TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The multilayer film further: comprises a top layer (220) positioned adjacent to the insulating layer and opposite the back layer, where the top layer contains the crosslinked polyethene homopolymers or copolymers; and includes at least one additional layer including the polyethene that comprises linear low density polyethene (LLDPE), LDPE, medium density polyethene (MDPE) and/or high density polyethene (HDPE) as a major component. In the multilayer film: at least one of the insulating layer or the back layer includes at least 60 mole%, preferably 80 mole% of repeating units derived from ethene and the alkene comonomers, and at least 95 mole% of repeating units derived from ethane; at least two of the layers are co-extruded; at least one of the insulating layer, the back layer, the encapsulant layer or the tie layer includes at least one of flame retardants or anti-dripping agents; and the insulating layer and the back layer are bonded together. The insulating layer and the back layer each contain a polyethene comprising LLDPE, LDPE, MDPE and/or HDPE as a major component. The multilayer film has a thickness of 0.25-1 mm. The insulating layer contains no pigments. The back layer contains carbon particles. The plasticizer: is non-polar; comprises ethylene/ alpha -olefin copolymers or 4-10C polyolefin homopolymers; has a glass-transition temperature of less than -50 degrees C, preferably -70 degrees C; and is liquid at 20 degrees C. The polyolefin in the encapsulant layer is an ethylene/ alpha -olefin copolymer, where: the alpha -olefin moiety of the ethylene/ alpha -olefin copolymer includes at least four carbons; the ethylene/ alpha -olefin copolymer is a low crystalline ethylene/ alpha -olefin copolymer having a differential scanning calorimetry peak melting point of less than or equal to 50 degrees C; and the low crystalline ethylene/ alpha -olefin copolymer is a butene alpha -olefin. The encapsulant layer: includes greater than 70 wt.% of low crystalline ethylene/ alpha -olefin copolymer; further includes a coagent and an additional resin; and includes multiple layers. The silane in the encapsulant layer is an unsaturated alkoxysilane, which is an acrylic alkoxysilane. The crosslinking agent is one of a thermal curative or a photo-curative, where the thermal curative is a peroxide. The additional resin is an additional low crystalline ethylene/ alpha -olefin copolymer or one of an ethylene/butene copolymer or an ethylene/octene copolymer. EXAMPLE - Mixture of 75 parts of EXACT 9361 (RTM: Ethylene alpha -olefin copolymer), 25 parts of EXACT 8230 (RTM: Ethylene butene copolymer plastic material), 1 part of Luperox TBEC (RTM: Peroxide), 0.8 parts of TAICROS (RTM: 1,3,5-Tris(2,3-dibromopropyl)-isocyanurate) and 0.8 parts of SILQUEST A174 (RTM: Vinyltrimethoxysilane) was extruded to obtain a polyolefin-based encapsulant film. The encapsulant film was placed adjacent to a bottom layer of a backsheet (which was an extruded three-layer construction, each layer included 5% of Polybatch UV1952 (RTM: UV stabilizator), the top layer included high density polyethene, the middle layer included Lupolen 3020k (RTM: Low density polyethylene), and a bottom layer included Hostalen GD 9550 (RTM: High density polyethylene) containing 20% Polybatch LL8000 (RTM: Concentrate containing 70% titanium dioxide in linear low density polyethene)) to obtain the multilayer film.