What if we were talking about cocaine, rather than coal?

Australian prime minister Malcolm seems-like-Jesus-after-the-last-guy Turnbull has just decided to keep shipping coal, and ignore suggestions to stop digging any new mines. (World's largest coal exporter) Australia takes over 400 million tonnes of coal out of the ground each year, exporting over 300 billion tonnes and earning AS$37 billion last year.  

Let's pretend this was the president of Columbia talking about cocaine and re-analyse his arguments. 

You may think it's flippant to compare coal to cocaine but there are a few important similarities. First, they are both addictive. Coal creates dependencies. Once you build those power stations, you need to feed the habit. You can try putting other stuff in there instead, but it just doesn't give the same kick. Switch it off, and all those connections down stream will hit serious lows, and you'll get cravings and yearnings. Actually this is sounding more like heroin. 

Second, coal, like cocaine, will increase your productivity. It will give you extra power.

Third, coal, like cocaine, is a highly profitable item that can only be produced in certain parts of the world.

So let's translate a few of Turnbull's arguments and see how they sound. Words with an asterisk have been change.

***

"If *Columbia stopped exporting *cocaine, the countries to which we export it would buy it from somewhere else ... there is absolutely quite a lot of *cocaine around ... so if *Columbia were to stop all of its *cocaine exports it would not reduce *drug use one iota. In fact, arguably it would increase ... because our *cocaine, by and large, is cleaner than the *cocaine in many other countries."

He points out: "*Cocaine is a very important part...the largest single part of the global *drug mix and likely to remain that way for a very long time. "

He also uses the moral argument, which basically goes along the lines that we have been using *cocaine, it has helped us get where we are, so it would be unfair to deprive the rest of the world. As his predecessor said, *cocaine is "good for humanity".

"You have to remember that *drug poverty is one of the big limits on global development in terms of achieving all of the development goals, alleviating hunger and promoting prosperity right around the world – *drugs are an absolute critical ingredient. So *cocaine will play a big part in that."

He goes on that it's "important to take the ideology out - just approach it in a very clear-eyed, cool-headed, rational way".

*Farmers, *cartel bosses and other people involved in the *cocaine industry are applauding his decision.

Reading what he says, I don't think Turnbull even really believes this. He's just being pressured by people in the right wing of his party, and the billions of dollars income from exports. 

He'd much rather see people just surviving on sunlight. And I'm sure people in Australia would be able to help show them how to do that!

***

Read more
in the Guardian

Sydney Morning Herald 

Australian financial review

Notes:

Cocaine is not actually the same as coal in a couple of crucial ways:

1. Cocaine comes from plants, and is therefore a renewable source. Exporting a lump of cocaine this year does not stop you from exporting it next year.

2. Using cocaine has impacts on the users, but these are mostly confined to the user, and perhaps those in the immediate vicinity. As well as producing local pollution, coal leads to global warming, so has global consequences. You can safely export cocaine, and if you're not doing any of it yourself, there will be few ill effects. Coal, on the other hand, will affect your climate, wherever in the world it is burnt, and if you export it, people will burn it. I mean, they're not using it for rock gardens, are they!
3. It's difficult to get precise figures, but Columbia probably earns around US$4 billion from cocaine exports. Around a tenth of what Australia gets for coal. Somewhere around 200 tonnes is exported, although it's very difficult to know how much, because it seems to fall off the boat. This is less than a millionth of Australia's coal exports. Something the Australian government should seriously consider. Or start exporting whatever drugs they're taking!

Lesson 3. How to stop heat - Form factor

We now know from the first law that energy is heat, so the first step in low energy building is to lose less heat. So how do you stop heat?

The opening question has a very simple answer: You can't. The second law states that the heat will move from hotter to cooler, so sooner or later the heat will get through.

The universe is a casino, its currency is energy, and sooner or later we're going to lose it all.

You can't stop heat flow, but you can slow it down, and that is the basis of insulation. Intuitively we can guess that the amount of heat flowing through a wall is going to bigger if the wall is bigger. It's logical that doubling the area will double the heat flow. Also that doubling the thickness of the wall will halve the heat flow. Or at least it will take the heat twice as long to get through, since it has twice as far to go.  

It's also intuitive that a higher temperature difference between the two sides will increase the heat flow, and easy to imagine that twice the temperature difference will double the heat flow.

And then the material the wall is made of is going to make a difference.

These are all bound by Fourier's law. If you want to see the equation, you can google it. I'm not going to add it here since every equation added to a piece of text halves the audience. Luckily that is not holding true in my class, and so far the number of students seems to be holding steady, but there is always a chance that students will lose their energy over the course, and stop coming to class.

Fourier was also an accomplished mathematician and he apparently was into dimensional analysis. Applying dimensional analysis to his equation tells us that the units we need for thermal conductivity, the constant applying to materials, is Watts per metre Kelvin. You can see a long list of thermal conductivites here on engineering toolbox. The lower they are, the better they are at insulating.

Jumping straight in to our goal of low energy building, I decided we should try to build a house. This was just on paper, and we made a few assumptions. It was a cube with five-metre sides, insulated with 100mm of glass wool all around. It was going to be in Matsumoto in the winter, where it's zero degrees centigrade outside, and we want it to be 20 degrees inside. The building has no doors and windows, is completely airtight and is floating in air, so it's losing heat equally from all six sides. We worked out that this will lose heat at a rate of 1.2 kW.

This number has two significant implications. First, to keep the house at 20 degrees centigrade, we're going to need 1.2 kW of heating inside. Second, 100mm of glass wool is not going to be enough for a low energy building.

In the process of this, I told them about the U value, which is the heat loss per unit area, or the conductivity divided by the thickness of insulator.

Next, we went on to a couple more buildings, one a single-storied rectangle, the other single-storied and L-shaped. The rectangle lost more heat than the cube, and the L more still. 

This led me to form factor, which is the ratio of surface area to floor area. The most important area, as far as heat is concerned, is the surface area, since this is how it escapes from the building. Or if it is a hot climate, this is how it gets in. As far as the inhabitants of the building are concerned, the floor area is the important part.

For a given insulating material, and with the same desired heat loss, the thickness of insulation goes up with form factor.

We looked at form factors for a few more buildings, noticing that as the building get squarer and bigger, the form factor goes down.
Generally, the form factor goes down as buildings get larger, since larger buildings generally have more storeys, so the floor area is going up faster than the surface area. Below is a graph for an idealised cubic building with storeys two and half metres high. You can see it gets very difficult when you get very small buildings.

We looked at a few real buildings to consider their form factors.

The modern Tokyo mini-house and classic modular capsule block are not very impressive.

Nor is the typical Japanese apartment block with its balconies, rooms bulging out of a sensible thermal envelope and random sticky-outy bits of wall. Flying butresses can be excused on medieval cathedrals. Do we still need them now?

The Dome house in Miyazaki looks a bit better, but more about domes in another post.


My house is not too bad.

I also pointed out that the balcony on my house is separate to the structure, as you can see from the picture below before it was put on.

I'd hoped to say more about insulation, and what happens when we start using different materials together, but I was running out of time and that will end up in the next lesson.

There was time to show a picture of a lobster and a person and elicit some differences. The critical ones for our discussion are that Lobsters are cold-blooded and have their skeletons on the outside, while humans are warm blooded and have their skeletons on the inside. Not all cold-blooded animals have skeletons on the outside, but I think all warm blooded animals have theirs on the inside. There is no "list of warm-blooded animals with exoskeletons" on wikipedia, which I take to be conclusive proof.

The point is that evolution, with the wisdom of millions of years to try out designs, has decided this is the best strategy. Life is essentially a temporary defeat of the second law of thermodynamics, so when we're aiming at  low energy building we are wise to follow the lessons in biology and put the structure on the inside, and the insulation on the outside.

=== 

The calculations above are all done with idealised pencil drawings as walls, and relatively simple physics. Real buildings are going to make most of these effects worse, since walls of finite thickness are going to reduce the floor area, and details in and around windows and doors are all going to increase the surface area.

Things will generally only get worse. Entropy is also at work in the design process. So it's a good idea to start a building with as small a form factor as possible

Thank you to Nick Grant for great lessons and some great shared slides on slideshare.net/ecominimalnick.

And to Elrond Burrell, bloggin here: elrondburrell.com

It's all about power

Someone just drew my attention to a ridiculous blog post, suggesting  that cutting support for solar power may be in some way rational. Then I realised that I'd written the blog post. Evidently too hastily.

My correspondent had been inundated with phone calls from companies selling solar panels. I can believe this since during the short week while I was in the UK visiting friends and family, even I got phone calls from companies selling solar panels. 

My correspondent "finally relented and let the most sensible-sounding of the bunch come and do a free survey. He took measurements, fed figures into his laptop and shook his head sadly - 'it wouldn't be worth it', he said, apologised for taking my time, and left. His visit turned out to be worth it though, as it meant I could tell subsequent cold callers that I'd had a survey and it wouldn't be worth it."

I could have told him it wouldn't be worth it: he lives in a terrace running north-south, so the roofs are pointing East or West. You would think they could work this out before the cold-calls and sending out the surveyor. The fact that they can't suggests to me that they are assuming that every house is suitable for more panels and the least sensible of the bunch may have told him some. Or that cold-calling is incredibly cheap and being outsourced to sweat shops of low-paid workers, so thirty phone call are cheaper than one look at a map with a compass.  

Onto the more important question of why, oh why, the Tories are cutting money to solar.

I look at the numbers and see that right now a nuclear power station will produce more Watts to the pound than a solar panel will. It's certainly changing and there will a point when electricity from the solar panel will be cheaper. At some point it may even be worth putting them on roofs of terraces facing East and West, high up in the northern hemisphere. We will only get to this point if panels continue to be produced, economies of scale are realised, and techniques are made more efficient, both in production and installation. So we do need to support solar if we want a low-carbon, non nuclear future. 

This may be a very different way to how the government is looking at it. They have a choice between continuing on the solar road, or promising to pay a few billion pounds to one or two large companies, linked to the government of what will probably be the largest and most powerful economy over the next hundred years. Also a military force that The solar road will also end up with a lot of money going to China, but to several smaller companies, which are not always lucrative long term, (see bankruptcy of Suntech). 

As far as global warming is concerned, nuclear and solar are both low carbon. Nuclear is arguably lower. 

As far as cost is concerned nuclear and solar both have high initial cost and relatively low running costs. Arguably nuclear is cheaper. 

As for who pays, in both cases these costs are going to go on electricity bills. 

Who profits? Locally a nuclear power plant will create relatively fewer jobs for a relatively small number of companies, some of these jobs will be highly skilled. Solar power will create relatively more jobs for a much larger number of companies, many self employed and probably fewer highly skilled. 

In terms of big business, profits for solar will go to a larger number of companies, many in China. Profits for the nuclear plant will go to China General Nuclear Power Corporation (CGN), China National Nuclear Corporation (CNNC), and Electricite de France (EDF).

As far as supporting nuclear technology, which also keeps us in that elite club of countries with weapons of mass destruction, solar panels are completely rubbish. 

Historical aside

On 6th August, 1945, the first nuclear bomb was dropped on Hitoshima by the US and Britain. 

On 8th August, 1945, the London Charter (AKA Nuremburg charter) was signed, setting out how war-crimes would be punished. 

On 9th August, 1945, the very next day, another nuclear bomb was dropped on Nagasaki.

Doesn't history love irony!

Death squads, chemical weapons, biological weapons: all war crimes. Nuclear weapons? No comment.

Maybe this has got nothing to do with electricity generation. Maybe nuclear power has nothing to do with nuclear weapons. They certainly seemed to be connected when it was North Korea and Iran. 

Isn't this a pretty power station! Would you like to live underneath it? I'm much happier living underneath a solar power station. 

It's in Somerset. Quite a long way from London. People used to think Battersea was a long way from London.

More biased information from Greenpeace available here.

More biased information from the Times available here.

Guardian: Solar power in crisis

An elaborate article on solar in the Guardian from 20th October here:

Solar power in crisis: 'My panels generate enough power for two loads of washing'

A somewhat misleading title: how is panels generating enough power for two loads of washing a crisis?

The article is heavy on anecdotal details of consumers, suppliers and crystal-ball gazers. It even gives a few column inches to batteries, which are a clear challenge for an energy infrastructure based increasingly on variable supply. But it is somewhat lacking in deeper analysis of the actual topic in the title. It just seems to go on: Why, oh why, is the government trying to strangle this business?

Someone in the comments has done the relatively straightforward sums. Someone is paying four grand for your panels. There are a million houses out there with panels so far. That's costing people in Britain 4 billion pounds. Another 6 million houses and it's the same cost as the proposed new power station you call the most extensive object on earth.

The comments also mention that most of this subsidy is going towards Chinese businesses that are making the panels. Not that I have any objection to UK electricity buyers subsidising our comrades, although objections could reasonably be made.

This seems an interesting test case for the system of free market enterprise. What is happening is that the government is giving away bits of money, some in the form of grants, and some in drip-feed cash into the future.

There has been a mad rush for grants and an explosion of entrepreneurs setting out to install the panels. Some no doubt have done a fine job. Others sell panels for roofs that are not well suited to solar power, some delivering less than optimal installations.

I'm sure there are a lot of roofs that should have several more panels than were installed, and some that should not have any.

And if the government is going to pull the plug on subsidies, the solar installation industry will shrink. It's still going to make sense to some people to add panels without any subsidy, but for most people a financial incentive is needed to make the long-term investment for long-term savings.
It's a bit of a gold rush, so a lot of the people in the industry have only just arrived, and will head straight for the next gold-rush. The fly-by-night operations will vanish into the sunset, generating electricity in neither of those metaphors.

It would be good to see more rational subsidies, looking at where energy is used and where the best yields will come from. Couldn't they cap the amount of solar subsidies, and award them to the most worthy causes? For example prioritising arrays on south-facing terraces would provide energy where there are people. Installing panels in isolated areas may be a good way of reducing transmission power, but will really only be effective if local energy usage is synced with energy generation, and if there is some local storage. Otherwise there are going to be line losses both as energy is sent there in times of need and as it is sent back when generation is high.

If this is our energy infrastructure, then it needs some kind of long-term plan. The roads and railways were not built by letting people put down their own hard core or sleepers and rails and then giving them a few pennies each time somebody went past over the next ten years.

The timelessness of the Passive House standard

I was lucky enough to participate for a few days of a training course for Passive house designers and consultants led by Nick Grant in Herefordshire. I learnt many things, as well as reinforcing the knowledge I had, and brushing the rust off some maths skills. A couple of things really struck me. 

One was that the Passivhaus standard is timeless and objective. Many standards are somewhat arbitrary, and most standards are revised and changed from time to time. Passivhaus is based mostly on objective criteria that will not change, and most of those criteria are based on human comfort. Passivhaus guarantees that room temperature and humidity will stay around what we are physiologically suited to. The standard should guarantee good air quality, and prevent moulds and bacteria from building up.

The energy part of the standard is set to a low enough energy demand that the house can be kept at a comfortable temperature just by adding heat to the incoming air. This doesn't mean that the house has to be heated by the incoming air, but it does mean the heating demand will be very small. So whatever the heat source is, it's not going to use very much energy, and the house would not be too uncomfortable if it stopped working.

Although the standard is fixed, Passivhaus is not standing still. Where the changes and innovations are being made is in how to better estimate the performance of a building from its plans. This has been going on for at least thirty years and means that the Passivhaus estimation of a building's performance is within a few percent. Other energy estimations are often out by a factor of two.

In implementation there are always new technologies and techniques that can meet the standard at lower cost, and there are still locations and types of building that have yet to be made to the Passivhaus standard.

Passivhaus is neutral on a lot of things. In the goal to reduce energy use, most significant is perhaps embodied carbon. The Passivhaus standard is just looking at the building in its lifetime. Other standards are needed to reduce the carbon footprint while it is being made, and of course many people involved in Passivhaus are also looking for building materials and techniques that will reduce carbon from cradle to grave. Such buildings should still be trying for the Passivhaus standard so that energy use during the lifetime is kept low.

Also the standard is neutral on renewable energy. You can use wood pellets for a boiler, or burn fossil fuels. Whatever heat source you use, you will need less of it. If you're aiming for zero-carbon or plus-energy, starting with a Passivhaus makes it much easier when you stick some solar panels on the roof.

Lesson 2. What is energy?

In the quest towards low energy buildings, it's pretty important to have a good grasp of what energy is. My key questions for the lesson were: What is energy? How do you measure it? What is the second law of thermodynamics?

I should probably not have been surprised to find that some of my students didn't even know the first law of thermodynamics. So I told them a bit about James Joule, and the crucial link between beer and science that is often forgotten. The combination of the temperature-critical process of brewing, high-precision thermometers, newly developed electrical equipment and the desire to save money on the various industrial processes he was responsible for led Joule to discover and to prove that heat, work and energy were the same thing. Previously heat had been perceived as stuff. This was called caloric theory, and is where we get the unit of calories.

Calories are the normal measurement of energy in food, while we buy electrical energy in kilo watt hours, rate batteries in amp hours, buy oil in litres, gas in cubic metres or BTUs, and measure atomic energies in electron Volts. We're pretty confused about energy.

And as well as thinking of heat as stuff, and as the nights start to draw in, coming out with scientifically untenable concepts such as letting the cold in, we often intuitively confuse the idea of heat and temperature. To highlight this I asked two questions. First:

Which is hotter, a litre of hot air or a litre of hot water?

The answer is, of course, that they are the same. Actually, the question is, what do you mean hot? If we take hot as 80 degrees centigrade, then they are the same.

Next question:

Which has more heat, a litre of hot air or a litre of hot water?

Most people realise the answer is the hot water. Especially when it is rephrased: if you were to take a bottle to warm your bed, would you fill it with hot air or hot water?

Next question: How much hotter? 

I provided the specific heat capacity of Water (4.2 kJ/kgK) and the volumetric heat capacity of air (1.2 kJ/m³K) and they worked out that the bottle of water has over three thousand times more heat than the air.

And so to the first important teaching point: precision and accuracy. I showed them a picture of an analogue clock and a digital clock to demonstrate the difference. The analogue clock said it was five past eleven, when in fact it was twenty past. The digital watch said it was 14:27 and 36 seconds on the first of November. A much more precise answer, but several weeks less accurate.

People often confuse precision and accuracy, providing as many decimal places as possible and being fooled when many decimal places are provided. In all cases it is important to know the accuracy of the figures you put in, since the answer is going to be less accurate than these.

In the case of heat capacities, they change depending on the temperature, so the numbers are only accurate to within a few percent.

The other important thing is to know how accurate your answer needs to be.

In most cases, one significant figure is enough. You need to know whether the answer is 4 or 5. You don't need to know whether it is 4.13 or 4.12.

In the case of low energy buildings, we often need to choose between two alternatives and work out which will use less energy. A calculation to one significant figure will usually tell us. If we're choosing between water and air to transport heat through a pipe, we know that water will move over three thousand times more than air. It doesn't matter if it is three thousand or four thousand. In fact it doesn't matter whether it is three million or three.

And if the numbers are the same to one significant figure, then we may want to do a more accurate calculation. Or, more likely, we will decide that there is not much difference between the two alternatives in terms of energy use, and other factors may be more important, such as cost, or which one looks nicer.

So, it's important to know how accurate the numbers you use are, it's important to know how much accuracy you need, and you should not use more precision in your answers than your accuracy justifies.

After this digression from the meaning of energy, it was time for power.

Watt is the name of the inventor of the steam engine.

You have to say that with rising intonation for it to work properly.

He didn't actually invent the steam engine, but he probably invented global warming when he got one to work on a coal mine where it would pump water out of the mine, allowing them to dig out more coal, keep the pump pumping and so dig out even more.

He also gives his name to the unit of power. Power and energy is another source of confusion, with power the rate of change of energy. The use of kilowatt hours as a unit of energy does not help, although as a unit it's a pretty useful one.
One kilowatt hour is roughly equivalent to:
• leaving on a 100-watt lightbulb for 10 hours.
• 0.1 litres of paraffin　
• 0.1 m³ of gas
• 5 rice balls
• 20 litres of hot water
• 200 mobile phone batteries
• 0.04 milligrammes of uranium 235

(All figures are to one significant figure, except the atomic weight of uranium. Luckily I'm not teaching nuclear physics!)

Low Energy Buildings from Cambridge Carbon Footprint

An interesting range of approaches to low energy building that you can visit if you're in the Cambridge area. Most have detailed case studies.

View this email in your browser

Cambridge eco homes open their doors! We're really proud of the 15 homes taking part in this years Open Eco Homes. We've got DIY dreams, cosy custom-builds and everything in between. Book now for free tours this Saturday 19th and Sunday 27th September, or click the links below to take a tour through some of the eco home case studies.  They're a great example of how doing things differently can be both good for your home and better for the environment. Street Description Age 19 27 Insulation Energy Materials Water Other A Eachard Rd CB3 0HY Case Study NEW Semi-detached Restored home with thorough insulation & renewables. 1935 ✗ ✓ Internal & external wall, floor, loft Woodstove (for cooking, heating and hot water), solar PV Wood for building extension and conservatory Four water butts Wood fuel sourced partly from own garden B Sherlock Rd 2 CB3 0HR Case Study NEW Semi-detached Enlarged family home treated to ensure low energy living 1937 ✓ ✓ Internal (DIY & pro) & external wall, flat & pitched roof Heat recovery and ventilation system Woodfibre wall insulation, recycled plasterboard Low flow showers, low volume flush WCs Collaborative design and building approach C Oxford Rd CB4 3PH Case Study NEW Detached Ecorenovation of extended 1920s house 1927 ✓ ✗ Cavity wall, floor, loft conversion roof Solar PV Timber windows (with aluminium cladding) Bathtub siphoning Turn off larger of two fridges when not required D Madingley Rd CB3 0EG Case Study Detached custom-built home with low carbon design and materials 2010 ✓ ✓ Internal and external wall, roof and underfloor insulation Solar gain, ground source heat pump, woodstove Hemp & wood fibre wall insulation, Marmoleum Rainwater harvesting for toilets, laundering & garden Sedum roof, wildflower meadow, pond E Silverdale Av CB23 7PP Case Study Detached Custom-built timber frame home and office in Coton 2013 ✓ ✓ External wall, roof, interfloor, triple glazing Solar PV, heat recovery, passive solar FSC timber Dual flush toilets, water butt, water softener Flexible design for any future change of use F Eltisley Av CB3 9JG Case Study Mid-terrace Innovative low-cost ecorenovation 1902 ✓ ✓ Insulated loft conversion, floor, some triple glazing Woodstove, DIY awnings for cooling Reclaimed pine flooring, Marmoleum (eco-lino) Low flow showers, low volume flush WCs Wood store with sedum roof G Lingrey Court CB2 9JA Case Study NEW Semi-detached 'Zero-carbon' concept house & family home. 2015 ✓ ✗ Insulated panel construction, some triple-glazing Solar PV, heat recovery, heat-saving shower FSC-certified timber cladding Water-saving WCs, showers and baths Green roof, herbs, fruit and veg growing H Gilbert Rd CB4 3NX Case Study Semi-detached Extended and comprehensively insulated home 1930 ✗ ✓ Internal and external wall, floor, loft, thermal-lined curtains Solar water heating, woodburning stove Reclaimed bricks Water butts Bike shed, wood store J Fen Rd CB4 1BS Case Study Semi-detached Thoughtful ecorenovation with low carbon heating 1897 ✓ ✓ Internal and external wall insulation Solar thermal, woodstove Reclaimed wood Two water butts for chalk-free garden watering DIY solar thermal installation K Chesterton Rd CB4 1DA Case Study Detached Radical refurbishment of Victorian home 1896 pm pm Internal & external wall, floor, loft Solar thermal, heat recovery & ventilation Water butts, dual flush WCs, low-flow showers Sunpipe L Nuttings Road Case Study CB1 3HU Semi-detached Low-carbon, low-cost family home 1950s ✓ ✓ Cavity wall, loft, hot water tank, under bath, triple layer curtains Solar PV & thermal, woodstove, heat recovery Eco-paint, wool insulation, Rainwater harvesting, spray taps, toilet 'Hippo' Sedum roof, vegetable growing, terracotta fridge M St Barnabus Rd CB1 2BY Case Study Semi-detached Highly-insulated home with low-carbon lifestyle 1897 ✓ ✗ Internal wall, roof, floor, double- and secondary-glazed sashes Zone heating controls, woodstove, passive solar Reused building materials and furnishings Water butts, low water-consuming lifestyle N Coleridge Rd CB1 3PN Case Study NEW Semi-detached Thorough ecorenovation of family home 1930 ✓ ✓ External wall (brick slips), floor, converted loft insulation Zone heating Salvaged French door Dual flush toilets, water butt, water softener Vegetable garden, O Mowbray Rd CB1 7TG Case Study NEW Detached Newbuild PassivHaus standard home 2015 ✗ ✓ Wall and roof insulation, airtight structure. Mechanical ventilation & heat recovery Wood frame & walls. Recycled newspaper insulation Rainwater harvesting for garden and WCs. Mechanical heat recovery filters pollen P Topcliffe Way CB1 8SJ Case Study NEW Detached Economical ecorenovation for low energy family living 1963 ✓ ✓ Cavity wall, loft and external wall Woodstove, solar PV & thermal, heat recovery Rainwater harvesting, DIY greywater toilet Book Now Feedback from past Open Eco Homes visitors has been overwhelmingly positive (we're now in our 6th year  running it). Visitors love learning from other householders on how they've made their homes warm, and saved money on their bills. And don't forget that we've also got five follow up events to help get you started on your own home. Keep reading below for more info on these, and for dates for out next round of thermal imaging training just announced! Best wishes, The CCF Team Open Eco Homes Open for free visits on Sat 19th & Sun 27th September, householders show how they save energy. including: draft-proofing, many types of insulation and low-carbon energy sources such as wood-stoves, solar and heat-pumps. Smart behaviour and taking control of home-energy too. There's a wide variety of Open Eco Homes: retro-fitted & new-build low cost & really stylish simple & high tech Householders will show visitors how they save energy, cut bills and stay comfortable. http://openecohomes.org/        www.cambridgecarbonfootprint.org info@cambridgecarbonfootprint.org 01223 301842

Evolved from a monkey - though not very far

Marsha Blackburn may not think she looks like a monkey. 

She also doesn't think that humans are causing global warming. This would not be so alarming, if she wasn't the vice chair of the US House Committee on Energy and Commerce. 

That's a bit like having someone on a medical committee who doesn't believe in the germ theory. 

Where do they get these people?

Of course it's ridiculous to suggest that humans evolved from monkeys. It would be like saying you are descended from your cousin. Actually humans and monkeys evolved from a common ancestor, just like you and your cousin descended from your grandmother. 

And Ms Blackburn may have missed a few other key events in human evolution since our branching away from the other apes. We already share with other primates some self-awareness, social intelligence and mental processes that distinguish us from other parts of the animal kingdom.

Ms Blackburn and the conduits of her DNA were probably part of the cognitive revolution. This allowed humans to indulge in abstract thought. Before this we still roamed around in bands, but could only really communicate about immediate and concrete matters. The cognitive revolution meant that large groups of humans could follow myths, leading to cooperation at scales beyond immediate kin. In the past these myths included worshipping the sun and sacrificing children. More recent myths included growth economics and the belief that a grey-haired old man created the earth for us and that he sent his hippy son to remind us.

Ms Blackburn was probably part of the cognitive revolution, or perhaps she is just aping the other primates in her band, and mirroring them as they jump up and down screaming. 

Around a hundred thousand years after the cognitive revolution, and a couple of hundred years ago came the scientific revolution. This was just another myth, but different in an important way. The scientific revolution provided us with an objective way of reaching facts. No longer were we bound to follow the most popular stories. We could produce hypotheses, test them, and establish facts. The power of science is evidenced daily, in the cars that drive by or the planes flying in the sky. When Nasa gets a satellite to land on a comet we have further evidence supporting science. 

I think Ms Blackburn may have missed the scientific revolution. She is on the house energy committee, but I doubt she even knows what energy is. Representing Tennessee, she probably just thinks energy is coal, and her job is to increase its use. 

But of course we have to remember that science is still just another myth, and the fact that it happens to be a very successful one does not guarantee it will prevail. If the world's richest and most powerful economy can promote people ignorant of science into positions of power, then we have to worry that it may just be a flash in the pan, and we are heading back into the dark ages. 

News of this appeared on 24th September, 2015 in the BBC's Science and Environment coverage, Believing in neither it is unlikely she noticed.

http://www.bbc.com/news/science-environment-34342808

Lesson 1: What is a low energy building? Into the unknown

The course I'm teaching on low energy building just started. The first lesson of a course has to start with an introduction. In fact not one introduction but many. Not just introducing the content to the students, but also introducing the teacher to the students, the students to the teacher and the students to each other. 

Before the course, I had no idea how many students would turn up, and what their levels would be in regard to English or the content of the course. In the worst case I would have had a small group where half of the students just wanted to learn about low energy building and had no interest in the English language, and the other half were only interested in practicing their English and not wanting to learn anything about low energy buildings. As it happened there were certainly a couple of people who seemed a lot more interested in the topic than in language learning, and one student who confessed in class that he was just there because it was in English, but he promised he would study hard! The rest of them seemed to be interested in both the content, and the opportunity of practicing English while learning about it. There was not a huge turnout, and if I do the course again next year I'll have to consider whether to do it in Japanese.

There are three things I want to learn about new students: What are they doing here? What do they know? and how is their English? More specifically my questions for them were:
Why are you taking this course?
What language do you want to speak when talking to other students?
What is a low energy building?
Why should we make low energy buildings?

So what is a low energy building?

There are several interpretations to this:
An igloo is one example of a low-energy building. It just takes a couple of people an hour to make. Materials are all locally sourced: blocks of ice, glued together by water, which is made from the blocks of ice. Similarly a teepee takes little energy to make. In both cases they have a limited impact on the planet.

There are also a wide range of eco-friendly buildings, for example with grass roofs, water collection and composting. 

An empty house is another example of a low energy building. Low energy because nobody is living there! 

Another definition still could include buildings with their own generating potential, for example covered with solar panels.

The definition which I'm going to focus on in the course is a building that uses very little energy. There are various standards for this, and I'll be looking mostly at Passivhaus. The course is not a Passivhaus course, but Passivhaus has asked most of the questions about low energy buildings, and it seems to have most of the answers.

Great Passive House blog!

Check out Elrond Burrel's blog: Passivhaus in Plain English

Elrond is a New-Zealand born, UK-based architect, who builds some very nice passive houses. 

I especially liked Elrond's "Ten things I hate about passivhaus" which includes gems such as: not being able to just check boxes to deliver sustainable buildings, not being able to hide poor details, and arguing with building services engineers. Read it here.