- Underwater Photovoltaic Research from the U.S. Naval Research Laboratory — Say What?
- Twitter Storm to End Fossil Fuel Subsidies
- The Healing Power of New Energy (Friday Fun)
- 1st Solar Hackathon! This Weekend in Oakland
- 40 Top Eco-Apps
- What’s a Heat Pump?
- NREL Helps Make Solar Panels Last
- Westinghouse Solar to Ship “Plug n’ Play” DIY Solar Panels Down Under
- Leveling the Energy Playing Field: Senate Bill to Allow Renewable Energy MLPs
- Fuel Costs of a Honda Fit EV: $0.03 to $0.04 per Mile?
- More Cleantech News!
Posted: 08 Jun 2012 08:53 AM PDT
Scientists at the U.S. Naval Research Laboratory, Electronics Science and Technology Division, dive into underwater photovoltaic research to develop high bandgap solar cells capable of producing sufficient power to operate electronic sensor systems at depths of 9 meters.
Underwater autonomous systems and sensor platforms are severely limited by the lack of long endurance power sources. To date, these systems must rely on on-shore power, batteries or solar power supplied by an above water platform. Attempts to use photovoltaics have had limited success, primarily due to the lack of penetrating sunlight and the use of solar cells optimized more towards the unimpeded terrestrial solar spectrum.
“The use of autonomous systems to provide situational awareness and long-term environment monitoring underwater is increasing,” said Phillip Jenkins, head, NRL Imagers and Detectors Section. “Although water absorbs sunlight, the technical challenge is to develop a solar cell that can efficiently convert these underwater photons to electricity.”
Even though the absolute intensity of solar radiation is lower underwater, the spectral content is narrow and thus lends itself to high conversion efficiency if the solar cell is well matched to the wavelength range. Previous attempts to operate solar cells underwater have focused on crystalline silicon solar cells and more recently, amorphous silicon cells.
High-quality gallium indium phosphide (GaInP) cells are well suited for underwater operation. GaInP cells have high quantum efficiency in wavelengths between 400 and 700 nanometers (visible light) and intrinsically low dark current, which is critical for high efficiency in lowlight conditions.
The filtered spectrum of the sun underwater is biased toward the blue/green portion of the spectrum and thus higher bandgap cells such as GaInP perform much better than conventional silicon cells, states Jenkins.
Preliminary results at a maximum depth of 9.1 meters reveal output to be 7 watts per square meter of solar cells, sufficient to demonstrate there is useful solar power to be harvested at depths commonly found in nearshore littoral zones.
Posted: 08 Jun 2012 08:41 AM PDT
Oakland, 7 June 2012 — Campaigning organizations from around the world will join forces on June 18 for a 24-hour 'Twitter storm' in which tens of thousands of messages will be posted on the social networking site demanding that world leaders use Rio+20 to agree to end fossil fuel subsidies.
The 24 hour clock will start at 6PM UTC in Sydney, when activists will begin to flock to Twitter with messages that will also be projected in iconic spots in Sydney, New Delhi, London, Rio, and other locations. In recent weeks campaigning groups have collected over 1 million signatures demanding that leaders act now to end subsidies and start to invest in clean energy solutions. (1)
According to figures compiled by Oil Change International, countries together are spending as much as $1 trillion dollars annually on fossil fuel subsidies. (2) The International Energy Agency estimates that by cutting these subsidies, the world can cut global warming causing emissions in half and significantly contribute to preventing a 2 degree temperature rise, the number most scientists say we need to stay under to prevent runaway climate change. (3)
"We are giving twelve times as much in subsidies to fossil fuels as we are providing to clean energy, like wind and solar. World leaders shouldn't be subsidizing the destruction of our planet, especially since these subsidies are cooking our planet," said Jake Schmidt, International Climate Policy Director at the Natural Resources Defense Council.
In May, leaders of the G20 again pledged to eliminate fossil fuel subsidies. They first made the commitment in 2009 but have yet to implement the policy change at the country level.
While global warming emissions rise and gas prices spike, fossil fuel companies continue to make massive profits, which brings into doubt the need for subsidies. ExxonMobil, for example, paid an effective US federal tax rate in 2010 of 17.2 percent, while the average American paid 28 percent.
Participating organizations include 350.org, Avaaz, Greenpeace. Oil Change International, Natural Resources Defense Council, and others.
Image: twitter bird via Shutterstock
Posted: 08 Jun 2012 08:03 AM PDT
Thought that made for a good Friday share.
Also, if you haven’t seen this gem, you have to watch this Colbert segment on climate change:
Posted: 08 Jun 2012 06:46 AM PDT
Oakland to Host the First Solar Hackathon: Call for Developers (via Ecopreneurist)
Can you build an app in a weekend? Do you thrive in dynamic teams? Are you a creator, visionary and executor all in one? This weekend's hackathon in Oakland promises to provided another platform for all those hackers looking to intersect the emerging field of clean energy, tech and the internet,…
Posted: 08 Jun 2012 06:42 AM PDT
40 Eco-Apps that Put Technology to Work for the Environment (via Global Warming is Real)
Technology may not be a panacea to solve the climate crisis, but green applications (eco-apps) are helping to drive awareness and foster responsible action. There was a time when eco-apps did little more than provide lists of so-called "green" products and services. Now green-themed apps have turned…
Posted: 08 Jun 2012 06:37 AM PDT
What is a Heat Pump? (via sustainablog)
Heat pumps provide efficient, reliable methods of heating homes and buildings. Because they use much lower amounts of fossil fuels, they also help reduce carbon dioxide emissions and other greenhouse gas emissions. A heat pump draws heat from the ground, or from outdoor air, and transports it to another…
Posted: 08 Jun 2012 06:31 AM PDT
During 30 years on a rooftop, a solar panel gets bombarded by UV rays, soaked by rain, buffeted by wind, pounded by hail.
How well it stands up to that beating is a crucial factor in setting the warranties of solar modules — and in convincing the public that solar energy can be counted on like the sun rising in the east.
The U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) plays a crucial role in improving the reliability of the photovoltaic (PV) panels that are being installed on rooftops in record numbers.
NREL helps set standards for reliability and serves as a neutral third party in tests of manufacturers’ new solders, edge seals, and glues. At its Golden, Colorado, campus, NREL subjects solar panels to heat, humidity, and mechanical stress to simulate conditions in Denver, Phoenix, the Philippines, and elsewhere.
In March, leading scientists and engineers in the industry gathered at NREL for the PV Module Reliability Workshop. The workshop encouraged a frank discussion of reliability problems that can plague solar power companies.
What standards are needed for the glue in the edges that seal a panel’s top and bottom? How does weather affect cracking? What can be done to prevent one glass panel from creeping away from the other?
NREL Stresses Edge Seals to Predict Failure
Solar modules must be sealed to keep out moisture — and that’s why edge seals are so crucial.
NREL scientist Michael Kempe exposes edge seals to different configurations and environments using Atlas Weather-Ometers.
On what looks like a whirling see-through geodesic dome — albeit just two feet in diameter — NREL scientists attach matchbook-sized samples that simulate the construction of PV modules to determine at what combination of UV radiation, high temperature, high humidity, and mechanical stress those samples can fail.
It’s important that manufacturers not just check for single stresses. By demonstrating that a combination of two or three factors can cause a failure, NREL is helping manufacturers prepare for the worst.
“We help manufacturers to know what kind of stress to put on their samples to determine if Sample A is better than Sample B,” Kempe said. “Every tiny detail, every aspect of these things has to be examined.”
A typical 12-millimeter-wide edge seal should keep out moisture anywhere in the world — from Salt Lake City to Bangkok — if it maintains a good adhesion, Kempe said. And the cost is between $1 and $2 a module, whether it is a tape-style edge seal or a hot-melt extrusion.
For humidity tests, NREL uses a vacuum oven to expose samples to controlled relative humidity using saturated salt solutions: lithium chloride for low humidity; magnesium chloride for 25% to 31% humidity; sodium nitrates for higher humidity.
Testing Leads to Good News on Panel Creep
NREL has been able to share good news with the industry.
In the case of “creep,” NREL’s sophisticated tests showed that the problem isn’t as big as was feared.
In a solar module, two pieces of glass are adhered together with a plastic encapsulant that may be solid at one temperature but flow — or “creep” — at another temperature. If it flows during the expected lifetime of a solar module, solar panel components can be displaced, and that can cause a short, break electrical connections, or even cause fires.
The stakes are high: a one-centimeter creep can expose live wires to the elements, and that can cause arcing or other serious safety problems.
NREL’s tests found that most encapsulants used today or proposed for future use do a very good job of preventing creep. But showing that failure is possible keeps manufacturers from becoming complacent.
Last summer, Kempe and his colleagues used eight different encapsulants from six manufacturers to assemble several mock and actual solar modules. The scientists then evaluated them side by side in an objective manner, and in a way that uncovered strengths and weaknesses of the various encapsulants without pointing fingers at individual companies. The industry’s trust in NREL made the tests possible. “They were able to participate without the fear of being singled out,” Kempe said.
The researchers put insulating materials on the test modules and deployed them in Arizona so they would reach the highest temperatures (104°C) that are likely in the field.
The only material that crept significantly in the outdoor experiments was one that was intentionally formulated improperly so that it would still melt at moderate temperatures.
“All the other plastic materials that people in the industry were considering for encapsulation were essentially OK outdoors,” Kempe said. “It would only be under very extreme circumstances that you might have a problem. The standards community realized that this stumbling block was not nearly as big an issue as was suspected.”
Stress, Temperature Tests Help Prevent Cell Overheating
Shown here is a close-up of the inside of an Atlas CI 4000 Xenon Weather-Ometer used to test small samples of solar panels. NREL scientists apply temperature, humidity, and mechanical stress to the samples to show industry how they can fail.
NREL also works on the problem of concentrating PV cells overheating in a module. Concentrating PV uses lenses to focus more sunlight on a solar cell. The solder or epoxy that adheres the panel’s glass and edges will fatigue with time because of temperature changes that happen with the weather, NREL scientist Nick Bosco said. When the attachment goes bad, heat can’t escape, and the cell overheats.
NREL uses high-frequency weather data to model the changes in cell temperature for Houston, Los Angeles, Albuquerque … wherever a company wants a climate test. The data are publicly available.
The most damaging locales are those with high temperatures and partly cloudy skies. The frequent temperature changes when clouds pass by can cause extra stress. “In Golden, Colorado [site of NREL's main campus], where we get hot mornings and then clouds roll in every afternoon, that can be more damaging than in Phoenix where you don’t have many clouds,” Bosco said. “We’re early in the process, but we’re seeing easily a 20% to 40% difference between certain locations.”
To test the effect of temperature cycles on the modules, NREL uses various solders and epoxies to attach pieces of the panels, and then exposes them to different temperatures at varying intervals. Researchers test thermal cycling in indoor chambers and expose modules to outside conditions, comparing the results.
“We’re interested in how cracks grow in the solder as the module goes through cycles,” Bosco said. “Our instruments can image the cracks on a computer, analyze them, and measure their size. We’ll do that periodically, then put the module back in the chamber, do more cycles, then measure the growth rate of the cracks as a function of the number of cycles.”
Bosco is working on models and experiments to determine the amount of damage the attachment will accumulate. The goal is for the indoor test chamber to accurately reflect outdoor conditions.
“The amount of damage the attachment accumulates is different for every city, and we’re hoping to model that,” Bosco said. “We’re hoping to be able to make real-life predictions based on location.” So many cycles in the chamber is equal to so many years outside. “So, a company might expect similar crack growth after so many years.”
The challenge for industry is to design solar modules that are very durable and reliable, yet not overly expensive. NREL scientists and their industry counterparts agree they can meet that challenge.
“They’re looking for a route to a less expensive design and architecture of a cell assembly,” Bosco said. NREL is able to figure out why a solution works, not just that it does work. It can report that a change in design or materials has this or that consequence in reliability. And NREL shares that knowledge with the industry to help the technology move forward.
NREL scientists and their industry partners have learned that an accelerated test will mean different things in different locations — and that the material and architecture of the design can influence reliability dramatically. “You can certainly have an expensive bad design,” Bosco said. And, of course, a good product that is incorrectly installed can fail.
As tempting as it is to accelerate the testing so that new, presumably better products can get to market sooner, testing experts know that validating a product for 20 or 30 years of useful life is complicated without comparisons to real-life durability.
So, NREL and the industry keep a poultry analogy in mind. “When you’re trying to hatch an egg, you give it 25 days at about 40°C, and you get a chicken,” Kempe said. “If you try to accelerate the time by accelerating the temperature, you get a boiled egg.”
The results of NREL’s testing will provide the technical basis for changes to reliability standards.
Today, the standards aren’t robust enough to predict the overall longevity of solar panels. NREL, the PV industry, and the attendees of the PV Reliability Workshop are working toward the day when tests and standards can determine the lifetime reliability of a module.
“What can come out of this is a graded test sequence,” Bosco said. “If you pass, say, Level A, it means the module is good for a lifetime in these certain locations. A stricter Level B certification will provide a similar lifetime warranty in more damaging locations.”
Learn more about NREL’s PV performance and reliability testing.
Posted: 08 Jun 2012 05:24 AM PDT
Westinghouse Solar apparently sees a bright future in Australia. In the midst of merging with CBD Energy, one of Australia’s largest non-utility suppliers of solar energy equipment, Westinghouse and CBD on June 5 announced they are to begin distributing Westinghouse’s DIY “plug n’ play” solar power systems, dubbed Instant Connect, in Australia.
“In parallel with our efforts to complete our pending merger with CBD, both companies are committed to growing the business in a collaborative effort. As a first step, CBD, through its solar subsidiaries, has agreed to market and install our solar power systems in the Australian and other international markets,” Westinghouse Solar CEO Margaret Randazzo stated in a press release. “The Australian market enjoys a sound regulatory environment for solar, and provides an opportunity for us to grow revenue in a non-US market devoid of risk of punitive tariffs.”
For its part, CBD sees promise in Westinghouse’s award-winning plug n’ play DIY solar PV systems, and in the brand recognition of the Westinghouse name. “A key reason for pursuing this merger was the strength of the award winning technology that Westinghouse Solar possesses,” explained CDB managing director and CEO Gerry McGowan. “When coupled with the significant brand awareness the Westinghouse name provides, one of the first items on our agenda was to bring these integrated ‘plug-and-play’ solar power systems, with fewer parts, superior safety and faster install times to the Australian market.”
Australians installing more rooftop solar than grid operators can handle
Shipping its Instant Connect solar panels to CDB in Australia may well be a forerunner of assembling them there. In a joint venture with Tianwei, one of China’s largest renewable energy companies, CBD, through eco-Kinetics, is establishing a solar panel and equipment manufacturing operation on Queensland’s Gold Coast.
The issue highlights the ambivalence of large-scale, centralized electric utilities have for distributed rooftop solar power, and the importance of buildiing out smart grid and transmission infrastructure if utilities are to really capitalize on solar and wind energy potential and market opportunities.
Australians’ average energy bills have been rising fast while the cost of solar PV systems has fallen dramatically. The cost of installing a solar PV system in New South Wales (NSW) ranged from A$2,000 ($1,970) to A$12,000 ($11,811), depending on size of system as of October 2011, according to CBD. That results in a payback period of six years at projected electricity prices.
CBD-Westinghouse Solar Merger
Westinghouse Solar and CBD Energy signed a definitive merger agreement on May 9. Expected to close in Q3, the agreement calls for Westinghouse Solar shareholders to receive approximately 3.7 CBD common shares for each share held. Preferred shareholders are to receive CBD preferred shares convertible into common stock. Taken together, Westinghouse Solar common and preferred shareholders will own approximately 15% of the merged company, shares of which are to trade on a US stock exchange.
The merger with CBD puts Westinghouse Solar on firmer financial ground while also providing a base to expand internationally. That’s not to say that Westinghouse Solar expects to bow out of the US market by any stretch, however.
On the contrary, management of both companies say they intend to expand in the US. “The merger with Westinghouse Solar is expected to be highly beneficial for CBD. The US market is rapidly developing into one of the largest and most stable end-markets for solar energy systems,” McGowan explained. “The merger provides CBD an immediate point of access with an experienced management team capable of driving rapid expansion for the combined business.”
CBD’s also been expanding in Europe. It has secured a $25 million credit facility that enables it to prioritize and develop and expand its project pipeline of European turnkey solar PV projects on a Build-Operate-Transfer (BOT) model primarily aimed at institutional investors. Management estimates the credit facility will “support the development and sale of solar projects totaling more than A$35 million ($34.45 million) revenue per quarter.”
CBD’s total revenue has grown substantially in recent years, from some A$17 million ($16.7 million) as of June 30, 2009 to A$165 million ($162.4 million) at the end of fiscal year 2011. Cash flow, as measured by EBITDA (earnings before interest, taxes, depreciation and amortization) have improved from a negative A$3.3 million to a positive A$7.9 million over the three-year period.
Posted: 07 Jun 2012 10:01 PM PDT
One of the ways the US federal government subsidizes the fossil fuel industry — natural gas and oil distributors in particular — is through Master Limited Partnerships (MLPs). These special purpose investment vehicles exempt investors who form them from certain corporate income taxes. The catch is that MLPs have to distribute most of their income to partnership shareholders on a quarterly basis.
Sen. Christopher Coons (D-Delaware) believes renewable energy industry participants could benefit greatly if they were allowed to form MLPs, and he, along with Sen. Jerry Moran (R-Kansas), on June 7 introduced legislation — The Master Limited Partnerships Parity Act — to make it happen.
Leveling the Playing Field for US Clean Energy Development
As it is, the U.S. tax code confers preferential treatment on investors in oil, natural gas, coal extraction and pipeline projects — they’re the only ones allowed to form MLPs. In fact, natural gas and oil companies are have been benefiting from being able to form MLPs for nearly 30 years.
Odd as its seems, the IRS code specifically excludes MLPs from investing in renewable energy companies and project portfolios, 24/7 Wall St. points out. Coons’ wants to level the playing field. In addition to gaining support from the Obama Administration, his bill has garnered five Republican co-sponsors for his legislation.
Fast-track passage of the Master Limited Partnerships Parity Act (MLPPA) couldn’t come at a more opportune time. Key federal renewable energy tax credits are on the wane and federal government stimulus spending enacted to avoid a banking system and economic collapse have run their course. Meanwhile, persistent concerns about a debt-credit crisis spreading from Europe and efforts to rein in bank leverage and boost capital requirements are tightening credit and lending conditions.
Opening Up as Much as $6 Billion of Private Capital for Renewable Energy
Affording renewable energy industry participants, the ability to form MLPs would open up significant new opportunities for them to raise lower-cost capital at a time when financing options are regressing to the point where renewable energy financing is increasingly reliant on tapping the relatively small market for tax equity financing.
As much as $6 billion in capital that’s currently excluded from renewable energy projects might be invested in renewable energy MLPs, according to a study from the Maguire Energy Institute at Southern Methodist University, Paul Ausick noted on 24/7 Wall Street.
In a June 2 New York Times article, Stanford University’s Dan Reicher and Felix Mormann succinctly explained the boost allowing renewable energy companies to form MLPs would provide to the US renewable energy industry.
Coons’ MLPPA would expand the definition of “qualified” MLP sources to include clean energy resources and infrastructure projects. If passed, MLPPA would allow MLPs to be formed for solar, wind, marine and hydrokinetic, hydropower, combined heat and power, municipal solid waste, geothermal, fuel cells, and closed and open-loop biomass. It would also enable MLPs to be formed for a range of alternative transportation fuels, including cellulosic ethanol, biodiesel, and algae fuels.
A diverse group of clean energy industry leaders, industry associations, and public interest groups are coming out in support of Coons’ MLPPA, including the American Council on Renewable Energy (ACORE), the American Wind Energy Association (AWEA), Clean Energy, Third Way, Covanta, DuPont, NRG Energy, the Solar Energy Industry Association (SEIA), the Wind Development Coalition, the Advanced Biofuels Association, the Biomass Power Association, the Advanced Ethanol Council, Environmental Entrepreneurs, and the Natural Resources Defense Council (NRDC).
Posted: 07 Jun 2012 05:02 PM PDT
Based on the fuel efficiency info just released for the Honda Fit EV, the new leader in the EPA’s fuel efficiency ratings, one of our readers did some quick calculations and came up with some interesting facts. I thought I’d quickly repost a few or these for more eyes to see, and also elaborate on them.
From Bob_Wallace: “kWh per mile for the Honda = 0.29. At $0.08/kWh that’s just slightly over 2 cents per mile.”
He then noted that a 50mpg gas-powered vehicle (aka ‘gasmobile’) would need $1.16/gallon of fuel to drive for so cheaply. I don’t think you can find that anywhere these days, do you?
Notably, not every place has electricity selling for $0.08/kWh. The average price of electricity for residential customers in the US is a little under $0.12/kWh these days (or about $0.0959 for all sectors combined).
But, even if you’re paying $0.12/kWh for electricity, you’d need gas to be at $1.74/gallon for a super fuel-efficient (by US standards) gas-powered car getting 50 mpg to be running for the same price.
However, the average fuel economy of vehicles sold in the US is actually far less than 50 mpg, it’s just approaching 24 mpg (May 2012). For such a car, you’d need gas to be selling for $0.8352/gallon to match the average fuel costs of a Honda Fit EV. Wow, good luck with that!
Now, I thought I’d run one more comparison while I was at it (yeah, this has turned into not such a quick repost). I thought I’d compare the Honda Fit EV to the most popular car on the roads these days, the Toyota Corolla. The Toyota Corolla has an average fuel economy rating of 29-30 mpg according to the EPA. Going with the slightly better 30 mpg, the car would still need gas to be $1.044/gallon to have the same fuel costs as the Honda Fit EV (running on electricity at the average US residential rate).
And imagine if that EV is actually getting its electricity super cheaply from solar panels!
As a wrap up, here’s a bullet-point comparison of some different options and possibilities:
Which option would you choose?
Posted: 07 Jun 2012 06:08 AM PDT
Energy Efficiency & Going Carbon Neutral
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