Representatives push for DOD investment in renewable energy

ladajo · Post by **ladajo** » Wed Sep 07, 2011 8:27 pm

Micro wind turbines are already in use and have been by military units. What they have bought is unit and mission dependant.

Joseph Chikva · Post by **Joseph Chikva** » Fri Sep 09, 2011 5:12 am

ladajo wrote:Micro wind turbines are already in use and have been by military units. What they have bought is unit and mission dependant.

Thanks, I did not know.
I have found for example this: http://windpoweruk.com/300W-portable.html

The 300w portable wind turbine can supply about 50kWh of energy per month
Net Weight 12.5kg

Is this (50kWh of energy per month) enough for application we are discussing? If turbine produces 300W only if wind speed exceeds 12m/s?
And at lower speed power is much lower.
For example at 6m/s generator produces only about 90W (see graf)

ladajo · Post by **ladajo** » Fri Sep 09, 2011 4:13 pm

There are some newer blade designs that are much smaller composite units, that work realy well at a low diazmter low speed. Sufficient for battery charging for sure.

Think about how well these work in the mountains of afghanistan and other places where you have terrain/environmental enhancment of ground winds. One other trick I have seen is a micro turbine attached to a kite (and a balloon on one occasion) and flown above the ground layer. Even better wind.

These things are very useful at times.

Joseph Chikva · Post by **Joseph Chikva** » Fri Sep 09, 2011 5:12 pm

Ok, thanks.
I did not know.

KitemanSA · Post by **KitemanSA** » Fri Sep 09, 2011 5:26 pm

ladajo wrote: One other trick I have seen is a micro turbine attached to a kite (and a balloon on one occasion) and flown above the ground layer. Even better wind.

You have tangentially identified the one real potential for RELIABLE wind energy IMHO, tethered mills; mills that are flown into the jet stream and provide power down thru the tether.

That saphire SC makes this even MORE intreging.

If the mill is big enough, microwave transmission may also be feasible.

FYI
http://www.skywindpower.com/ww/index.htm

ladajo · Post by **ladajo** » Fri Sep 09, 2011 5:32 pm

My own idea is to use an oscillating kite tied to a flywheel rig driving a generator. A wind powered piston if you will.

Giorgio · Post by **Giorgio** » Sat Sep 10, 2011 8:35 am

@ladajo
http://kitegen.com/

ladajo · Post by **ladajo** » Sat Sep 10, 2011 10:13 pm

Ringraziamenti per la pioggia sulla mia parata.

Actually, I was thinking more on a vertical oscialltion, with out the winding part. But I like what they came up with.

Giorgio · Post by **Giorgio** » Sun Sep 11, 2011 11:11 am

It's quite an easy and elegant solution.
They have more than 2 years delay in development due to bureaucratic issues.
Their next tests should be in the 2000-2500 mt height (6000 to 8000 Ft), but getting approval to operate at that altitude in Italy is like getting approval for a new nuclear reactor model in USA. I start to doubt that they will ever get it.

ladajo · Post by **ladajo** » Mon Sep 12, 2011 2:15 am

They should move to South America.

KitemanSA · Post by **KitemanSA** » Mon Sep 12, 2011 12:58 pm

In the roaring 50s (50-60 degree south latitude), the jet steam almost reaches the ocean. MASSIVE wind energy potential there.

Get a used oil tanker, install some LH tanks, and go sailing with kite generators. Use the electricity to mine the H from water.

Meet up with transfer tankers when you get near full.

Joseph Chikva · Post by **Joseph Chikva** » Mon Sep 12, 2011 1:24 pm

KitemanSA wrote:Get a used oil tanker, install some LH tanks, and go sailing with kite generators. Use the electricity to mine the H from water.

Useless idea.
I would believe in utilization of wind energy for radio's, forward observer equipment's, etc. I doubt in usefulness. But not sure and may be I am wrong.

But electrolyze of water for hydrogen production, aluminum production or chlorine require very big amount of electric energy. Renewable assets being in reasonable size could not produce so much energy.
If you are still interested in the evening (Tbilisi time) I can provide you data how many kW*h is needed for production of 1 ton of above mentioned products.
Not renewables but hydro or fission energy is used for aluminum and chlorine production.
And hydrogen now is produced not via electrolyze but via steam reforming mainly of natural gas.

KitemanSA · Post by **KitemanSA** » Mon Sep 12, 2011 3:31 pm

Averaging 1kW/m² is not a bad return. And in the roaring 50s it would only take tethers about 1-2 km long, unlike in the northern hemisphere where you need 6-10km tethers to reach winds speeds that give such good results. Such long tethers are plenty difficult to manage in a variable wind.

Joseph Chikva · Post by **Joseph Chikva** » Mon Sep 12, 2011 4:02 pm

KitemanSA wrote:Averaging 1kW/m² is not a bad return. And in the roaring 50s it would only take tethers about 1-2 km long, unlike in the northern hemisphere where you need 6-10km tethers to reach winds speeds that give such good results. Such long tethers are plenty difficult to manage in a variable wind.

As promised I will provide you data how much kw*h is needed for producing of unit of mass hydrogen.
By memory I remember e.g. 1 metric ton aluminum requires about 13000 kW*h.
I am afraid that payback period of your proposal to produce hydrogen using wind energy will have hundreds years order.
The investment cost of 1kW installed power vs. annual production of kW*h, etc.
For note hydrogen now is produced in big amounts for ammonia. But nobody produces even using much cheaper electricity from NPP or HPP. Renewable energy is costly. Yes, you do not spend any fuel but you have very high cost of installed power and not stable energy source.
The situation with hydrogen production can be changed in near future when the price on natural gas will exceed some limit.
But source of electricity will be only nuclear or hydropower. Due to in times lower production cost. And, certainly, fusion is more preferable than fission.

ladajo · Post by **ladajo** » Thu Sep 15, 2011 3:43 pm

Joeseph,
Check this site out...I think it can help you understand further about field deployable renewable systems.

http://www.tacticalsheltersystems.com/