Technology

Rabu, 20 November 2013

Ultra-Efficient Solar Power

Ultra-Efficient Solar Power

Doubling the efficiency of solar devices would completely change the economics of renewable energy. Here is a design that just might make it possible.

Harry Atwater thinks his lab can make an affordable device that produces more than twice the solar power generated by today’s panels. The feat is possible, says the Caltech professor of materials science and applied physics, because of recent advances in the ability to manipulate light at a very small scale.

Solar panels on the market today consist of cells made from a single semiconducting material, usually silicon. Since the material absorbs only a narrow band of the solar spectrum, much of sunlight’s energy is lost as heat: these panels typically convert less than 20 percent of that energy into electricity. But the device that Atwater and his colleagues have in mind would have an efficiency of at least 50 percent. It would use a design that efficiently splits sunlight, as a prism does, into six to eight component wavelengths—each one of which produces a different color of light. Each color would then be dispersed to a cell made of a semiconductor that can absorb it.

Atwater’s team is working on three designs. In one (see illustration), for which the group has made a prototype, sunlight is collected by a reflective metal trough and directed at a specific angle into a structure made of a transparent insulating material. Coating the outside of the transparent structure are multiple solar cells, each made from one of six to eight different semiconductors. Once light enters the material, it encounters a series of thin optical filters. Each one allows a single color to pass through to illuminate a cell that can absorb it; the remaining colors are reflected toward other filters designed to let them through.

Another design would employ nanoscale optical filters that could filter light coming from all angles. And a third would use a hologram instead of filters to split the spectrum. While the designs are different, the basic idea is the same: combine conventionally designed cells with optical techniques to efficiently harness sunlight’s broad spectrum and waste much less of its energy.

It’s not yet clear which design will offer the best performance, says Atwater. But the devices envisioned would be less complex than many electronics on the market today, he says, which makes him confident that once a compelling prototype is fabricated and optimized, it could be commercialized in a practical way.

Achieving ultrahigh efficiency in solar designs should be a primary goal of the industry, argues Atwater, since it’s now “the best lever we have” for reducing the cost of solar power. That’s because prices for solar panels have plummeted over the past few years, so continuing to focus on making them less expensive would have little impact on the overall cost of a solar power system; expenses related to things like wiring, land, permitting, and labor now make up the vast majority of that cost. Making modules more efficient would mean that fewer panels would be needed to produce the same amount of power, so the costs of hardware and installation could be greatly reduced. “Within a few years,” Atwater says, “there won’t be any point to working on technology that has efficiency that’s less than 20 percent.”

Amazing Technology

The History of Technology

A History of Technological Ingenuity

Hess has made smart use of technology to serve its customers and create value since the company’s founding in the 1930s. That’s when Leon Hess installed heaters in oil delivery trucks to warm and thin heavy industrial oil so that it could flow easily, speeding delivery and enabling him to reach more customers more quickly.
Technological ingenuity has played a role in each stage of the company’s growth: building pipelines, terminal delivery systems, exploration of oil fields, deepwater drilling, horizontal drilling, staged fracturing and asset optimization.
Hess created its Exploration & Production Technology group to further the application of technology and the identification of innovative solutions. The company also deploys a Global Process Excellence group based in Marketing & Refining to leverage best practices across the enterprise and around the world.
An array of pipe fittings in a machine shop in Seminole, Texas, where new and existing wells were drilled or deepened to reach the Residual Oil Zone.
Hess people have been studying ways to get more oil out of this formation. The upper portion, known as the Main Pay Zone, has produced more than 660 million barrels of oil since 1937. However, with an estimated one billion barrels still in the ground, the potential remains huge. Hess employed a three-step method to increase productivity.
· New wells were drilled and existing wells deepened to reach the Residual Oil Zone. These wells were connected to field facilities with new pipelines and related infrastructure.
· The project required the development of a way to produce and deliver pure carbon dioxide from a field miles away in New Mexico. Work included drilling or redeveloping 47 wells, installing 60 miles of gathering lines and building a new electrical sub-station to drive two 6,000-horsepower compressors.
· The Seminole gas processing plant was expanded to handle the additional production and improve performance.
Flexible risers, heavyweight hoses from production equipment on the ocean floor, are a critical link up to a surface vessel that produces, processes, stores and offloads oil from nearby fields on to tankers.
Hess Corporation is the first energy company to use a new ultrasound method to help test the integrity of flexible risers, heavyweight hoses carrying thousands of barrels of oil a day from production equipment on the ocean floor to an FPSO, a vessel that produces, processes, stores and offloads oil from nearby fields on to tankers.
For the second time in a decade, Hess Corporation has pioneered the design of a super-fast computer. This one, using 900 processors and 450 graphics processing units to simultaneously process massive amounts of seismic data, is capable of processing data 20 times faster than its predecessor. This allows Hess geoscientists to pour over huge amounts of seismic data and analyze it quickly. As a result, when geoscientists need the valuable sub-surface data to make intelligent exploration decisions, the information available. In the past the company relied on suppliers to analyze data. Now, Hess can do it, and do it quickly.
Hess geoscientists around the world are using an array of new computer-driven tools, hardware and 3D software to find oil and gas. The software is a suite of products (Interpretation Platform Initiative-IPI) for the company’s petrotech community to improve and speed the interpretation of sub-surface geology. As the cost of exploration and drilling rises, increased speed and accuracy all contribute to the company’s success.
Hess offices in London, New York, Houston and Kuala Lumpur now feature Telepresence rooms -- advanced video conferencing facilities with such clarity they cause meeting participants to forget that those across the table are actually an ocean away. Telepresence is to video phones as IMAX is to home movies. The addition of these rooms has enhanced and speeded global communication and reduced travel among the company’s employees – an essential improvement that makes Hess a more competitive and faster-acting operation.
The company is using forensic investigative techniques to solve metallurgical mysteries that lead to equipment failures. Each careful analysis and laboratory-driven investigation of a failed part or piece of equipment allows company engineers to improve the performance and longevity of assets across the globe, saving money in repairs and lengthening the life of expensive equipment.
Hess engineers, working on a team focused on the Valhall field in the Norwegian North Sea, have come up with an improved system to monitor production by embedding intelligent tracers into well architecture.
Intelligent tracers not only offer sub-surface information on the mix of oil and water, they indicate specific locations where the mix may occur. Hess engineers will apply the same technology at other assets around the world to improve production and profitability.
In Retail, a new credit card processing system at Hess Express stores, employs the latest credit- and debit-card processing technology to ensure that each transaction for gasoline and groceries is faster and more secure.
At the pumps, Hess Express customers will also notice that technology ensures accuracy in measuring their fuel and ensuring that their transaction cannot be tampered with and remain secure.
Hess Corporation is using new software to streamline audit and finance processing systems that track shipments, trades and spot sales of our products around the world. With speed and accuracy, then, we can service our customers in a timely way and track their shipments by the minute, no matter where in the world they may be.
The company is using solar-powered ground remediation technology to clear a site where creosote from a historic wood treatment facility contaminated the ground and the river bed on the Elizabeth River near our Chesapeake Terminal.
The company is developing new hydrogen fuel cell technology that is being used extensively in the forklift industry in programs that may lead to wider use with automobiles and trucks. In addition, a Hess facility has developed hydrogen fuel refill stations that can be used with any hydrogen fuel cell-powered vehicle.
Through the company’s Energy Marketing business, Hess is able to offer customers a way to offset their impact on the environment with a program that measures their energy use and offsets it with renewable energy certificates (RECs). RECs are part of Hess’ green suite of energy offerings that includes Demand Response and C-Neutral. Hess provides a broad range of energy solutions to help commercial and industrial customers meet their business and environmental needs. The technology behind this suite of programs is not unique to Hess, but the company’s leadership in applying it has been a significant boon to its customers.