Solar Panels: A New Challenge For Firefighting

Since the launch of SEDA Malaysia on Dec. 2011, more and more rooftop solar arrays will be installed on Malaysia residential and commercial buildings. New challenges emerge for firefighters when a blaze erupts on these buildings.

U.S.A.'s fire departments are facing the exact problem. A massive fire erupted in early September this year at the Dietz & Watson meats and cheeses distribution center in South Jersey. The 7,000 photovoltaic panels installed on the roof of the center were blamed for the “complete destruction of the warehouse” as they prevented firefighters from opening up the roof to ventilate the structure while posing the threat of electrocution.

Risks posed by solar photovoltaic panels are:

(1) The panels can be activated by any light source so electric shock is always a possibility since the panels “can’t be shut off”.

(2) Another main hindrance is that the panels are covering large areas of roofs, firefighters are limited in where they can cut, causing the inability to ventilate the roof to release trapped flames, which would help to prevent the fire from spreading.

(3) The panels on the roof also limiting the firefighters where they can exit, as an alternative, which reduce the escape and survival chances.

(4) The panels also pose the risks of shock and trip hazards.

(5) Firefighters also need to consider the additional weight of the panels on the roof structure that may be weakened by the fire.

More information can be obtained from the report by San Jose fire engineer Matthew Paiss called Home Power.

Despite this highly-publicized incident where solar panels complicated firefighting efforts, this occurrence is actually rare. "There are hundreds of thousands of solar systems nationwide and only a handful have been linked to fires since 1996,” according to U.S.A. Solar Energy Industries Association Vice President of Communications Ken Johnson when talking to The Star-Ledger.

To address the increased risks associated with fighting structure fires on buildings with solar panels, the Fire Protection Research Foundation released a 2010 study that highlights appropriate training techniques to prepare for firefighting in the alternative energy era. With the proper training and preparation, these new hazards can be safely mitigated.

Source: http://www.solarreviews.com/blog/solar-panels-in-the-line-of-fire-091213/

Do LED Bulbs Really Consume Less Energy Than CFLs?

LEDs are an emerging technology in illumination. More and more people are replacing compact fluorescents (CFLs) with LEDs thinking that they could save more energy. But are LED bulbs truly better than CFLs? If so, by how much? In order to answer these questions a full life-cycle analysis (LCA) is necessary.

The U.S.A. Department of Energy has done a very thorough analysis taking into account energy usage for manufacturing, transportation and in-use, how many bulbs are used over time for those that don't last as long, etc. Below chart shows the findings.

The unit of the energy consumption is in the unit of MJ per 20 million lumen-hours. The 20 million lumen-hours is derived from the lifespan of a 12.5 watts LED bulb multiply its light output, i.e. 25,000 hours x 800 lumens = 20,000,000 lumen-hours. In order to get this number we need 1 LED bulbs, 3 CFLs, 27 halogen bulbs and 22 incandescent bulbs.

CFLs ARE ON PAR WITH LEDs!

CFLs and LEDs are about the same on a LCA basis right now. Both consumed about 3,900 MJ per 20 million lumen-hours, which is about 1/4 of incandescent lamp. The study also indicates that by 2015, if LED development meets the performance targets, its life-cycle energy is expected to decrease by ~ half. The next generation LEDs should beat CFLs then.

Is A Hoax - Colour Squares Do Not Denote Content Of Toothpastes

It has been widely circulating online about that the color squares appear on the tubes denote the content of the toothpastes. It is something like:

Green: natural;
Blue: natural + medicine;
Red: natural + chemical composition;
Black : pure chemical.

IT IS A HOAX!

The squares, called "eye marks", are marks used in the packaging process. They tell the packaging machines when to perform certain tasks such as detecting and aligning squeeze tubes, cutting or crimping tubes.

I guess the answer is not as interesting as the "color squares reveal the content of toothpastes" but it is just a simple fact. Hope that it clears out some of the online myth.

Links:

http://www.hoax-slayer.com/squares-on-tube-hoax.shtml

http://wafflesatnoon.com/2013/03/04/hoax-meaning-of-squares-on-tubes/

What Is The Difference Between Hotdog & Sausage?

This morning I was having breakfast in a "kopitiam" (a traditional coffee shop found in Southeast Asia) style western food restaurant and saw a breakfast set of "egg & hotdog" on the menu. It prompted to me that I have been wondering about the difference between "hotdog" and "sausage".

So browsing thru the internet and found below definition that are widely used.

Sausages
The high quality traditional German sausages first came from Neu-Isenburg, a small town on the road from Frankfurt to Darmstadt. It is made of prime lean pork and a little salted bacon fat. It is then finely chopped into a smooth paste, put into pork casings and smoked.

Hot dogs
The stuff that we call hot dogs are made from very different ingredients and most probably came from America. These ingredients can be anything like pigs' and cows' hearts; and pigs' cheeks. Iced water is added at around 1/3 the weight of the meat and stuffed into narrow bullock runners (casing) and smoked.

It seems that the main differences are:
(1) Place of origin;
(2) Ingredients.