Imagine disributed generation system that provides back up power, demand reduction, alternative power, and utility infracface. A small unit is available that does just that. The core technology of the modular stationary power system (MSPS), marketed as the PowerTower, is a combination of advanced power electronics, electricity storage devices, and communication modules that make various applications for energy storage applicable and affordable.

The Power Tower for Renewables battery modules, shown here, use maintenance-free, sealed batteries for extended operating life. Courtesy of Gaia Power TechnologiesClick here to enlarge image

Until recently, the only backup solutions on the market were generators and uninterruptible power supply (UPS) systems, neither of which adequately addresses all backup needs. Specifically, generators are not always feasible and can harm electronic equipment and UPS systems are designed primarily for short duration information technology (IT) applications. Gaia Power Technologies has developed an MSPS system for backup that combines the power quality of a UPS system with the scope of a generator. As a result, the PowerTower provides enough energy to power critical circuits through more than 95 percent of all power outages and, unlike large noisy generators, can be easily installed by an electrician in a convenient indoor location.

The PowerTower offers a single, turnkey inverter/battery package in a grid-tied configuration eligible for federal and state incentives. The unit accepts power from a wide range of renewable and traditional power sources, and outputs clean, conditioned, and uninterrupted AC power - regardless of source quality or weather. The device also eliminates the need for costly and time-consuming self-assembly by including all balance-of-system components in a single unit listed ETL/UL 1741. And, the customer may add a single hardware interface for all power sources, renewable or not, to make sure all power is drawn from the source that can deliver it best.

The system has power electronics rated up to 1l kW of continuous power output with more than 25 kW of surge power to start motors, pumps and furnaces. The power modules can be configured for either l20 V or 120/240 V and can be connected with multiple battery modules to provide energy for as long as needed. The battery modules utilize advanced maintenance free, sealed batteries for extended operating life.

What makes the PowerTower different is that it bridges a gap that has existed in the power supply landscape for years. Most businesses or residences think of only either generators or UPS (uninterruptible power supplies) when they think of backup power. However, for many, these systems are too costly, impractical, insufficient, or undesirable. The PowerTower can be installed easily indoors, move with you should you go, requires no lengthy permitting process, generates no emissions, and provides up to several days of power. It can also integrate power from multiple sources for efficient hybrid solutions, including having the ability to maximise the efficiency of solar panels.

The PowerTower is available as either a stand-alone unit or in a hybrid configuration with a generator. The standard unit provides enough power to get through most power outages and with optional additional batteries, can handle outages of several days or more. A hybrid PowerTower/generator unit provides backup power indefinitely and reduces genset runtime and fuel consumption by up to 75 percent.

The PowerTower arrives ready to accept the grid, as well as any future alternative power sources, such as solar cells. Additionally, all units accept power input from generators of any size, making it easy to charge the batteries for outages of several days or more.

Reducing Demand Charges

Electric utilities charge most businesses not only for how much energy (kWh) is consumed, but also how fast kilowatts are consumed. That’s because power consumption for many businesses varies significantly during the course of a day. In order to assure adequate generating capacity and avoid blackouts, utilities must have the capacity to serve the highest level of power that might be demanded. Maintaining that capacity is expensive, and the cost is passed on to businesses in the form of the demand charge.

This kilowatt charge is known as a peak power or “demand” charge and can be based on as little as 15 minutes of use per month, but can represent up to half the cost of the total bill.

Until now the only way for a business to decrease its demand charges has been to alter its day-to-day energy use or the manner in which equipment uses electricity. Gaia has also developed a PowerTower solution that requires no behavior modification on the part of the business. A PowerTower for demand reduction lets a business help meet its own peak demand with an onsite battery unit. It is viewed as an energy storage-based system that reduces kilowatt demand and lowers the cost of electric bills, while adding to the stability and reliability of the electric grid when reserve margins are tight.

Maximizing Solar Installations

There is also a turnkey PowerTower package consisting of an inverter/battery package in a grid-tied configuration eligible for federal and state incentives. The unit accepts power from a wide range of renewable and traditional power sources, and produces uninterrupted AC power. Gaia’s PowerTower eliminates self-assembly by including all balance-of-system components in a single unit ETL listed to UL 1741. The system can also be integrated with existing solar installations. The proprietary modified charge controller allows the PowerTower to operate in tandem with an existing inverter, removing the major barrier to upgrading existing installations to include energy storage.

Licensing Underway for Air-Hybrid Generator Engine

A Massachusetts company has begun licensing the rights to a first ever hybrid power generator technology that could be used for residential power backup and in industrial power plant settings. Recent studies show that the unique air hybrid internal combustion engine technology can provide significantly increased efficiency levels while dramatically decreasing the level of toxic emissions.

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Computer modeling at Southwest Research Institute in San Antonio, Texas previously conducted on mobile applications, revealed that in relatively constant load and speed applications - such as with a genset - the Scuderi Split-Cycle Engine Technology could dramatically increase efficiency and decrease emissions. Despite the theoretical potential, the lab also cited “significant technological challenges.” Southwest is now building two prototypes that will be a major test of the engine’s viability. And a Scuderi Air-Hybrid Generator would have the additional capability of recapturing energy normally lost through waste heat, increasing efficiency by up to 25 percent to 50 percent and decreasing toxic emissions by up to 80 percent.

The Scuderi Group, which is developing and marketing the technology, includes experts in fluid and thermodynamics, engine technology, patent and commercial law, licensing, government relations, business management and finance. The air hybrid technology is based on the research and inventions of Carmelo Scuderi (1925-2002), who spent more than 40 years inventing, developing and commercializing new technology. He may be best known in the engineering profession for his oil-less compressor technology that changed the method used by the refrigeration and air-conditioning market to recycle ozone-depleting refrigerant chemicals.

Although he retired in 1994, Scuderi continued to believe that the internal combustion engines in vehicles and gensets were too inefficient. His original drawings outlined the Scuderi split-cycle engine. Although split-cycle engines have been around for a century, the Scuderi family believes the elder Scuderi’s design represents a low-cost way to increase efficiency and lower emissions.

Several auto manufacturers have licensed the Scuderi technology to incorporate into their vehicles as an alternative approach to regenerative braking currently available on a growing range of hybrid vehicles, whereby kinetic energy generated in braking is transferred to batteries that help power the vehicle and boost acceleration.

The alternative hybrid concept is predicated on an engine that heats air and also compresses it for later use. Half of the four-stroke engine is a compressor and the other half is a two-stroke engine. Half the cylinders take in the fuel and compress air, while the other half handle the power and exhaust strokes. The same number of power strokes are produced from each revolution, but the cylinder designs can be optimized for their different tasks, providing several thermal efficiencies, emission improvements and reduced friction.

In transportation applications, the technology is called the Turbosteamer and employs high and low temperature steam circuits to extract enough heat at midload conditions to generate 580 psi steam pressure, lowering the exhaust temperature by 1,025 degrees F. That allows the reuse of about 80 percent of the waste heat. The pressure generated drives a small steam engine connected to the crankshaft. This steam circuit produces 14 horsepower and 15 pound-feet of torque under peak operation on a 1.8-liter four-cylinder engine. Overall, the system improves fuel efficiency by 15 percent and unlike in gas electric hybrids employing regenerative braking, that figure improves at higher steady-state speeds. And the power it provides is 100 percent recycled. It is never parasitic. The Scuderi Engine, along with its Air-Hybrid feature, is expected to almost double vehicle mileage and reduces toxic emissions by as much as 80 percent.

The technology can be applied to any internal combustion engine including gasoline, diesel, bio-diesel and natural gas.

“Applying our unique air-hybrid engine design to a power generator application provides manufacturers and power plant facilities with a brand new alternative to generating power using far less fuel while cutting emissions to historical levels,” said Sal Scuderi, president of the Scuderi Group, who along with brother Steve, is also an engineer. He says the duty cycle of an electric generator is less stringent than for cars and trucks. Electric generators run at narrower speed and load ranges, therefore the inherent advantages of the Scuderi Air-Hybrid Engine - faster flame speed, lower NOX, and higher efficiency - could be more advantageously tuned to meet these narrower conditions.

“Generally, power density and efficiency are a trade off in any mobile engine application,” says Scuderi. “But this is not the case in a stationary power generator, which means that the Scuderi Air-Hybrid Engine can be designed for maximum efficiency.”

The first air-hybrid engine prototypes are expected to be completed in 2007.

Project Spec Sheet

Ritz-Carlton Hotel, San Francisco

Project Managers: UTC Power, Carrier Corp.

Project Funding: U.S. Department of Energy, PG&E Corp.

Electrical Engineer: Randall Lamb

Mechanical Engineer: Carrier Corp.

PROJECT PLAN: INSTALL FOUR 60 KW MICROTURBINES AND A DOUBLE-EFFECT ABSORPTION CHILLER, PLUS PROVIDE DISTRIBUTION GRID INTERCONNECTION.

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• Baseload electric and year-round chilling. Cooling output of 120 Refrigeration Tons (RT) and electrical output of 240 kW on ISO basis.
• Keep two existing electric chillers and use an existing cooling tower with recirculation loop
• Exhaust from four 60 kW microturbines is collected in a manifold and used to drive a double-effect absorption chiller.
• Arrangement achieves an overall fuel utilization rate of more than 80 percent at ISO conditions.
• Project team and PG&E worked to devise an interconnection protection scheme. Microturbine load following control was incorporated to prevent incidental export to the grid. Additional microturbine (under power) relaying was incorporated and coordinated with changes to PG&E network protectors.
• Project costs: Turbine, $224,640; CHP unit/chiller, $141,000; Mechanical, $158,000; Electrical, $344,000; Total cost, $1.012 million.
• System commissioned December 2005