WHAT IS STORED HYDROGEN ENERGY? •••••

HOW IT WORKS :: click image to enlarge

LONG LIFE CYCLE

Storage System
Performance testing region

Solid Hydrogen Storage v. Lithium Batteries

Lithium

Hydrogen

For Automotive Applications:

Product safety, cycle life, energy density, capacity and environmental/hazardous waste issues all currently hinder the full escalation of lithium-ion batteries for automotive use.  Solid hydrogen technology has addressed these issues and has been proven to work safely, has a robust and lengthy cycle life inherent in its design and does not have any environmental/hazardous waste disposal issues.

Steven Ashley in the July 2009 publication of aei writes:

“Current electrochemical energy-storage systems often leave much to be desired in terms of energy density and capacity.   The limitations of large-format, high power batteries for vehicles are even more severe.”

In the auotmotive applications to date, most vehicles carrying lithium-ion alternative energy sources are the high end vehicles such as the Mercedes-Benz S-Class mild hybrid, the BMW 7 Series hybrid, unavailable plug-in hybrid prototypes from Toyota and Ford and a delivery vehicle from Azure Dynamics.  

The Toyota Prius, Honda, and Ford Escape and Fusion electric gas hybrids are good vehicles but they are powered by nickel-metal hydride units, (NiMH) and are still a bit pricey for the common driver.  However, through an increase in manufacturing volumes, they will continue to drop in price.  A joint venture between Toyota and Pansonic EV Energy Company and Marsushita Electric Industrial Company holds 80% of the world’s market share in NiMH batteries.   By 2010, the auto industry estimates there will one million OEM applications of NiMH vehicles produced.   The high end vehicles are out of reach for the common driver and they need relief now.   Hydrogen is abundant and available.

Fundamental breakthroughs in electrochemicals must first occur for advanced lithium-ion technology capabale for full-sized use, affordability and long-range use.   Hydrogen Energy Systems, LLC has the technology, now, that can give full-size use and long-range use in both the conversion markets and, eventually, OEMs.  

Our system has run successfully on Toyota Prius for three generations. The chart below indicates the low emissions from our system using State of California Emissions Standards:

SULEV - Super Ultra Low Emission Vehicle
PZEV - Partial Zero Emission Vehicle

We are currently converting a 6,000 lb. off-road vehicle to run on our proven automotive system. The vehicle is outfitted with a Chevy big block engine with Corvette LS1 technology and fuel injection to prove how hydrogen is the ultimate fuel.   Horsepower does not have to be replaced and the ICE, converted to hydrogen, has the same performance but less emissions as fossil fuel. See table above.

In Mr. Ashley’s article, safety is discussed throughout.  Quoting Richard Doisneau, Chief Technology Officer, Saft Battery Group in Bagnolet, France, “We must be humble and admit that large-format vehicular battery technology is not yet fully mature.   Many desirable characteristics for a battery are to some extent contradictory.”   Greater energy density means greater safety countermeasures required, for example.

For Stationary Applications:

At present, there does not exist any Lithium ion-sized batteries capable of powering a demand of one (1) megawatt of storage or greater.   Utilities are looking for a mega watt of power or greater for grid applications.

Our system can be scaled from a few kilowatts to many megawatts.   Hydrogen Energy Systems, LLC is currently scaling up our storage vessel to 70kg of storage which is capable of powering a 1 MW genset or fuel cell for one hour.   This storage can be banked for as many hours of operation as the application demands

Our low temperature metal hydride technology is the same as any other hydrogen storage mechanism for metal hydrides in that the hydrogen atoms occupy interstitial sites in the charged state. That is where the similarity ends. These hydrogen atoms are fully reversible. In the discharged state, the hydrogen atoms can easily desorb from the metal hydride alloy host matrix at the ambient condition. The main difference is that our metal hydride material has a higher number of available sites for hydrogen in the lattice than other counterparts:

• For the AB5 based materials, (Currently used in the nickel metal hydride battery negative electrode), the Metal to Hydrogen ratio = 1:1 and the maximum weight percentage is 1.5%
• For the AB2 based materials, (used for our system), the Metal to Hydrogen ratio = 1:2, (theoretical limit), that is equivalent to 3.8 % by weight. In practical devices, the ratio is close to 1:1.1 – 1.2 which is equivalent to 1.8-2.0 % by weight depending on hydrogen charging conditions. This is why our storage materials still have rooms to improve the material storage density. Intrinsically, MH has very good volumetric density that means high hydrogen storage capacity by volume.

There are important issues such as absorption and desorption kinetics and material thermal dynamic constraints (the temperature that can release hydrogen from the storage matrix) that have not been critically addressed in Department of Energy funded programs to date, including those complex hydrides, chemical hydrides, etc. None of the reversible hydrides can have the same absorption/desorption kinetics as the AB2 based MH used in our technology. A company called Millenium Cell (no longer in business) had sodium boron hydride material that is non-reversible, it had good desorption kinetics but needs to recycle and reprocess before it can be reused. Our technology does not require recycling and reprocessing.

The so-called carbon based sorbent materials are all physisorbed hydrogen systems (may contain weak chemically bonding characteristics) whereby hydrogen adsorption takes place at very low temperature that is not stable at the ambient temperature and has very poor volumetric density (requiring a large volume to store a small amount of hydrogen at very low temperatures). There is no practical hydrogen storage application known.

The bottomline is, our technology has been successfully demonstrated in various applications: portable canister devices, onboard vessels and stationary tubular vessels all of which are working devices.

Please go to www.hydrogen.energy.gov/annual_progress.html to see all of the “RESEARCH” being done on hydrogen storage by some of the world’s colleges, universities and corporations.

It is important to point out that this is a progress report which implies there are no commercial-ready applications such as Hydrogen Energy Systems represents. Our technology applications are for Utility and Automotive. If you do a random sampling of any of the projects listed, you will see the emphasis is on transportation. Our technology is proven. HES has commercial ready storage and vehicle technology. You can drive it or see small scale applications that work. Our mission is to scale it up to utility grade applications of 1MW or greater.

Critical to any storage technology that is chemically based or carbon based, (which many of these reports indicate), it is not green, carbon-free which inherently carries the additional environment management responsibilities and proper disposal costs for the end of life-cycle of the product. These are not issues for the HES technology.