Khali_002Is Saudi Arabia signalling the end of the oil age?  There has been a lot in the press overt the last few days about the sell off of Aramco and this signifying the end of the oil age.  The Saudis have been quoted as saying they think the oil age is coming to an end and this is why they want to sell off their state oil company Aramco.  This would yield a 2 trillion dollar sovereign wealth fund which they would invest abroad to survive after the oil age.  However as some sceptics in the press rightly raise is this really what is going on?

Firstly, its only going to raise 2 trillion dollars if the country flogs the lot.  Is Saudi Arabia really going to sell everything off leaving no control over any part of it.  There is talk of selling 5% for starters.  Still a huge amount of money but hardly a sovereign wealth fund.

The second question is are the Saudis going to open up their books to the world particularly as regards reserves, which many people think are overstated?

Lastly, will the Saudi public actually see the money after the last few days news about the “Panama Papers”?

A sovereign wealth fund is a great idea but can only help an economy not substitute for it.  Saudi Arabians will need something to do on a day to day basis.  Also as this article suggests maybe they have not given up on oil totally after all…


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Beware energy scams

The recent CMA report brought despair to many of us since it seems to open up the way to mass energy scams.    The whole basis of crime has been altering in the developing world over the last 10 years or so, really since the advent of the internet.  There was a time when most crimes were physical.  People would break into your house, mug you, murder you, hold up banks etc.  This type of crime has been falling over the last 20 years in all developed countries whatever their criminal justice systems are like.  The exception is gun crime in the US, but even there overall crime is down.  No one is quite sure why this is happening and there are dozens of theories.  (Mine for what its worth on why there are almost no bank jobs in the UK is that getaway is almost impossible due to the traffic in city centres.)

However a new type of crime and a completely different type of criminal is making an appearance.  It started with the “419” scams from Nigeria.  Moved on through the “I’ve been robbed on holiday please send me some money” scams.  Now we are onto empty the bank account through getting hold of your mobile phone details (for online banking).   There are also lots of telephone scams and many of these are energy scams.  Such is the volume of this stuff its threatening to send the crime statistics into reverse.  A couple of interesting questions are raised by all of this.  The type of person that is doing these “white collar” crimes is very different to the type of person who broke into your house (who quite frankly didn’t have the intelligence to make as much money doing anything else).  Before the internet were all the potential white collar criminals working in other jobs wishing they could find some fraud to get involved in?  And are there a bunch of people now sitting around wishing they could steal cars?  In other words in Christian terms are people inherently dishonest?

All this does not help us when we are deluged with scam emails (which we are) or scam phone calls.  We get a lot of these phone calls and most of these are energy scams.  The green deal was cut by this government last summer but you would believe how many calls we had on this subject claiming grants were available.  We then moved onto a lot along these lines;

“every house in Scotland needs a boiler up to current regulations by the end of 2016″

Quite untrue for existing properties.  More recently its a more generic one about the government (not sure which one) wanting all properties to meet energy standards by the end of 2016.

What can you do?  Not a lot since a lot of the calls come from abroad.  This is why the CMA report is so worrying since it will open the floodgates of energy scams again.  If you sign up to the UK’s telephone preference service (easy to do online), then its illegal to contact you from within the UK.  There is a text number 7766 I think to block texts as well.  When I have challenged people who have rung me saying this the UK based ones put the phone straight away.  The problem is for overseas calls, one of these swore at me and said he was in Spain.  BT is joining other providers in attempting to stop this using lists of banned numbers.  But the basic advice is don’t buy online.  Keep your number to yourself.  Block calls if you can and if an offer seems to good to be true it probably is.  Lastly prepare for a deluge of ones offering you to switch to a cheaper energy supplier.


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One thing we have learnt this week – Israeli tower of power

220px-Solar_troughs_in_the_Negev_desert_of_IsraelIsrael is building the world’s tallest tower of power (solar tower) in the Negev desert.  Whilst I’m not going to get into the politics of Israel/Palestine I disagree with actions on both sides.   However, its fair to say that since 1948 Israel has felt surrounded by enemies and after the 1973 oil shock this has influenced its energy policy to a certain extent.  It as we wrote in our book became one of the largest utilisers of solar hot water panels (along with Japan).  However, despite its sunny disposition its been slow on the solar PV uptake, although in recent years this surged.  Still only 10% of Israel’s energy is set to come from renewables by 2020.  This tower of power will generate 1% of Israel’s electricity consumption.  It works by having many thousands of mirrors (50,000) focus their reflected rays onto a central focal point (240m high).  This heats either water or increasingly salt solution up which drives turbines.  Using salt allows the heat to be stored for longer so these towers work after dark.

This tower of power is quite a lot of effort for 121MWp of energy.  I wonder whether it might been better to have stuck PV modules on buildings?   Its also a potential terrorist target.


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