Creative problem solving is evident in recent developments in alternative energy. A hybrid energy storage system, a high-yield solar tracking system, a renewable electric charging station and a waste heat recycling system each were designed by extending the best aspects of existing technologies into new and beneficial solutions.
Hybrid energy storage
Designed to be cost-effective and environmentally friendly, hybrid energy storage systems are a means to address power quality and short-duration disturbances. Ninety-eight percent of power disturbances last less than 10 sec, according to the Electric Power Research Institute (www.epri.com). The patent-pending Hybrid VDC XEB storage system from Vycon uses a flywheel as its primary power backup source to absorb power glitches and an integrated VRLA battery for longer power outages.
Cost savings are inherent in the design. “With the hybrid system, the characteristics of the flywheel enable the battery to be smaller than if it were a stand-alone design, allowing lower capital and maintenance costs while supporting backup times of two to three minutes,” says Dann McKeraghan, Vycon’s (www.vyconenergy.com) vice president of sales and marketing. Additionally, because the VDC XEB flywheel covers for more than 98% of battery discharges, it reduces the frequency of battery cycles and extends the battery’s life.
Reliability and suitability for industrial environments are further benefits. “Monitoring of the flywheel and battery is a standard feature,” adds McKeraghan. “Performance, operation variables and alarm conditions are tracked and can be viewed remotely, as well. Flywheel DC energy storage has long been suited for harsh environments with its wide operating temperature range capability.”
Directional solar tracking[pullquote]
Solar tracking systems automatically align the solar mirrors or modules with the angle of the sun’s rays to maximize the amount of energy captured. Siemens’ (www.industry.siemens.com) Solar Tracking Control System joins the Simatic S7-1200 control unit with software to manage the dual-axis solar unit tracking, delivering as much as one-third higher energy yield than stationary photovoltaic systems. To calculate the sun's position, Siemens’ tracking control software applies the solar positioning algorithm that was developed at the U.S. Department of Energy’s National Renewable Energy Laboratory (www.nrel.gov).
High-performance drives and solar inverters enhance solar tracking and make the most of solar energy with power grid connectivity. “Products such as Sinvert inverters that span the residential, commercial and utility markets along with Siemens Simatic S7-1200 and Siemens Sinamics drives provide flexibility to handle functions that ensure continual operation of systems, while maximizing the in-feed of energy into the grid,” says Rick Myers, senior director of Solar VMM for Siemens Industry.
Renewable-powered charging station
A new charging station energized by wind and solar power is reportedly capable of fully charging an electric vehicle in four to eight hours. The Sanya Skypump combines the Sanya hybrid wind/solar streetlamp from Urban Green Energy (www.urbangreenenergy.com) with the GE WattStation Electric Vehicle Charging Station from GE Energy Industrial Solutions (www.geindustrial.com).
“The Sanya Skypump allows remote sites with significant carbon emissions to offset their energy consumption while providing a reliable, Earth-friendly method to charge their battery-operated equipment and electric vehicles,” says Mateo Chaskel, a senior engineer at Urban Green Energy.
The turbine is modern in appearance and requires little maintenance. “The dual-axis design of the vertical-axis wind turbine that is part of the Sanya Skypump virtually eliminates noise and vibration while decreasing wear on the bearings, making them last the life of the turbine,” says David Droz, business development associate at Urban Green Energy. Pilot installations in New York, Beijing and Barcelona precede a formal market launch in 2012.
Waste heat recycling
Progress is being made in efforts to leverage low-to-medium-grade waste heat from factories, power plants, diesel generators and cars for cooling or producing electricity. A thermal-activated cooling system prototype developed by researchers at Oregon State University (OSU, www.oregonstate.edu) successfully converted 80% of every kW of waste heat into one kW of cooling capability. The findings were published in the professional journal Applied Thermal Engineering.
“Currently, energy-intensive plants have enormous amounts of waste heat not being used, including food, chemical processing and refinery operations,” says Hailei Wang, a research associate in OSU’s School of Mechanical, Industrial and Manufacturing Engineering. “In some circumstances, a significant amount of extra energy is provided just to dissipate the waste heat.” He predicts that heat-activated cooling technology with power generation capability will have a broad impact on energy practices across diverse industries.
Email Contributing Editor Sheila Kennedy, managing director of Additive Communications, at [email protected].