Wednesday 9 December 2009

Government pre-budget report - going greener?

With the Copenhagen climate summit going on this week, one might possibly be forgiven for being just a little cynical at the timing of the UK government's raft of announcements on encouraging people to go greener.  This is at the same time as seeking rafts of cuts elsewhere, increasing various taxes and so on in an attempt to halve the uk's deficit within the next 4 years.  The BBC news story can be found here .

On the plus side it has to be good news for those who care about moving to sustainable energy sources and reducing usage elsewhere.  Amongst the proposals are a boiler scrappage scheme - 125,000 homes will be offered up to 400 pounds to replace old out-dated boilers - although the man from British Gas says there are 4 million old boilers in UK households.  From a somewhat selfish point of view I find this of interest since our boiler is old and inefficient.  I would love to replace it and save some of the cost of a new boiler at the same time.  Having looked at alternatives I see little option (at least in the affordable bracket) at the moment other than to replace our existing boiler with a more efficient condensing model.  The question is whether to keep the hot water storage tank for a future rooftop water heating system.

The government is also saying that any electric company car vehicles will be exempt from company car tax for the next 5 years.

The place where it all starts to get misleading is the suggestion that those who have their own wind turbines or solar panels will be able to make on average 900 pounds a year, tax free, by selling excess energy back to the grid.  This is not your average householder but those who have enough land to make a serious size installation of  turbines or significant acreage of solar panels.  We currently use about 7500 kWh of electricity a year - perhaps a little less now - at around 10 pence a unit that is around 750 pounds.  Even if the government pays a premium, I would have to generate at least twice that to be able to earn 900 pounds.  My calculations for a typical domestic wind turbine shows that we would fall a long way short of continually generating the necessary kW of power for our own needs, let along the 2 kW plus necessary to earn my 900 pounds.

The payback time on a typical wind turbine today is about 12 years in a total 20 year life.  Making the income tax free will improve the return, but it won't (or at least shouldn't) encourage small households to go and install their own turbines and solar cells.  If someone wishes to be altruistic and get themselves off the grid at whatever cost then fine, but don't be misled by all the fine words.

Sunday 25 October 2009

Wind turbines, radar and fuel out of thin air!

There is an article on the BBC news website today about the problem of wind turbines causing radar clutter.
This was something I hadn't thought about - although I once had a summer job at what was then Ferranti's Radar Systems Department where the issue of clutter was very much in the engineers' minds.  Apparently the problem has been delaying the deployment of significant amounts of wind based energy generation.  Qinetiq have come up with a coating for the blades to reduce the problem - although it's not going to completely solve it.  As they say, every deployment is different.  I imagine the defence industry with all the technology that has been developed to make planes invisible to radar will be in demand to help solve this particular issue.

If one was being cynical, then one might suggest that not flying planes is compatible with deploying new energy generation facilities - but that's unlikely to be popular and I suspect that some of the issue is to do with defence of the realm.

On a slightly different topic, I caught a bit of an edition of James May's big ideas on Dave last night.  One of the ideas he explored was the idea of creating fuel out of thin air.  There's a group in the desert of Mexico who are looking to use CO2 from the air combined with Hydrogen from the electrolysis of water to create fuel.  The program was rather short on science - either because they were dumbing it down or because the proponents have secrets that they don't wish to share.  The one thing they did share was that they need to split the CO2 into CO + O - which requires temperatures on the order of 2400 degrees centigrade.  They've built a solar furnace to help them do this - and demonstrated cooking sausages and rather more impressively melting steel with it.  A bit reminiscent of those science fiction death rays.  I'd have to find out more about this - it's not clear how far along the technology really is - but they seemed to suggest that hooking their furnace up to their machine for generating fuel would allow them to generate 2 to 3 (presumably US) gallons per day.
That's not a whole lot - but I wonder how it compares in terms of efficiency with making biofuels?  Given that one is trying to reverse an exothermic reaction which gives off a whole lot of energy (when one burns the fuel) - it would seem that it's going to take a whole lot of energy to do the recombination of hydrogen and carbon monoxide to create it in the first place.

Saturday 24 October 2009

Mixed messages and looking ahead...

Governments in democracies have a tough job.  They have to balance priorities - which leads to them taking actions that are frankly illogical.  If they do things that are unpopular they don't get voted back in.

If one believes man-made global warming is a serious threat - and the warnings of those doing the science should be taken seriously - as the British government at least professes to - then surely one should be taking rapid and urgent action.  That would mean educating the population and above all legislating to force us to stop burning fossil fuels without at least capturing all the carbon.  This would mean dramatically reducing private car use as well as building large amounts of renewable energy generation and almost certainly a number of nuclear power stations to bridge the gap.  In the absence of that we would have to reduce the amount of energy we're consuming for both domestic and industrial purposes.  These are likely to unpopular moves until the large majority of citizens are convinced of an impending crisis - by which point it will probably be too late.  Even then, they will be unlikely to vote for such measures unless the rest of the industrialised world follows suit or leads the way.

This is a classic prisoner's dilemma - if the UK acts in isolation then our economic prosperity will suffer - and our overall effect on the amount of CO2 in the atmosphere will be negligible.  This is the justification for the Kyoto agreement - but if the biggest CO2 producers - in particular the USA - don't sign up, then nothing will happen.  Countries in the west (or anywhere else for that matter) don't have a great record on altruism.  There is also a great deal of distrust - how do you make sure that everyone is playing by the rules?

The car scrappage scheme is an example of just how illogical things can get.  Ideally we want to reduce the number of fossil fuel burning cars on the road to reduce CO2 emissions, pollution and congestion - but the economic prosperity of the country is suffering in a deep recession - so the government wants to stimulate economic activity in an area that has been hit hard.  They also need the vehicle duty paid on the 30 million vehicles in the country in order to balance their budgets.  Their response is to introduce a scrappage scheme whereby one can trade in one's vehicle, providing it's more than 10 years old, to get a discount on a new car. The argument is that newer cars produce less CO2 than old ones.  That might be true depending on what one trades in compared to what one buys to replace it - but the difference is pretty small in the overall scheme of things.  If one was forced to buy an electric or even a hybrid vehicle then the argument might be valid - but that's not required.  This is just one example - there are plenty of others where government policies conflict.

Looking ahead to when the oil price becomes ridiculously high and we don't have enough bio-fuels to replace it, one can foresee a shift in economic activity.  As the cost of transporting goods and people by ship and plane becomes too high, globalisation will be replaced by localisation.  Electronic communications links and the internet will stay in place, but countries will regenerate their manufacturing and agricultural industries to bring the supply of goods closer to the consumers.  Whether we will be able to generate enough electricity from renewable sources to provide for this industrial need is another question!

Tuesday 20 October 2009

Hydrogen - Economically Unviable?

I have been reading a book that I referred to in an earlier post called "The Hype About Hydrogen" by Joseph Romm.he examines the case for switching to hydrogen as the energy carrier for the future.  Romm worked in the US Department of Energy between 1993 and 1998.  From mid 1995 he held the number 2 spot in the office of Energy Efficiency and Renewable Energy.  He is well qualified to explain the facts and issues surrounding a potential future hydrogen economy - and there are many.  The book is heavily focused on the US, although he does look at Iceland as a place where a hydrogen economy may be viable, primarily because they have excess geo-thermal energy that can be used for the generation of hydrogen.

Romm is convinced that man-made global warming is a real threat.  He is equally convinced that there will not be a viable hydrogen based economy for some decades.  There are many technical and economic problems to be overcome, which makes current US policy look distinctly flawed.

He primarily investigates the issues surrounding fuel cells.  These are devices that take hydrogen in one end (or a substance from which hydrogen can be released), air (providing oxygen) in the other and generate electricity and water.  On the face of it clean energy.

Fuel cells are not a new idea - they've been around since the 19th century, but they've never made it into mainstream production, primarily because of the cost and technical issues associated with them.

There are different types of fuel cell - some operate at low temperature, but require to be fed from an external source of hydrogen.  These tend to be expensive because they need platinum catalysts.  Others operate at high temperature.  They can form their own hydrogen from sources such as natural gas - but they take a while to get up to temperature.

There are all sorts of challenges to overcome if a hydrogen based economy is going to be viable.  Generation of hydrogen - if the goal is to get off fossil fuels because of the related greenhouse gas emissions, then the CO2 released as a by-product from reforming natural gas needs to be captured and sequestered.  If the electrolysis of water is to be used as a source then we need a lot more electrical energy than we currently produce.  Another problem is transportation.  The energy density of hydrogen per litre is only a third that of petrol - so moving it around using hydrogen is not very efficient.  It takes up a lot more space than the equivalent energy volume so requires bigger tanks.  It damages pipes that are used to carry it.  Being a very small molecule it leaks.  There are other health and safety issues that need resolved - for example if it does catch fire it burns with a clear flame making it impossible to see.

Stationary high temperature fuel cells seem to be a potentially viable option for buildings - but the energy and potential CO2 emissions required to generate the hydrogen need to be taken into consideration.  If not using renewable energy sources - which are currently in relatively short supply - then fuel cells are generally not more efficient than burning the natural gas in a power station - and a lot more expensive to make.

The bottom line is that there is no set of easy solutions to these problems.  Much more research and investment is needed to overcome them.  In the meantime, plug in hybrid vehicles and other forms of renewable energy being developed in Europe and elsewhere will rule the roost for some years to come.  Romm's plea is for the US government to change its policy and invest more in other forms of energy generation.  He doesn't advocate abandoning hydrogen - but suggests it should be seen as a longer term option.

This is an informative book.  It presents the numbers and the sources of information used.  It's not the easiest of reads - but I'd recommend it for those wanting to be better informed about the subject.

Saturday 10 October 2009

Fuel - replacing oil with bio-fuels

The calorific value of petrol is approximately 10 kWh per litre, diesel is about 11 kWh per litre and jet fuel is about 10.5 kWh.
(As a family we currently use about 20 litres per week in our diesel powered people carrier, which translates to approximately 30 kWh per day - that's 50% higher than our electricity usage but much lower than our currently rather excessive gas usage.)

Much is being made of the possibilities of bio-fuels to replace oil based products.  These are fuels produced from plants that are processed and converted into oils - which can then be refined in a similar manner to traditional oil to produce petrol, diesel and jet fuel equivalents.  I still have a lot to learn about this whole industry - but there are a number of challenges to making this a viable approach for replacing fossil fuels for vehicles.

So called first generation bio-fuels have received a lot of bad press because of the land area that they take up.  Farmers have converted land previously used to grow food because of the grants available - resulting in shortages of certain food crops and pushing up food prices.  The simple fact of the matter is it takes a LOT of land area to fill a petrol tank.  Taking some facts from Mackay's Book, 1 hectare of rape will produce about 1200 litres of bio-diesel.  That would run our car for a year at our current rate of consumption.  There are about 33 million vehicles registered in the UK - as a first order of approximation we'd need 33 million hectares of rape seed or similar.  The only slight problem is that the total area of the UK is only 24 million hectares - and a good portion of that couldn't be farmed!  And we haven't even started thinking about planes yet!

There are a couple of easy to read sites promoting the use of bio-fuels for aviation.
http://www.flyonbiofuels.org/?gclid=CJPgjLTHr50CFYIA4wodlnSohQ
http://enviro.aero/Default.aspx
In particular they promote the use of algae as a more efficient and less environmentally damaging way of converting sunlight into fuel.  The benefit is that algae don't (necessarily) take up land area that can be better used for food production.  They can grow in all sorts of fresh and saltwater environments.  The catch however is that to grow them efficiently you need to feed them with concentrated CO2 - of which ironically there is a limited supply.

The aviation industry currently uses about 250 billion litres of aviation fuel (kerosene or Jet-A) per year.  The above sites suggest that 1% of this could come from bio-fuels by 2016 and as much as 15% by 2020 and 50% by 2040.  These figures seem wildly optimistic to me - although perhaps genetic engineering or some other technique can improve on the efficiency of the growth process.  Currently a farm in the US feeding algae with 10% concentrated CO2 produces 0.01 litres per square metre of bio-diesel per day.  That's about 36500 litres per hectare per year, or about 30 times more than rape seed.  Better, but a long way short of good enough.  To get to 125 billion litres just for aviation will require 3 million hectares of algae farms.

Thursday 1 October 2009

At last someone sensible in a position of "power"

Today I read an article on the BBC website that increased my optimism that the UK government may start to take some meaningful steps towards energy management.  It's a report of comments by the new Chief Energy Scientist...none other than Professor David MacKay.  For those that haven't read earlier blogs, he is the guy who wrote the book "Sustainable Energy Without the Hot Air" - free copies available for download from www.withouthotair.com - or buy it from Amazon.

It turns out he starts his new job today, working for the DECC - Department of Energy and Climate Change.

Why do I think this is good news?  Well to put it simply he does the sums and cuts through the crap that gets peddled by the ill informed.  If the government actually listen to him and allow him to guide the formation of policy, then it's possible that the changes necessary to get us off our fossil fuel habit may actually get made.

MacKay seems to accept the man-made greenhouse gas emission causing climate change argument - he points out that the sources and sinks are out of balance - although he accepts that it's not a firm conclusion on the available evidence.  I remain more of a sceptic, but I am convinced that consuming all the fossil fuels in such a short time span is a very bad idea - so controlling greenhouse gas emissions as a means to an end is a reasonable idea - even though it may lead to some less than ideal policies.

I hope MacKay can inject some of his enthusiasm and a real sense of urgency into the DECC - and act as a real mover and shaker for doing what is necessary and overcoming what appears to be our nation (and world) wide head in the sand approach to energy generation and consumption.

Saturday 19 September 2009

Carbon, carbon everywhere...is trading a means to an end?

Much has been made about carbon trading as a means of reducing CO2 emissions recently, but what is it and how does it help?

I have read a few articles about carbon trading, this one by Australian economics correspondent Peter Martin is a fairly clear explanation of the theory and the ideas behind it.

There are many more articles on the web, but a lot of them seem to require a good grounding in the financial jargon and technology that goes along with futures and derivatives markets.  As with so many ideas and principles involving governments and economists, once the financial markets get involved there seem to be a large number of people looking to get rich by distorting the original scheme beyond recognition. Much of the recent credit crunch and near collapse of the banking system is due to exactly such behaviours.

The theory is that the best way to promote change is to put a framework in place and then let the free market go to work on it.  The problem with this approach is that establishing such a framework that is robust and not subject to distortion caused by the ingenuity of those seeking ever more involved ways of making money is extremely difficult.  It is at this point that governments tend to abdicate their responsibilities.  Governments trying to explain such complexity to their constituents are up against it - many of the members of the government don't understand it in sufficient detail themselves.

Another problem with such an approach is verifying the basis on which carbon emissions are verified.  You can't see CO2, so measuring how much any individual enterprise is emitting relies on measuring their energy usage and calculating the equivalant amount of CO2 produced.  Then one has to figure out how much of that energy came from fossil fuels versus renewable sources.  As I'm sure most people are aware, even if we wanted to buy our energy entirely from renewable resources today there isn't nearly enough to go around.

It's all very well selling permits, but how do you know whether the system is being operated properly.  Wherever money is involved there will always be those willing to play fast and loose with the rules.  Regulating such a system globally seems nigh on impossible to me.  One non-profit organisation that is participating in the market by offering a certification scheme is The Gold Standard, based in Switzerland.  I don't yet understand how they are accredited to do this work - other than acting as a neutral 3rd party with a collaborating set of participants.

The CO2 emissions control is driven by the theory that such emissions are contributing to climate change.  This may or may not be true, but if nothing else it helps drive the move away from finite resources of fossil fuels towards more sustainable sources of energy.  That has to be a good thing, but how do we determine what are acceptable levels of CO2 emissions?  This is an arbitrary number plucked out the air.  How do we determine who is allowed to emit how much?  Who issues the permits?  How do we monitor and control the market?  Who plays the role of central authority?  Who do we entrust with the role of verification?  What happens if someone goes into carbon debt and then goes bust before they've bought new permits?  These are a set of very complex problems, with the solutions open to abuse and obfuscation.  What happens if we later determine that we need to reduce CO2 emission further?  Do existing permits have a lifetime attached to them?

Personally I think this scheme will prove to be unworkable - but that won't stop a lot of people spending a lot of time and money trying - and a few people getting very rich along the way through the usual market speculation.