International standards

Wednesday, 17 February 2010

Three months after the first post, things seem to have been very busy, but I'm not sure how fast they have been moving.

We've decided to make a Passive House. This means it must follow strict standards for insulation and airtightness. It will need a mechanical ventilation system that will transfer the heat leaving the building to the heat coming in, so it will maintain ambient temperature.

Whenever I talk about insulation, people seem to automatically say how hot it's going to be in the summer. This seems intuitive but not completely logical. After all, thermos flasks can keep cold things cold, and fridges and freezers are insulated too.

Just like the old joke from the days when David Beckham played for England and Wayne Rooney still had his own hair:
They were stopping for lunch at the England training ground and took out their packed lunches
Rooney: What's that you got there Becks?
Beckham: It's a thermos flask. Posh Spice bought it for me for my birthday
Rooney: Ooh that's good. What's it do?
Beckham: Well, it keeps hot things hot, and cold things cold
Rooney: Sound. What you got in it?
Beckham: Three cups of tea and a choc ice!

There's also a very strong sense in Japan that this country is completely different to the rest of the world, and what happens in Germany cannot be used here. As far as I can tell the same laws of thermodynamics apply, and water and air have more or less the same chemical composition in both places. The climate is certainly a bit different though.

Summer temperature is about five or ten degrees warmer in Matsumoto than in Germany, and five or ten degrees colder in the winter. Also there is a difference between average monthly highs and lows of over ten degrees every month, with August having average highs of 30.5 and lows of 19.8. January swings from 4.9 to -5.5. As well as looking at averages, the extremes are also interesting. In 1987 there were two days when nighttime temperatures stayed above 25 degrees. This was a record. In other words, on pretty much every day of every year, opening the windows at night is going to let in air below 25 degrees.

1943 saw 155 days where the temperature fell below zero. This makes me think that the cold is a more serious problem than the heat!

There are places in Austria with a similar temperature range, for example Eisenstadt or Baden. Searching for "passive house" on the internet in English, you find lots of people making them in the US and talking about making them in the UK. Searching for Passivhaus in Eisenstadt, I found most of the hits were estate agents selling those that have been built over the past twenty years!

Divest from the fossil fuel industry

Pressure is rising from groups calling for investors to stop putting money into the fossil fuel industry. For example, Stanford University is divesting from the coal industry.

People have been saying that it's a bit like the anti-apartheid campaign, when the withdrawal of investments from South African countries brought the regime to its knees, but this may be a problem on a wider scale. Oil is the life blood of our economy and fossil fuel burning is currently our major activity, thermodynamically speaking. It's going to take some bigger, more fundamental changes to get to a world like in Star Trek, even though we already have the mobile phones, tablets and dress codes without ties.

While portfolios free of oil industry stocks are part of the solution, they may not be the whole answer. These companies are incredibly rich and powerful, and momentum will keep them going in the same direction. They are fed growth economics by the economy that they are feeding and making grow. Divesting from them may work, but there may still be enough money out there that will not ask questions beyond the annual income and return on investment.

Also, these companies are run by people who are not complete idiots. They have consciences, and they have children and grand children. They will be very aware that the polar ice is melting, because it's allowing them access to more fossil fuel reserves. Global warming actually means more access to more oil. And they have sharp scientific minds that will be able to join the dots to anthropogenic climate change. They will be well aware that burning the known reserves of fossil fuels will produce far more global warming gases than even the most conservative climate scientists predict is safe.


But as the quote from Upton Sinclair said back in the 1930s: “It is difficult to get a man to understand something, when his salary depends on his not understanding it.”

What the fossil fuel industry needs to do, in the long term interests of the planet, is quite simple:

• Plan a year-on-year reduction in production of fossil fuels.
• Keep a fixed or increasing amount of known fossil fuel reserves in the ground.
• Reduce the amount of fossil fuels sold to people who will burn them.
• Stop wasting money exploring for new fossil fuels. 
• Stop spending money trying to convince people global warming is not happening.

If the companies can adopt these policies, they will become more stable in the long term. Divesting from these companies may be helpful, but another tack is to encourage the shareholders of them to insist they include these policies. Since pension funds often have share portfolios, and share portfolios often have oil shares, this could be a lot of people.

Certainly, if companies in the oil industry change to these policies, they are likely to lose some of their lucrative business, but they will still have plenty of resources to manage. And anyway, there are plenty of companies that have managed to diversify into different businesses.

There was a company in Italy that used to make saddles, but branched into handbags, and is still in business. A stationery shop in Manhattan had been going fifteen years before changing their business to jewellery. And there's a company in Japan that had been making playing cards for around 80 years before it started making video games.

Thanks to http://www.bestoftheleft.com/

Global Warming or Climate Change?

What's in a name?

These terms are often used interchangably. I think there is a difference, and I've tended to use climate change for two reasons. First, politically global warming seems to have taken a lot of flak and climate change seems a little more neutral. Global warming has been attacked and was famously banned from the White House. I imagine using climate change will lead to less knee-jerk reactions and has more chance of getting through to people.

Second, climate change is more scientific.

"Warm" seems to be a bit vague, and often rather nice, while potentially global warming is neither. Also "warm" refers to temperature, and there are all those confusions between temperature and heat.

During reports of record snowfalls on Fox news, the announcer was saying that Al Gore must be feeling really stupid now. Of course, colder weather is a very likely part of a warmer planet when you start looking at the heat of the system, and the way that heat moves around, or stops moving around.

You can even see this on a very small scale if you're in a hot room and have a glass of water with ice in it. The water is pretty much staying the same temperature, but that's because the ice is melting. The ice is also staying the same temperature, since the melting bits of it are no longer ice, but there is less and less of it, and the amount of heat in the system is increasing. When the ice is completely gone, the water temperature will start going up. Interestingly, the level of the water will not go up in this experiment, but if you had Antartica and Greenland in your glass, with the ice on top of them, then you may be in trouble.
The weather reporters know all this, since they were awake in the physics lessons at elementary school, but increasingly weather is getting reported on the news where scientific ignorance is almost a qualification for the job.

It turns out I may be completely wrong about using climate change. A report by the Yale Project on Climate Change Communication suggests that global warming is associated with greater certainty, scientific consensus and understanding that humans are involved, at least on the political left. And everyone, left and right, seems to associate global warming with a greater sense of personal risk.

So I'm adding a tab for Global Warming. This translates into Japanese 地球温暖化 (chi-kyu on-dan-ka, literally Earth-temperature-warm-ification) or usually just 温暖化 (ondanka, warming). They have no need for another term!

Read more from nasa
And Climate Outreach UK

I think I heard this first from On The Media
The picture of the glass and the table (representing Antarctica and Greenland) is from 4-designer.com  

Power conditioner - doing so much more than just inverting

I've been using the terms inverter and power conditioner loosely and interchangeably for the past couple of years, but realise this may be very misguided. I'd assumed those boxes were simply turning the direct current of the panels into the alternating current running through my house and around the local grid.

I should have stayed awake for more of those lectures on power electricity.

Perhaps I did realise there was more going on inside the box, but since our roof is basically evenly exposed to direct sunlight, I've never worried about shading. I know that people recommend shading should be avoided. Recently I heard a story of a solar array that stopped working for a couple of hours a day as the shadow of a telegraph pole crossed it.

Looking at things in terms of current and voltage, and seeing the solar arrays as several solar cells in parallel and in series, it starts to make a bit more sense.

Taking the metaphor of electricity as water, we can roughly equate voltage with how high the water is, and current with how wide the channel is. So a tall, thin waterfall would have a high voltage and low current, while a low, wide waterfall would have a low voltage and high current. The amount of power in each could be the same, and in electrical terms, power is voltage times current.

So we can think of a solar cell a bit like a bucket, on your roof, filling up with drops of sunlight rather than water. And it has a hole in the bottom, so that the water can come out and be used. The power conditioner changes the size of the hole.

Actually, several cells are connected with each other in  parallel to make panels, and the panels are then connected together into columns of six, in our case, then four columns of six are connected in parallel. These then go into the power conditioner.

The relationship between the voltage and current is not straightforward, as you can maybe imagine with a hole in a bucket. If the hole is very big, then all the water is going to go straight out of the bucket, so you have no voltage, but a high current. If there is no hole at all, the voltage will get very high, until it's overflowing, but there will be no current. In electrical terms, these are the closed-circuit current, and open-circuit voltage. As you can imagine if you were fitting a little water wheel to the hole in your bucket, you may want to play around with the size of the hole to get the most power out of it.

The curve for a solar panel is something like this, where the voltage increases with a slight fall of current until the MPP where the current starts dropping very quickly. That's the Maximum Power Point, since the power is the voltage times the current.

The job of the power conditioner is to find that maximum power point, and keep the voltage and current there to get the most out of the panels. The only way it can find it is by experimenting with the load it applies to the system, tuning in to the ideal current. It would be great if it could know just from the voltage and current whether it is at the MPP, but since the curve changes depending on the angle of sunlight, cloud cover, temperature of the panels, dirt, shading and birds flying past, it can't find out without doing another experiment.

The strength of sunlight increases the current, but does not make a huge difference to the voltage.

A number of problems can happen. A solar panel is made up of several cells. If one cell is in shade, the current for that cell will drop. Since the cells are in series, that means the current for the whole panel will drop. To stop this problem, each cell has a bypass wire over the top.

This is what causes the telegraph pole problem, and the basic rule with solar panels is: don't put them in the shade. They should ideally never have any shade. But if they do, at least try to keep it to early mornings and late afternoons.

If some of the cells or panels in a column are shaded, the effect is the same as if all the cells in the panel, or all the panels in the column are shaded. If a bird flies past there could be be a dip in the current. If a bird landed on the roof and stayed there, this would cause problems, but this is unlikely to happen since the panels get really hot.

Which brings us onto the problem of temperature. The open-circuit voltage drops with temperature by around 1% per degree, and the current goes up a tiny bit.

I haven't actually measured the temperature of the panels on our roof, but I know the air underneath them can get up to 80 degrees. Since the air is cooling the panels down, the panels at the top of the roof are going to be slightly hotter than those at the bottom, so they will have different voltage characteristics. This shouldn't be a huge problem, since the optimum current is not going to be very different between panels, and the voltages will add up in series. But I need another post to look further into this question.

For now, the clear messages I've learnt are that shade should be avoided from all panels, and that the panels in an array should all be the same under the sun. And of course, if it's a partially cloudy day, the power conditioner is going to be very busy making constant re-calibrations of the optimum power.

The VI graphs are from mpoweruk.com. They also have a cool table of the efficiency you get from panels at different angles to the horizontal and pointing in different directions, for 35 degrees latitude, which may be useful for anyone living around that neighbourhood, which in fact I do. The only part of the UK near that latitude is Gibraltar.

Starting to feel slightly warm in the White House

Barack Obama arrived on the Normandy beeches last week, a few days after pushing through legislation that could clean up US energy. The White house has so far been slow to realise we are in a green house, but are the Americans going to rush in and save the day, just as they did back in 1944?

There is certainly going to be a fight. The President of the most powerful country in the world has some executive powers, as does the Environmental Protection Agency, formed by unsung hero Richard Nixon. So their plan doesn't have to go through the republican-led democratic chambers, but it may have to get past an army of lawyers. 

This building still as yet unaffected by climate change - must be well insulated. at least from science

The more interesting part of the political environment where this is playing out comes in the curious bedfellows of the right: Christian fundamentalists and oil barons. 

Politics is very difficult to understand, even when it's local, but the way it often works in big parties is that you get fringes that hold the balance of power. With the Republicans, the religious right hold a lot of votes. The oil industry hold a lot of the money.

I should also mention the tobacco industry.

For several years, tobacco was fighting to save it's reputation from allegations that it caused cancer. The strategy of the industry was two-fold. First, support scientific studies that disprove the links between smoking and cancer, also known as junk science. And second, attack the scientific basis that means it is possible to prove something random and probablistic like cancer comes from smoking. 

This same tactic became very useful in the global warming "debate". Money has been spent so effectively debunking the science behind climate change, that some people actually believe climate change itself is a conspiracy. They believe that secret organisations are funding the research to topple the western economies.

Again, there is a strong anti-science element to this. To some extent this comes down to epistemology. In hard sciences, like physics and chemistry, we can usually set up experiments that will pretty much prove or disprove our theories. We can't do this with the climate. There's no way to go back and stop the industrial revolution to see if that would make a cooler planet. We can certainly carry on experimenting by burning fossil fuels, but we don't have a control group, so there is nothing to compare our results against. 

But what does this have to do with religion? Why on earth would the religious right be jumping into bed with oil company executives? Doesn't the bible warn us of the rich and powerful? Isn't there something just un-christian about making money by selling poison to people? And wasn't the eleventh commandment, thou shalt not pollute they neighbour's groundwater supply?

The only possible link I can find is connected with this anti-science. Similar to the science of climate change, biology and geology have some elements that cannot simply be proved by experiments in the lab. For example it's impossible to go back in time, from generation to generation, to see whether evolution really did happen, and whether we have common ancestors among the apes, and going further back still throughout all life on earth.

There has certainly been a backlash against evolution among the religious fundamentalists, and I don't think this is a recent thing. At the Scopes Monkey Trial back in 1925 the State of Tennessee found John Scopes guilty of teaching evolution and fined him $100. In fact it probably goes back to the time of Darwin himself, when religious enclaves across the United States were shielded from the kind of debate that took place in more secular areas, and could see the theory of evolution for what it is: an affront to the very foundation of Christian belief. If only America had been colonised before Galileo, there may still be swathes of North America where people believe the earth revolves around the sun.

So basically this is how it works:

God hates science;

The oil industry hates science (except when they need it to get the oil out of the ground);

So the oil industry loves God (your enemy's enemy is your friend). 

I may, of course, be completely missing the point. 

Also, watch out Barack, what does that say on your badge? In God we trust?

Carpets and air conditioners

Spent Saturday morning cleaning the room for the kids' after-school club. Part of this annual ritual is replacing the carpet. Last year we took the old carpet up to reveal the tatami mats below. I wasn't sure what was going to happen to this carpet, wondering perhaps if it was going to be beaten and then put back on the floor. A new one appeared and the old one was taken away. It turns out this happens every year.

Carpets are not that expensive, but they're certainly not free. Tatami mats are expensive, so it may make financial sense to protect them.

It's difficult to make sense of it in terms of ecological accounting and oil economics. Tatami is a low-carbon agricultural product that is completely recyclable. It is basically woven straw. Traditionally when they are worn out, they are taken out into the fields where they will draw insects away from crops, or they could be left on soil before planting to keep the weeds down.

Anyway, they present a part of a cycle that leaves a light tyre-print on the planet.

Carpets, on the other hand, are usually an amalgamation of materials that are far less friendly. Many are synthetic, with acrylic fibres glued onto a plastic backing. The fibres are all short and not much use for recycling into other textiles, even if they could be separated from the rest of the materials.

"Where are we going to throw this away?" somebody asked. Good question! Probably not into recyclables.

And don't even let me get on to the air conditioner.

Net-zero houses going mainstream

Some news from Proud Green Home about net-zero homes going mainstream. 

I think the key development to make this possible has been the reduction in cost of solar panels. Of course it would be very difficult without all the low-energy building technology, but without a way to generate electricity all bets are off.

The definition of net zero is also a little suspect. If a building is off-grid and not drawing any power from the outside, then it can certainly be said to be net zero. If it is connected to the grid, taking power from the grid and sending power back, then there should be a certain amount of daylight between the generation and the consumption. This is necessary to account for line losses and grid inefficiency.

The electricity that a house draws from the grid is a lot less than the power fed into the grid from thermal or nuclear power stations, because energy is lost in the wires carrying it and in the step-up and step-down transformers that convert the voltage to travel over the long distances we like to keep between out houses and those forms of dirty power. This is called the primary energy factor and varies from country to country. We used the number 2.7 to evaluate our house.

Even if a house uses fossil fuels directly, for example with a gas cooker or oil-fired boiler, you have to take into account the energy used getting the fossil fuels out of the ground, so you can't simply look at the energy use as the amount of energy going in to the house, but you have to add the amount of energy used to get that energy out. This is something like 10% of the energy you get out of them.

Similarly, when we supply our electricity to the grid, a certain amount of it is going to be lost, inadvertently heating up the wires between our house and wherever the electricity is used.

Also we have to address the issue of embodied carbon. In other words, how much energy was used in building the house, and how much carbon did that release? With a net-zero house, the question is: How many years will it take to pay back the carbon released during construction? 

Anyway, there tends to be a trajectory of good ideas from pipe-dream to realm-of-nutters to community-hobby-horse to common practice. Net-zero houses now seem to be breaking through from realm-of-nutters to community-hobby-horse.