German solar power plants produced a world record 22 gigawatts of electricity – equal to 20 nuclear power stations at full capacity – through the midday hours on Friday and Saturday, the head of a renewable energy think-tank said.
The Montalto di Castro Photovoltaic Power Station in Italy is one location where solar electricity is already as cheap an investment as traditional fossil fuel sources.
In the world of renewable energy resources, solar power is the epitome – abundant, reliable, and green. For decades scientists and engineers have been working tirelessly to improve the efficiency at which photovoltaic cells convert sunlight to electricity. If they can simply make PV cells efficient enough, then they would be cheaper than fossil fuels and most of the world could switch over to the better technology. Getting solar power to be as cost-effective as traditional electricity sources is known as reaching “grid parity”, and several locations around the world have already succeeded in making it a reality. How can the rest of the world join in? While scientists and engineers will be crucial in that development, loan officers and bankers may hold the key to bringing solar power to the masses.
Researchers at Queen’s University in Canada have compiled a comprehensive study of solar power plants and found that improvements in financing, and industrial streamlining could allow for the technology to become as cost-effective as traditional electrical sources. In other words, a much larger part of the globe could currently reach grid parity if cheap loans and better supply chains were available.
“The major generation cost for solar PV [photovoltaics] is the upfront cost and the cost of financing the initial investment, which means the LCOE [levelized cost of electricity] is very dependent on the financing methods available and manufacturing cost reductions”
—Branker, Pathak, and Pearce, A Review of Solar Photovoltaic Levelized Cost of Electricity, 2011
The study was led by Joshua Pearce, along with K. Branker and M.J.M. Pathak of Queen’s University. It found that variations in financing interest rates could alter the cost per kilowatt-hour by ten cents (Canadian) for typical solar plant configurations. Considering that the retail cost of electricity in Canada is just around ten cents, this financial-dependence is a large consideration for building new solar power plants.
Pearce and his colleagues also found that many previous studies were too conservative in their evaluations of photovoltaic cells. Most analysts assume solar cells will lose 1% in peak output every year, but PV systems from the 1980s showed considerably less loss in the past two to three decades. The Queen’s University team found 0.5% loss to be a better estimate and typical losses might be expected to be 0.2 to 0.5%. As such losses compound every year, that small difference in calculation can lead to big changes in the projected cost-effectiveness of a solar power plant. In other words, such plants are much better investments than they’ve previously been thought. Especially when one considers that most other levelized cost of electricity (LCOE) evaluations peg solar cells at having effective lifespans of 20 years, when Peace and colleagues found 30 years to be a better estimate. As even older technologies from the 80s are going longer and stronger than most analysts assumed, the return on investment for building solar plants is higher than generally accepted.
Which means many more solar power plants could reach grid parity with current levels of technology. As the Queen’s University team pointed out, British Petroleum test systems in California and Hawaii have already succeeded in reaching grid parity. They are not alone in that success. Nikkei Electronics Asia declared Italy had reached grid parity last year. The Montalto di Castro Photovoltaic Power Station competes with traditional sources in the nation. In fact, Italy’s solar industry has grown remarkably in the past three years, up to one gigawatt of produced power. Nikkei and other industry analysts believe Southern Europe is primed for solar grid parity.
The rest of the world is quickly catching up. In the past decade, total solar power production has increased from less than 1 GW to around 16 GW. Since 2008, the cost of photovoltaic modules has dropped by a remarkable 60%! This exponential growth in total global solar electricity output lines up well with the projections of futurist Ray Kurzweil. His much discussed predictions say that the world will continue to double solar power production every two years. In 20 years the world would produce around 15,000 GW – the total amount of energy humanity consumes in all forms.
A world almost completely powered by the sun in just two decades seems like science fiction, but the work of Pearce and his colleagues seemingly corroborates some of Kurzweil’s predictions, at least in the near term. Current investments in solar power are not as large as they could be, not because of a lack of government mandates, nor because photovoltaic efficiency isn’t increasing quickly enough. Instead high interest rates in loans, overly conservative estimates on return in investments, and preferences for short term returns in energy markets have undervalued solar power plants. In 2010 new investments in solar power were only around $26 billion (USD), about one-fourth of that put into wind.
While solar grid parity hasn’t been reached universally, it has been well documented in a few locations. If Pearce’s LCOE study was to be applied, it’s likely that many more such locations would be found to already be cost-effective for photovoltaic cells. Improving the solar cell industry to take advantage of economies of scale, more efficient supply lines, and more experience in installation/maintenance will only increase the number of solar-ready locations.
And, of course, the biggest factor, the actual quality of the photovoltaic technology is only going to keep improving. At 8% efficiency the entire world could obtain all the electricity it needs from solar cells covering land equivalent to the size of Colorado (~ 100,000 square miles). Some of the most recent, and experimental, PV cells have surpassed 40% efficiency.
The current solar industry is small, providing just one-thousandth the electricity consumed by humanity. Yet with the right investments, that fraction is ready to grow exponentially in the years ahead. Solar grid parity is already here for some of us, and it’s much nearer than the rest of us may believe.
[image credits: ‘Anna’ via Wikicommons, Enel, BP, Nikkei Electronics Asia, KurzweilAI.net]
[sources: Branker, Pathak, and Pearce 2011 (preprint)]
By John D. Sutter, CNN
Obvious statement: Lots of middle schoolers have been outside.
But I’m going to go out on a limb and say that almost none of them look up at the trees, see the Fibonacci Sequence in the branches, and use that insight to develop new and more-efficient methods of arranging solar panels.
Stuff like that only happens to Aidan Dwyer.
This 13-year-old from Long Island, New York, was a presenter at the recent PopTech conference, where he spoke with CNN. He says his method for arranging solar panels – based on the mathematics of tree branches – is 20 to 50% more efficient than traditional solar arrays, especially in low-light conditions, such as cloudy days in the winter or in places where there are lots of trees and tall buildings.
“My design is like a tree,” he said, “but instead of having leaves it has solar panels at the ends (of the branches).”
Dwyer created a prototype of this tree-like solar panel array for a science fair with the help of his granddad. He ordered the solar panels online and the pair built the rest of it together. For his efforts, he won the Young Naturalist award this year from the American Museum of Natural History in New York. (You can see a photo of the solar-panel prototype on that museum’s website).
This idea for this energy-saving project hit Dwyer when he was going for a walk in the woods near his home in New York:
One day I was just walking through the woods – well, on a winter hiking trip – and I noticed that the tree branches collect sunlight by going up into the air. And I thought: ‘Maybe if we put solar panels on the ends of the branches it would collect a lot of sunlight.’
He also made another mind-boggling observation: That tree branches spiral up the trunk based on a mathematic concept called the Fibonacci Sequence. I had to look that equation up before my interview with Dwyer, but I didn’t really need to. He can explain it off the top of his head:
The Fibonacci Sequence was made by a medieval mathematician, Fibonacci, and he played with a math puzzle to figure out how fast rabbits could reproduce over time. How it’s done is you start with 0 and 1, and then you add the two numbers in the series together to get the next number in the sequence. So it’s like 1, 1, 2, 3, 5, 8, 13, 21, 34, and so on.
The fraction for an oak tree is 2:5, which means five branches spiral around the trunk two times to reach the same starting point. So, if you start out at 75 degrees, and you get five branches to go around the trunk twice, then you’ll be back at 75 degrees.
Dwyer said he’s been contacted by professors and other middle schools who want to work with him on this project, but not all scientists are impressed with his work. Some science bloggers have tried to debunk some of Dwyer’s concept, saying, among other things:
Aidan did not actually discover a more efficient way to convert solar energy into power as he claimed and these numerous publications reported. In fact, Aidan’s essay, while extremely well written, contains methodological flaws and incorrect conclusions.
That blog post, on a site called The Optimiskeptic, questions whether Dwyer used the right measurements to make his conclusions:
I’m not entirely sure why Aidan thought that he could measure power intake by measuring voltage on his solar cells. I’m not entirely sure why the different arrangements yielded different voltage totals … I do know that solar cells are designed to convert energy from photons into potential energy in the form of electrons: ‘charging the battery.’ Levels of voltage have nothing to do with how charged that battery is, however, and at no time during his experiment was Aidan actually measuring how much power was being converted by each of the solar cell arrangements.
Dwyer, for his part, says the bloggers are missing the point:
Some of the commenters were encouraging me and some were giving me ideas to expand my research. But some, I felt like they didn’t understand my project. Their points weren’t really related to my project. I was trying to see if the tree design could collect more sunlight – not more open current voltage. But I also measured open-current voltage and it collected 20% more (than flat-panel solar arrays).
Furthermore, he said, his panels collected 50% more light in low-light conditions than flat-panel arrangements, like those found on top of homes.
So there. Of course, science is a conversation. Debate is a good thing. Who knows whether Dwyer’s tree-based solar panels really will change the world – but how cool is it that a 13-year-old has come up with an idea that even has thepotential to bump the clean-tech industry a bit into the future?
Dwyer is among the people most shocked by all the attention his project has gotten. He’s not sure what to make of it all – or how to handle conversations with adults for that matter:
At PopTech I feel a little lonely because I’m the youngest one there – like, by a big range. It’s pretty lonely being the youngest one … I don’t know how to start a conversation with an adult yet – so I just have to wait for them to ask me questions, and all that. They just come up to me and go ‘You’re that kid!’ And then they ask me about my project and they ask me about how I found that idea and then the conversation forms.
One thing I found particularly impressive about Dwyer is that he come across as smart, composed – and normal. The phrase “child genius” brings to mind the social-awkwardness of the kids in “The Royal Tenenbaums” or overly-adult-seemingness of that child actor in “The Sixth Sense.” Dwyer doesn’t emit those qualities. He seems like pretty much any other middle schooler you might meet – until you ask him about Fibonacci.
“I’m starting to get into photography. I do a sailing program in the summer. I play golf – and I, like, hang out with my friends,” he said.
Those friends, by the way, don’t quite get all this solar-panel business.
“They’re really impressed – but they don’t really understand it,” he said, cracking a nervous smile. “I don’t really talk to them about it.”
He saves those conversations for reporters – and for his conference lectures, of course.
“Yes, Solar really does work in your state, especially if you live in the south! ” Below you will find a short overview on why the South is great for solar .