Alternative Energy

Alternative energy news, and information about renewable energy technologies.

Oct 29

Sharp Solar Breaks Conversion Efficiency Record

Posted in Energy Industry | Photovoltaic Cells | Solar Power

We still have to miles to cover before solar power can replace the fossil fuels and become a cheap and effective solution for common folks. But it is indisputable that sun is the single greatest fuel source we can harness to our advantage. Solar energy can leave its impact on a global scale in a significant manner. Everyone who is blessed with a hot, sunny spot by the grace of the nature could one day power their homes entirely by photovoltaic roofs. Even it seems possible that large solar arrays could feed power plants that keep the lights on in entire municipalities.

Sharp Corporation’s technical team has come up with an impressive solar power development. Though its nothing new for the research and development team as they often come up with solar gadgets from televisions to mobile phones. This time the Sharp broke the solar conversion efficiency record. According to the company, it’s a title-holding 35.8 percent cell conversion efficiency with the help of a triple-junction compound cell. Sharp team has been working on this project since 2000.

These compound cells are chiefly used on satellites. The triple-junction cell has a group of three photo-absorption layers and it uses indium gallium or arsenide to boost efficiency. To boost the efficiency of triple-junction compound solar cells, it is important to improve the “crystallinity” in each photo-absorption layer. Sharp has successfully formulated an InGaAs layer with high crystallinity by using its unique technology for forming layers. The whole exercise resulted in the formation of layers that minimized waste and hitting a record conversion efficiency of 35.8%. Hopefully this kind of technology will trickle down to the consumer market too.

If everything goes right with this project then solar power will lose its just some pie-in-the-sky image. Solar power will emerge as effective power source sooner than expected. Still solar cells are being used in a variety of products but developments like 35.8 percent efficiency attaches wings to clean and green energy sources. Sharp’s triple-junction compound cell just broke a world record by showing a 35.8% cell conversion efficiency.

To boost the efficiency of triple-junction compound solar cells, it is important to improve the crystallinity (the regularity of the atomic arrangement) in each photo-absorption layer (the top, middle, and bottom layer). It is also crucial that the solar cell be composed of materials that can maximize the effective use of solar energy. Traditionally, germanium is used as the base layer due to its ease of manufacturing. However, if we care to look from the view of performance, even though germanium produces a large amount of current, the majority of the current is wasted, without being used effectively for electrical energy. How to get rid of this significant hurdle? The answer to this problem was to form the bottom layer from InGaAs (indium gallium arsenide), a material with high light utilization efficiency. However, it is quite difficult to produce high-quality InGaAs with high crystallinity.

Sharp has overcome this hurdle of forming an InGaAs layer with high crystallinity by making use of its proprietary technology for forming layers. The end desirable result is the amount of wasted current has been reduced to minimum and the conversion efficiency, which had been 31.5% in Sharp’s previous cells, has been successfully increased to 35.8%.

Gary Schabel

Great, but whats the cost? May be to expensive even with the high efficiency. Even if they are cheep, with out storage they only solve half the problem.
Eric Spindler

I disagree with the statement “miles to cover” because it makes people think it’s too big a challenge to break away from fossil fuels. The first step in that chain is to conserve and not over-use fossil fuels…act like there is a ration going on.

Keep in mind, the government was giving tax credits to people who upgrade to alternate energy in their home and at businesses.

How many years have we been buying solar powered garden lights?…It is THAT simple. Let’s start build co-ops in our neighborhoods and get the monkey off our backs.
Andrew Brown

I have used solar to power my office and supplement my vehicles successfully for years. I think in my case many miles have been covered by the fossil fuels not used while idling or working…
Esteban Rafael Negrete Montero

It’s not so far away… Cell efficiency is still relatively low, compared to what theory says we can achieve (nanotechnology will help a lot in this in the future), and the decent cells are extremely expensive. What is really near is thin film technology, in which cells are actually printed on to a plastic substrate. Even if the efficiency is rather low compared to other cells, the will over compensate with their extremely low cost. Just imagine going to your local home-depot, getting a roll of “plastic”, unravel it over the roof like if it was wallpaper and covering all the roof, and even maybe the walls of the house!

We are not miles away of green tech, its just the market follows what people buy. We need to change the people, not the market or the tech.
Andrew Brown

IMO Low efficiency vs. cost is a weak sales pitch. If your solar panels get shaded they cease to function and another resource is wasted. Plastering them ‘all over your’ house isn’t going to bring your price per watt down.
Jos Conil

The “miles to go” remark is true in today’s context because the efficiency of today’s solar cell is very very low. A glance at the energy figures below is enough to convince us about the vast unused potential of the Sun.

The total solar energy absorbed by earth’s atmosphere, oceans and landmasses per year is about 3,850,000 exajoules (EJ) while the total energy use as per 2005 figures is 487 EJ(primary energy use) + 56.7 EJ(electrical energy) =543.7 EJ, which means that harnessing about 1/7000 of the total solar energy can meet all our needs!.

Obviously, all that solar energy-esp the parts absorbed by air & earth- is not available for PV electric conversion, but considering the fact that we need only a minuscule fraction to meet our needs, it is very evident that any increase in solar cell efficiency and cost effectiveness is good news for the world.
GYANENDRA PRAKASH JOSHI

m/s emcore and spectrolab have already claimed long back that triple junction cells manufactured by them have efficiencies more than 38% at higher concentrations ie at 500 suns(500 watts per metre sq ). This I have verified by conducting measurements.It is not clear whether the efficiencies touted 35.8% is at what irradiance ie watts/sq meter.I expect clarification by M/S SHARP.
http://SmallHydro.com Jess

I am curious what the expected lifespan for these cells? Is this particular InGaAs technology better than current silicon at ~25 years?
http://pickensplan.com Gregory Smith

We’ve been discussing this energy conversion process for over a year now, so it is great to see a manufacturer use what the NREL labs discovered last year. However, they need to look at through-put to increase the volume of electricity acceptable, which would multiply the efficiency by 2X to approximately 68% efficient. How is this done? By allowing the cascade of electrons to continue to the conversion point at the inverter or direct current junction. By use of proprietary wire and connections within the panel, the wasted heat energy can be allowed to flow out all the way to the converter, reducing heat by 30% and increasing throughput by about 37%. And yes you can contact me…