Why Venture Capitalists have been Investing in Solar: Smaller, cheaper, faster

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    Mar 22, 2011 9:53 PM GMT
    There's a lot to be optimistic about when it comes to energy - and future sources are probably not going to come from the middle east but they could indeed be nuclear - from the sun. What's needed next are great batteries - but those are coming as well.

    http://www.scientificamerican.com/blog/post.cfm?id=smaller-cheaper-faster-does-moores-2011-03-15

    The numbers are staggering and surprising. In 88 minutes, the sun provides 470 exajoules of energy, as much energy as humanity consumes in a year. In 112 hours – less than five days – it provides 36 zettajoules of energy – as much energy as is contained in all proven reserves of oil, coal, and natural gas on this planet. [...]

    The cost of solar, in the average location in the U.S., will cross the current average retail electricity price of 12 cents per kilowatt hour in around 2020, or 9 years from now. In fact, given that retail electricity prices are currently rising by a few percent per year, prices will probably cross earlier, around 2018 for the country as a whole, and as early as 2015 for the sunniest parts of America.

    10 years later, in 2030, solar electricity is likely to cost half what coal electricity does today. Solar capacity is being built out at an exponential pace already. When the prices become so much more favorable than those of alternate energy sources, that pace will only accelerate.
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    Mar 22, 2011 10:34 PM GMT
    I'd like to see the day when solar power completely replaces coal, oil, and natural gas.
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    Mar 23, 2011 4:28 AM GMT
    You won't see this in your lifetime. Right now the best efficiency in the commercial world is about 20%.

    I worked in undergrad on Gratzel cells. We had efficiencies of about 8-9% from around 50 cells. The best ones are about 12%. It cost less than $100 to make each one; however, one of our post-docs made the most costly material so that lowered the costs. Platinum was used. That was the most expensive metal. However, these cells were very small in size-around 2cm x 2cm.

    You can actually purchase a kit to make your own Gratzel cell for about $500.

    These are the cheapest and most easiest to construct cells in the market currently.
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    Mar 23, 2011 4:37 AM GMT
    I read something about quantum dots increasing the theoretical efficiency of solar cells recently, but I can't find the original article. Here's the closest:
    http://www.technologyreview.com/energy/26405/?a=f
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    Mar 23, 2011 5:05 AM GMT
    JACS article saidWe report nanocrystalline TiO2 solar cells sensitized with InAs quantum dots. InAs quantum dots of different sizes were synthesized and incorporated in solar cell devices. Efficient charge transfer from InAs quantum dots to TiO2 particles was achieved without deliberate modification of the quantum dot capping layer. A power conversion efficiency of about 1.7% under 5 mW/cm2 was achieved; this is relatively high for a nanocrystalline metal oxide solar cell sensitized with presynthesized quantum dots, but this efficiency could only be achieved at low light intensity. At one sun, the efficiency decreased to 0.3%. The devices are stable for at least weeks under room light in air.

    However, this was only one of the studies. A 1.7% increase is huge, when most nanocrystalline cells of TiO2 have about 6% photoelectric effeciency conversion.

    This is compared to 2% photoelectric efficiency from traditional silicone based solar cells.
    Earlier, I gave quantum efficiencies, which is basically how much light is trapped between rods of TiO2. Photoelectric efficiency is the actual effeciency between light and power generated. The best Gratzel cells have photoelectric efficiency of 6%. Our had 4-5%. But this was many years ago, and I believe the university is still working on the project.
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    Mar 23, 2011 5:35 AM GMT
    carminea saidYou won't see this in your lifetime. Right now the best efficiency in the commercial world is about 20%.

    I worked in undergrad on Gratzel cells. We had efficiencies of about 8-9% from around 50 cells. The best ones are about 12%. It cost less than $100 to make each one; however, one of our post-docs made the most costly material so that lowered the costs. Platinum was used. That was the most expensive metal. However, these cells were very small in size-around 2cm x 2cm.

    You can actually purchase a kit to make your own Gratzel cell for about $500.

    These are the cheapest and most easiest to construct cells in the market currently.


    Have a look at thin film solar. I think this probably offers the most promise but it requires a significant amount of space. What it is however is cheap. The cost is under the magical $1 per Watt install cost (see companies like First Solar and Nanosolar). This will happen in our life times that solar is economical.
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    Mar 23, 2011 6:01 AM GMT
    Solar cells like the ones we have now, platinum and all, I think will never be the technology that will be there when we replace fossil fuels.

    I think it should be something mimicking what plants already do... seen a bit of research there, but as a non-scientist engineer I got no idea how that is really going.

    On the other hand, the sun is pretty much an enormous "naked" fusion reactor... fusion as a viable option here on Earth has to come of age sometime in the near future, no?
  • FRE0

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    Mar 24, 2011 9:57 PM GMT
    Wind and solar are intermittent sources of energy. We need electricity 24 hours per day, 365 days per year, and not just when renewable energy happens to be available.

    On average, the sun shines for less than 40% of the time and for part of that time, it is too low in the sky to provide much power. The amount of solar energy the earth receives daily is meaningless; most of it is over water anyway.

    Wind generators, on average, provide only about 20% of their rated power because usually the wind is not blowing at a speed which enables the generators to produce their rated power.

    Because of the above, to provide the average amount of power required, wind and solar generation capacity would have to be about five times greater than the capacity of coal or nuclear power since coal and nuclear provide continuous power. Even that assumes adequate power storage capacity which with current technology does not exist at an exceptable cost.

    The solution to replacing fossil fuel for generating electricity is nuclear. However, we should be using liquid fluoride thorium reactors (LFTRs) instead of uranium reactors. For more information on LFTR technology, check the following links:

    http://www.youtube.com/watch?v=eU3cUssuz-U&feature=player_embedded

    http://www.youtube.com/watch?v=RSzEjWz5T44&feature=player_embedded#at=16
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    Mar 24, 2011 10:09 PM GMT
    FRE0 saidWind and solar are intermittent sources of energy. We need electricity 24 hours per day, 365 days per year, and not just when renewable energy happens to be available.

    On average, the sun shines for less than 40% of the time and for part of that time, it is too low in the sky to provide much power. The amount of solar energy the earth receives daily is meaningless; most of it is over water anyway.


    I wouldn't discount solar for that reason - the times that you actually need solar is that 40% of the time - which could eliminate the need for peaker plants at the minimum (ie you need the electricity during the day when it's at its peak particularly when it's hot during the day for the air conditioning). The rest of the time, would depend on the development of batteries and I suspect that's coming as well.
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    Mar 24, 2011 10:29 PM GMT
    Too many of you are trained to look at this from the prism provided by the oil and gas industry. It's not as cut and dry as they lead you to believe.

    Use solar and wind when it's available, and switch over to current technology when it isn't. I do this in my home, and it's quite efficient. Yes, it's expensive, but you save a boat load via taxes and subsidies. I use propane 20% of the time, solar the rest of the time, and when I'm not on the grid, the solar panels actually pay for my electric bills by feeding back into the grid (my electric company hates me - tried to cut me off at one point but they failed miserably). I plan to convert to geothermal this summer so that, come fall, I'll be able to heat my home upwards of 55-degrees (f) without the use of gas. Anything over that will run on gas, but only after the sun sets, or if it's too cloudy for solar to run the system.

    My wood burning stove is fitted with a catalytic converter that reburns 90% of the smoke, meaning that when I do burn wood, my impact on the environment is minimal. This technology is over 5 years old, so I'm currently looking into more recent and efficient technology. One burner I'm looking at lowers pollutants by 95%.

    Sadly, OP, a lot of VC's are buying into these technologies because they know the oil and gas industry will acquire them, leaving VC's with a pocket full of gold (so to speak). Dont' believe me? Watch the movie, 'Who Killed the Electric Car.' The oil and gas industry owns more solar, geothermal, wind and algea-energy patents than all private co's combined. What do they do with these once they acquire them? They bury them and sue anyone who infringes upon them. In other words, they limit the ability for us to seek out alternatives to oil and gas.

    Go figure. icon_confused.gif
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    Mar 24, 2011 10:57 PM GMT
    I've been 100% off-grid since May 1, 1998. I have no regrets. I use my computer, printer (several hours daily). I have a TV that I rarely watch, a DVD player, and a Bose. My cost to convert was cheaper than getting electricity run to the farm from 1/2 mile.

    The problem isn't the efficiency of the technology. The problem is in the waste of current electricity. If people would cut their electrical power needs, solar and wind would help a lot more than expected.

    I had to learn to conserve in order to keep from having to spend tens of thousands in solar to equal grid power. My system has a payback of around $13 per month. That is a hell of a lot cheaper than grid electric.

    Solar and wind could help enormously, but only when people begin to cut back on their demands on the grid. However, today's technology in solar and wind can never replace current demands.

    My rural friends continue to have power outages. I don't... well.. unless I make a mistake, (LOL) but we won't go there. lol
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    Mar 24, 2011 11:02 PM GMT
    ^
    ^
    ^
    And then there's this. I'm liking where this is going.