http://www.techbriefs.com/component/...machinery/7062

http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf

https://www.google.com/url?sa=t&rct=...73rrKo2WfKxvxg

I have built mirrors like these to test here on Earth as part of an ongoing programme of development.

There are two approaches. One is to vary the thickness of the film and inflate it so that it forms a "Henckey Curve" which approximates a paraboloid. The other is to impress facets into a film so that when the film takes a spherical form, the facets correct the spherical aberration.


A film of aluminum 0.0038" thick (0.09652 mm) and 50 mm wide formed into a ribbon that traces out a spherical helix

http://mathworld.wolfram.com/SphericalHelix.html

forming a highly reflective hemispherical surface that focuses light precisely to a focal point along the axis of rotation of the hemisphere. The polished aluminium roll, is sandwiched between two sheets of PET plastic film only 2 um thick (0.00007874 inches) to maintain brightness, and impart scratch resistance

http://www.dymax.com/index.php/adhes...-hard-coatings

this forms a very stable system. The aluminum is available commercially in great abundance for the manufacture of canned beverages.

Another hemisphere formed of aluminum struts fabricated from a similar foil, is sandwiched between two layers, resulting in a largely transparent, but very strong surface. This surface is formed the same way, as a strip of material formed into a spherical helix, and the surface itself is joined to the reflective hemisphere to form a closed system with a flexible join at the equator of the sphere. The sphere is evacuated after test at the factory, and shipped cupped with others to the point of installation. Once inflated a sphere is formed that is quite stable and sits in an altitude azumith drive that tracks the sun.

A radius of 2.6 meters (8ft 6in) has a 21.237 sq m collector area and the resulting 5.2 meter (17 ft) diameter sphere, once inflated. Total material consists of 10.8 kg (24 lbs) of aluminum and plastic. It intercepts and reflects 21,200 Watts of solar energy. This is far heavier than a flightweight system for space use, but very tough and well suited for terrestrial applications. Packed 4 per inch along the length of a 53 foot carrier 2,500 units may be carried totalling 60 tons in a single shipment. Production methods that produce 1200 units per hour have been developed. This is approximately 12 truckloads per day.

Sunlight focused 20,000 to 1 on a 36.77 mm diameter target, efficiently produces hydrogen from rainwater collected from the sphere's exterior and pumped to the solar powered MEMS device.

http://www.microfabrica.com/capabili...-materials.php

A single sphere produces 1.485 kg of hydrogen 11.880 kg of oxygen from 7 litres of rainwater and 7 litres of process water per day. That hydrogen forms 2.970 kg of methane per day whilst absorbing 8.1675 kg of CO2 from the atmosphere per day. The methane is reduced to 2.775 kg of propane per day resulting in 0.2475 kg of process hydrogen.

http://www.cnet.com/news/miracle-tec...ter-into-fuel/

Propane, not counting its value as a carbon neutral fuel, is worth $0.57 per US gallon. ($0.30543/kg) so each sphere produces $0.847578 per day. $309.58 per year. $2,929.72 present value when discounted at 8.5% over 20 years. When used as a clean petrol replacement, and sold for $2.12 per kg (equivalent pricing in NZ for petrol (USD$8/gallon) - this is 7x greater value

The cost of the sphere is $7.70 in raw material, another $2.30 in assembly and transport costs. A total of $10.00!! The wafer type solar device that converts sunlight and water efficiently to hydrogen, costs $24.60 - and another $0.40 to install, creates a device that costs $35.00 complete!

At one bar the sphere holds 6.573kg of hydrogen gas. At sixteen bar it holds 105.17 kg of hydrogen. This is a 36 day (month's) supply of hydrogen.

Supplying a fuel cell system,

http://www.iphe.net/docs/Meetings/Ge...%20-%20PDF.pdf

each sphere supports a 4 kW averaged load. 2500 units 10 MW. At $0.18 per kWh This produces $6,311.52 per year over 20x the value of the propane!

A pipeline that carries a mixture of propane and hydrogen gas from the area of production to home based combined heat and power systems, that also bottle propane as needed when arriving by pipeline, for vehicle use and cooking produces significant returns.

With 100 solar balloons per hectare of land, each hectare produces 297 kg per day of of hydrogen fuel which supports a combined production of easily transmitted sunfuels that are then used in homes, offices, factories and retailers, to produce heat, power and fuels locally, without adverse effect on the environment.