One thing we have learnt this week – organic farming

harvest finished in autumn_optThe BBC consumer programme  “You and Yours” was turned over to organic farming for a whole programme on Monday.  The programme looked at a variety of aspects of organics from a Danish and UK perspective.  Denmark was chosen since it has the highest proportion of organic food sold in the world.  In it I learnt something surprising.   Organic farming could improve crop yields.

The general thought is that yields of organic crops are lower than non-organic crops.  This is for a variety of reasons.  Firstly most crops with the exception of legumes have been bred (using classical methods) to require huge volumes of nitrogen based fertilizers (see past blog posts on this site).  This produces high yields but takes a lot of energy and at a large environmental cost.  A large part of the destruction of the Great Barrier reef is down agricultural run off, as well as climate change.  Soils are also being destroyed by excessive use of nitrogen based fertilizers.  Another reason for lower crop yields (and production of meat) is pests and diseases.

Imagine my surprise when one of a number of farmers interviewed who was embracing organic farming was doing so to raise yields.  This farmer grew wheat (needs loads of nitrogen) but his harvest had dropped from 3 tonnes/Ha to 1tonne/Ha.  The reason?  Lots of black grass in his wheat.  I’d not heard of this, although I do recognise it.  Its a common and attractive garden plant, although clearly a huge pest.  It turns out the best way to deal with it is organically.  Other farmers were switching for economic reasons, they take a hit on yields but get a higher price.

The programme also looked at the alleged health benefits (better nutrition) of organic food.  This is much more contentious and difficult to prove.  To prove this you need to grow exactly the same crop variety, in exactly the same soil, under exactly the same environmental conditions, harvest it at the same time and analysis the crops in the same lab using the same instrumentation and reagents at the same time (and I’ve probably missed something out).  As this can prove difficult even in the same field, few studies have been done.   There have been some studies that suggest that organic milk has a higher content of 3-ω-fatty acids, one of the two essential fatty acids we need but cannot make.  However it has a lower concentration of 6-ω-fatty acids (the other one) and its unclear how much milk has anyway of this fatty acid.  It not listed as one of the main sources.  On a follow up report on today’s programme more questions were asked about the health benefits of organic food.  There are some studies to suggest that some pesticides act as “gender benders”.  This site had a look at this regarding fracking.  This seems plausible to me since a very wide range of different compounds can act in this way.  I would also point out that so many pesticides are withdrawn from use due to safety concerns.

I buy organic food on occasions and grow organic food, but I would not get hung up on it.  Its more important to eat a balanced healthy diet with as local food as possible.  However having said that it seems crazy not to buy something that avoids a whole heap of problems and is not sustainable in the long term.


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air pollution

1024px-Diesel_particulate_filter_01I’ve read a recent bit of research on air pollution from China.  The research looked at particulate  (PM10) levels across the major cities in China and the effect on mortality?  The findings were unsurprising in many ways but also showed some surprises.

  • PM10 levels vary widely from city to city.
  • A 10μg/m3 change in PM10 concentration raised the death rate by a mean of 0.44%.
  • The previous 2 days PM10 levels had a significant effect on death rates.
  • The effects were greater for cardiovascular and respiratory disease deaths.
  • Older people were much more vulnerable than young people to death.
  • The PM10 concentration had less effect in more polluted cities.

Of course diesel engines (much in the news at the moment) are not the only cause of PM10s.  So are a wide variety of other sources from coal fired power stations (common in China and other places but closing like mad), vehicle tyres, wood burning, petrol engines, industry and gas central heating.  So local effects are likely.  It could also depend on prevailing weather conditions.

The fact that the previous two days particulate concentrations is not surprising either.  Weather and the fact that the PM10 concentrations have to have a biological effect helps to explain that one.  You would also expect since you are looking at mortality that the cause of death will have to be acute.  It should be remembered that scientists are coming to the conclusion that long term effects are also occurring on fertility and the brain etc.

The last two conclusions are more surprising.  In the West PM10s have been found to have acute effects on the very young as well.  The last finding is even more surprising.  This suggests that air pollution effect are not cumulative?   One drawback of this useful piece of research is that other pollutants were not examined such as NOx, SOx, these also have effects on human health and maybe responsible for some of the mortality.  There is much to think about here as policymakers worldwide grapple with this problem.

BMJ 2017;356:j667


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One thing we have learnt this week – energy storage

Kraftwerk_Huntorf_innenEnergy storage gets talked about a lot at the moment.  When this subject is mentioned its almost always Li ion batteries.  There are other options for energy storage but these are tending to get forgotten about.  There is pumped storage of course but there are a also a variety of mechanical systems.  These include flywheels (there is I believe a small demonstration scheme in New York) and compressed air systems.  One of these has been operating in Germany since the 1970’s with 290MWp capacity and another smaller 110MWp in the US since the 1990’s.  Both seem to have operated without any problems.  It would be useful not to put all our eggs in the Li ion basket just in case there is not enough lithium for cars and other uses.

The technology is fairly straightforward.  A bit like a cycle tyre you use excess energy to compress air (to about the same pressure as a tyre) and store it under pressure, when you want energy you let the air flow out through turbines.  There are few drawbacks though.  If you ever pump a tyre up you will know the pump gets very hot.  This is because the molecules of air are colliding more and more with each other as the pressure increases.  As you will remember when you let the air out the opposite effect occurs.  The valve gets very cold.   This hot/cold dichotomy is regarded as a problem I think since the turbines work both ways and the kit cannot be expected to withstand extremes of temperature.  The air is usually cooled on compression and then warmed on decompression.   In principle the heat can be recovered from the compression phase and used in the second – either directly or indirectly and thereby raise the efficiency of the process.  Another drawback is implied by the above photo of the German plant, its not pretty, basically it looks like a huge warehouse.  The energy density is relatively low of such systems so it makes sense only to build very large schemes- hence extenuating the aesthetics problem.

The reason I’m writing this is that I learnt of a scheme in Northern Ireland to use caves with a larger compressed energy storage scheme.  The scheme has been awarded the funding as part of the EU’s TEN-E project (despite Brexit).  A little bit more background.  Northern Ireland has its own grid.  As far as I know its not connected to the Republics’ grid but is to the UK grid.  Electricity has always been more expensive in Northern Ireland, so much so that when the solar PV grant scheme was operating it was much more generous to take this into account.

Putting compressed energy storage into caves has drawbacks.  The oxygen must not react with the rock or interact with micro-organisms and of course must not leak.  For these reasons old salt workings are ideal and this is the type of cave at Islandmagee.

I hope this scheme goes ahead since one heck of alot of EU money has gone into it so far with even more to follow.  Whether this type of energy storage solution will become commonplace if caves are used I think is open to question.  Like nuclear each scheme would end up being individual and bespoke which makes it more expensive.  The uglier warehouse type could be very cheap to build though.  The technology is believed to be competitive with other energy generation systems.


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The biggest environmental problems

car data 2016The was an environmental sermon at church this week.  This got me thinking about what I considered the biggest environmental problems.  Whilst I don’t think we’ve got climate change and peak oil entirely licked, things at least on the energy front are moving strongly in the right direction.  Trump of course threatens action on these but even he will find it difficult to force up the costs of wind, solar and energy storage.

The biggest environmental problems currently in my view comprise the particulates issue and plastic pollution*.  The second of these is a real shocker.  Go anywhere in the country and shredded plastic is stuck on trees.  My garden is not completely immune and most if it is down to me, from bits of plastic sheeting I have used to cover stuff which has shredded in the wind.  My pledge is collect all this as I find it from now on.

On the former there was some very interesting articles on the radio this morning.  The Mayor of London Sadiq Khan is to introduce a congestion charge for diesel cars and independent emissions testing.  The most revealing interview was with the government’s former chief scientific advisor Sir David King who advised government 20 years ago when the decision to encourage diesels was made.  He said the decision was made to go far diesels for climate change reasons knowing that there was a problem over particulates but trusting the car manufacturers who promised to solve it.  The problem was they have not.  The graph above shows the depth of the problem on NOx.  The data is official data for current models on sale in the UK (source DFT).  The difference is extremely highly significant for over 2000 different models and shows that petrol cars produce significantly less NOx.  The error bars show the standard deviations of the data.  There is no doubt we need to change to petrol/electric/walking/cycling as fast as possible.

* of course these problems are related to the other two anyway.


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One thing we have learnt this week – solar fuels

Bill Gates recently visited a lab developDSC_2305ing solar fuels at Caltech.  Readers of this blog will know that I’m not a great fan of the so called hydrogen economy.  The problem with hydrogen is that has a very low energy density compared to other fuels.  Another drawback is that it will require a whole new infrastructure.  Add some carbon atoms to the hydrogen and the energy density increases dramatically.  There are long standing ways of doing this one way is to use the Fischer-Tropsch method.  In this an alkane carbon chain of any length can be built from carbon and hydrogen by tweaking the reaction conditions.  Whilst this method may have some applications in making chemical feedstocks in a post oil world the energy return is very poor since the reaction only occurs at very high temperatures (400-500°C).

What if you could make such fuels at low temperatures using light as the energy source to to split water to hydrogen and oxygen and then combine the hydrogen and carbon from carbon dioxide at low temperatures.  Sort of like photosynthesis, in fact some groups are trying to use this as a basis for making solar fuels.  Algae is one possibility people have been working on.  If the problems with this could be cracked then many of the drawbacks of the renewable economy.  There would be a source of renewable transport fuel, a way of tying up carbon from the atmosphere and even a means of storing renewable energy inter-seasonally.  However as we outlined in our book there is one major problem with all this.  That is land area.  If you considered using every plant as fuel on the planet then its unlikely there would be enough for our energy needs.  The land area to make even an appreciable dent in the liquid fuel replacement problem would be huge.


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Nuclear decommissioning costs

Nuclear decommissioning costsNuclear decommissioning costs are rising exponentially.  I heard Chris Huhne the disgraced former Energy secretary on the today programme this morning.  The UK government has had to pay out £100 million in compensation over the way it awarded a clean up contract.  However as Chris Huhne said this is not the real scandal.  The real scandal is not how much money has been wasted here but how much nuclear decommissioning costs have risen and are rising.  He helpfully gave some figures and those in the graph above come from him and I assume are correct I listened again and noted them down.  I’ve taken the “present” to be 2016 rather than 2017 since he was not explicit about the year.

What is truly frightening is how much nuclear decommissioning costs have risen in the last 5 years.  The current total is £171 billion or 8% of the national debt.   Chris Huhne gave a number of reasons for the very high cost.  Even reactors with the same design name i.e. “Magnox” were individual designs with major differences even the design of the fuel rods, such as shape.  Chris Huhne thought this would be better in the US where large numbers of reactors were built with the same design.  Another reason was of course that no thought was given to dismantling the stations.  The last reason is simply Sellafield.  Its a radioactive disaster area and tellingly records have been lost so people do not know precisely is stored there.  Whilst this cost is small when looked at from the point of view of spreading it over generations the frightening thing is the way is going up.  (It should be stated that the Department for Business, Energy & Industrial Strategy have graph on their website stating that costs other than Sellafield are falling).

This however all the above made me think.  First I doubt if the situation is much better in the US.  A large number of different designs were used there and the problem with nuclear power is that the individual plants take so long to build that design changes between plants are inevitable.  I also doubt any thought was given of how to take them down.  Secondly are we about to repeat the same mistakes?  We could be.  If EDF stagger through building Hinckley C its unlikely they will build any other reactors.  (Notice how since the deal was signed last autumn nothing has happened).  The Japanese have dropped out and there is talk of Chinese and Koreans coming in.  Even if they do then they are going to build only the odd reactor or two.  We will still end up with a number of completely different designs to cope with.  As for planned dismantling which is supposed to be built in.  First do not underestimate the difficulties of someone in 70 years time being to get hold of the instructions (how are they to be stored?) or understanding them especially with language difficulties.


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Solar health

2017-03-19 16.26.37The NHS is in fine solar health or at least growing solar health.  My father is unwell and has been in and out of hospitals over the last month or so.  It been noticeable that both hospitals that have given him treatment have solar panels on at least part of their roofs.  The systems are large by domestic standards but smaller than one I saw nearby on a nearby supermarket (that it had to be said was a very big system).

Its always struck me that hospital roofs were a huge potential solar resource from when I worked in a hospital building.  Hospitals are huge buildings and have vast amounts of roof space.  They also use enormous amounts of electricity.  At least in the UK they are not generally architectural masterpieces either so sticking PV modules on the roof is not going to ruin the building and may often improve its aesthetics.

One problem looming is that the government has made systems below 50kWp subject to business rates although discussions and lobbying are going on.  There are lots of other sustainability issues the health service needs to sort out.  Nevertheless well done NHS lets get every roof covered to solar PV.


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One thing we have learnt this week – Let there be light

Let there be light is not just Gods command in Genesis 1v3, but also a Tearfund campaign.  A major problem in the developing world is a lack of light at night.  This affects everyday life to a massive amount.  On earth day (coming up soon) try switching everything off for a few hours and see how it feels trying to read by candle light*.  This is a big problem for children doing their homework, safety for women etc.  But even small amounts of power can benefit the community in other ways.  For example pumping water, charging mobile phones, possibly even using computers and TV’s.  Small battery powered fridges could be used to store medicines.  Another advantage is it would replace dangerous and ineffective and particulate/CO2 emitting alternatives such as candles and paraffin lamps.

The technology for this is of course the rapidly becoming ubiquitous PV.  The cost of these has plunged and the efficiency increased.  The same thing is happening with batteries.  Bring the two together and you have a major solution to a major problem of worlds poorest having no access to electricity.  Both lithium batteries and PVs are very low maintenance and ideally suited to rural parts of the developing world.  Their installation and maintenance will of course create jobs.

The “Let there be light” campaign is asking the UK government to fund solar panels and batteries through its overseas aid programme.  We are not talking about covering mud huts in metres of PV on roofs in the same way as here, but giving an individual householder a panel and a battery.  A number of years ago Channel 4 had a very left wing presenter (surprisingly) gave a climate sceptic documentary.  Part of his argument was that renewable energy would never work and was incapable of powering so much as a fridge.  We know it can because its already happening.  The “Let there be light” campaign is asking us to widen access so that this is the first generation where everyone has access to bright light at night.  Lets prove him wrong.  Join in here.


* In the tropics it gets dark pretty much at 18:30 every night of the year and in my experience the daylight just vanishes.

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Pacific renewables

Sunset_from_AkaiamiLike the history of the first and second world wars in the Pacific, Pacific renewables and their energy story is somewhat obscure.  However, the problems faced by these Islands due to climate change and the attempts they are making is somewhat inspiring.  Most of these Islands with the exception of Hawaii are low lying (at least in part).  Many are atolls which are barely above sea level.  Like the Maldives in the Indian Ocean they are threatened by rising sea levels and like this Island nation but with less publicity some (like the Cook Islands) are going for a 100% renewable target.  The second problem is one of energy costs.  The Pacific islands have a reputation for being generally very expensive.  This is because most products used are imported, the supply lines are long and the populations are relatively small.  This includes energy.  A friend of mine worked with OM in Hawaii.  She said power prices were very high.  Most electricity came from coal power and the coal was imported.

Not only do these Island states need to set an example due to climate change but the drop in wind and solar and the coming drop in energy storage gives them an economic opportunity as far as electricity prices are concerned.  The solar resource is great in these Islands and the system requirements not huge.  The Island of Yap (part of the Federated States of Micronesia) is aiming for an initial 25% renewables target to reduce dependency on expensive imported diesel using solar and wind.  The Cook Islands are aiming for 100% renewable electricity by 2020 as was stated above, using solar and energy storage.  The story of Pacific renewables is an inspiring but ongoing one, watch this space.


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One thing we have learnt this week – pollution affects economic growth

2015-09-22 14.12.40This week there has been a first, a government admits pollution affects economic growth.  The Chinese government has stated that economic growth is going to be lower (only about 6%- although in reality its probably much lower than this).  One reason they gave was the pollution crisis in China caused (mainly) by traffic and coal fired power generation.

The admission that pollution affects economic growth is a first by a government that I can think of and must mean the situation in parts of China really are serious.

Hardly a day goes by without new science on the particulate issue.  Over the last week or so the news has covered the facts that particulates and NOX can give heart disease, can affect the foetuses in the womb, can penetrate the testes and possibly has affect on brain development (this is probably not all the news).  We also learnt that omega-3 fatty acids might prevent the damage caused by this type of pollution.  On the lunch time news they covered a scheme in London where monitors are fitted to prams to plot low pollution routes through neighbourhoods.

Therefore the Chinese governments stance is to be welcomed and supported.  It is slightly depressing that it takes a non-democratic government to admit  that pollution affects economic growth, this really rather obvious.  This particulate problem is becoming as bigger one as the hole in the ozone layer or climate change.  The solutions are not politically easy even in China but we need to grasp the metal and get on with it.


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