Donald Wagner's Comments

January 24, 2014

Raising the CPV Bar: New Efficiency Records for Solar Cells And Modules

To get higher efficiency you really need to split the spectrum and concentrate it then redirect the appropriate wavelengths to the cells specialized for those wavelengths. The rainbow concentrator ( is one promising way. They did this with just one inexpensive lens.

January 24, 2014

CPV Solar Manufacturer Soitec Sets Its Sights on 50% Efficiency

To get higher efficiency you really need to split the spectrum and concentrate it then redirect the appropriate wavelengths to the cells specialized for those wavelengths. The rainbow concentrator ( is one promising way. They did this with just one inexpensive lens.

January 07, 2013

Debating 4 Dirty Myths on Clean Energy

I would have mentioned Germany for points three and four:

"We need new technology, period" - A residential installation is about 1/2 what it is in the US!! This has to do with time and cost to get permits and other soft costs.

"Can Alternative Forms of Energy Make a Difference?" - Germany has already had several days where 50% of the power during midday was from solar power plants.

December 11, 2012

12 Solar Power Myths and the Saving Grace of a Worthwhile Cause

Nice article.

Myth 10 about Moore's Law not applying to the solar industry is true, however the "experience curve" as in most industries does apply, where each doubling of the total volume will result in lower prices.

I liked your explanation with Myth 11. With comparing the solar installations to cars. This is a diverse market where areas with good sunlight should use concentrated photovoltaics (CPV). Also if panels are on your rooftop, since the space is limited, the higher efficiency panels probably make more sense while for a large bulk maegawatt scale electrical generation, space may not be as big of an issue.

November 27, 2012

Funneling Solar Energy: A New Way to Harness the Sun

Any idea of the efficiency? I assume that this would be used with a lens the separates and concentrates the light like a Rainbow Concentrator. Is this correct?

November 21, 2012

The Solar PV Ecosystem, A Brief History and a Look Ahead

This is probably the best long term summary of the solar industry I have read.
Nice Job :^)

November 07, 2012

Hurricane Sandy: "It's Global Warming, Stupid"

There were four factors that influenced the extent of the devestation:
1) The hurricane hit shore close to the high tide
2) A Northern storm forced the hurricane inland instead of going out to sea
3) There was an unusually large storm that was unusually late in the seaon
4) The ocean is higher than it was a century ago.

The first two items were bad luck. The last item and obvious effect of climate change. The third item is partially due to climate change. A good analogy is comparing homeruns in the steroid era of baseball. There were a lot more home runs and a lot more records broken (e.g. Barry Bonds). Without the steroids a lot fewer home runs would have been hit. While without climate change we would still have natural catastrophes, now they will be larger and happen more often, and it will be getting worse.

October 19, 2012

Solar Junction Does it Again, Sets New CPV Efficiency Record

cliff -
One way to extract nondirect sunlight for a CPV system is using a scavanger cell ( the idea is that while you will have an average of 947 suns on the solar cell, you will probably still have between 200 and 20 suns for about twice the area. So you have a simpler less expensive cell surrounding the main solar cell. I don't believe any commercial systems currently do this. Note that these higher concentration systems are using smaller solar cells .5cm x .5cm rather than 1cm x 1cm to help with the heat issue.

To get higher efficiencies, besides going to more junctions, you can also have a 6 termimal solution so you don't have to worry about current matching.
Splitting the spectrum (which is is how the current submodule record is currently set)and have several different solar cells with different bandgaps receive the appropriate parts of the spectrum.

October 19, 2012

Solar Junction Does it Again, Sets New CPV Efficiency Record

Cliff: Prism Solar does something similar, using holograms and TIR to increase efficiency. Too concentrate and separate the spectrum it is easier to use a single Fresnel lens which can be created very inexpensively using injection molding. Check out the Rainbow Concentrator at for details. I am not sure what you mean by "currently I see only 20% coverage for single-axis tracked systems"

August 07, 2012

Can Clean Energy Strike Back Against the Growing Smear Campaign?

This is just history repeating itself. As Mahatma Gandhi said 'First they ignore you, then they ridicule you, then they fight you, then you win.' According to the US Energy Information Administartion (, solar energy production grew from 611.793 Million Kilowatt hours in 2007 to 1813.994 Million Kilowatt hours in 2011 which is a 195% increase!! Total electrical energy production went from 4156744.724 Million Kilowatt hours in 2007 to 4105734.47 Million Kilowatt hours in 2011 which is a -0.012% decrease. For fossil fuel companies, solar is basically an minor annoyance (in April 2012 providing 0.104% of electrical energy), but a fast growing annoyance. It is in their best interest (although not for the people in general or the environment) to skew the laws in their favor and to push the FUD factor (fear uncertainty and doubt). It seems that the party of anti-science should be labeled that way and let people know it is science that gave them their IPhone, big screen TV, internet etc.

May 30, 2012

Germany's Day in the Sun: Solar Hits 22 GW Mark

With time of day use and forced curtailment, it won't be long before the solar electricity producers start using flywheels (or more unlikely batteries) to save the energy that would be sold cheaply or curtailed and sell it later at a higher cost. If there is a big enough price differential (about 15%) between the lowest cost at night and the highest cost in the morning, then they could also be buying the electricity when it is low and selling it when it is high in the morning. It looks like the bottom line is that what was the peak prices (hot summer afternoons) may now become low price points. Eventually this may but pressure on the infrastructure to carry the electricity, but this can be alleviated by having micro stations (which could be where the flywheel for a subdivision would be). This would allow the people in these subdivisions to buy and sell power without having to go through a middle man most of the time which should put no load on the long haul power lines and be cheaper.

Eventually as solar becomes more prominent, then the peak costs will be during the winter. Then you will start seeing some long haul high efficinecy electric lines running North-South where the areas closer to the equator will be selling electricity to areas farther from the equator. Interestingly, this puts North Africa, Saudi Arabia as energy producers for Europe and Mexico and the Southern United States in the role of power producers for North America. For intra-country power, Chile could benefit the most from an efficient long haul power line.

Donald Wagner

Donald Wagner

I have been working in the solar industry for about six years and have patent # 7206142. We are currently looking to produce and scale up our solar power solutions.

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