The Energy Matrix
A Science Ebook e-zine
Spring 200
8 Edition  
List of all editions

Battery versus  Ice

The energy matrix examines the full spectrum of future energy sources and associated problems.  It is meant to be a thought provoking publication for students who will be our future technocrats, engineers, and physicists.  We will include concepts such as solar, DG, CHP and concepts that are not practical today such as ice engines.  Send Comments to



Battery Powered Cars

The hybrid car to the right is not a true electric battery driven car. All the Energy required for operation comes from gasoline. As viewed from the front, a six cylinder engine at left is inline with the electric traction motor at right.  When rapid acceleration is required, the traction motor works in tandem with the gasoline engine to give the car a quick response to sudden power requirements. The electric traction motor gets its power from the litium ion battery. The electric traction motor makes it possible for the gasoline engine to increase its power output in a gradual manner without sucking up a lot of gasoline.  The battery delivers up to 200 kilowatts.  Once the vehicle reaches a steady speed on a level road, the gasoline engine main-

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 Water Versus Battery
as an energy storage medium 

When researching electric cars, I was surprised that the energy density of ice (latent heat per kilogram) was greater than the energy stored in today's batteries. Though the weight of battery is not

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Index for all Editions


Combined Heat & Power (CHP) 

DC Power Grid

District Cooling

Ethanol Viability

Hybrid Cars

Ice made with Coal

Ice Energy Density versus Battery

Heat Storage


Nuclear Energy

Solar Heat Storage in CO2

Solar Heat Storage in Water

Storing Carbon Dioxide

Stoves - Corn Burning

Stoves - Wood Pellet Burning

Stoves - Coal Burning

Tar Sand Oil


Yucca Mountain

Substituting Coal for Diesel

Compact Fluorescent Lights


















Energy Storage
Battery versus Ice

critical, the cost is.  Batteries are expensive and have limited live spans.  A typical car battery stores about one kilo-watt hour of energy and costs about $100.00. Its life span is at best seven years.  Deep cycle industrial batteries last much longer but cost more.  The table below show clearly how low the energy density of batteries are compared to gasoline. There are 2.69  kilograms of gasoline in a gallon.


Energy Per Kilogram in Mega-Joules
From Reference A

Gasoline or Diesel                             46
Grude Oil                                            42  
Graphite                                             32.7
Zinc air battery  (future)                     .4 to .7
Ice (latent heat)                                    .3
Lithium Ion (In Use)                            .26
Lead Acid                                            .1
Water (Top of 100 meter dam)              .001


Cooling power of Ice

The above table shows that the energy stored in water's latent heat (water to ice) is greater than the energy density of a lithium ion  battery.  Yet the cost of the 110 pound lithium battery is about $4000, and water is cheap.  The cost of typical home heat pump is about $4000.  The latent heat of ice is 144 Btu per pound. If you add 40 Btu to the 32 degree Fahrenheit water you get 72 degree or room temperature water. That is by adding 184 BTU to a pound of ice you get 72 degree water.  If you add 184 Btu to a pound of 72 degree water you get  256 degree of water at about 16 psi.  Storing a large quantity of water above the boiling point is dangerous.  I am just comparing the energy storage capability of water with that of batteries, not designing a system.  However some European utilities are experimenting with storing solar energy in extremely high pressure tanks.  Steam would later be bleed of tanks to drive a turbine to produce electricity. 


You can't make lightbulb glow with hot or cold water.

I agree that you cannot run a fan or light bulb with ice.  [Even though an ice engine would be a great idea on a planet with a temperature of 300 degrees Fahrenheit, and the first vacuum type steam engines used  low pressure steam, that is not relevant to this article.]   However, a major summertime demand for energy is air conditioning and hot water. The home's major power requirement in Winter is heat and hot water.  If system is not attached to the electric grid, than you will still need batteries to store solar energy for night time use.  If you are connected to the power grid, buying your nighttime electricity from the utility might be the best way to go.


My point is that it is cheaper to store excess solar or cheap night rate electricity in water than it is in batteries.

Of course you will will need a heat pump to produce chilled water or ice from excess solar electricity. Heat pumps can chill water in a tank until water is near freezing and than an ice cube maker can add ice cubes to the chilled water.  Ice water could than be routed to a water to air heat exchanger for cooling rooms, and than the warmed water could be returned to ice water tank.

Frequently electricity is cheaper at night than it is during day.  Thus, making ice water at night and using it for cooling during day is a way to cut down electricity usage during peak demand hours. This would also reduce risks of brownouts during day. 
























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