Posted on February 23rd, 2017 in solar by Spencer R.
A startup has created a method for using a particle accelerator to slice microscopically thin silicon wafers that reduce the cost to manufacture solar panels by more than 60% by eliminating waste material by 50 to 100 times.
The company, Rayton Solar, kicked off a Regulation A+ equity crowdfunding campaign in July. The campaign, which received SEC qualification last month, has garnered more than $7 million in equity reservation investments, according to its founder Andrew Yakub.
Since the SEC's qualification last month, the company has received an additional $844,000 from crowdfunding.
Bill Nye, the host of the science television series Bill Nye The Science Guy, visited Rayton's Santa Monica, Calif., headquarters and put his name behind the company by producing a video explaining the process of using a particle accelerator to manufacture silicon wafers.
Rayton Solar was founded in 2012 when Yakub, then a design engineer at the UCLA Particle Beam Physics Laboratory, saw the need for a less expensive method for producing silicon wafers, the basis for solar panels.
Along with working at the University of California, Los Angeles, Yakub was running a solar installation company at the time that relied on a federal grant program that made installing solar cost effective. With the grant program due to expire, Yakub wanted to invent a cheaper and more efficient solar cell.
The raw material of most conventional solar cells today is crystalline silicon. While silicon is the second most abundant element on Earth, it must first be refined in a furnace at temperatures as high as 1,800-degrees Celsius and undergo other expensive chemical processes before reaching the solar-grade purity of 99.999%, which allows it to collect light that can be turned into electricity.
Once in pure crystalline form, manufacturers use diamond saws to slice ingots from the silicon crystal to be used in solar cells, which make up solar panels. The sawing process, however, can turn as much as half of the material into dust, and the silicon wafers produced are up to 200 microns (about .007-in) thick.
Yakub said he patented a method for slicing silicon ingots using a proton particle accelerator, which produces a wafer just three microns thick and with no wasted material.
The proton particle accelerator costs about $2 million, Yakub said. But even with the added expense, manufacturers would still see at least a 60% reduction in silicon wafer manufacturing costs, he said.
One particle accelerator, Yakub said, can produce enough silicon wafers to manufacture six megawatts worth of solar cells per year, which is enough to equip about 1,000 homes with solar panels.
Today, thin-film silicon cells are already used to make a small number of solar panels. The manufacturing process -- called vapor deposition -- can be slow and more expensive than standard silicon crystalline production.
"This employs the use of a growth crystalline substrate where the new silicon is grown slowly on top to 30-50 microns. This method is slow and energy intensive, but also requires the use of 30-50 micron thick silicon," Yakub said. "At Rayton, we use a well-known technique of growing a large single crystalline boule (the ingot) and then exfoliating a thin 3-micron-layer of silicon off of it. We are a 'top down' technique while the vapor deposition methods are a 'bottom up' technique."
Tyler Ogden, a solar analyst at Lux Research, said Rayton Solar is developing "a flashy technology, merging two of the hottest applications of physics – particle acceleration and photovoltaic generation – but with dubious prospects."
"Their attempt to apply particle accelerator technology currently used for medical applications to cleave a thin wafer from a float-zone silicon ingot is an elaborate solution to reduce silicon waste. The process needs to occur in a vacuum, is likely very energy intensive, and requires a completely novel cell architecture to ensure adequate performance from the thin wafer," Ogden said.
Rayton, Ogden continued, is embarking on a "a science experiment that seeks to displace industry standard processes and as such are decades away from commercialization and are unlikely to get there."
Yakub, however, said that because the growth of a single crystal ingot is already industrially scaled and produced worldwide, Rayton Solar doesn't experience the same complications from the silicon crystal growth method used in thin-film solar cell production.
"And we can ensure that the highest quality of silicon is used in our exfoliation step. Going down to 3 microns from 30-50 microns realizes further cost reductions," Yakub said.
One issue that arises from slicing silicon to only 3 microns thick is that its efficiency, or ability to collect light photons, is greatly reduced. Because the slicing technology is so efficient, however, electronic-grade or float-zone silicon can be used, which has a vastly higher efficiency compared with standard silicon used for solar cells, Yakub said.
"Float-zone silicon is 10 times more expensive as a raw material, but we use 100 times less of it so therefore it becomes more economical," Yakub said. "So Rayton's process creates solar panels that are 25% more efficient than the industry standard."
Yakub, whose company is privately held, plans to run the fund-raising campaign over the next year and then license the particle accelerator technology to solar panel manufacturers.
"Our plan is to prove this works with one machine at a commercial scale as a proof of concept," he said. "Then we can license the technology out to larger manufacturers."
Posted on February 22nd, 2017 in solar by Spencer R.
On a recent Wednesday evening on the island of Ta’u—one of the outer islands in American Samoa—most of the people in all three villages are at pese—or church choir—practice. The annual island-wide youth group showcases are coming up and each choir senses the pressure of having to perfect their routines.
For the Faleasao village choir, there is added pressure from being the smallest village on the island. But this year, the underdog choir believe they have a special routine that will blow away the competition. Their secret weapon: Disney's Moana. Specifically, an adapted version of the song "We Know The Way," complete with synchronized dance moves to mimic life as voyaging islanders.
In a nearby home, a TV is tuned to a local Samoan news station, but the sound is muted. The only noise is the low humming of a box fan and the distant singing of the village choir. Musu Fuiava Mutini happily hums along, glued to her tablet device. Mutini, 82, is a village elder who has seen her home change immensely through the years.
“Before, there used to be lots of people living here," she says. "But in the time of Hurricane Tusi in 1987, everything was destroyed. Most people moved away, to Pago Pago [capital of American Samoa] or the U.S.” She pauses and sighs, caught in a distant memory. "This island is very different now."
In many ways, islands like Ta’u are a microcosm for our planet. Space and resources are both limited and the success of human communities depends on the effective management of these critical components. In looking toward a more sustainable future, the hundreds of residents of Ta'u have put their faith in a new solar energy project, which some say they would like to see replicated around the world. (See how Pacific Islanders are living with climate change.)
THE SOLAR REVOLUTION
In November, Ta'u saw the completion of a new solar-powered microgrid, which shifted the entire island’s energy generation from 100 percent diesel fuel to 100 percent solar. (The island's population varies with the season but usually falls between 200 and 600 people.)
The solar project was installed by SolarCity, a California-based company recently purchased by Elon Musk’s Tesla. The $8 million project was funded by the U.S. Department of Interior and the American Samoa Power Authority (ASPA).
Located on seven acres of land on the northern coast of the island, the system includes 5,328 solar panels, generating 1.410 megawatts of electricity. The energy can be stored in 60 Tesla Powerpacks—large batteries that allow Ta'u to stay powered for up to three days without any sunlight.
Installation of the panels wasn't easy—Ta'u is some 4,000 miles from California. Extra considerations had to be made for the island’s extreme humidity and likelihood of severe tropical storms. As a result, the system was built with the capability of withstanding Category 5 hurricane winds.
The last time Ta’u underwent an energy revolution was in 1972, when ASPA constructed a diesel power plant and provided island-wide electricity for the first time. Prior to that, kerosene lanterns were the primary source of evening light. For the few families who could afford it, small home generators were a luxury. For everyone else, life moved at a slower, simpler pace.
Introducing diesel generators to Ta’u essentially introduced a new way of life. Suddenly, lights turned on with the flick of a switch and the list of activities around the villages and inside homes increased drastically. With electricity also came new ways of preparing and preserving food, thus changing local diets. Pretty soon, the loud humming of diesel generators became a part of the island’s soundtrack.
THE MODERN ISLAND DILEMMA
Even with the relatively small amount of energy consumers on Ta’u, the offset of fossil fuels from switching over to solar power is significant: about 110,000 gallons of diesel, not to mention the amount of fuel it takes for shipping. These numbers can make a strong argument for bringing these types of renewable energy projects to island communities, but the reality is that there is still trepidation around the idea of uprooting the status quo.
“There are islands that have conferences upon conferences where all they talk about is sustainability,” says Danielle Mauga, one of ASPA’s engineers, when asked about the decision to proceed with this multi-million dollar project.
“A lot of other islands are working towards the same goal, yet this island has managed to achieve a major milestone by being able to claim energy independence with solar power,” says Mauga. (Learn about a solar microgrid in Haiti.)
Aside from the environmental concerns of burning diesel fuel, another side effect was the loss of the self reliance of old. Instead, people on Ta'u relied on the shipment of food, supplies, and drums of oil.
That left them at the mercy of shipping schedules. Although a supply vessel is supposed to arrive every fortnight, delays due to weather and mechanical problems are frequent, sometimes even stretching for months. Rationing of food and fuel is a regular occurrence.
Many other Pacific islands face the same reality of dependence on imported goods and energy.
THE COMMUNITY PERSPECTIVE
But since switching over from diesel power to solar power, life on the island of Ta'u has gone on as usual. People in all three villages resumed their daily routines—work, tending to the plantation, going to church, resting, repeat—without missing a beat. In fact, when ASPA and SolarCity officially “flipped the switch” for the solar power plant (and simultaneously switched off the diesel generators) in November, the lights around the island barely flickered.
When the diesel power plant was built over four decades ago, the changes were immediately felt by the community. This time, the new solar facility—though just as monumental of a technological shift—does not have the same life-changing sensation for consumers of the public utility. Switching from kerosene lanterns to a light switch is a much more obvious disruption to daily island life than switching from diesel to solar power.
But this is exactly what makes the Ta’u solar energy project a success, say the project's backers. People can go about their normal routines without any interruption, even though everything has changed behind the scenes.
And yet, it seems as though everybody on this little island is aware that they are a part of something special. Ask anyone in Ta’u what they think about the project and they will probably mention one of two things: relief that they no longer have to rely so heavily on unreliable shipments of fuel, and an understanding that 110,000 gallons of diesel fuel is no small amount.
The project has also seemed to sow the seeds of sustainability. In the island's classrooms, children yell out buzzwords like “Going Green” and “Saving the Planet” when asked to reflect about solar energy, while adults see it as a boon that will save them money and stress in the long run.
Looking up from her tablet, village elder Mutini says the solar panels may help brighten the future of the island. "I think these new changes to the island are good blessings," she continues. "Maybe the changes will bring more people back here again.”
A ROADMAP FOR THE FUTURE?
Just as ancient Polynesians once viewed the ocean as a set of pathways between islands, Samoans today also have a deep sense of interconnectedness with the world beyond their shores. Technology, connectivity, and travel options have improved exponentially, thus making the distance between even the remotest islands seem closer than before.
The solar project on Ta’u may also help inform conversations that are taking place on other islands around the world. Communities want to know if renewable energy is worth the investment, if the technology is reliable, and if people will respond well.
Ta’u's elders hope their future will more closely resemble their distant past, when people were self-sufficient and living in harmony with their environment.
Posted on February 22nd, 2017 in solar by Spencer R.
Every mouthful of food eaten by virtually every creature on Earth depends ultimately on the sun. But it can do much more than nurture the crops that feed us − and humans are starting to exploit this potential in striking new ways.
Farmers are now using solar energy to do far more than simply enable their crops to grow. Already it’s helping them to irrigate their fields and to clean their dairy equipment.
Only about 5 per cent of Africa’s cultivated land is irrigated, compared with Asia’s 41 per cent. Until recently, the other available methods have been manual irrigation, which is time-consuming and laborious, or petrol or diesel pumps, which are too expensive for many farmers and also add to greenhouse gas emissions.
But now there’s another way – solar-powered irrigation pumps. One pioneer of this technology is Futurepump, based in Kenya but importing the pumps from India.
Its top-of-the-range SF1 pump costs about US$650, but the company says it pays for itself in one to two years and will enable farmers to save $100-200 a year.
Solar energy converted
The pump’s solar panel directly converts solar energy into electrical power, which is transferred to a simple motor that rotates a flywheel, whose turning moves a piston up and down to draw water through the pump cylinder.
The pump, which can produce enough water to irrigate about half an acre of land per hour, works on sunny and cloudy days, in the early morning and late into the evening – and is easily transportable.
Another Kenyan solar energy entrepreneur is SunCulture, which has developed what it calls its AgroSolar Irrigation System. This draws water from any source − for example, a lake, river, stream, well or borehole − using solar power.
The solar panels provide the pump’s power directly without the need for batteries or inverters. Water is pumped into a raised storage tank by day, and all the farmer needs to do in the evening is to open a valve on the tank so that the water flows down through a filtration system and onto crop root zones via drip irrigation tape.
SunCulture’s system costs US$890, and farmers using it have reported yield increases of 300 per cent or more. Trained technicians and agronomists provide buyers with on-farm training, soil analysis and agronomy support by mobile phone and via a call centre.
Both SunCulture and Futurepump have been longlisted in the 2017 Ashden Awards, an annual international competition to encourage sustainable energy.
Proximity Designs, the winner of one of Ashden’s 2014 awards, is based in Myanmar, and introduced treadle pumps and other sustainable agriculture technologies to the country a few years ago.
It has now launched a solar irrigation pump, the Lotus, described as “radically affordable”: It costs US$345, a price that provides buyers with the pump itself, 260W of solar panels and a stand.
The Lotus can pump more than 15,000 litres of water a day, and the company estimates it will take farmers about 11 months to pay back their costs when they convert from a diesel pump.
Farmers in dry parts of Myanmar can expect this return to be even quicker.
Accessible to farmers
Designers had difficulty in creating a pump to fit neatly into the 2-inch tube wells that are found throughout Myanmar. But the product had to be easily accessible for rural farmers.
In the Mandalay region, for example, water levels are low and falling, making an alternative to increasingly expensive diesel pumps really important.
In Central America, Costa Rican dairy farmers have found another use for solar energy, and one which again means higher incomes for those who adopt it.
A solar company, Enertiva, has designed solar water heaters that supply hot water for washing farmers’ milking equipment and tanks.
The country’s buoyant dairy industry has high standards, inevitably meaning high costs as well − including for electricity or gas to provide the hot water essential for keeping milking equipment clean.
Farmers who used the fossil fuels can save around US$1,400 per year with the solar heaters, so can pay back their loan within one year.
Enertiva’s technology, which will work throughout the tropics and is now also being used in Guatemala and Panama, won an Ashden Award in 2015.
Posted on February 22nd, 2017 in solar by Spencer R.
Matt McDonough and his crew rolled up to the Brooklyn Park home around 8 a.m., unloaded their ladders, harnesses and tools, and got to work tiling another roof with solar panels.
It was a typical workday for the four-man team. They don't talk much as they check electrical connections and begin hauling equipment up to the roof of the single-story 1920s home because, after hundreds of installations, they have it down to a science. The job will take a day, maybe two, and when it's done, they'll be on to the next one.
"There's never a time we don't have work," said McDonough, who leads one of 10 installation crews at Solar Energy World.
Business is booming for Solar Energy World and other solar companies in Maryland, as sun-sourced energy becomes more affordable and accessible. Attracted by solar-friendly policies and mounting demand, solar companies are flocking to the state and hiring in droves. Maryland added 1,160 solar jobs in 2016, a 27 percent jump from the previous year, bringing the industry's employment to more than 5,400, according to an annual solar jobs census by the Solar Foundation.
The U.S. solar market nearly doubled last year, with production capacity growing 95 percent to 14,626 megawatts, according to a preview of the upcoming U.S. Solar Market Insight report, a collaboration between the Solar Energy Industries Association and GTM Research. While residential capacity grew steadily, the biggest gains last year came in utility installations, many of them made to address state rules.
Earlier this month, state lawmakers voted to override Gov. Larry Hogan's veto of a requirement that a quarter of the state's electricity come from renewable sources by 2020. The move accelerated a previous goal that renewable energy account for 20 percent of the state's electricity by 2022.
Across Maryland, from the Eastern Shore to Harford and Howard counties, solar companies have installed acres of solar arrays on farmland to sell power to utilities and others.
But these big projects don't drive employment like rooftop installation and maintenance does, according to the Solar Foundation, a research and education nonprofit organization.
"We're constantly interviewing," said Geoff Mirkin, CEO of Solar Energy World, "so if and when the next opening comes up, we're ready."
The Elkridge company's revenue nearly doubled to $31 million in 2016, up from about $16 million in 2015, and expects more growth this year, which means more hiring. Mirkin, who has 93 employees, wants to add two more installation teams, for a total of 12, by the end of March and is considering establishing new field offices to expand the company's service area beyond the Baltimore-Washington region.
SolarCity, one of the nation's largest full-service solar companies, is expanding its service to customers of Easton Utilities, along Maryland's Eastern Shore, this year.
The company has five offices and more than 800 employees in Maryland, making the state one of SolarCity's larger markets, a spokesman said.
Solar companies looking to grow face a unique hiring challenge: How to find workers with experience in a relatively new line of work.
"The solar industry is growing so quickly, it doesn't have a tremendous pool of qualified candidates to choose from," said Andrea Luecke, the Solar Foundation's president and executive director. "They're really hiring a lot of people by looking for basic competencies, people who have transferable skills and are willing to put in the time to help the company grow."
That's the case for Direct Energy, a Texas company that established its solar business by acquiring Howard County-based Astrum Solar in 2014. This year, the company expects to add up to 15 workers in Maryland to its Mid-Atlantic division, which employs between 60 and 70 solar employees in the region. Another 100 support staff are based at Direct Energy's solar headquarters in Columbia.
"The vast majority of people we hire, it's their first job in solar," said Anthony Bramante, Direct Energy's head of residential solar for the Mid-Atlantic division.
Bramante and Mirkin, of Solar Energy World, said they look for workers with experience in construction or electrical work who can be trained in the intricacies of solar installation.
Ethan Goddard had just graduated St. John's College with a liberal arts degree when he heard a radio ad for Solar Energy Services and decided to apply for an installer job. Two years and a few promotions later, he's a commercial project manager at the Millersville company.
"There was a certain point after I got promoted to a crew leader I remember thinking, 'I might have stumbled on a career,'" said Goddard, 25, of Annapolis. "It was something I never thought would happen."
McDonough, the Solar Energy World installer, built custom doors for 10 years before making the move to solar. He'd heard the pay was better and liked the idea of doing something "for the better good," he said.
Workforce development programs in Maryland have honed in on the solar industry's appetite for workers and openness to on-the-job training.
Civic Works, a community services organization in Baltimore, last year launched a three-month solar job training program for city residents who have struggled in the past to secure jobs.
"We just saw that the industry was exploding and there were a ton of job openings," said Evie Schwartz, an associate director of outreach and production. "The companies were growing, but there was a skills gap."
The program, run through the nonprofit's Baltimore Center for Green Careers, partners with local solar companies to include two-month apprenticeships. The program also covers basic construction skills and social skills, and guarantees job placement for all graduates.
Civic Works is expanding the program to include career development for solar employees, to help them advance professionally.
It also plays into an initiative Baltimore launched last year to bring solar panels to the rooftops of low-income city residents. The state Public Service Commission finalized regulations last week for community solar programs, through which a group of homeowners or renters can share the costs and benefits of a solar installation.
Betony Jones, associate chair of the climate program at the Center for Labor Research and Education at the University of California-Berkeley, cautioned against workforce development programs that focus exclusively on solar skills. Participants would be better off learning solar as part of a broader skill set that they can apply to construction or electrical jobs outside the solar field, she said.
"When you're just investing in solar training, it can almost be a dead-end job," Jones said. "It's a good entry-level job, but you kind of hit a plateau as a solar installer if all you know is solar."
While some solar businesses can't seem to hire fast enough, others said last year wasn't the boom previous years have been because of growing competition and the deflating effect that has had on prices for renewable energy credits, a key incentive for homeowners and businesses to invest in solar panels.
"There's definitely more demand for solar, but there's a lot more competition, as well," said Rick Peters, president of Solar Energy Services. "We've been a bit of a victim of our own success."
Homeowners and businesses sell their solar energy for renewable energy credits, which energy suppliers buy to meet state requirements for using renewable energy. In Maryland, however, the price of a renewable energy credit has collapsed to $18, from about $120 a year ago, according to SRECTrade, a renewable energy credit transaction and management firm that tracks bid prices.
Peters said the drop slowed sales and Solar Energy Services had to lay off a few workers, though they have been hired back as business picked up again.
He said he isn't sure whether the state's mandate to increase the amount of renewable energy used will make much of a difference, but is hopeful it will help.
Others credit the state's policies with bolstering solar businesses.
Sunrun, a San Francisco-based residential solar company has done system installation and leasing in Maryland since 2011, but opened its first field office in the state in December 2015.
The company spent much of last year hiring, and now employs 50 people at its Linthicum Heights office, said Andy Newbold, a Sunrun spokesman.
"The bottom line is Maryland set up an environment that was conducive to solar businesses coming to the state," Newbold said, "and we're obviously not the only ones selling here."
Posted on February 22nd, 2017 in solar by Spencer R.
As marines, Rye Barcott and Dan McCready had plenty of experience performing under pressure, but neither had much knowledge about the high stakes world of investing and finance. That didn’t stop them from leaving their well-paying day jobs to start their own firm.
Launched in 2013, Double Time Capital invests in utility-scale solar farms in North Carolina. In just over three years, the firm has raised seven funds, totaling $80 million, from investors including Prudential Financial, Burt’s Bees, former Bank of America chief executive Hugh McColl, Jr., and former Duke Energy CEO Jim Rogers, who now advises the company. Altogether, Double Time has financed 36 solar energy projects, which collectively produce roughly 10% of North Carolina’s solar power and power around 30,000 homes in the state.
Strictly speaking, Double Time is not a venture capital firm. It often invests in projects that are still under construction, and may not produce a profit for several years. However, solar farms typically take advantage of various state and federal tax credits to help with building costs. (North Carolina, for example, offered a 35% tax rebate for renewable energy projects until 2016. It has not been offered since, but Barcott says that does not affect its projects currently under way.) As a result, says Ethan Zindler, head of policy analysis at Bloomberg New Energy Finance, such funds typically need fairly sophisticated investors, who can make use of the tax credit while they wait for the solar farms to start producing energy. Investors are eventually rewarded because state utilities are required by law to purchase a percentage of their power from independent energy producers, including solar farms, usually through fixed multi-year contracts.
It’s a complicated time for solar energy producers. On the one hand, Barcott and McCready’s plans run counter to many of the prevailing national trends around alternative energy. The falling price of fossil fuels such as coal and natural gas has dampened enthusiasm for projects like solar and wind in some sectors, for one. The Trump administration is also openly hostile to the idea of climate change, and seems uninterested in making clean power a cornerstone of any new national energy strategy.
At the same time, it’s possible the Trump administration will eventually warm up to solar: there’s a growing national demand for clean energy. But perhaps more importantly given the political climate, solar projects have the potential to create jobs and stimulate spending. Today, they account for nearly 40 percent of all new power infrastructure buildouts in the U.S. in 2016 according to industry research.
Hostile president or not, Barcott and McCready are confident they found a market opportunity. While SolarCity, Vivint and their ilk install individual solar projects on commercial and residential roofs, Barcott and McCready wanted to address the financing needs of the utility-scale solar developers, which provide power directly to the electrical grid via solar farms. Even a small farm—typically around 40 acres, with more than 80,000 panels—costs upwards of $10 million. And such projects have a huge need for capital.
“Solar isn’t just cleaner, smarter energy, or good American infrastructure, it’s also a component of our national security and, ultimately, our energy independence,” McCready says.
Barcott and McCready discovered their interest in solar via paths that were sometimes circuitous and overlapping. Both served in the marines during the second Iraq War, although they actually met later at Harvard Business School in 2009.
After graduating, McCready worked at McKinsey as a management consultant, and grew increasingly intrigued with solar power, particularly after learning marines in Afghanistan had used small, portable solar panels to supplement their reliance on diesel engines. Barcott worked for Duke Energy, where he led a clean energy investment team for Rogers. At one point, Barcott called McCready in for assistance on a solar deal, and they began discussing their own venture in 2012.
Barcott and McCready hit the ground running—in fact "Double Time” refers to the military command for speeding up the rate of a march. They held more than 1,000 meetings to win potential investors in the year leading up the launch of their first fund. At times, they even enlisted some Gonzo tactics to find prospects: They once attended a multi-day conference for investors, and decided to post flyers near elevators of the venue, offering Marine Corps-style workouts starting at 7 a.m. As it turns out, an executive from Prudential showed up for one. Prudential is now an anchor investor in two of Double Time’s funds.
Both men say their ultimate goal is for the firm to have a positive impact. “We believe in building a business that can have a transformative role, and that can have a positive effect on climate change,” Barcott says.
And that sits right with investors like Rogers, who says the current political backlash against alternative energy sources will vanish as the price of solar solar energy continues to drop. By some estimates, it’s fallen by 62% in the last eight years, and it could soon be cheaper than coal. “As solar comes closer to being the most affordable option in the market, it does not matter who is president,” Rogers says. “Affordability will win the day.”
Posted on February 21st, 2017 in wind by Spencer R.
A wind turbine spinning its blades in a valley in southeast India asks a turbine on a plain in Iowa if it should slow down or speed up its rotation. Sound like the stuff of science fiction?
It’s not, according to GE’s VP of Software Research Colin Parris. GE has been developing software, sensors and networking technology that enable wind turbines to talk to each other, not only within the confines of a particular wind farm, but even across the planet.
Such technology, and others like it, could help boost wind farm capacity, lower costs of operating wind farms, and potentially help wind energy compete more effectively with fossil fuel power. “A machine consulting with another machine...now that could be transformational,” said Parris, in a recent interview.
Much of the success of wind energy around the globe has resulted from larger and lower-cost turbines that can produce more power, combined with increasingly savvy and maturing wind developers and financiers, as well helpful subsidies from governments. However, computing tech can also contribute, adding smart intelligence to machines, helping them operate more efficiently, and alerting developers about needed maintenance.
According to some research, these types of technologies could add a 4 percent to 8 percent increase in annual energy production of a wind farm. That could be a lot on a large wind farm with hundreds of megawatts of capacity.
GE, one of the world’s largest wind turbine makers, has built a number of computing and data-dependent technologies that are working on what some call “wind orthodontics.”
Here are five ways computing technology is boosting wind energy.
Wind energy forecasting: Predicting when and how much the wind will blow is a major issue for power companies and grid operators. Because solar and wind energy are variable, that makes it harder to predict just when these resources will generate energy, compared to natural gas, coal and nuclear plants. If a cloud drifts over a solar field, or the wind suddenly picks up, the energy produced can drop or soar significantly.
In India, the government relies on accurate GE wind forecasts to help determine how much extra power needs to be spun up from coal and natural gas plants to make up for any wind shortfalls, said Parris. If GE forecasts more wind power than actually is generated, the Indian grid might face a blackout. If GE forecasts less wind power than actually occurs, grid operators could be wasting energy and money.
GE isn’t the only company that has invested in energy prediction engines. IBM has its own wind and solar forecasting systems. GE is also looking at doing solar forecasting as well, but currently isn’t offering the tech commercially.
Wind farm optimization: If you have a wind farm of, say, 50 or 100 turbines, the turbines in the front of the pack might access more wind flows, while blocking some of the wind turbines in the back. To overcome this issue, GE connects wind turbines with wireless networks and control devices and uses data and software to adjust the angle and speed of blades and rotors so that the most wind energy can be produced by the turbines collectively.
Called “wake management,” the computing tech can deliver 0.5 percent to 2 percent more annual energy production from wind turbines. While that might sound like a drop in the bucket, at a big farm, it adds up.
According to consultants SgurrEnergy, some wind companies are also using lidar technology to ensure that the plane of a wind turbine’s rotor remains perpendicular to the wind, enabling it to access as much energy as possible.
Wind farm maintenance: When a wind turbine breaks down, it’s a big deal. Turbines are commonly hundreds of feet tall, and when they become inoperable, that sometimes means that a worker has to go to the top and check out what’s wrong. And when the blades of a turbine aren’t turning, electricity isn’t being produced, which means money isn’t being made.
GE has built algorithms based on historical wind turbine activity and real-time wind energy data that can predict when wind turbines need to be maintained and alerts developers to when they could break down. The industry calls it "predictive maintenance."
The American Wind Energy Association says that in 2011, close to $40 billion worth of wind turbines in the U.S. went out of warranty, meaning the owners of the wind turbines will need to invest in their maintenance directly. Algorithms could help reduce upkeep costs.
Drone inspections: Drones could play a new role in helping wind developers maintain turbines, and GE has already been experimenting with such technology.
Drones, carrying cameras, can fly up to the rotor and blades and inspect turbines to see if anything is out of place. Those cameras could use computing vision software to detect failures, rust, or corrosion.
Talking wind turbines: There are a lot of reasons why wind turbines might want to talk to each other across a farm, across a state or across the planet.
An older wind farm that’s been generating electricity for years could give advice to a newer, younger farm that’s operating under similar conditions. Or a wind turbine at the front of a pack could let its fellow turbines at the back of the pack know it’s adjusting its blade and rotor angle or speed.
“We have wind turbines talking to each other, and they can ask each other questions about failures, wind direction and security, or about collaborating more effectively,” explained GE’s Parris.
Such communication technology would require the turbines to be networked with wireless connections, and use sensors and software to let other turbines know how they’re operating and how they should operate
Posted on February 17th, 2017 in wind by Spencer R.
While homeowners are more familiar with photovoltaic solar panels, large-scale wind power is an increasingly important part of the growth in renewable energy.
For the first time, the total installed capacity of wind energy in Europe now exceeds the total output of electric powerplants fueled with coal.
And that imbalance is likely to grow as more wind generation comes online over the next decade, both on land and offshore.
The statistics, collated by WindEurope, are laid out in a blog post this week by Navigant Research.
Total new wind-generating capacity installed in 28 EU member countries last year added up to 12.5 gigawatts, with a bit more than 10 percent of that located offshore.
The 2016 number was down slightly on the previous year's total, but that reflected a fast push to complete wind projects in 2015 before Germany reduced its incentives as of January 1 last year.
Total installed wind capacity in Europe is now up to 154 gigawatts, though of course capacity is generally larger than actual utilitzation for renewable sources.
Still, wind provided more than 10 percent of Europe's electricity last year, and renewables—both wind and solar—grew enough to allow older fossil-fuel plants to be decommissioned altogether.
Europe's total coal generating capability now stands at 152 gigawatts, and will almost surely fall further in coming years as countries work to reduce the greenhouse-gas emissions of the generating sector.
Fully 86 percent of the 24.5 gigawatts of new generating capacity installed in Europe last year was renewable.
Total investment in wind generation last year was $30 billion, and Germany led the field with 44 percent of the total new wind capacity installed.
For the decade and a half since 2000, the 342.3 gigawatts of new capacity in wind (41.7 percent) and solar power (29.5 percent), along with natural gas (28.8 percent) allowed retirement of a like amount of generation from fuel oil, coal, and nuclear.
Analysts, including those at Navigant, expect offshore wind to represent the bulk of new capacity going forward.
The U.K., for one, has eliminated financial incentives for wind installations on land, but retained them for offshore wind farms—whose costs have already fallen below levels not expected until 2020.
While it can be hard to generalize about grid mix in Europe as a whole, Germany, the U.K., and much of Eastern Europe carry a legacy of largely coal-fired generation due to their natural deposits of the fossil fuel.
Germany has led the switch to renewable energy over the last decade, although France points to its nuclear power—which provides more than half the nation's electricity—as another low-carbon technology.
Posted on February 17th, 2017 in solar by Spencer R.
A local scientists is paving the way when it comes to solar energy. He is hoping we could soon see the technology developed at Sandia Labs in Albuquerque homes.
It is a growing field.
“It works by getting sunlight in and turning it into electricity,” Murat Okandan, mPower CEO said.
Scientist Murat Okandan says people are realizing the benefits of solar energy and are using it more and more, but he says there are limitations.
“The standard cells are fragile and brittle so if you bend and flex them, they’ll break,” Okandan said.
It is why Okandan worked with other Sandia Labs scientists to develop new ways of processing cells.
He calls them Dragon scales. They are flexible, durable, solar cells.
“This will allow you to make it lighter, make it larger areas and fold up into very tight areas lets say for satellites or UAV’s and be able to then fly longer distances or cover larger areas,” Okandan said.
Imagine a version of these prototypes folded up to fit in your backpack. Take it on a camping trip to charge your laptop or phone. Its flexibility even makes it possible to go on clothing.
Eventually, Okandan sees this wrapped around homes or even cars, covering all exposed areas to get the most out of the sun’s rays.
“Having it start here and hopefully go at a much larger scale is a very exciting opportunity,” Okandan said.
This was made possible thanks to a program at Sandia labs. It allows scientists to leave to start their own business with their technology, while guaranteeing their job at the labs for up to three years.
“mPower is taking technology developed at the labs to the energy sector, so its a win-win,” Mary Monson, Sandia National Labs said.
mPower just got its license to commercialize the technology last month. The program at Sandia labs that allowed Okandan to start mPower has also allowed for 46 other tech companies to form in New Mexico.
Posted on February 17th, 2017 in solar by Spencer R.
Posted on February 16th, 2017 in solar by Spencer R.
While our recent look at residential solar may lead you to believe harnessing that power is a newer initiative, humans have been exploiting solar energy for thousands of years to heat their homes, cook, and produce hot water. Some of the earliest written references to technology consciously designed to capture the Sun’s rays come from ancient Greece. Socrates himself said, “in houses that look toward the south, the sun penetrates the portico in winter, while in summer the path of the sun is right over our heads and above the roof, so that there is shade.” He is describing how Greek architecture exploited the different paths of the Sun through the sky at different times of the year.
By the fifth century BCE, the Greeks were struggling with an energy crisis. Their predominant fuel, charcoal from trees, was scarce since they had stripped their forests in order to cook and heat their houses. Wood and charcoal were rationed, and olive groves needed protection from the citizenry. The Greeks addressed their energy shortage by carefully planning the layout of their cities to ensure that each house could take advantage of the sunshine in the way Socrates described. The combination of technology and enlightened government policy worked, and a crisis was avoided.
Technologies for harnessing the thermal energy in sunlight have only continued to grow over time. Colonists in New England borrowed the ancient Greek homebuilding techniques to keep warm in the harsh winters. Simple passive solar water heaters, little more than a black-painted barrel, were sold commercially in the United States in the late 19th century. And more elaborate solar heating systems were developed to pipe water through absorbing and/or focusing panels. The hot water is stored in an insulated tank until needed. In climates subject to freezing, a two-fluid system is used, where the Sun heats a water/antifreeze mixture that passes through coils embedded in the storage tank, which does double-duty as a heat exchanger.
These days, a variety of sophisticated commercial systems are available for water and space heating in the home. Solar thermal systems are deployed throughout the world, with the largest installed base per capita found in Austria, Cyprus, and Israel.
But modern solar truly starts in 1954 with the discovery of a practical way to make electricity from light: Bell Labs uncovered the fact that silicon could make a photovoltaic material. This finding created the foundation for today's solar cells (essentially the devices converting light energy into electricity) and ushered in a new era of solar power. Aided by intense research ever since, it's an era that continues today as solar appears poised to become the dominant source of power in the future.
What is a solar cell?
The most common type of solar cell is a semiconductor device made from silicon—a cousin of the solid-state diode. The familiar solar panels are made from a number of solar cells wired together to create the desired output voltage and current. Those cells are surrounded by a protective package and topped with a glass window.
Solar cells generate electrical power using the photovoltaic effect, a fact that didn't come from Bell Labs. Instead, this was first discovered in 1839 by French physicist Alexandre-Edmond Becquerel (son of physicist Antoine Cesar Becquerel and father of physics Nobelist Henri Becquerel, the discoverer of radioactivity). A little more than a century later, Bell Labs had its solar cell breakthrough, providing the foundation of the most common solar cells.
In the language of solid state physics, a solar cell is formed from a p-n junction in a silicon crystal. The junction is made by “doping” different areas of the crystal with small amounts of different impurities; the interface between these regions is the junction. The n side is a conductor with electrons as the carriers of current, and the p side has “holes,” or areas with missing electrons that act as current carriers within the crystal. In the region near the interface, the diffusion of charges creates a local “built-in voltage” across the interface. When a photon enters the crystal, if it has enough energy, it may dislodge an electron from an atom, creating a new electron-hole pair.
The newly freed electrons are attracted to the holes on the other side of the junction, but they are prevented from crossing it due to the built-in voltage. However, if a pathway is provided through an external circuit, the electrons can travel through it and light our homes along the way. When they reach the other side, they recombine with the holes. This process can continue as long as the Sun continues to shine.
The energy required to transform a bound electron into a free one is called the “band gap.” It’s the key to understanding why photovoltaic (PV) cells have an intrinsic limit on efficiency. The band gap is a fixed property of the crystal material and its dopants. Those dopants are adjusted so that solar cells have a band gap close to the energy of a photon in the visible region of the spectrum. This is a practical choice, because visible light isn’t absorbed by the atmosphere (phrased differently, we humans have evolved to see in the most common wavelengths).
Photons come in fixed amounts of energy, which means their energy is quantized. That also means a photon with energy less than the band gap (say, one in the infrared part of the spectrum) won’t create a charge carrier. It will simply heat the panel. Two infrared photons together will do no better, even if their combined energy would be enough to bridge the gap. A photon with excess energy (an ultraviolet photon, for example) will knock an electron loose, but the excess energy will also be wasted.
Since efficiency is defined as the ratio of light energy striking the panel divided by electrical energy extracted—and since much of this light energy will necessarily be wasted—the efficiency can not be 100 percent.
The band gap of a silicon PV solar cell is 1.1 electron volts (eV). As can be seen from the diagram of the electromagnetic spectrum reproduced here, the visible spectrum lies just above this, so visible light of any color will produce electrical power. But this also means that for each photon absorbed, excess energy is wasted and converted into heat.
The upshot is that even if the PV panel is flawlessly manufactured and conditions are ideal, the theoretical maximum efficiency is about 33 percent. Commercially available solar panels typically achieve about 20 percent efficiency.
Most of the solar panels commercially deployed are made from the silicon cells described above. But research into other materials and strategies is underway in laboratories around the world.
Some of the most promising recent research for silicon alternatives has involved materials called perovskites. The mineral perovskite (CaTiO3) was named in 1839 in honor of Count Lev Aleksevich Perovski (1792-1856), a Russian mineralogist. It can be found on every continent and in the clouds of at least one exoplanet. The word “perovskite” is also used for synthetic compounds that have the same orthorhombic crystal structure as the naturally occurring mineral (or a closely related one) and share a structurally similar chemical formula.
Depending on which elements are used, perovskites can display a wide variety of useful properties, such as superconductivity, giant magnetoresistance, and photovoltaic activity. Their use in PV cells has generated a great deal of optimism, as they have shown an unprecedented increase in efficiency from 3.8 percent to 20.1 percent in the past seven years of laboratory research. This rapid rate of progress inspires confidence that further gains are likely, especially as the factors limiting efficiency are becoming clearer.
Recent experiments at Los Alamos showed that solar cells made from certain perovskites attained efficiencies similar to silicon’s, while potentially being cheaper and easier to work with. The secret to perovskite’s appeal is the ability to routinely grow defect-free crystals of millimeter-scale in a thin film. This is a huge size for a perfect crystal lattice, which allows the conduction electron to travel through the crystal without interference. This crystal quality partly compensates for the somewhat less-than-ideal band gap of about 1.4 eV, compared with silicon’s nearly optimal 1.1 eV.
Much of the research directed toward increasing the efficiency of perovskite cells involves searching for ways to eliminate as many crystal defects as possible. The ultimate goal is to manufacture an entire cell’s perovskite layer in the form of a perfect crystal lattice. Researchers at MIT have recently made significant progress on this. They have discovered how to “heal” the defects in a film made from particular perovskites by exposing it to intense light. The advantage over previously devised methods of defect removal, involving chemical baths or electrical current, is that no physical contact with the film is required.
Whether or not perovskites will lead to revolutions in solar panel cost or aggregate efficiency is still unknown. While they’re easy to make, so far most perovskites decompose rapidly, which sharply limits their utility.
Research is underway in many places to attack the decomposition problem. A collaboration between scientists in China and Switzerland invented a novel way to form perovskite cells that obviates the need for hole motion (see above). Since the layer devoted to hole conduction is susceptible to degradation, the material will be far more stable once that layer can be eliminated.
A recent report from Berkeley Labs describes how perovskite solar cells might one day attain their theoretical maximum 31 percent efficiency while still being cheaper to manufacture than silicon cells. The Berkeley researchers measured the conversion efficiency of individual grain surfaces using photoconductive atomic force microscopy. They found, to their surprise, that different facets have markedly different efficiencies, with some exhibiting the maximum possible.
The researchers now believe that they can find a way to grow bulk films with only the most efficient facets interfacing with the electrodes. This could lead to the entire cell running at 31 percent. If this pans out, it would amount to a revolutionary advance in solar cell technology.
Other research directions
Research in photovoltaics is proceeding rapidly on many fronts. Some of these approaches are still in the early stages and far from being put into production, but they may become mainstream in the future.
Making a solar cell with several layers is possible since the band gap can be tuned by adjusting the doping. Each layer would have a band gap tuned to a particular wavelength of light. These “multi-junction” cells can attain 40 percent efficiency but remain expensive. As a result, they’re more likely to be found on NASA spacecraft right now than on a terrestrial roof.
The layering concept has been combined with perovskites in research performed by a collaboration between Oxford and the Institute for Silicon Photovoltaics in Berlin. While attacking the material deterioration problem that is a critical weak point of this class of materials, the team found that it had discovered a perovskite with a tunable band gap. The team was able to create a version with a 1.74 eV band gap, nearly ideal for layering with silicon. This might lead, after further development, to an inexpensive cell with 30 percent efficiency.
Groups at Notre Dame University and elsewhere have developed a photovoltaic paint made from semiconducting nanoparticles. The material is not yet efficient enough to replace conventional PV panels, but its manufacturing process is simpler. Among the advantages of semiconducting nanoparticles is how they can be applied by painting over a variety of surfaces. This makes installation potentially far easier than attaching rigid panels.
A few years ago, a team at MIT made significant progress in the search to develop a practical solar thermal fuel. This is a substance that can store solar energy internally and stably over a long period of time and release it as heat “on demand” when exposed to a catalyst or some triggering heat. Solar thermal fuel accomplishes this through non-reactive transformations of its molecules. In response to solar radiation, the molecules are transformed into photoisomers: the chemical formula is the same, but the shape is different. The light energy is stored as added energy of the intramolecular bonds in the isomer, which can be thought of as a higher energy state of the original molecule. When triggered, the molecules snap back to their original shape, transforming the stored bond energy into heat. The heat can be used directly or converted to electricity with a thermoelectric generator, or heat engine. This idea potentially eliminates the need for batteries, as energy storage is integral to the system. The fuel can be transported if desired, allowing the energy to be used elsewhere.
Since the work at MIT, which used fulvalene diruthenium, several laboratories are trying to solve problems with manufacturing and material costs in order to develop a system where the fuel is sufficiently stable in its energized state and can be “recharged” then used many times without deterioration. Just two years ago, the same scientists at MIT (along with others from that institution and from Harvard) created a solar thermal fuel that they demonstrated could be put through at least 2,000 cycles with no decrease in performance.
Their innovation was to attach the fuel (in this case, azobenzene) to carbon nanotubes. This caused its molecules to line up in an orderly array. The result is a solar thermal fuel with 14 percent efficiency and an energy density similar to a lead-acid battery.
More recent work has given birth to a solar thermal fuel in the form of a transparent film that can be applied to car windshields, where it can melt ice at night using energy absorbed during the day. The pace of progress in this area leaves little doubt that solar thermal fuels will soon make the leap from the laboratory to becoming a familiar technology.
Another way to create fuel directly from sunlight (an approach sometimes described as artificial photosynthesis) has been developed by researchers at the University of Illinois at Chicago. Their “artificial leaves” use sunlight to convert atmospheric carbon dioxide into “syngas,” which is a mixture of hydrogen gas and carbon monoxide. Syngas can be burned directly or converted into more conventional fuels. The process has the added advantage of removing CO2 from the atmosphere.
A team at Stanford has created a prototype PV cell using carbon nanotubes and fullerenes rather than silicon. Its efficiency is far below that of even ordinary, commercially available silicon solar cells, but it uses nothing but carbon as a raw material. The Stanford prototype contains none of the toxic materials that form part of the electrodes in conventional solar cells. It’s a more environmentally friendly alternative to silicon, but it still needs to see its efficiency rise before becoming economical.
Meanwhile, research into other materials and manufacturing techniques continues. One promising area of research involves monolayers, layers of materials one molecule thick (like graphene). These result in PV materials that, while only a few percent efficient in absolute terms, are thousands of times more efficient than conventional solar cells per unit mass.
Other researchers are attempting to develop practical “intermediate band” solar cell materials. The idea here is to use nanostructured materials or special alloys to create a lower energy level that can be used as a stepping stone for photons without enough energy to bridge the band gap. This makes it possible for two low-energy photons to kick an electron into the conduction zone, something that is impossible with standard solid-state devices. These cells are potentially more efficient, since they can convert a wider range of wavelengths into electrical power.
This variety of research in diverse approaches to photovoltaic cells and materials, and the rapid and steady progress since the invention of the silicon solar cell in 1954, inspires confidence that the enthusiastic adoption of solar electricity will not only continue but increase in the near future.
And such efforts won't come a minute too late. A recent meta-study concluded that PV power has exceeded the energy investment return of oil and gas: more energy is returned from solar power per unit of energy invested than for these fossil fuels—a dramatic turning point.
There is now little room for doubt that solar energy will eventually be a significant, if not the dominant, form of power both on an industrial and an individual scale. So for the scientifically minded, one can only hope that the consequent reduction in the need to burn fossil fuels happens before the global climate suffers irreversible changes.