The Tibetan tents are the other extreme - very low embedded energy, quick to build or erect, but a major health hazard to the occupants. Minor improvements in the design can drastically improve the quality of life for the occupants.

What's the health hazard? fumes?

Peter.

The coal fired brick may indeed not be sustainably produced,but the coal is going to be burnt anyway,and the energy derived therefrom mostly used to produce steel used in cars,or run electric lighting and so forth-not in sustainable activities.

I unhappily will never be able to travel to China,but being acquainted with the habits of poor but fairly self sufficient people here in the mountians of the American south,I would bet that those overengineered bricks are still in use hundreds of years from now if they are as good as the ones commonly used here.

Given the fact that the coal WILL be burnt,I can't immediately think of a better use of it.

I expect to see the solar stoves in common use here in the states in poorer communities within a few years.

As to the health hazards of fires in tents,it seems to be well established that smoke inhalation is a major source of health problems when people live in similar structures.One good friend of mine died of CO poisoning inside a modern house a a result of a leaky flue and a furnace located under a faily tightly sealed den.It seems unlike that a traditional yurt or other movable structure would be THAT airtight.

In regard to the changes in design that you suggest there are a couple of points. In Beijing they are building back to traditional designs in the backstreets behind the large edifices that you see on the main streets - with the gated compounds. This also holds true out in the rural villages, where the use of the flat roofs (Qinghai is a very dry state) allows for a significant heat capture in the winter (and thus they wouldn't be excited about the "whitewash" recently advocated by the Secretary of Energy).

We talked a little about the transfer of technology for small scale solar houses along the lines of the DOE Competition and they (state government) seemed very interested in following up on that. Remember, however that in Qinghai they want to put the dwellings where it is not possible to run power (low demand, high cost) and where they may be transporting in the materials by yak. In those places servicing the solar equipment has (see Botswana) been a significant problem, although apparently solved in Bhutan using the "Barefoot University" approach.

Ralph: What minor design improvements to the tents do you recommend for improving occupants' quality of life?

It is important to differentiate between building technologies and cooking methods. In the case of tent structures, it is actually the fuel (dung is the least clean fuel per unit energy extracted) combined with the type of stove used that makes the situation so hazardous, rather than the building structure itself.

Building structures in this region are highly insulated against the cold winters, but this at the expense of worsened indoor air pollution. Health is threatened in many traditional lifestyles due to limited energy options for both cooking and heating.

The article mentions solar energy options for people in Qinghai. However, neither rural villagers nor nomads are able to employ these technologies. The solar water heaters are difficult to transport and often leak (with adobe roofs this causes many problems) or break during the frigid winters, with temperatures well below -20C. The solar cookers available (and pictured) weigh around 95kg. About 20% break en route to villages, and they are too heavy for use by nomads or those living in tents.

These are some of the many challenges to overcome while also incorporating traditional knowledge and cultural patterns to produce a locally-adapted solution. We've been working on and studying these issues, and we welcome any comments or suggestions you may offer: http://www.OneEarthDesigns.org

Um! While I'm not sure of all the details, firstly labor costs are much lower, but secondly they take the heater water and run it down pipes that go down the outside of the building and in through a hole in the wall.

This may not be that bad for a single dwelling, but where you have a host of these pipes coming down from the roof of an apartment complex it is quite ugly. So I image that there is a significant installation cost in the US that goes toward making it a bit more aesthetic.

I did, however, having looked at the construction, ask the same question but the other way on, namely why are they so much more expensive than electric heaters. The answer that I got was due to the monopoly on manufacture, which is done by companies from abroad (mainly I think Japan, but I am not sure of that) who have control of the process.

Since I wrote the piece I took the train from Xining City to Shanghai, and we saw that while solar water heaters were not that common in the villages of Qinghai, as we descended into Xi'an and beyond they become much more prevalent and were about 50% likely to be on the top of apartment complexes in the larger cities.

Have a look on ebay for panel costs. £300-£500 for evacuated tubes. £1500 for a complete diy kit. £3000 installed. So, yup.

Also rather than simply feeding your DHW tank, you might as well install a "Heat Bank" or "Heat Store" which can then feed heat to your central heating as well. Replumb your existing boiler to feed the heat store, plumb the radiators to use the heat store as a source. Add a wood burning stove as a source as well.

If you DIY, payback can be 3-5 years. Otherwise, 5-10.

Profit margins on solar water heaters are huge.

The US price for solar water heaters is "set" by the UK/American firms that make the evacuated vacuum tubes, and of course, installation labor is a considerable sum in addition at regular construction / plumbing contractor rates in the US.

Then there is the markup --- many of the importers of the lower cost Chinese product --- are making whopping margins well above shipping cost, duties, etc.

2 to 4X their cost FOB China is not uncommon.

Look at your regular run-on-the-mill Walmart item. If it cost $10, you can be reasonably sure that the Chinese manufacturer got paid not much more than $2.50 less freight and insurance.

That $20 pair of jeans was sourced from China for less than $5.

I don't know about the US of A Daxtatter, but here in BC Canada I am selling and installing them for around $1,500.00. Depending on location (roof, ground, etc) and configuration. ie. compact units like here: http://best-solar-water-heaters.com/products.htm , evacuated solar tubes seperate from reservoir (with recirc pump) , system in combination with instant gas water heater (not for fifteen hundred bucks of course)
Just to say, they can come cheap. The ones I currently install are imported from China btw. manufactured by a company named THpower.

Dax,
The local guys who cut your grass around here "on the side"charge about one third what it costs to get the guys with business phones,insurance,and accurate tax returns.

I would also hazard a guess that the average Chinese is not burdened with a building or plumbing inspection for such a minor job,nor a "realtor" or banker prissily demanding exact conformance to somewhat arbitrary installation standards.

The costs of civilization can add up fast!

It will take the Chines a long time to build a welfare/bueracrat state comparable to ours-which is spartan compared to most of Europe.

The most expensive AND inefficient workers worldwide I have ever encountered were in the USA, Atlanta. This was for an exhibition and I have done these all round the world, States, Europe and Asia. Everything had to be done by unionised labour which in fact meant they stood and watched my guys do the work, they had to transport stuff 100m from the loading bays at huge charge, basic stuff wasn't done e.g. no electric supply!!, stuff I had ordered months before wasn't delivered on time... My experience was typical of many others at the show:-(

The solar heaters work pretty well in rural areas where the line from the tank to the house is short --- and where the climate permits water to be warmed to lurkwarm (beats the heck out of cold water for baths).

The evacuated tube panels shown are better than 80% efficient. Can easily raise water temperature above 50C even in the UK under cloud cover. Bright sunshine is not required.

Oops! Thanks for catching the error with the currency, which I have corrected.

We probably saw more of the heaters on high rises rather than single dwellings as we came down from the mountains. (But then that is where most of the population in the cities live).

The haze appeared at around 6:30 am as we travelled by train to Shanghai from Xi'an. Prior to that, and all the way down the valley from Xining the air was clear, and, until Xi'an, pleasantly cool.

The worry about overgrazing, whether by goat, sheep or yak is a significant worry, and is (so I was told) one of the contentious issues in Tibet, where the government want to rest and restore some of the pastures, right where the herders have traditionally migrated their flocks. We could clearly see the damage when we stopped along the road on the drive over to the Yellow River.

So are there any funds in the Obama Plan for say ..

The American Solar Corps to build and install solar hot water heaters and solar ovens ?

Any program in China ? Israel ??

Emissivity of aluminium. 4% polished. 20% if dull
Copper II oxide 90%
Carbon black 85-90%

So potentially a 5-20 fold increase in performance. Basically someone needs to sell "solar kettles" with the properties you describe, along with solar cookers.