NOVELTY - An interlayer sheet comprises a poly(vinyl butyral) composition. It has an E120 value of 8-15 N/mm2, and provides glass laminates which pass the EN 356 P2A test.    USE - Interlayer sheet for glass laminate and encapsulant layer of solar cell laminate (claimed).    ADVANTAGE - The interlayer sheet can provide glass and solar cell laminates having superior penetration resistance.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a glass laminate comprising layer(s) of a rigid sheet and layer(s) of the interlayer sheet where optionally the rigid sheet is in direct contact with the interlayer sheet or which optionally comprises two layers of rigid sheets that are glass with the interlayer sheet laminated between the glass sheets;    (2) a solar cell laminate comprising encapsulant layer(s) and a solar cell layer that comprises solar cell(s) that may be electronically interconnected, where the encapsulant layer is formed of the interlayer sheet and is laminated to the solar cell layer;    (3) a method for manufacturing a solar cell laminate comprising providing an assembly comprising from top to bottom an incident layer, a front-sheet encapsulant layer comprising the interlayer sheet, a solar cell layer comprising solar cell(s) that may be electronically interconnected, an optional backsheet encapsulant layer, and a backing layer and laminating the assembly to form the solar cell laminate; where the step of lamination is optionally conducted by subjecting the assembly to heat; or where the step of lamination is optionally conducted by subjecting the assembly to heat and pressure and/or vacuum; and    (4) a method of producing a glass laminate or a solar cell laminate comprising selecting an interlayer sheet comprising a poly(vinyl butyral) composition having an E120 of 8-15 N/mm2, measured according to the ISO EN 527 standard, at an elongation of 120%, and optionally normalized to remove variations in the E120 that result from differing cross-sectional areas of individual test specimens; forming a glass laminate or a solar cell laminate by laminating the interlayer sheet to glass sheet(s); and conducting an EN 356 P2A test to measure the resistance of the glass laminate or the solar cell laminate to penetration.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a laminate.    Ball (10)    Float glass (12)    Air sides (12a)    Tin sides (12b)    Polymeric interlayer (14)