Sustaining Future

Thursday, February 12, 2009

Distributed Power

Green Peace has been advocating decentralised power co-generation for quite some time, especially in the cooler region of the world. A small power station among cities where the 'waste' heat can also be used as a heating sources for buildings nearby and the electric power generated is used locally as well.

It is great to see support coming to USA too. As noted, the original centralised power system was designed for costly generators and cheap grid network. The problem has reversed as the reliability of the generators are better than the grid. There are 207 benefits of small generators.


Tuesday, February 10, 2009

Fire Resistant Homes

Many people, who has just escaped from the devastating Victoria Bush Fire, are determined to rebuild. This poses an interesting question; what kind of home will be safe in such environment? Building with fire resistant material certainly helps a long way. Here are some information from source:

Sand stone with fine grains can moderate fire successfully without having serious cracks. Most of other stones will disintegrate into small pieces when heated during fire and cooled afterwards and hence unsuitable.

Bricks are bad conductor of heat. They have no serious effect of heat until the temperature during fire rises above 1200 degrees to 1300 degrees. At the time of construction if good quality mortar is used and brick work constructed by skilled mason, brick masonry offers good resistance to fire. See the brick wall still standing here in this photo

Concrete is a bad conductor of heat and an effective material for fire resistant construction. It offers higher resistance to fire than any other material. The actual behavior of concrete in case of fire depends on quality of cement and type of aggregate which form concrete. In case of reinforced and pre-stressed structures, it also depends on the position of steel in concrete. Unfortunately, concrete production emits a lot of green house gas.

Using special designed barrier, such as Pyrotite Technology for the external walls. Or apply fire retardant and fire resistant coatings that can withstand extreme temperatures (up to 2000° Fahrenheit) for an extended time (over two hours) [source]. May be you may consider adding a fire-proof tent at the highest point of your home, see this patent.

Surprisingly, straw bale which has super insulating properties and excellent flame resistance due to lack of internal air channels is also a green and effective choice.

Metal roofs with two layers of fire resistant barrier which withstand burning embers or 'living' roofs [remember to reduce fuel before fire season!].


Victoria Bush Fire

Last weekend's bush fire in Victoria turned out to be one of the worse bush fire we have ever faced. The week before, we have the record-breaking 4 consecutive days of temperature over 44C which basically fried every thing dry. On the day, we have a record breaking 46.6C with strong northern wind and single digit humidity. While some fires were spontaneous, unfortunately, the authority has identified cases where arsenic may be involved.

The damage and destruction was widespread. As shown in the photo above, whole towns were wiped out. At this point, there were 181 people confirmed dead, over 4000 people homeless, hundreds were in emergency units with burn, over 700 homes totally lost.

On a slightly brighter side, the Bush Fire Relief Fund set up by the Victoria Government together with Red Cross has already reached 28M and several fund raising efforts will be coming in next few days. Record number of people donated blood in the last few days.

Could this bush fire be avoided in the first place?

Scientists are now pointing the fingers towards the worsening weather pattern. While the southern part of Australia is extremely dry (drought for the last couple of years, Melbourne's water storage is at record low), there are flooding in the northern part of the continent (one month's worth of rain was dumped within days in Queensland). Extreme temperatures (two hot weather records were broken within two weeks) are expected to continue.

If we are to put a value to climate change, we now have a vivid case.

cross-posted to Random Walk in Learning