1989 Record for Solar-to-Grid Efficiency Finally Broken

This January, on an exceptionally clear and cold day, scientists for the Sandia National Laboratory and Sterling Energy Systems recorded a 31.25% solar-to-grid efficiency, nearly 2% better than the 1989 record.
The efficiency record, according to the scientists working on the project, brings us another step closer to getting solar to compete with coal power prices.

Solar-to-grid efficiency is very different than solar panel efficiency, which already has exceeded 40%. Unfortunately, getting the power from a solar panel (which is direct current) onto the grid (which is alternating current) requires several steps, each of which eats away at efficiency.

These solar collectors, which use concentrators to heat a Sterling engine, produce alternating current, so less energy is lost getting the power onto the grid.

The scientists contribute their success to 1. The increased reflectivity of the mirrors, which now approaches 95%, and 2. A rather ironic "Perfect Storm." This perfect storm consisted of a perfectly clear day, with 0% moisture and no particulates, the day was 10% brighter than average.

Additionally, the cold weather helped as well. Sterling engines operate by exploiting the difference in temperature between a hot end and a cold end. Solar energy heats up the hot end, but the only thing to cool the cold end is the ambient temperature.

Now we just have to hope that these solar concentrators can be scaled up, or made cheap enough to start, at least on cold days in New Mexico, to compete with coal.

Read the full press release after the jump.

Via Metaefficient

Sandia, Stirling Energy Systems set new world record for solar-to-grid conversion efficiency

31.25 percent efficiency rate topples 1984 record

Sandia and Stirling Energy Systems set new world record for solar-to-grid conversion efficiency. The record establishes a new solar-to-grid conversion efficiency of 31.25 percent. The old record, which has stood since 1984, was 29.4 percent. (Photo by Randy Montoya)
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ALBUQUERQUE, N.M. —On a perfect New Mexico winter day — with the sky almost 10 percent brighter than usual — Sandia National Laboratories and Stirling Energy Systems (SES) set a new solar-to-grid system conversion efficiency record by achieving a 31.25 percent net efficiency rate. The old 1984 record of 29.4 percent was toppled Jan. 31 on SES’s “Serial #3” solar dish Stirling system at Sandia’s National Solar Thermal Test Facility.

The conversion efficiency is calculated by measuring the net energy delivered to the grid and dividing it by the solar energy hitting the dish mirrors. Auxiliary loads, such as water pumps, computers and tracking motors, are accounted for in the net power measurement.

“Gaining two whole points of conversion efficiency in this type of system is phenomenal,” says Bruce Osborn, SES president and CEO. “This is a significant advancement that takes our dish engine systems well beyond the capacities of any other solar dish collectors and one step closer to commercializing an affordable system.”

Serial #3 was erected in May 2005 as part of a prototype six-dish model power plant at the Solar Thermal Test Facility that produces up to 150 kilowatts (kW) of grid-ready electrical power during the day. Each dish unit consists of 82 mirrors formed in a dish shape to focus the light to an intense beam.

The solar dish generates electricity by focusing the sun’s rays onto a receiver, which transmits the heat energy to a Stirling engine. The engine is a sealed system filled with hydrogen. As the gas heats and cools, its pressure rises and falls. The change in pressure drives the pistons inside the engine, producing mechanical power, which in turn drives a generator and makes electricity.

Lead Sandia project engineer Chuck Andraka says that several technical advancements to the systems made jointly by SES and Sandia led to the record-breaking solar-to-grid conversion efficiency. SES owns the dishes and all the hardware. Sandia provides technical and analytical support to SES in a relationship that dates back more than 10 years.

Sandia is a National Nuclear Security Administration laboratory.

Andraka says the first and probably most important advancement was improved optics. The Stirling dishes are made with a low iron glass with a silver backing that make them highly reflective —focusing as much as 94 percent of the incident sunlight to the engine package, where prior efforts reflected about 91 percent. The mirror facets, patented by Sandia and Paneltec Corp. of Lafayette, Colo., are highly accurate and have minimal imperfections in shape.

Both improvements allow for the loss-control aperture to be reduced to seven inches in diameter — meaning light is highly concentrated as it enters the receiver.

Other advancements to the solar dish-engine system that helped Sandia and SES beat the energy conversion record were a new, more effective radiator that also costs less to build and a new high-efficiency generator.

While all the enhancements led to a better system, one aspect made it happen on a beautiful New Mexico winter day — the weather.

“It was a ‘perfect storm’ of sorts,” Andraka says. “We set the record on Jan. 31, a very cold and extremely bright day, a day eight percent brighter than normal.”

The temperature, which hovered around freezing, allowed the cold portion of the engine to operate at about 23 degrees C, and the brightness means more energy was produced while most parasitic loads and losses are constant. The test ran for two and a half hours, and a 60-minute running average was used to evaluate the power and efficiency data, in order to eliminate transient effects. During the testing phase, the system produced 26.75 kW net electrical power.

Osborn says that SES is working to commercialize the record-performing system and has signed power purchase agreements with two major Southern California utilities (Southern California Edison and San Diego Gas & Electric) for up to 1,750 megawatts (MW) of power, representing the world’s two largest solar power contracts. Collectively, these contracts require up to 70,000 solar dish engine units.

“This exciting record shows that using these dishes will be a cost-effective and environmentally friendly way of producing power,” Osborn says. “SES is actively engaged in the commercialization of the system, called the ‘SunCatcher,’ including continuing to prepare it for mass production, completing project site development and preconstruction activities, and establishing partnerships with substantial manufacturing and industrial organizations to develop a cost-effective manufacturing process and supply chain. The demonstrated high efficiency means more energy is generated for the given investment, lowering the cost of the energy delivered.”

SES was formed in 1996 to develop and commercialize advanced solar technology. The company maintains its corporate headquarters in Phoenix, Ariz, project and technical development offices in Tustin, Calif, and engineering and test site operations at Sandia National Laboratories in Albuquerque.

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Man's affect on world's oceans revealed

Almost half of the world's oceans have been seriously affected by over-fishing, pollution and climate change, according to a major study of man's impact on marine life.

Ocean monitoring system 'vital to mankind' James Lovelock's plan to pump ocean water to stop climate change Acidic oceans threaten marine life An international team of 19 scientists have published the first ever comprehensive map showing the combined impact of human activity on the planet's seas and oceans.

t shows that more than 40 per cent of marine regions have been significantly altered, while just four per cent remains in a pristine state.

Previous studies have largely focused on the impacts of specific activities such as pesticide runoff or fishing, or have looked at damage in certain areas.

The North Sea is one of the most heavily affected regions, along with the South and East China Seas, the Caribbean, the east coast of North America, the Mediterranean, the Red Sea and the Persian Gulf. The least affected areas are near the poles.

Dr Ben Halpern, of the University of California, presented the new findings at the American Association for the Advancement of Science (AAAS) conference in Boston.

Dr Halpern said: "This project allows us to finally start to see the big picture of how humans are affecting the oceans.

"The big picture looks much worse than I imagine most people expected. It was certainly a surprise to me."

Activities and impacts included in the study include fishing, ocean acidification caused by pollution, temperature change, species extinctions and invasions, and the shipping, oil and gas industries.

The researchers developed models to quantify and compare how 17 human activities affected marine ecosystems.

For example fertiliser runoff has been shown to cause significant damage to coral reefs but has less effect on kelp forests.

They gathered data from across the world and collated the results to give each area a score for man-made damage and changes.

The results, published in the journal Science, show that 41 per cent of the world's oceans and seas have been significantly affected by multiple human activities.

Coral reefs, seagrass beds, mangroves, rocky reefs and shelves are among the most seriously altered ecosystems.

The team hope their work will provide information to help policymakers decide on priorities for conservation action.

Dr Kimberly Selkoe, of the University of Hawaii, said: "Conservation and management groups have to decide where, when, and what to spend their resources on.

"Whether one is interested in protecting ocean wilderness, assessing which human activities have the greatest impact, or prioritising which ecosystem types need management intervention, our results provide a strong framework for doing so."

Coastal regions were shown to be particularly badly hit. The North Sea was the 24th most affected region of 232.

The effects of over-fishing in the North Sea have been well-documented, while the close proximity of heavily populated areas, shipping, oil and gas extraction have all affected a region that is relatively shallow and enclosed, and therefore slower to repair damage.

Co-author Dr Mark Spalding, a marine scientist at the conservation group Nature Conservancy, said: "What is surprising is the truly global spread of human impact.

"But it's not all doom and gloom. In some areas, such as the Great Barrier Reef, strong integrated conservation measures are being introduced.

"The map provides a challenge for us to start to think seriously about conservation and management, and gives us pointers to the priorities and different states of urgency of response required."

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World’s Largest Marine Protected Area Created in Pacific Ocean

Vast Ocean Reserve Conserves Vital Resources for Human Well-Being

Arlington, VA – The small Pacific Island nation of Kiribati has become a global conservation leader by establishing the world's largest marine protected area – a California-sized ocean wilderness of pristine coral reefs and rich fish populations threatened by over-fishing and climate change.

The Phoenix Islands Protected Area (PIPA) conserves one of the Earth's last intact oceanic coral archipelago ecosystems, consisting of eight coral atolls and two submerged reef systems in a nearly uninhabited region of abundant marine and bird life. The 410,500-square-kilometer (158,453-square-mile) protected area also includes underwater mountains and other deep-sea habitat.

Kiribati first declared the creation of PIPA at the 2006 Conference of the Parties to the Convention on Biological Diversity in Brazil. On January 30, 2008, Kiribati adopted formal regulations for PIPA that more than doubled the original size to make it the largest marine protected area on Earth.

Kiribati and the New England Aquarium (NEAq) developed PIPA over several years of joint scientific research, with funding and technical assistance from Conservation International's (CI) Global Conservation Fund and Pacific Islands Program. The CI support for PIPA is part of the Coral Reef Initiative in the South Pacific (CRISP).

"Kiribati has taken an inspirational step in increasing the size of PIPA well beyond the original eight atolls and globally important seabird, fish and coral reef communities," said Greg Stone, the NEAq vice-president of global marine programs. "The new boundary includes extensive seamount and deep sea habitat, tuna spawning grounds, and as yet unsurveyed submerged reef systems."

Located near the equator in the Central Pacific between Hawaii and Fiji, the Phoenix Islands form an archipelago several hundred miles long. They are part of the Republic of Kiribati, which comprises three distinct island groups (Gilbert Islands, Phoenix Islands, and Line Islands) with a total of 33 islands to make it the largest atoll nation in the world.

"The creation of this amazing marine protected area by a small island nation in the Pacific represents a commitment of historic proportions; and all of this by a country that is under serious threat from sea-level rise attributed to global warming," said CI President Russell A. Mittermeier. "The Republic of Kiribati has now set a standard for other countries in the Pacific and elsewhere in the world. We are proud to be associated with this effort that helps the people of Kiribati, and we call on governments and private conservation groups everywhere to support Kiribati in its efforts and make similar commitments to protect their own natural systems."

The Phoenix Islands were featured in a major article in National Geographic in February 2004.

Three NEAq-led research expeditions since 2000 found great marine biodiversity, including more than 120 species of coral and 520 species of fish, some new to science. Some of the most important seabird nesting populations in the Pacific, as well as healthy fish populations and the presence of sea turtles and other species, demonstrated the pristine nature of the area and its importance as a migration route.

Protecting the Phoenix Islands means restricting commercial fishing in the area, resulting in a loss of revenue that the Kiribati government would normally receive from issuing foreign commercial fishing licenses. NEAq and CI are helping Kiribati design an endowment system that will cover the core recurring management costs of PIPA and compensate the government for the foregone commercial fishing license revenues. The plan allows for subsistence fishing by resident communities and other sustainable economic development in designated zones of the protected area.

Keeping oceans and marine ecosystems intact and healthy allows them to better resist the impacts of climate change and continue their natural role of sequestering atmospheric carbon that causes global warming.

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