Artificial photosynthesis, a promising technology for future energy production

What is artificial photosynthesis

It is a chemical process that replicates the natural process of photosynthesis, a process that converts sunlight, water, and carbon dioxide into carbohydrates and oxygen. The artificial photosynthesis term is commonly used to refer to any scheme for capturing and storing the energy from sunlight in the chemical bonds of a fuel, a solar fuel.


Photosynthesis is a natural process to convert sunlight, carbon dioxide and water into usable fuel and emitting useful oxygen in the process. Photo: de engineur


Promising technology for future energy production

The technology is absolutely promising! Prof. Michael Grätzel, a Swiss pioneer of artificial photosynthesis was awarded the world’s most prestigious technology award - the Millennium Prize - worth £660,000 (about RM3.35 million) for his effort and contribution towards development of future energy.

Since the 1970s, Grätzel has been developing the Dye-Sensitised Solar Cell (DSSC), a device that mimics the ability of plants to capture photons of light and turn them into electricity.


How it works

DSSCs use special dyes to capture the energy in light at different wavelengths, like the chlorophyll of plants. Although still under development, the excitement surrounding DSSCs lies in the fact that while they only convert around 11% of the light energy into electricity, which is well below the efficiency of conventional solar cells, they are much easier and cheaper to construct, and are expected to be much more cost-effective.


TheGreenMechanics: This reminds me of a researcher friend at a local university saying (or rather posting on his FB page) something like "charging your phone by plugging it to the tree". Well it's very possible!

Calculating power factor from electricity meter reading

Power factor, PF,  in the electrical installation can tell us about how efficient the plant, factory, building, or installation load is operating at.

Low power factor cost money and  in most cases is against the law. In Malaysia, TNB/SESB set a minimum power factor of 0.85 that every consumer must achieve and if yours falls below this value, you will be charged with power factor penalty in a staggered manner.

Calculating power factor without taking your toolbox with you

kVA² = kW² = kVAR²


From this equation, we derive the power factor:




In the case of SESB, a subsidiary of Tenaga Nasional Berhad, the power factor penalty is calculated as follows:-

If the Average Power Factor of any consumer in any month is found to be:

(a) Below 0.85  and up to 0.75 lagging, a supplementary charge of 1.5% of the bill for that month for each one-hundredth part (0.01) below 0.85 will be added to the bill for that month; and

(b) Below 0.75 lagging, in addition to the charge above, a supplementary charge of 3% of the bill for that month for each one-hundredth part (0.01) below 0.75 will be added to the bill for that month.


Example:



Say, a premise is categorised under Commercial Tariff Class 1, CM1, and billing meters show the followings during January 2013 monthly meter reading:

kWh meter     : 2,660
kVARh meter  : 2,190

The average power factor for that month, according to the formula is

PF  = kWh / [SQRT(kWh² + kVARh²)]
       = 2,660 / [SQRT(2,660² + 2,190²)]
       = 0.77

which is below 0.85 but above 0.75, and hence a PF penalty of 1.5% supplementary charge for every 0.01 part applies.

Supplementary charge	=	100*(0.85 - 0.77)  x  1.5% x  Monthly bill
	=	8 x 1.5% x RM890.10
	=	RM106.81

Calculate monthly bill
First 200 kWh	=	200 x 33.0 cents     = RM66.00
Next 2,460 kW	=	2,460 x 33.5 cents  = RM824.10
Hence, monthly bill	=	RM890.10
Total bill	=	RM996.91

The PF penalty is about 12% of the monthly bill and for a larger installation/premise, this could be a lot of money. Plus, if you continue to register PF of below 0.75, the utility company has a provision to stop supplying power to your premise until you rectify the situation.


Reason for posting this? I'm putting this formula up here for ease of future reference. I can refer to it from my mobile device, too. Also, this maybe useful for the accountants and administrators who receive the bills and in need of quick answer on how/why they were penalised.

India to have highest transmission voltage at 1,200 kV

Malaysia's TNB transmission lines maximum voltage is 500kV while it is 275kV for Sabah. The quest for higher voltage substations and transmission lines is driven by the increasing amount of power consumption. The higher the voltage, the more power can be transmitted over hundreds or thousands of kilometres.

For now China is still holding the record with its 800kV lines, but this would be soon overtaken by India with the proposed construction of 400/1,200kV substation in Deoli.

To put things into perspective, the distribution lines voltage right before your low voltage (230V) home supply is 11kV in most cases.

Any danger or health effect of high voltage lines to human? There're concerns but No evident to show so far.


World's max voltage substation in Vidarbhaites
Times of India

NAGPUR: The project may not benefit the region but Vidarbhaites can take pride from the fact that Deoli, near Wardha, will have world's maximum voltage substation in four to five years. Powergrid, a central sector PSU, has decided to set up a 400/1,200 KV substation at Deoli. 1,200 KV is the highest voltage proposed in power transmission. Presently, the highest voltage used is 800 KV by China, which is also developing a 1,100 KV system.

Powergrid will lay a 380 km long 1,200 KV transmission line from Deoli to Aurangabad in the first phase. In the next phase, it will construct a 400/1,200 KV at Deoli and then a 1,200/400 KV substation at Aurangabad.

A company official said that a substation was being set up in Bina (Madhya Pradesh) for testing the 1,200 KV system. "We are developing 1,200 KV equipment with the help of private companies like Crompton Greaves, ABB, etc. as they are not available in the world. The test substation will be ready in three years and then we will begin work on the Deoli substation. Once the technology is commercially successful, we will also market it abroad."

Elaborating on the Bina project, the official said that the project cost is estimated at Rs 40 crore. "We will have a 400/1,200 KV transformer at one end and a 1,200/400 KV one at the other. We will then do a load test and find solutions to whatever problems we encounter. Bina was chosen as we have 400 acre land available there."

He said that a 400 KV line could transmit 600 MW power while a 800 KV line's capacity is around 2,000 MW. However, a 1,200 KV line could transmit over 6,000 MW.

Explaining the need for such high voltages, another official said that transmission distance was less in most countries due to their small size.

"United States is a big country but it has distributed generation. However, in India power generation is concentrated. Most thermal plants are located in Chhattisgarh and Jharkhand while hydel plants are coming up in the Himalayas. However, demand for power is elsewhere. The higher voltage lines can not only carry more power, but they also have lower losses."

Source - Times of India

Sewage-treating bacteria may generate electricity

You've heard of bio-fuel (biogas) harvested from the sewage treatment process. This biogas is then used as fuel to help turn the turbines and produce electricity.


                   A sewage treatment facility in Malaysia. Photo by Hitachi PT


New science of electro-microbiology

What is relatively new to us is the fact that certain microbes can generate electrical current outside their own cells. What this means is that, we can bypass combustion and the expensive turbines to generate electricity. We just need to find way/s to harvest energy from microbes outer cells.

Scientists likened the process to the movie The Matrix where humans are hooked up to machines to provide electricity. In this case, microbes would be connected to devices to generate electrical current.

Major obstacle - for now - is the high cost of making such devices, and on how to improve their efficiency, and power capacity capacity of the devices.

Interesting! And in a long run, this should be the cheaper, better option.

+            +            +             +           +            +            +

Read the full article on Using sewage-treating bacteria in electricity-generation.

LONDON (Reuters, August 9, 2012) - Microbes used to treat human waste might also generate enough electricity to power whole sewage plants, scientists hope.

The technology is based on the relatively new science of electro-microbiology that is finding uses for the discovery that certain microbes can generate an electrical current outside their own cells. In the context of sewage treatment, they would purify waste water by consuming the organic matter in it and use that energy to generate a current that can be harvested and stored.

Co-author of the research, published in the U.S. journal Science, Bruce Logan of Pennsylvania State University, compared the process he is developing to the movie The Matrix, where hfumans are hooked up to machines to provide electrical power.

"In our article we describe a process which is somewhat like that but what we do is use certain micro-organisms which can be connected to devices to generate an electrical current that can be used to generate power," Logan said.

An estimated 3 percent of the electricity generated in the United States is used to run waste water treatment plants and at least 5 percent goes into the whole water infrastructure, said Logan, adding: "That's clearly not sustainable."

Logan says the technique, still in its infancy, has sparked interest from companies including Siemens and General Electric, as well as a number of small startup firms. There are some major hurdles, including the high cost of making the devices needed and improving their efficiency and power capacity.

"Right now it's a bit expensive," Logan said.

"What we really need to do is get the cost of the materials down and start putting the technology out into practice and that takes other things than just science and engineering. It takes political will and funding."

The same technique could see microbes used to generate biofuels, hydrogen gas, methane and other valuable chemicals from the cheap and abundant product of our trips to the bathroom, say Logan and fellow researcher Korneel Rabaey from the University of Ghent in Belgium.

Source: Reuters