Alternative & Renewable Energy News

Design complexity of multi-junction solar cells can be addressed by numerical simulation, as evidenced by case studies excerpted in Photovoltaics World. The article features optimization schemes to model temperature-dependent behavior, tunnel diode design, and current-voltage properties under specific illumination conditions. Application of TCAD to multi-junction cell and through-silicon via simulation is explained in a brief video.

Using modular, prefabricated heliostat systems enabled eSolar to construct the 5 MW Sierra SunTower solar power plant in Lancaster, CA, in less than one year. The only power tower of its kind in the U.S. supplies 4,000 homes and relies on complex software to focus 24,000 mirrors on thermal receivers mounted atop central power towers.

Two 16 kW hydrogen fuel cells and an electric propulsion system will power this 35 ft bus. The vehicle is one element of a U.S. Department of Defense project designed to evaluate all phases of a clean hydrogen fuel cycle. Details noted in Green Car Congress include a 100 kW continuous power rating and lithium-ion battery pack.

The H2KT project will provide energy storage and allow Greenland to expand hydropower production and reduce diesel fuel imports. Hydrogen from hydro-powered-electrolysis will be stored for future fuel cell conversion to heat and electricity. Located at national energy company headquarters in Nuuk, the hydrogen and fuel cell plant will also supply other communities for local energy production.

Exploitation of low-temperature geothermal resources can expand with a biphasic heat-trapping fluid developed at Pacific Northwest National Laboratory. Addition of nanostructured metal-organic heat carriers to the fluid will improve process thermodynamic efficiency. As a result, notes Science Daily, binary plant generation capacity should approach that of conventional steam cycles.

A hinge perpendicular to the rotor, and a teetered hub, are salient features distinguishing Nordic Windpower's two-bladed wind turbine, reports Technology Review. The lighter design of the hub linking the rotor and driveshaft brings a 20-25% cost reduction relative to three-bladed designs. Community-scale systems will be developed before utility-sized prototypes come online in 2012.

Like solar cells, paper money, and T-shirts, batteries can now be printed. The 1.5 V units will be cost-effectively produced on a large-scale with a silk-screen printing process. Less than 1 mm thick, layered zinc anode-manganese cathode batteries can function in limited power or short service life applications.

Proven at the lab scale, the Helioculture process promises production of 20,000 gal/year per acre of ethanol or hydrocarbons. Genetically engineered microorganisms fed concentrated carbon dioxide and water inside the photoreactor developed by Joule Biotechnologies, MA, excrete fuel continuously. The high-yield system could supply all U.S. transportation fuel from a 70,000 square mile area.

Watch how quickly this robot assembles solar modules. An Earth2Tech article implies these machines may become the worker bees of the solar industry in its pursuit of lower costs. Attainment of global solar capacity of 500 GW/year translates to 4 million jobs, but with adoption of automation human labor needs can drop to 1 million. Growth of solar industries bodes well for alternative energy advocates but increased automation may undermine green employment opportunities in this field.

Design an aircraft that can average at least 100 mph on a 200-mile flight and achieve over 200 passenger miles/gal for a chance to net $1.5 million. Administered for NASA by the Comparative Aircraft Flight Efficiency (CAFE) Foundation, the CAFE Green Flight Challenge invites hybrid, electric, solar, and biofuel-propelled craft designs for submission. Best performance by a bio-fueled aircraft will also garner a $150,000 prize at the July 2011 competition to be held in Santa Rosa, CA.

A Goad for Geothermal?

Given the pending economic and energy supply superiority of geothermal energy relative to fossil fuels touted in a recent report, shouldn't energy producers start drilling?