Solar Panels Used by Marines in Afghanistan Cut Fossil Fuel Consumption 90%

[Fledermaus]

The purpose of the panels is to power up Marine operations while reducing the quantity of fuel supply that rebels may target. There were doubts about the efficiency of the system, since it hadn’t been used in a war before.

According to Sgt. David Doty, one of the company’s squad leaders, the energy produced by the solar panels has lowered the fuel consumption of his generators from 20 gallons to only 2.5 gallons a day. Enemies blow up and fire at convoys, thus the more gas is saved by the Marines with solar power, the less they’ll have to transport.

Patrol Base Sparks can use the generators instead of using the panels, but this is not recommended during nighttime, because the enemies can spot the marines’ positions, being guided by the noise made by those generators.

The Marines also have a flexible solar panel to recharge their radio batteries. This sort of solar panel is called Solar Portable Alternative Communication Energy System (SPACES). Powershade, a photovoltaic waterproofed canvas is put on a standard tent in order to light it up. The ZeroBase regenerator, a large power source, collects enough sunlight for more than 15 computers and more than 20 lighting systems.

http://www.greenoptimistic.com/2011/01/19/afghanistan-marines-solar-panels/

[midnight]

1. Let's bring that technology home along with those troops...

[jwirr]

2. This may be something good that comes out of a bad situation. nt

[LawnKorn]

3. Navy ships are going to need big solar arrays

From the article it says:

The Army set up a 500-megawatt solar plant in California not long ago, while the Navy has planned to halve its petroleum use by 2015

A quick internet search gives a rule of thumb of 100,000 square feet of PV solar per MW of electricity.

Since the Ticonderoga class cruisers get their electricity from gas turbine generators (petroleum fuel), and the AN/SPY-1 radar is rated at 4 MW radiated power, that is going to be a big solar array just to run the air search radar.

[Arctic Dave]

4. They will probably speed up the cruiser class ships decommissioning.

That and install renewable energy systems at all the ports.

[TheWraith]

6. More likely they'll go for things like biofuels.

I know the Navy has been switching a chunk of their consumption to biodiesel.

And chances are more future classes of ship will be nuclear driven, in addition to just subs and carriers.

[Kolesar]

7. 4 MW of "effective radiated power", I would expect

The radar is definitely a high gain antenna, probably 20 decibels, so that means that the radio amplifier is 2^6 times smaller, or one sixty fourth of the power. Probably one one hundredth, so 40 kilowatt.

Still is a lot of juice. Why can't people just love each other?

[oldhippie]

9. and that 4 MW is probably "PEAK" effective radiated power .....

... and the average power is considerably less. The PRF depends on the mode the radar is in.

Still gonna take one hell of a PV array.

[OnlinePoker]

8. It's only just started construction.

From this article, it won't be ready until 2022. It also says that the base (Fort Irwin) only uses 35 MW of electricity so will have 465 MW to shed (though they are looking at storage to make them energy independent when the sun's not shining), so this will put green energy in the grid. If my calculations are right, the $1.5 Billion cost comes out to $3 per watt, but the army doesn't have to worry about buying land to set up the array.

http://www.wired.com/dangerroom/2009/07/army-starts-solar-plant-next-step-care-about-cilmate-change/

[txlibdem]

5. ZeroBase regenerator

This is a pretty cool unit. It stores the energy collected by its solar panels in batteries and you can also hook it up to a wind turbine. Or you can charge the batteries with a fossil fuel powered generator for silent power throughout the night.

http://www.thezerobase.com/wp-content/uploads/2010/09/ZB-ReGenerator-Case-Study-United-States-Marine-Corps-9-1-10v.pdf

[NickB79]

10. Oh, the irony. Soldiers fighting for fossil fuel reserves use solar to cut fossil fuel consumption

Will wonders never cease.

[wtmusic]

11. He'll need about 6 of the arrays shown in the picture

to generate that kind of energy every day.

[Fledermaus]

12. Nope. Thats the system

LED lights and efficient radios

[wtmusic]

13. Not enough, by a longshot.

17.5 gallons x 34.12 kWh/gallon (energy density of gasoline) = 597 kWh of energy saved per day.

A rough average yield for PV solar is 1 kWh/day per square meter of panel - so he'd need 597 m² of panels. If he was close, we could make allowances for efficiency, but more likely he's just full of it.

[Fledermaus]

14. First there is no generator thats 100% efficient.

How efficient is an internal combustion engine? How efficient is a generator when it is running idle with no real load?

[wtmusic]

15. I can't find numbers for gasoline/electric generator efficiency

but this source claims diesel generators can produce 3-4 kWh/L.

http://www.newworldencyclopedia.org/entry/Electrical_generator

Diesel fuel has a specific energy of 12.83 kWh/L, so according to this source diesel generators are 27% efficient. Plugging in these numbers he would still need 161 m² of panels, or about about 20x what's shown in the picture. Making generous (and admittedly sketchy) allowances for 30% load efficiency gets us down in the neighbourhood of my original estimate of six of those arrays being required to come up with the energy he claims he is. And we're still not making any allowance for solar panel load inefficiency.

[Fledermaus]

16. 15% or less

27% on a cold day at one specific rpm. Any thing outside of that rpm is less. Any thing outside the best operating temperatures is less. High altidues...less.

A good guess would be 15% or less.

The rest of your post does not make any sense.

[wtmusic]

17. Phrases like "or less" are lifesavers, aren't they?

But fortunately utilities avoid them when choosing how to invest $billions.

I'll try to be clearer:

Specific energy in 17.5 gallons of gasoline = 597 kWh.

597 x .15 efficiency (your figure) = 89.55 kWh net electrical energy available for consumption.

He needs 89 m² of panel. Looks like he's got maybe 8 m² there, so he's shy by a factor of eleven.

You're going the wrong way.

[Fledermaus]

18. Your estimate of generator output was off by 560%

[wtmusic]

19. I stand corrected, and you're still wrong. nt