I have a question more than a comment.

Efficiency is calculated as the percentage of radiating energy that the sunlight hitting the cell contains vs. the electrical energy put out?

I just want to make sure I'm comparing apples to apples on some of this stuff.

That's how I've always seen it listed. The Earth receives some 1000 watts per square meter in ideal sunlight conditions, so a cel of this type that is one meter square should produce around 185 watts of electricity.

Good news, on the face of it. Only the extremely expensive monocrystalline panels used in spacecraft are even more productive per unit of area. Earth-bound PV applications are almost always stationary and usually completely off-grid, e.g. emergency-use phone booths or measuring stations in the middle of nowhere.

Beyond these niche apps lie rooftop and facade installations for (semi-)autonomous buildings as well as solar farms that feed into the grid (in co-operation with fully amoprtized hydro dams). These markets will take off once TCO per kWH becomes competitive with conventional power generation.

TCO considerations must factor in not only the specific productivity but also the specific cost of the material, plus that of any mounting frames and protective surfaces, if applicable. Unless the panels can double as roofing material, their weight and wind resistance leads to additional framing costs. Add to that power converters and battery storage (if applicable). The incremental cost of construction labor and cleaning overheads can be significant. Weather-related damage can be significant. Finally, for glass facade applications, the color of the light permitted to pass through is critical.

On the plus side, PVs reduce incident radiation and hence, air conditioning requirements. Of course, PVs also displace electricity generation based on fossil fuels and/or nuclear fission. In this context, incident solar radiation is typically more predictable than local wind patterns. Some countries/states provide financial incentives to promote PV installations, ostensibly for these reasons.

Only if you take all relevant factors into account can you make a solid investment decision based on the true costs and benefits of PV power for a given application. Since none of this is discussed here, it's unclear what the target market for this record-breaking material will be.

It doesn't mean much to me until they discuss dollars and cents. I was more interested in the company that developed a method of making them cheaper. People generally don't turn away from PV because they don't have the space, but because of the cost.

JRod.

The multicrystalline aspect is highly attractive in the $/sq m department. It does not rely on costlier, and currently scarcer, polycrystalline Si (Poly-Si), and it comes close to the 21-24% max efficiency currently claimed by Poly-Si. Multijunction cells are still way ahead in efficiency, 25-36%, and far more expensive as well (>$35/sq cm). They are geared towards spaceraft, and possibly large concentrator systems.

Roll to roll nanotech may reduce cost per watt.
www.nanosolar.com
This guy recharges is EV Porsche kit car using PV panels.
http://www.renewables.com/SolarCharging.htm

Given the high efficiency of this panel perhaps costs could be reduced if cheep reflectors or lenses were used to channel larger amounts of sunlight into the panels.

The Max Plank Institute is doing some interesting stuff with "photonic fusion" whereby lower energy long wavelength photons are forced together to form higher energy shortwavelength photons to make use of more of the light for PV use.

PV cells make a nice "green" statement, but if you want to save money, go around and replace incandescent lights with CFLs. Halogen spots present a problem - I do not know of any CFL replacements and LED lighting is too expensive still and the colour temperature is all wrong.
Wait 2 - 3 years for Leds.
Wind generation might work out if you have the space and local plannign laws permit it.
Basically, if you are considering installing PVs, consider usage reduction first, then solar water heating, then, and only if you want to impress the neighbours, put up PV panels.

Hey Neil, great idea, and at least one other company is already doing this: sunball solar appliance. I've been watching them for a while, they sound very promising.

http://www.greenandgoldenergy.com.au/

It's way cheaper to buy fresnal lenses than solar cells: it's one of those "why didn't they think of this years ago?" things. The sunball solar appliance is also sealed with two axis tracking motors to track the sun all day as well. There are some issues, such as having the right solar cell that can handle the extra heat and UV radiation, etc., but I think they have it all figured out.

I can't get the link I gave above to work for some reason, I guess you need to do a google search of "sunball solar appliance" or something similar. Sorry.

Coincidentally, I saw this article today:

http://biz.yahoo.com/prnews/061016/sfm089.html?.v=66

They are claiming 22% efficiency. Is this a different measurement or something?

LOL, every time I think I've had a brainwave.... But then solar cookers have been used in africa for quite a while. BTW. your link to the sunball worked.

LOL, every time I think I've had a brainwave.... But then solar cookers have been used in africa for quite a while. BTW. your link to the sunball worked.

Sunpower uses a different design than Kyocera.
The efficiency ratings are all done the same way using sun simulators.
There is usually a lively discussion of PV on the USEnet alt.solar.photovoltaic news group.

As well as being a different 'design' SunPower uses mono-crystalline silicon wafers, this Kyocera cell uses multi-crystalline silicon wafers.

Mahonj - CFL halogen downlight replacements are available, see: http://www.neco.com.au/categories.asp?cID=47

Neil:
PV loses its efficiency drastically when it heats-up. This is the reason why PV is not used with solar concentrators.

Mahonj:
One addition about efficient indoor lighting: 1kW of incandescent lighting means that air conditioner should work harder – with not so great efficiency – to compensate for this home “heater”. And electricity tends to be the most expensive at that time.

PV loses its efficiency drastically when it heats-up. This is the reason why PV is not used with solar concentrators.

Actually, some PV designs do use high concentration (500x). This also involves using cell materials that perform better when warmer (like GaAs and related semiconductors), higher efficiency cells (tandem, for example), and of course a very effective heat dissipation system.

One reason to use high concentration is that cell voltage increases logarithmically with light intensity, at least up to a point.

High concentration is only useful for direct sunlight. Optical systems have difficulty with diffuse light, such as that coming through clouds or haze, although there are non-imaging optical systems that can achieve some modest level of concentration even then.

Andrey- in most offices I have worked in they use flourescent lighting. At home I don't think I've ever seen anyone with a ton of lights on during the day (when a/c use is at its highest) but just turning off all those lights (as I doubt anyone needs that much light) when not in use would be more effective than replacing them with CFLs...of course CFLs AND not having lights on unnecessarily combined together is even better.

That is correct. Kyocera's record is for multicrystaline and Sunpower's are monocrystaline. The major difference is still in the design however.

Fresnel lenzes concentrate light onto a PV but has the nasty side effect of heat. Solar water heating wants solar heat. It seems to me that a combination of water heating and PV would make sense. Water warms up as it cools the PV and all components are happy.

What would the percentage efficiency be of such a panel.

Speaking of heat generated via solar concentrators, one way to use the heat generated would be to use thermoelectrics. One side would be the heat sink for the PV element, and the other, the coolant. This would require the TE system to have a wide temperature high thermal-electric energy efficiency conversion band, economically viable, and be small+light enough to mount onto concentrator systems. However, it could be 10 yrs until something of that nature would be available. Until then, Stirling engines, and other mechanical waste heat energy recuperators, are viable options.