NOVELTY - Elongate photovoltaic (PV) module for use in a solar energy conversion plant for the production of electricity from incident light, the PV-module comprises a top portion with a support panel (G) carrying on a front side a set 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).    USE - The elongate PV module is useful in a solar energy conversion plant for the production of electricity from incident light (claimed).    ADVANTAGE - The elongate PV module can be efficiently used in building large-scale solar power plants in a material-efficient, labor-efficient and cost-effective manner.    DETAILED DESCRIPTION - Elongate photovoltaic (PV) module for use in a solar energy conversion plant for the production of electricity from incident light, the PV-module comprises a top portion with a support panel (G) carrying on a front side a set 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), where 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, where the collapsible portion includes at least the top portion, where 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), where the 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 pre-determined characteristic climate conditions for the deployment site. INDEPENDENT CLAIMS are:    (1) solar power plant comprising a set of PV-modules; and    (2) a method of installing an elongated PV-module at a deployment site for use in a large-scale solar energy conversion plant for the production of electricity, where the PV-module comprises a top portion having a support panel (G) carrying on a front side electrically connected PV-cells and a transparent protective layer (A) sealed to the support panel (G) so as to encapsulate the PV-cells between the support panel (G) and the protective layer (A), where the PV-module in its installed state 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), and that the method comprises the steps of providing both the top portion and the bottom portion at the deployment site, where at least the top portion is provided at the deployment site as a lengthwise collapsible portion of the PV-module in a collapsed state, expanding the collapsible portion at the deployment site, and filling the one or more ballast chambers (I) through one or more openings in the bottom portion with an amount of a ballasting material (H) having a weight sufficient to fix the PV-module to the supporting surface under pre-determined characteristic climate conditions for the deployment site.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of an elongate PV-module.    Transparent protective layer (A)    PV cells (D)    Support panel (G)    Ballasting material (H)    Ballast chamber (I)