Stationary energy storage

 Corvus Energy, harnessing the power of large format lithium-ion battery systems for marine propulsion, will spotlight its proprietary technology at the International Tug & Salvage (ITS 2010) Conference May 17-21 at the Westin Bayshore Hotel in Vancouver, B.C. Corvus Energy executives will be on hand throughout the event at booth #121.

The conference marks the world debut of “BRAtt class” training tugs, the first of which will feature Corvus Energy’s battery and management system utilized as the house power bank. The first BRAtt, a direct diesel-powered version, will be available for demonstration to ITS registrants. This tug will be followed up by delivery of an all-electric BRAtt and a hybrid diesel-electric BRAtt — using Corvus Energy technologies — to the Western Maritime Institute in 2011.

“The BRAtt tugs will provide an important platform to introduce our powerful, maintenance-free lithium-ion battery technology as a viable alternative to conventional propulsion systems,” said Corvus Energy CEO Brent Perry. “Fuel savings and decreased maintenance in a hybrid can provide ROI in only a few years, with a huge benefit to the environment in the form of decreased emissions.”

The BRAtt training tugs are the joint brainchild of Ron Burchett and Vancouver-based Naval Architects Robert Allan Ltd. ( — a collaboration that recognized the global need for cost-effective Z-drive training vessels. The 7.8 metre long, 450 horsepower BRAtt features most of the same technology and operating systems as found in full-size Z-drive tugs. It is also designed to be an affordable alternative to full-sized tugs for harbour duties, including boom deployment, yarding and line-handling.

To date, the marine industry has been unable to take full advantage of hybrid or full electric propulsion technology due to the large size and weight of traditional lead-acid batteries. Corvus Energy’s lithium-ion batteries are smaller, lighter and more powerful — and the battery chemistry and proprietary battery management system allows these batteries to last up to 10 times longer than lead-acid batteries.

Lithium Power – Energy Systems for the Next Generation of Vessels. Power for a Green Future

A brief description of the benefits of lithium energy battery technology, will be followed by a brief history of its growth, and a comparison of modern battery systems.

There will then be brief descriptions of working scenarios and the benefits of hybrid and electric applications, including an outline of how to mitigate costs, improve ROI, and develop an understanding of the impact on the environment.

The paper will touch on all aspects of the benefits of using lithium technology today, and how it will be impacting the future of vessel design, construction and use in today’s vessels. It will demonstrate the financial and environmental gains that are possible today.

Battery Principles and Basics

The smallest working unit in a battery is the electrochemical cell, consisting of a cathode and an anode separated and connected by an electrolyte. The electrolyte conducts ions but is an insulator to electrons. In a charged state, the anode contains a high concentration of intercalated lithium while the cathode is depleted of lithium. During the discharge, a lithium ion leaves the anode and migrates through the electrolyte to the cathode while its associated electron is collected by the current collector to be used to power an electric device.

The electrodes in lithium-ion cells are always solid materials. One can distinguish between cell types according to their electrolytes, which may be liquid, gel, or solid-state components. The electrolytes in gel and solid-state cells represent a structural component and do not need additional separators for the effective separation of electrodes and avoidance of short circuits. Cells come in button, cylindrical, and prismatic forms.

For low-energy and low-power applications, a cell often represents a full battery. For high-energy and high-power applications (such as transportation or stationary storage) a number of cells are packaged in a module, and a number of modules are packaged in a battery.

Lithium ion based battery systems have dominated every market they have ever been introduced into, including cell phones, laptop computers, power tools, and most recently, automobiles. Utilizing newly developed technology, Corvus is now poised to enter the untapped market of large foot print lithium ion batteries. There is a strong demand in many industries to replace the existing lead acid based batteries with smaller and lighter batteries. In addition to being less costly than the existing battery systems, the new Corvus battery system has opened up the doors for new applications. These include hybrid/electric marine propulsion applications such as environmentally sensitive harbor tug boats, pure electric passenger ferries, high performance sailboats, improved personal yachts and submersibles. Corvus lithium ion batteries are also ideal for light weight solar array batteries and portable wind power storage batteries. There are also a number of military battery applications which would benefit from Corvus technology.

The team of engineers at Corvus has extensive experience in battery power design and powertrain development, as well as in the production of battery storage systems for all its applications. This unique combination of experience and capability provides the customer with a seasoned, value-added approach to the integration of high performance battery storage technology to their projects. The various industries can now tap into this resource in order to provide solutions to their world-wide market needs and secure a premier position in their respective fields.

The Technology

Battery storage solutions in most of today’s industries utilize lead-acid based technology. For large scale applications, the size and weight of the lead acid batteries make them too unwieldy and dangerous.

Corvus has taken a number of the most advanced lithium ion cells on the market today, combined them with its’ own proprietary battery management system and packaged it all in a small, standard enclosure. A number of these enclosures can then be connected together to make the large battery packs. Different applications may require different size battery packs. So, with a standardized small enclosure, all that will be required for each different application is to simply increase or decrease the number of small enclosures needed. For each new battery pack, this technique permits faster design times and simpler manufacturing.

Corvus provides its’ own proprietary electronics in every enclosure. In addition Corvus provides its’ own proprietary computer-based, supervisory system to monitor and control the state and health of each of the small enclosures.

Corvus Energy’s combined battery technologies provide superior power in a standard Group 8D format. The battery module can be integrated into existing applications or can be configured to meet power storage requirements from 6.2kWh into the tens of thousands of kWh.

Corvus Energy, founded in 2009, is currently focused on harnessing the power of advanced lithium-ion battery systems for marine propulsion, with an increasing interest from stationary energy storage markets.