Can Batteries Replace Power Generators?

May 18, 2011, 12:44 pm
Can Batteries Replace Power Generators?
By MATTHEW L. WALD

Battery-to-Grid, instead of Vehicle-to-Grid (which is battery to grid as well, just on a greatly more distributed scale). Virtually identical in practice, and a great idea.

CHARGED AGAIN!
Sorry but this sounds absurd. There's no such thing as a free lunch.

For generators requiring fuel, both are devices for managing stored energy. Both hold the stored energy in reserve until it is needed.

The article is focused on how quickly they can provide a release of the stored energy when it is needed and how easily they can be turned off when you DON'T need them (questions important to grid management).

A couple of other characteristics would be how much energy is stored, how easily the stored energy is replenished, and how much energy is lost in the management process. There are others, but I think you get the idea.

time. If this worked then total power plant size could be reduced. Electricity produced at night stored and put into the grid during peak hours.

Problems will be a triple loss of efficiency with the conversion from AC to DC and back again to AC, and the the life of the batteries.

From the OP:
"Batteries, on the other hand, could be charged at night using relatively cheap capacity from Long Island’s most efficient generators, combined cycle gas plants. Those use about 7,000 B.T.U.’s of energy per kilowatt-hour, compared with 10,000 or 11,000 for the simple-cycle plants."

The difference in efficiency of the two styles of power plants is from 42% to 57% higher.

Batteries will cause a small loss of efficiency but nowhere near 42%. It's a win, win.

Now, people have claimed on this board that Lithium batteries are much better but I have NOT found any real evidence of that, but every other battery generally has a power in, power out ratio of about 25% i.e. for every FOUR watts you use to charge the Battery, you get one watt out.

Hydrogen Fuel Cells generally provide one watt from every two watt used to charge the Fuel Cell
http://en.wikipedia.org/wiki/Fuel_cell

Fuel cells was all the rage around 2000, then Lithium batteries came into wide spread use and took the thunder from Fuel Cells. Fuel cells tend to be aimed at larger vehicles, around 2000 for use in electric cars, but then Toyota used regular Lead Acid Batteries for the Prius and that seems to have killed off Fuel Cells for automotive use.

Electric Fly Wheel is 90% efficient, for every 100 watts you put into a Fly Wheel, you get 90 watts out of it.
http://en.wikipedia.org/wiki/Flywheel_energy_storage

The problem with Fly wheels is they are expensive AND dangerous if power gets to low or are involved in an accident where the fly wheel escapes from the device and who knows what damage it will do (Used extensively on spacecraft do to its light weight and efficiently for cost and it being damages are minor concerns in that environment).

The actual most efficient use of electrical power for storage is used in Virgina. Excess electrical power is used to pump water up stream and stored behind a dam, when additional power is needed, the dam is opened and used to generate Electrical power. Hydroelectric dams are the fastest and most efficient method to get more power on the grid, thus tends to be kept in reserve till all other sources are in full use. Plans have been made to expand this type of "Electrical" Storage, for its costs are much lower then Fuel Cells or Fly wheels.

Sorry, unless you are looking at Lithium, Fuel Cells, Fly Wheels, or water storage, the energy savings is NOT there and this article does NOT mention the type of "Battery" and the 90% efficiency mentioned int he article would imply a Fly Wheel NOT a true Battery. Sounds like wishful thinking more then a real plan.

The Lupo 3l, in production from 1999-2005, and did 100 KM to a Liter of Gasoline (78mpg in US terms). The Lupo did this by:

1.2 litre 3-cylinder diesel engine with turbocharger and direct injection (61 hp, 140 Nm)
Use of light-weight aluminum and magnesium alloys for doors, bonnet (hood), rear-hatch, seat frames, engine block, wheels, suspension system etc. to achieve a weight of only 830 kg (1,830 lb)
Tiptronic gearbox
Engine start/stop automatic to avoid long idling periods
Low rolling resistance tires
Battery location moved to rear for better weight distribution

Notice one of the key features is that the engine turned on and off as needed, going down hill, waiting at a red light, the engine would stop. If you touched the gas pedal the engine would re-start. Did even better fuel economy then the Prius, but never sold in the US. Expensive for such a little car (aluminum and magnesium alloys cost more then steel) so production was stopped in 2005.

http://en.wikipedia.org/wiki/Volkswagen_Lupo

You usually do much better research than this.