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 BilPat4342@AOL.com
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-
Water Versus Battery
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
Energy Per Kilogram in Mega-Joules
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.
Send Comments to BilPat4342@AOL.com