New Record For Solar Cell Power Efficiency

mdsolar writes "Renewable Energy Access is reporting that a consortium led by researchers at the University of Delaware has achieved 42.8% efficiency with a silicon solar cell. The method uses lower concentration (factor of 20 magnification) than the previous record holder (40.7% efficiency) so that it may have a broader range of applications, since tolerances for pointing the device will be larger. They are now partnering with DuPont to build engineering and manufacturing prototypes. They expect to be in production in 2010. On a roof, such cells would require less than half the surface area to produce the same amount of power as today's standard solar panels, which have an efficiency of about 17%."

Comments

Smog

[Rixel]

Hopefully, Solar Cell efficiency will keep ahead of smog cover in major cities.

Waiting

[Cassius Corodes]

Im waiting for them to reach above 100% efficiency before I'll buy

hmmm.

[apodyopsis]

I'm interested in solar power as a means of lowering the fossil dependency - but there are other, better means of doing so. The CE manufacturers need to meet them half way and mandate more efficient devices that consume less power and bring back the humble ON/OFF switch that actually did turn off the power. Is it that hard to walk to the TV? And, of course, wind and tidal need to be followed up.

The main problem is the general public. Everybody wants wind power (but not in their back yard) you have to actually change the law and rubbish collection to get them to recycle, and everybody needs to buy the latest and most powerful gadget on the market.

Making a more efficient solar cell is an excellent step, but I'd be more interested in a more *cheap* one so they can be taken up on a mass scale.

Re:hmmm.

[JaredOfEuropa]

There is also the huge number of people who believe that the consensus of thousands of scientists on climate change is a "global conspiracy" and their fear that it may eventually mean, shock horror, more taxes.

This believe is partly justified. The conspiracy isn't by the scientists, and isn't a global conspiracy either, but the climate scare has given the meddlers of any political stripe the perfect pretext to push their own agendas. The climate debate has been thoroughly politicised, at the expense of proper science. That does not mean that all conclusions are incorrect or made up, but very often peer reviews are sorely lacking, and many reports have had chapters and sections stricken in the final draft, because those sections could cast doubt on the severity or existence of human impact on the climate. In many cases scientists voicing such doubts have not been gainsaid, but fired from "scientific" institutions. Because a widespread doubt in our impact on the climate would spoil the party for the meddlesome politicians. The political stakes are huge, perhaps the largest of any issue in our history.

Why are long term trends not taken into account in these reports, for example. It is rubbish to say that we cannot accurately predict climate that far into the future because our short-term predictions are not very good. After all, we cannot predict the little ups & downs in next month's weather, but we can predict that winter will follow summer and autumn, and we know what the trends are in each of those seasons. The long-term trends in global weather can be predicted as well.

On a geological timescale, we are in high summer. Winter is coming, and in 10.000 years we'll be in an ice age. The start of the downward trend in average temperatures is imminent (which means anywhere between now and 1.000 years)... Perhaps that is why the IPCC report does not look any further than the year 2100, the scary hockeystick curve will flatten out after that year, and if you look even further it will drop. Our distant descendants (if any) may even be grateful for the extra CO2 we have released, since it might make the next ice age a little less severe.

But with all that said, conservation and reducing our dependancy on a limited resource is a good thing. But I refuse to join in the mindless panic.

Re:hmmm.

[pjabardo]

These are *VERY* wise words!

Instead of making more money, people could work less. Instead of buying all sorts of shit, people could do much cleaner things such as talking, writing, riding a bike, going to a brothel, taking a walk, singing, playing a part on a play, painting, fighting (if not pushed too far it is not necessarily bad for some people...).

It is way too simplistic to say that there is a law of nature that says we will end up using every resource available. We are supposed to be rational beings even if we often do stupid things. One of the things of being rational (or partly rational) is that we can choose what we do. We don't simply answer any call of the wild (even if there is such a thing).

We are changing from a production society to a consumer one. We are becoming a bunch of morons that just sit and receive stuff. Not very different from the Eloi in H. G. Wells' The Time Machine. I don't think just consuming is satisfying enough. It is much easier (and faster) just to watch a movie than it is to tell a story and we end up watching 10 movies. Maybe a little boredom is good for creativity. It certainly is much cleaner than riding a car 100 km to do anything "new".

Solar cell? Pfftt.....

[ihaveamo]

I'm working on a lunar cell at the moment... the other 50% of a day is totally untapped!!

Re:feasible

[Calinous]

The most efficient use of solar power is the water heating system. Solar panels are a distant second for now - as they are very costly for the power they can produce (we assume your house needs heating or hot water). Depending on conditions, wind power might be a cheaper overall choice than solar panels.
        But in places like California, solar panels indeed pay for themselves

someone convince my local government

[Shivetya]

that renewable sources of energy are a good thing.

why?

because my HOA (home owners association) does not permit them. As such it would take State or local laws to override the HOA; because in many States the HOA rules have strong legal backing at the State level.

This is akin to the problems satellite TV faced in many locales. There were numerous ordinaces, both at the HOA and local level which blocked satellite dishes. Even the small ones we are accustomed to today were blocked. It took a Federal Law to end that restriction. Unfortunately its going to take another such law to allow many of us to use renewable energy. Hell, I cannot even get rain barrels approved even though they would not be visible from the street.

Efficiency is less important...

[Anonymous Coward]

...than price per watt. We got plenty of space we can cover with solar cells so it's not important that they are extremely efficient, just cheap enough so it doesn't cost much to cover large areas.

Re:What a pointless comparison

[Calinous]

Assuming your car has 20 square meters of surface, all of it oriented towards the sun. In Ecuador. With 100% efficient solar panels.
      You can get at most 20 HP of power from that. In your real situation, with maybe 5 square meters of surface available in the morning, and lower solar power, and the 40% efficiency solar cells, you get 2HP (or 1.5KW). Does it help? A bit, yes. If your car can load itself all day with energy, and know when she will reach destination, she could bleed the electricity storage battery (and reload it later). This way, you could get 10 square meters of max power, 8 hours a day, and with perfect efficiency in rest (charge, discharge, motor) you get 80 HP hours - or two hours at 40HP. Good enough for a commute... but...
      Now, you could buy solar panels at $5000 per kW (and 20 pounds). Assuming double efficiency is treble the price - you need $15,000 per square meter, so you'll pay $150,000 for solar on your car. Is it worth to drop your fuel consumption 50%? Or completely?

Re:Another kind of efficiency

[dwandy]

It takes more than 3 years to pay back your monetary investment.

"Three years" should not be a 'too long' perdiod to re-coup your investment.

• That's less than 4% of an average lifetime.
• I'd take an investment that was guaranteed to pay back 100% every three years.

I don't see energy getting any cheaper on this planet, and I don't see energy consumption decreasing.

The problem is it's not just the solar panels: it's the batteries and other infrastructure (and then maintenance!), and the last time I looked at it, it was closer to 20-yrs to pay back a whole system, and the system had a 20-yr life expectancy. That's break-even assuming it makes it to life expectancy.

What I am interested in is directly attaching an AC unit to a solar panel. Where I live it's generally only hot when it's sunny, so the AC would run for free.
Since the AC is one of the most expensive things to run it's win-win-win-win:

• I can run it guilt-free
• It runs whenever it's hot
• I don't need the other infrastructure
• I will still pay for the panel in a relatively short time.

Re:feasible

[knarf]

That is why the two should be combined... Water-cooled Photovoltaic panels give the best of both worlds: cooler PV panels which are more effective PLUS warm/hot water for heating, hot water or - indirectly - cooling. The technology is out there. It is simple. It works. As to why is is not used that much yet? Good question.

A search on 'water cooled pv' gives some interesting documents about experiments done with this combination. Read them and then go and build something like that. My 2 puny 11 watt panels are somewhat to small for this application but anyone who has (plans for) panels on the roof AND a need of warm water does him/herself a disservice by not looking in to this IMnsHO...

fail

[jovius]

Yes, this is great, but solar power will eventually fail completely, and there are no guarantees for long-term investments beyond five billion years from now.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Not too bad

[Gr8Apes]

I looked into this recently. Installing a ground based heat pump instead of a regular air conditioner would have been around $6K (instead of $2K for the AC). Note that this was for an old style 12 SEER AC unit that's no longer available against a 25+ SEER heat pump (get added bonus of generating heat). AC units have almost doubled in cost, and now are about $4500 installed (new US regulations require higher SEER units).

Why didn't I get the ground based system? Because when it's over 100 F and your main AC unit dies, I couldn't wait for the ground based unit installation taking over a week. I will plan for one at my next house though.

Re:Spot on.

[JaredOfEuropa]

By unplugging all of my electronic devices (there are many of them) when not in use we saved around $30 U.S. a month. Where was all that energy going? Not sure.

It goes to heat production, mostly. However I prefer a step forward rather than taking a step back by having to turn everything off. It is possible to make equipment have a minimal power consumption on standby, by only running a small circuit that looks for the "On" button being pressed on the device. A lot depend on how you power this circuit... a transformer is a notoriously bad way of doing it.
Some equipment behaves nicely on standby. Use a Wattmeter to check how much your stuff actually consumes in standby mode; you'd be surprised how little some things consume when idle, and there is little use in unplugging these completely. You might also be surprised at the large amount of power drawn by plug in transformers (The "wall warts"). Removing these when you are not using them saves a lot.

Another good way to save without sacrificing convenience, is to use a "master-slave" power block with your computer. I have a lot of inefficient transformer power supplies next to the computer, for printers, routers, LCDs, speakers, etc. I installed a "master-slave" system, that will automatically switch off all this rubbish when the computer is switched off. The power draw of this system when idle is minimal compared to those transformers, and you don't have to switch off every individual piece of equipment either,

Put some things into perspective

[ilovethesun]

Hi,

I will try to put a summary to the interested folks around:

A photovoltaic system is composed today by:
- Module
- Inverter DC/AC
- Mounting system
- Cabling
- Measuring/Protection electrical stuff

Most of the cost today is the module. Systems go (net) for 4-5$/Watt.
More efficient cells (and modules) mean less installation costs. For the future, it will be important since cell and module prices will go down.

Today, in California, if you take a system lifetime of 25 years, the kWh equivalent "price" is about 25-30cent.

System price decrease is expected to be 5-10% yearly for the next 5-10 years at least. This means that very soon the PV power will be cheaper than the one sold by the utility.

PV systems are perfect for distributed energy: a centralized power plant is not really cheaper or more efficient than a 5kW roof installation. And the energy transport kills the small margin that you had in favour of the big thing. That is why most utilities are not hot about PV: it is against their business model.

For the moment, it is not cheap to get "disconnected" from the grid. Therefore, a mix of PV and other electricity is necessary. PV has a nice peak at max. consumption peak. However, the evening consumption must be covered otherwise. Wind, biomass, ocean waves, geothermal, whatever.

PV in order to charge e-cars is OK today already. A car that uses 10 liter to do 100km, at a 20kW mean power, is using 20kWh energy for 10 liter gas, at 1$/liter it would be 50 cent/kWh. Make the calculation with your local gas price/gallon and you see that, even today, it is competitive. And cleaner. Only e-cars are not yet developed/deployed as they need to be.

About Solar-thermal energy for cold- it works for mid-big sized equipments, it is cheaper and especially more reliable than electricity... PV supporting electrical AC is still a bit more expensive but both run a nice race.

Ah, the typical guy asks about energy payback times: depending on technology, after 1-4 years your system has produced the energy needed to make it. Longer times belong to PV prehistory and to right-wing-thinktank analysis.

Cheers!