Saturday, May 31, 2014

Do Electric Cars (EV) Generate Harmful Magnetic Fiels?

The sell of electric cars, or electric vehicles (EVs), is on the raise due to environmental reasons. At the same time the doubt or worry about impact of magnetic fields generated from EV to human body also in the raise.

A comprehensive study has been conducted by European scientists should put those fears to rest. An electromagnetic safety research project funded by the EU and bringing together experts and research institutes from 10 countries to look into the level of magnetic fields from EVs. The team used 8 different vehicles (100% electric cars, hybrids, plug-in hybrids, fuel cell, gasoline, diesel) and mannequins, with sensitive sensors in the head, chest, and feet, to simulate and measure the exposure to real human drivers. They found that in all cases, exposure to magnetic fields in electric cars was lower than 20% of the limiting value recommended by the ICNIRP (International Commission on Non-Ionizing Radiation Protection).

The measurements taken at the head-height were less than 2% of that recommended value for EVs. Interestingly, gasoline and diesel-powered cars measured at around 10% of the limiting value. Hence, the team concluded that there is a good safety margin and should have no cause for concern.

The main problem with health hazard caused by magnetic fields from EVs is the placebo effect. People who believe that they are being harmed might feel that harm. This means that the main way to cure those ills is informing people.

Tuesday, May 27, 2014

Why Is Wave Power Lagged Behind Other Renewable Sources?

The beginning of the idea to use tidal wave to generate energy was dated back to 1799 when the first known patent was filed. In 1910, Bochaux-Praceique had realized the idea to use wave energy to light and power his house at Royan, France. A renewed interest in wave energy was motivated again by the oil crisis in 1973. But until today, no commercial scale wave power operations exist yet.

So, what slows the development of tidal wave power down?

Operating in the ocean is far more difficult than on land. Saltwater is a hostile environment for devices causing them to corrode much faster, and the waves themselves offer a challenge for energy harvesting as they not only roll past a device but also bob up and down or converge from all sides in confused seas. Even though this provides enticing opportunities for energy capture, but at the same time a challenge for optimum design. Also, roaring ocean costs a lot more to send crews to do installation and repairing.

The other reason of lagging in wave power development is that it has never been high in R&D priority. Most of the resources have been put in wind and solar.

In spite of the challenges inherent, wave power is progressing, albeit slowly. Until the cost disadvantages can't be overcome, it simply won't make sense to build wave farms in most places when more wind or solar capacity could be built for less.

Wednesday, May 21, 2014

Battery Made From Cotton

Battery has become an essential thing in our life. Ranging from cellphones, power banks, electric and hybrid cars, emergency lighting, etc, are all powered by battery, like lithium-ion battery. Of course, lithium-ion battery has it downside. It is expensive, runs hot and even causing fire, takes long time to charge and has limited charge-cycles, and acts as hazardous waste when disposes.

A new start-up called Power Japan Plus (you can tell it is from Japan) has come out with a revolutionary battery made from cotton. YOU ARE RIGHT! Cotton, the raw material of the fabric of your cloth. The new battery is called "Ryden".

Power Japan Plus has modified the cotton fibers to create a new type of carbon fiber to form the anode and cathode of the Ryden battery and an organic fluid is used as an electrolyte. So, practically the whole battery is made up of organic components.

What is the advantages of "Ryden"?
(1) it charges 20x faster than lithium-ion battery.
(2) it has over 3,000 charge and discharge cycles comparing to only few hundred to thousand cycles for lithium-ion battery.
(3) easy to manufacture as it doesn't use any rare metals.
(4) it doesn't run hot.
(5) fully recyclable.

Power Japan Plus expects to manufacture up to 5,000 Ryden batteries this year as part of a pilot run, so it could still be many years before we see the breakthrough tech implemented into electronic gadgets and cars.

Wednesday, May 14, 2014

Many Ways To Use Baking Soda As Super-Cleanser

Baking soda is commonly available in most of our kitchens. Besides cooking recipes, it also serves as a non-toxic and biodegradable cleaning solutions. Below are few DIY ways to use baking soda to clean.

(1) Unclog drains
Pour a cup of baking soda, followed by a cup of white vinegar, into the drain, and plug it with a stopper for 15 minutes. Then flush with water. Repeat if necessary, with no worry.

(2) Clean pot
Fill your pot with few inches of water and add 2 tablespoons of baking soda. Simmer for 15 minutes and then use a wooden spoon to scrape off any leftover.

(3) Remove bad smells
Many bad smells are the result of slightly acidic molecules, use baking soda to neutralize bad odors. Keeping an open container of baking soda in your fridge, cabinets or closet will reduce bad smells. It’s good to replace the soda about once every six months.

(4) Freshen mattress
Sprinkle baking soda on mattress and make the bed. When you change the sheets next, vacuum it up.

(5) Clean carpet
Sprinkle baking soda on carpet and then vacuum it, or use it with water to scrub off any stain.

(6) Clean oven and fridge
Mix baking soda with water and spread it over the interior of the oven or fridge. Then let it sits overnight and use a spatula to gently scrape off the dried paste and wide with cloth.

(7) Clean any surface
Baking soda paste to clean tiles, marble, counter tops and linoleum floors without harsh chemicals.

(8) Grout
Use an old toothbrush and baking soda to get residue and grime off of grout.

(9) Toilet
Just sprinkle, scrub and flush.

(10) Whiten linens
Mix equal parts of baking soda and lemon juice to make your white towels, sheets and clothing whiter. This mixture works as a mild bleaching agent.

(11) Remove onion smell from hands
After done chopping, rub a sprinkle of baking soda and a few drops of water into a paste in hands. Rinse it off after a bit of scrubbing and the onion smell will be gone.

(12) Shampoo
Mix a ratio of 1 tablespoon of baking soda per cup of water in a bottle and shake it up. Pour it on your hair and massage it around for about a minute before rinsing. You'll get a squeaking clean feeling! Some people like to follow this with a rinse of apple cider vinegar.


Tuesday, May 13, 2014

Black Silicon Solar Cells

Natcore Technology’s black silicon wafers are now in production line to be manufactured into solar cells. This has been done by one of the world’s largest photovoltaic manufacturers, which is located in China’s Hunan province. 

What is "Black Silicon?" It is referred to the apparent color of the surface of a silicon wafer after it has been etched with billions of nano-scale holes per square inch. The black color is not a color at all but results from the absence of reflected light from the porous wafer surface.

Five batches of the black silicon wafers were produced in the trial run and achieved 15.7%. This can easily be increased by optimizing the process. Also, this achievement, in the manufacturing environment, proves that black silicon process is commercially viable in real production line.

Dr. David Levy, Natcore’s Director of Research & Technology, they put these cells through the Chinese manufacturer’s process with essentially no modification to the process itself, except for the fact that certain steps were completely removed. The removal of these steps projects could low production cost as much as 23.5%.

Friday, May 9, 2014

What Is The Future Of Silicon Thin-Film Solar Technology?

The future of silicon thin-film solar technology is looking bleak and expected to go downtrend. 

DuPont has decided to terminate their silicon thin-film operations by the end of 2014. Silicon thin-film market share is likely to keep falling in the short run, according to the analysis of EnergyTrend.

The price gap between silicon thin-film and crystalline silicon has been narrowing. According to Arthur Hsu from EnergyTrend silicon thin-film's price is quoted at US$0.58/watt while crystalline is at US$0.6/watt. The difference has decreased from the original US$0.1/watt to now only US$0.02/watt. Silicon thin-film has lost its price competitiveness. Meanwhile, crystalline silicon conversion efficiency is around 17.2% while thin-film remains at 8% to 10%. Efficiency gap between the two will continue to increase as crystalline  silicon's efficiency goes up.

Another reason leading to the closing of silicon thin-film operations is the halting of new technology development by equipment manufacturers. In fact, relevant manufacturers were hoping to rely on Tandem technology’s commercialization to improve silicon thin-film's efficiency. However, after acquiring Oerlikon’s thin-film business, Tokyo Electron has ended Tandem technology development, which crushed thin-film manufacturers’ final hope.

Sunday, May 4, 2014

Only Costs US$80 In Parts To Manufacture Priced US$1,500 Google Glass has taken apart the recent mostly talked Google Glass product to estimate the components' cost.They found that the priced US$1,500 Google Glass only has components worth US$79.78 inside it, including assembly and testing. The breakdown is shown below.

Of course, the cost mentioned above hasn't included engineering design costs, initial start up manufacturing costs. So, definitely the raw cost will be higher than US$79.78. Not mentioning about licensing fees of intellectual property right for technologies which Google might have used in the device from thirty party.

So, the chances are unlikely that the company is getting rich on sales of Google Glass. However, if sales hit the range of millions within the next couple of years, good chunk of Google's revenue might flow from selling this device.

Thursday, May 1, 2014

Promising New Solar Material To Achieve High Efficiency At Low Cost

On March 26 I had talked about a new material, perovskite, that Nanyang Technological University has researched to use it as solar at day and light panel at night.

Now researchers at National Renewable Energy Laboratory (NREL), U.S.A., are analyzing perovskite to be a potential low cost, high efficiency, solar material. What makes perovskite device structures so remarkable is that when processed in a liquid solution, they have unusual abilities to diffuse lights a long distance through the cell, this means more time for the material to absorb the lights which translates to higher efficiency. Also, perovskite-based solar material is very easy to fabricate using liquids that could be printed on substrates like ink in a printing press, or made from simple evaporation. These properties suggest an easy, affordable route to solar cells. All theses indicate a potential for low-cost, high-efficiency devices.

The picture on the left shows a NREL's researcher applying a perovskite precursor to make a perovskite film.

Perovskite's efficiency has grown from 3.8% in 2009 to 16.2% now. That's better than a four-fold increase. By contrast, efficiencies of single-crystal solar cells grew by less than 50% during their first 5 years of development.

The theoretical maximum efficiency of a perovskite-based solar cell is about 31%. Several companies are already interested in forming cooperative research and development agreements so they can work with NREL on perovskite.