Sustaining Future

Wednesday, July 16, 2008

Vertical Farm

Since New York Times' article on vertical farm which I have blogged before, there is a bit of interest on the blog sphere on that.

Saving valuable land space for food production in City is a great idea, but there is one important consideration which seems to be missing in all the reporting.

Plant grows by photosynthesis. Photosynthesis needs light. In a high rise structure, which would be quite wide and deep, there will be the issue of getting light into the centre of the building.

At the end of the day, all the energy we have come from the Sun. If we are going to use renewable energy, that will be dependent on the amount of sun light (and wind which is caused by the Sun shining on nearby land mass) available to the building. I am afraid in reality, vertical farm, without additional energy input, would only be a good idea on paper.

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Tuesday, July 15, 2008

Alternative Energy: The Pressure Wheel

This is a simple and cheap system for increasing the pressure of water. However, it is NOT the same as increasing the power.

Just like electrical power, if the current is held constant, the power increases with voltage. However the system's power performance will depend on the available current output as well.

For the water wheel to generate higher power, it is NOT enough just by increasing the pressure of the available water. The volume at that pressure is a factor as well.

This is just simple Physics.


Sunday, July 06, 2008

Mopping Up the CO2 Deluge

To battle global warming, it's not enough to reduce emissions. We need to soak up what's already there.

Dude, when you mess up something, don't you just walk away!

Well beside this common moral stance, there is also a good reason behind it. The Earth will take care of that if you don't. It just takes about 100,000 years. If our life span is like that of the Earth, it won't matter. Unfortunately, because the Earth do the job for us, we shall all suffer the consequence of our past actions if we don't act to clean up now.

Reduce green house emission is NOT enough! We need to clean up the mess we did in the last 100 years.


Thursday, July 03, 2008

Growing algae vertically, high yield and low water consumption

All explained in the video.

18 gallon of oils per acre per year if you grow corn. However, using this technique, you can produce more than 20,000 gallon on the same land the same time.

Why produce biofuel from corn and starve the world at the same time?


Plastic Bags, to ban or not?

Treehugger is running a story on the success of plastic bag ban in China is working. A debate is also brewing in Australia here on a trial in Melbourne to charge shopper AUD0.10 per plastic bag at supermarket check out - as a mean of reducing the use of plastic bags.

The argument is that the "green" alternative bag is also non-biodegradable. As they reach their useful life cycle, they will be posing an environment issue as well. Are are replacing one evil with another?

Biodegradable plastic bags are now available.

Th ban should be on "non-biodegradable" bags, not the bags themselves.