Monday, 26 June 2017

Jargon - A glossary for the low energy builder

​Here is a brief glossary of jargon related to low-energy building, including English, Japanese and an English ​definition. It will soon move to a permanent page, where I hope to update it.

A​r​gon​ アルゴン​​: An inert gas used in multi-pane windows. It insulates around 50% ​better than air.

Astroturf movements​ 人工芝運動: Groups paid for by large corporations to appear to be grass-roots organisations, often supporting their projects or fighting against regulation. A victory of capitalism over morality!

​Cellulose insulation セルロースファイバー: Fibre-based insulation made from wood fibres, sometimes loose and blowable, and sometimes pressed together and bonded with its own resins. (Not universally acclaimed.)

Eco​ エコ​​:​ see green

EPS​ 発泡スチロール​​: Expanded polystyrene. Low-cost foam-based insulation material.​ Being foam-based it does not allow much air or water vapour to pass through. When installed it is important to avoid gaps, which can halve the performance. If used within a wooden structure in earthquake prone areas, it's possible that gaps will appear after quakes. Don't confuse with XPS​, which is much stronger, although can retain more moisture.​

​Fibre​glass​ グラスウール​​: Low ​cost fibre-based insulation material. Being fibre-based the insulation perfomance comes from air trapped between the fibres, which can move allowing water vapour through. A vapour barrier is therefore necessary to keep the building airtight. Not particularly pleasant to handle, but once installed there are no health risks until the building is butchered or demolished.

Green​ グリーン​​:​ see eco

Green bling (derogatory and somewhat archaic)​: Devices, fittings and coverings that can be added to building to make them "green". According to an arbitrary calculation, 90% of the ​building's environmental performance depends on invisible elements integrated into the structure and integral to the conceptual design. The effect of green bling is often like ordering a salad with your steak in the interest of becoming vegetarian.

Green wash​ing グリーンウォッシング​​: Portraying ​products, processes and activities as environmentally friendly without making any fundamental exchanges except in the advertising copy. (See

Kazoo blow​er​​ カズーブローアー(告発を不正にする者): ​Person who creat​es​ a lot of noise that will support the status quo and drown out ​voices of concern or dissent. (cf whistle blowing; see also astroturf)

Krypton​ クリプトン​​: Another inert gas used in multi-pane windows. ​This is another 50% better at insulating than argon, and allows windows to be much thinner while reaching high performance. Since the frames will also be thinner, and frames and their thermal bridges lose the most heat in window installations, making window panes thinner may not be such a high priority.

Low-e​ ​低E: A coating applied to internal window faces which has low emissivity. This reflects low-frequency back into the building, and improves the performance of windows.

​Mineral wool​ ロックウール: Another fibre-based insulator like fibreglass, but made from ceramics. A little more expensive than fibreglass with the same performance, but not as nasty to handle

Natural materials​ 自然材料:​ ​A somewhat vague term usually ​referring to products with no synthetic chemicals, made from trees. Often these trees were planted in neat rows, cut with chainsaws, transported by diesel-powered vehicles to processing mills running on thermal power stations.

Polyurethane​ 発泡ウレタン: ​​Another foam-based insulator that performs better than polystyrene.

​Thermal bridge サーマルブリッジ・熱橋: ​An extra loss of heat caused by joins between insulating materials, geometry of external structures and additional non-insulating materials. Which heat losses are usually calculated over areas, thermal bridges are calculated over lengths. As insulation improves, thermal bridges become more significant since a larger proportion of heat is lost through them, and also more critical as they can result in cold spots that will attract condensation.

​Vacuum 真空: ​In theory the best insulation material available, since vacuums contain nothing which will conduct. This is sometimes used in multipane windows and insulation panels. I can't help being skeptical about the long-term performance since there is a big pressure difference between the atmosphere and the vacuum, leakage will not be zero, and eventually this will be filled with air. This may take one month, one year or ten years, but you should be planning a building to last for fifty or a hundred years.

Vapour barrier​ 蒸気障壁:​ A membrane usually applied on the inside of the external walls, or within 25% of the insulation from the inside. This stops moisture from the internal air from getting through the walls where it would cause condensation. Some wall finishes act as vapour barriers. Highly insulated buildings should also be air tight, to prevent heat being lost or gained through leaking air. Depending on the performance, vapour barriers may also act as air barriers.

Warm edge​ ウォームエッジスペーサー: ​A technology used around the edges of multipane windows which prevents heat leaking through that weak link in the window assembly.

XPS ​押出ポリスチレン​​: Extruded Polystyrene. The same chemical composition as EPS, but extruded rather than expanded, and stronger. Suitable for use under and around foundations.

Friday, 23 June 2017

Satisfaction questionnaire

Here is a satisfaction questionnaire for house builders to get feedback, inspired by one of the questions on the form we got when we moved in. 

Congratulations on moving into your new house!

Now that you've moved in, how does it feel to be in your new house?

Were the extra building charges adequately explained?
Yes, the explanation was excellent and I was in no way shocked by the unreasonable and unexpected price hike
The explanation could have been better, but I got the general idea
Perhaps you need to tell us again

How many problems have there been since you moved in to your new house?
Only about half a dozen
Ten or so
Definitely less than a hundred

When there were problems, was it easy to get in touch with us?
Yes, the phone was always picked up quickly
Yes, the email I sent didn't bounce
Yes, I knew you were there when I came round to the office, although it did seem strange that you'd turned the lights off

How many times did you have to complain about the problems before we actually did something?
Three times
I gave up complaining after the fifth time

When we finally did get in touch with you, how good a job did we do at pretending we cared?
It genuinely seemed that you didn't have anything better to do than listen to us
I think I saw you nodding
Not sure, you were too busy looking at your phone

Did we tell you about our other satisfied customers?
Yes, I heard about them several times
You told us about one satisfied customer several times.
You have other satisfied customers?

(Note: Clicking these buttons will make no difference to anything, much like the satisfaction surveys you are often asked to fill out!)

Friday, 16 June 2017

Just planning ahead to make a battery charger for electric cars

"Are we nearly there yet?" the kids ask from the back seat.

"Yes we'll be there soon," I say, and I'm sure we will be. Soon is always too late for some but takes others by surprise.  

So we are half way through the ten-year contract with the Chubu Electric Power Company, and when it ends there is almost no chance that we will be paid as much as the 48 yen per kWh we are now getting. The tarriffs have been steadily falling each year, as was originally planned. Solar panel prices have also been falling, so the calculation of return on investment remains a little short of the ten-year contract that electricity companies are tied into for domestic installations of less than 10 kilowatts. Installations over 10kW are considered commercial, and they are tied into a lower price for twenty years. The prices of solar panels, as with all commodities, is somewhat arbitrary, and it is not completely clear whether the government is deciding the feed-in-tarriff rate based on the price of the panels, or wether the price of the panels is being set so that the feed-in-tarriff will pay the cost back. 
I think this graph shows that costs of solar installations over ten years met the residential electricity rates in the middle of 2014. At that point​, in theory at least,​ incentives become moot since it's cheaper for people to buy their electricity in the form or solar panels than it is to buy electricity company​. Of course not everyone has the capital to be able to do that, but the feed-in-tarriff was still above the price people were paying for electricity. According to solar, the amount you get for selling electricity is dropping by 2 or 3 yen per kWh per year. You could sell 1kWh for up to 33 yen in 2016, and it will be 30, 28 ​in 2018​ and 26 ​in 2019. So if I'm lucky and still able to get a new contract with my old panels, I may get over 25 yen per kWh when my contract runs out.

At 25 yen per kWh it's still worth my while to connect to the grid. My income from the panels will halve, but it will still be three times more than I pay for electricity. 

A worse scenario is that I get paid some market value for power generation, which could be around 11 yen. ​It may be a fixed rate or a floating rate. The worst scenario is that they don't pay me anything, but just expect that power to flow into their grid. I think that is very unlikely.

There has apparently been a deregulation of the electricity market, which in theory means I can shop around for the highest bidder for my electricity. Japan For Sustainability has an interesting story here about Renewable Energy Hopes and Hurdles Amid Full Liberalization of Japan's Electricity Market. "In April 2016, Japan woke up to a fully liberalized electricity market" the article begins, although even by ​June 2017 I can't help feeling that most people are still oblivious to this new reality. ​

Increased competition tends to bring down prices, which may be bad news for people trying to sell​ electricity​. You can find out here whether changing your electric company will give you cheaper bills: It's easy to find companies that will sell you electricity, but it's harder to find those that will buy it off you, unless you have larger sources. I searched around the website for, who offer 100% renewable energy, but ​they are not interested in buying renewable energy​ from my roof!

At some value less than 20 yen per kWh, it stops making sense for me to pay the electricity company the monthly flat rate to connect to them, since we​ make more electricity than ​we​ use. The big question going forward for anyone investing in renewable energy is how much electricity will cost. Jay Carlis claimed in 2013 that electricity prices are not going down and he​re's a Guardian article from 2011 about electric cars taking over.

More information:

Monday, 12 June 2017

10 tips to design Near Zero Energy Building

Allessandro Merigo, architect from Lumezzane, Italy, has written ten tips to design Nearly Zero Energy Buildings (NZEBs). In Italy all public buildings will be near zero energy from 2018, and all other construction from 2020. 

Read about refurbishing buildings too

1. Start with the shell 
2. Use appropriate software
3. Input real climate data
4. Avoid thermal bridges
5. Ensure air tightness
6. Think about air exchange
7. Reduce HVAC
8. Use renewable energy
9. Check the budget
10. Collaboration is the key of success

Note that only one of these is about producing energy, and seven are about reducing energy losses. 

Friday, 9 June 2017

Do solar panels have a dark side?

While browsing through the battlefield of prejudices and preconceptions that is the internet, I came across the graphic below, proudly showing how much better coal and oil are than solar power. This was a retort to Bernie Sanders boasting about the great contribution solar power was making to job creation. They cite the broken window fallacy, which is the mistaken belief that breaking a window is good for the economy, because of all the work it for glaziers, carpenters and painters. I can't help feeling that the broken window that this metaphor really applies to is the global environment, which the economy has been breaking for the past couple of hundred years, and has yet to seriously think about repairing. ​Anyway, the author's conclusion was ​that it takes 79 solar workers to produce the same amount of electric power as one coal worker produces.
Of course, he is missing the fact that almost all coal workers' 2016 efforts have now been burnt, while most of the solar jobs were installing production capacity. If all of these workers stopped for 2017, then coal and natural gas would produce zero kWh. Solar, on the other hand, would produce more or less the same amount. In fact those panels installed in 2016 will still be producing power for at least the next quarter century. In addition, many of the jobs in the solar industry are leading directly or indirectly to increasingly efficient solar panels and better ways of using them, so when those panels eventually need replacing, their replacements will be more efficient, cheaper, lighter, less energy intensive and with a lower environmental impact in their production and disposal.

This guy has a similar story, and once again it seems to be coming from the right, and firmly putting renewable energy on the left wing, and the left field. "Our lives are improved by finding ways to reduce the amount of labor in them, not increase it​," they both claim​.

​Of course, a lot of labour-reducing measures have not lead to a reduction in labour but an increase. In the 1930s John Maynard Keynes predicted that ​his grandchildren would be working 15 hour weeks. He didn't actually have any grandchildren, so that part of his prediction was wrong to start with. But his sister's grandchildren, interviewed here and now retired, worked a lot more than fifteen hours a week. In fact one claims it was more like fifteen hours a day. Work has expanded to fill the available time. Computers have not yet liberated the masses from work, but have enslaved millions behind their keyboards. Cheap products have just allowed people to buy more. One of the​noble aims of the industrial ​revolution was to provide every man with his own shirt, but it has just led to many overflowing wardrobes. ​A kind of Jevons paradox exists here too, as we spend all our time using these labour saving devices. But I digress from the solar issue.

​The bottom line is, of course, that solar panels do require work, energy and resources in their production, and looking backwards it's difficult to argue that they are using less carbon. Looking forward there is a different picture, and solar power and other renewables make zero-carbon energy production possible. Burning fossil fuels does not. There is no reason to ever build another coal plant in the United States​, or anywhere else for that matter.