We are already struggling to make low cost solar panels that have a high efficiency using light absorbed from the visible spectrum (which accounts for most of the sun's spectral irradiation [1]).
Furthermore, you can't just have solar cells that absorb a wide range of the solar spectrum, there is an optimum band gap for these materials of around 1.34 eV [2].
This means that the most popular solar cells in development, namely CIGS and CdTe are already occupying the niche for maximum efficiency.
The challenge now is finding new materials that are cheaper to make and show greater efficiencies whilst not relying on the use of rare earth/toxic elements.
(Hint: the real development in this area at the moment is hybrid perovskites [3])
You can't make single cells that absorb a wide range, but you can layer cells that absorb different spectras to achieve a much higher absorbtion in aggregate.
This is a great point. We shouldn't ignore other efficiencies though. When used on the building envelope, light energy that would otherwise heat the building is converted into electricity instead. Assuming a reasonable efficiency for the conductors and inverters, this reduces the overall building demand. Even small reductions in demand can have huge price benefits for wholesale electricity buyers during expensive summer months (i.e. large commercial buildings). Hence, even if these panels are less efficient than opaque panels (and really how could they not be?) there may be other ways they can make sense from both energy savings and cost perspectives.
As they say in the video, even if these are half as efficient as regular solar panels, you could still see them on other types of surfaces where current solar panels can't be used right now: think windows or smartphone screens.
We could also see them on large buildings or rich people's villas whose owners perhaps want to use energy from solar panels, but don't like the "look" of solar panels on those buildings. So then the choice becomes using this or using no other solar panels.
We really don't have a shortage of space to put solar panels. The challenge is making solar panels that are cost effective (e.g. $ per Watt).
In response to your edit: That is a possibility, that yes they may find a niche in the fancy of the rich.
But the point I'm making is that the article is hyperbolic and misleading.
Transparent solar is not the future of utility scale power generation. It is not going to solve any of the problems currently holding back solar power from becoming ubiquitous.
> ...screens and windows that soak up light could power your home or your phone
These two things don't compute. Oil is mostly used for mobile energy, and solar is mostly used for stationary energy. However...
I work in solar, and solar is a threat to oil. Why? Not because of transparent photovoltaics, but because it and batteries are getting so goddamn cheap. The Department of Energy has a goal of $0.06/kWh for solar by 2020[1], and Tesla aims to reduce the cost of lithium ion batteries by 50% by 2020[2]. That's only 4.7 years away.
When things get that cheap, we can just slap solar everywhere and have "gas stations" with excess inventory of swappable batteries for cars. It baffles me why more entrepreneurs haven't realized that 87% of the energy sources we use are going to be switching to other sources in our lifetimes[3].
Entrepreneurs have realized this, but energy is far more difficult than people will admit. Even if this works and is cheap, the real issue is batteries. Batteries are expensive and their manufacture entails environmental costs. There is no free ride. Yes, Tesla wants to reduce the price of batteries, but that doesn't make it so.
If this works you need many multiples of battery capacity as production. That is a staggering amount of batteries. And batteries don't have a long life. How is the battery life on a 10 year old computer?
I don't really get the constant focus of the energy conversation on transportation (< 1/3 of total energy use). If, as you say, we can get solar energy to the grid for less than coal then we're getting close to the time when no one will ever build a coal plant again. Then accelerating economies of scale will cause the price to fall to the point where we're shutting down fossil fuel plants, then to the point where we can make biofuels with solar rather than fossil fuels. Now GHG emissions are down 75-90% with a set of mostly evolutionary technical advancements.
Some environmentalists might not like that process because it's market-driven and doesn't involve any economy-shrinking monastic self-sacrifice (e.g. Kyoto protocol), but it is the reason I'm reasonably optimistic about climate change.
"It baffles me why more entrepreneurs haven't realized that 87% of the energy sources we use are going to be switching to other sources in our lifetimes"
What leads you to think entrepreneurs haven't realized this? What should they be doing once they do realize it?
My startup is in the SfunCube solar startup accelerator program[1]. So far, all of the entrepreneurs who have applied to the program are from within the solar industry (i.e. they previously worked at a solar company). Additionally, I organize the SF Cleanweb meetups[2], and we rarely see people from the normal tech companies/startups come to events to learn more about the space.
I don't really blame anyone for not realizing the huge opportunity in solar. It's not a very visible industry and used to be primarily a hardware space. Software has only come to the forefront in the last few years due to soft costs being such a huge problem[3]. If you're looking for an industry that desperately needs software and entrepreneurial talent, I'd highly recommend solar.
Only about half of oil production goes to energy and transportation. The other half goes to production of synthetic materials like plastic. Look around you, oil production is not going away any time soon.
Flagged for being totally hyped and factually incorrect (even the title is nonsense).
I really wished that people reporting on Solar/Wind and other alternative energy sources would at a minimum gain a basic level of understanding of the subject matter before writing nonsense articles like these.
I haven't had a chance to watch the video, but I question the thinking in various parts of this article.
The first thing that hit me was: Cell phones? Sure, they don't need a lot of juice so a tiny patch of solar could power them. BUT there's 2 problems: These panels work on UV and infrared. Unless your phone owner spends a lot of time outdoors, he won't be exposing his phone to that kind of radiation, neither of which is found (significantly) indoors. Second, where do people carry their phones? Where the sun doesn't shine - I'm referring to their pockets, of course.
I wonder about the efficiency of window panes on buildings too: UV and infrared are in short supply when the sky is overcast, whereas visible doesn't dip nearly as much. So this is low-efficiency technology capturing light that's mostly restricted to sunshiny days? I still think it makes a heck of a lot more sense to simply slap "normal" PV on the roof, or possibly the walls around the windows. This looks gimmicky to me and I'm not sure the author understands the technology.
They don't speak about the angles (vertical windows vs horizontal roofs) and how much can this impact the energy efficiency in practice.
Presumably it's good to have some vertical panels in a mix to produce energy in the late afternoon when the sun is low but I wonder if there is any quantified study available that would highlight whether or not this is worth the investment.
This isn't related to the clear solar panels from the article, but there's been significant research on this for traditional solar panels as well as solar concentrators.
Bottom line is, the mix of panels makes sense for northern cities (e.g. Albany) but not middle (e.g. St. Louis) or southern (e.g. San Diego).
Readit News
Furthermore, you can't just have solar cells that absorb a wide range of the solar spectrum, there is an optimum band gap for these materials of around 1.34 eV [2].
This means that the most popular solar cells in development, namely CIGS and CdTe are already occupying the niche for maximum efficiency. The challenge now is finding new materials that are cheaper to make and show greater efficiencies whilst not relying on the use of rare earth/toxic elements.
(Hint: the real development in this area at the moment is hybrid perovskites [3])
Basically, this is irrelevant cruft.
[1] http://zebu.uoregon.edu/~imamura/122/images/solar_spectrum.p...
[2] http://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limit
[3] http://www.nrel.gov/ncpv/images/efficiency_chart.jpg
(source: currently doing a PhD in a new photovoltaic materials)
We could also see them on large buildings or rich people's villas whose owners perhaps want to use energy from solar panels, but don't like the "look" of solar panels on those buildings. So then the choice becomes using this or using no other solar panels.
In response to your edit: That is a possibility, that yes they may find a niche in the fancy of the rich.
But the point I'm making is that the article is hyperbolic and misleading.
Transparent solar is not the future of utility scale power generation. It is not going to solve any of the problems currently holding back solar power from becoming ubiquitous.
> ...screens and windows that soak up light could power your home or your phone
These two things don't compute. Oil is mostly used for mobile energy, and solar is mostly used for stationary energy. However...
I work in solar, and solar is a threat to oil. Why? Not because of transparent photovoltaics, but because it and batteries are getting so goddamn cheap. The Department of Energy has a goal of $0.06/kWh for solar by 2020[1], and Tesla aims to reduce the cost of lithium ion batteries by 50% by 2020[2]. That's only 4.7 years away.
When things get that cheap, we can just slap solar everywhere and have "gas stations" with excess inventory of swappable batteries for cars. It baffles me why more entrepreneurs haven't realized that 87% of the energy sources we use are going to be switching to other sources in our lifetimes[3].
[1]: http://energy.gov/eere/sunshot/mission
[2]: http://www.greentechmedia.com/articles/read/Teslas-Giga-Batt...
[3]: http://www.pvsolarreport.com/the-next-internet/
If this works you need many multiples of battery capacity as production. That is a staggering amount of batteries. And batteries don't have a long life. How is the battery life on a 10 year old computer?
Some environmentalists might not like that process because it's market-driven and doesn't involve any economy-shrinking monastic self-sacrifice (e.g. Kyoto protocol), but it is the reason I'm reasonably optimistic about climate change.
What leads you to think entrepreneurs haven't realized this? What should they be doing once they do realize it?
I don't really blame anyone for not realizing the huge opportunity in solar. It's not a very visible industry and used to be primarily a hardware space. Software has only come to the forefront in the last few years due to soft costs being such a huge problem[3]. If you're looking for an industry that desperately needs software and entrepreneurial talent, I'd highly recommend solar.
[1]: http://www.sfuncube.com/
[2]: http://www.meetup.com/cleanwebsf/
[3]: http://www.nrel.gov/news/press/2013/5306.html
http://www.plasticoceans.net/the-facts/energy-consumption/
http://www.eia.gov/tools/faqs/faq.cfm?id=34&t=6
I really wished that people reporting on Solar/Wind and other alternative energy sources would at a minimum gain a basic level of understanding of the subject matter before writing nonsense articles like these.
Life is just too short to click on Bloomberg links.
Deleted Comment
The first thing that hit me was: Cell phones? Sure, they don't need a lot of juice so a tiny patch of solar could power them. BUT there's 2 problems: These panels work on UV and infrared. Unless your phone owner spends a lot of time outdoors, he won't be exposing his phone to that kind of radiation, neither of which is found (significantly) indoors. Second, where do people carry their phones? Where the sun doesn't shine - I'm referring to their pockets, of course.
I wonder about the efficiency of window panes on buildings too: UV and infrared are in short supply when the sky is overcast, whereas visible doesn't dip nearly as much. So this is low-efficiency technology capturing light that's mostly restricted to sunshiny days? I still think it makes a heck of a lot more sense to simply slap "normal" PV on the roof, or possibly the walls around the windows. This looks gimmicky to me and I'm not sure the author understands the technology.
Presumably it's good to have some vertical panels in a mix to produce energy in the late afternoon when the sun is low but I wonder if there is any quantified study available that would highlight whether or not this is worth the investment.
Bottom line is, the mix of panels makes sense for northern cities (e.g. Albany) but not middle (e.g. St. Louis) or southern (e.g. San Diego).
There's a great writeup with links to the raw data at http://physics.ucsd.edu/do-the-math/2012/08/solar-data-treas... (this entire blog is amazing).
Or maybe I've read the submarine [1] too much.
[1] http://www.paulgraham.com/submarine.html
"The technology still has a way to go because the cells must become more efficient to prove cost-effective, but their promise is big ..."