Disclosed is a lighter than air vehicle comprising a first envelope, a second envelope located inside the first envelope, and a tube connecting the first envelope to the second envelope. The first envelope and the second envelope are spaced apart so as to define a chamber between the first envelope and the second envelope. The chamber is filled with a lighter than air gas. A first opening of the tube is located at an external surface of the first envelope. A second opening of the tube is located at an internal surface of the second envelope, the second opening of the tube being at an opposite end of the tube to the first opening of the tube.

Disclosed is a lighter than air vehicle comprising: an envelope (34) containing a lighter than air gas (22), at least part of the envelope (34) admitting the passage of light (28) through the at least part of the envelope (34); and means for selectively redirecting the light (28) which passes through the at least part of the envelope (34). The vehicle may further comprises a plurality of devices (44, 50) for using incident light (28). The means for selectively redirecting the light (28) may be for selectively redirecting the light (28) onto a selected device (44, 50), for example, by switching the positions of two or more devices (44, 50) into the path of the light (28).

The invention relates to a device for the concentration of solar radiation in an absorber, comprising an inflatable concentrator cushion, which comprises a cover film element comprising a light-permeable entry window for coupling in solar radiation and a reflector film, which sub-divides the concentrator cushion into at least two hollow spaces, for the concentration of solar radiation in an absorber, comprising a pivoting apparatus, by means of which the concentrator cushion can be pivoted, in particular about its longitudinal axis, and comprising a retaining apparatus secured (mounted) to the pivoting apparatus for retaining the concentrator cushion, which retaining apparatus comprising an upper longitudinal member extending in the longitudinal direction of the concentrator cushion, suspending the absorber, wherein the upper longitudinal member is arranged on a substantially air-tight closed upper passage opening of the concentrator cushion.

A foam sandwich reflector and a method for making a foam sandwich reflector. The reflector and method incorporate a foam slab having a top and bottom surface. Each of the top and bottom surface of the foam slab have a coating of an adhesive layer. The adhesive coating on the bottom surface of the foam slab is a lower bonding layer that bonds the foam slab to the bottom high modulus layer. The adhesive coating on the top surface of the foam slab is an upper bonding layer that bonds the foam slab to the top high modulus layer; bottom high modulus layer composed of a metal, e.g., aluminum or steel. The reflector and method also include an optically smooth, highly reflective high modulus layer. The reflector is curved in one dimension, and the curve is configured to concentrate light when the reflector is in use.

An extremely low cost solar concentrator made of membranes or films is inflated into a Compound Parabolic Concentrator (CPC) a non-image concentrator. The portion of the inflatable concentrator, which is shaped into a CPC concentrator, is formed with reflective membranes or films, and the portions of the inflatable concentrator on the top of CPC and on the bottom of the concentrator are made of clear membranes or films. The incident light including parallel rays of light and diffuse light, as long as falling into the half acceptance angle of the CPC, will be concentrated to the bottom exit aperture of the CPC. Therefore, this type concentrator reduces the requirement to the accuracy of tracking for concentration. In addition, this type of concentrator demonstrates more tolerance to shape distortion for concentration than imaging system.

An elongate photovoltaic (PV) module for use in a solar energy conversion plant for the production of electricity from incident light, the PV-module comprising a top portion with a support panel (G) carrying on a front side a plurality of electrically connected PV cells (D), and a transparent protective layer (A) sealed to the support panel (G) so as to encapsulate the PV-cells (D) between the support panel (G) and the protective layer (A), wherein prior to installation of the PV-module at the deployment site a collapsible portion of the PV-module is configured to be collapsible in a longitudinal direction by folding and/or rolling, wherein the collapsible portion includes at least the top portion, wherein the PV-module further comprises one or more integrated ballast chambers (I) in a bottom portion of the PV-module arranged on a rear side of the support panel (G), wherein said integrated ballast chamber (I) after installation of the PV-module at the deployment site contains an amount of a ballasting material (H) with a weight sufficient to immobilize the PV-module on a supporting surface of the deployment site under predetermined characteristic climate conditions for the deployment site.