Spar beam for structurally connecting a first blade section and a second blade section of a wind turbine blade , wherein the wind turbine blade extends along a longitudinal axis (L) from a root through a first airfoil region and a second airfoil region to a tip , wherein the first blade section extends along the longitudinal axis to a first end and the second blade section extends along the longitudinal axis from a second end towards the tip, the first blade section comprising a first spar cap and the first airfoil region, the second blade section comprising a second spar cap and the second airfoil region, the first blade section and the second blade section comprising a pressure side , a suction side and a chord line extending between a leading edge and a trailing edge , the spar beam longitudinally extending along a spar beam axis (B) from a first beam end at a first beam axis position (pb1) to a second beam end at a second beam axis position (pb2) and being configured to be positioned such that the first beam axis position is located in the first airfoil region and the second beam axis position is located in the second airfoil region and a third beam axis position (pb3) between the first beam axis position and the second beam axis position is aligned with the second end of the second blade section, the spar beam having a first beam side configured to face the pressure side or suction side of the wind turbine blade, a trailing edge beam side configured to face the trailing edge of the wind turbine blade, and a leading edge beam side configured to face the leading edge of the wind turbine blade, the spar beam comprising a conductive beam sheath circumscribing at least a beam sheath angular distance of the spar beam about the spar beam axis and longitudinally extending along the spar beam axis from a fourth beam axis position (pb4) to a fifth beam axis position (pb5), the spar beam comprises a first fibre reinforced element including electrically conductive fibres, such as carbon fibres, and extending parallel to the spar beam axis, wherein the first fibre reinforced element is positioned between the conductive beam sheath and the spar beam axis and is configured to structurally connect the first and second blade sections. the spar beam longitudinally extending along a spar beam axis (B) from a first beam end at a first beam axis position (pb1) to a second beam end at a second beam axis position (pb2) and being configured to be positioned such that the first beam axis position is located in the first airfoil region and the second beam axis position is located in the second airfoil region and a third beam axis position (pb3) between the first beam axis position and the second beam axis position is aligned with the second end of the second blade section, the spar beam having a first beam side configured to face the pressure side or suction side of the wind turbine blade, a trailing edge beam side configured to face the trailing edge of the wind turbine blade, and a leading edge beam side configured to face the leading edge of the wind turbine blade, the spar beam comprising a conductive beam sheath circumscribing at least a beam sheath angular distance of the spar beam about the spar beam axis and longitudinally extending along the spar beam axis from a fourth beam axis position (pb4) to a fifth beam axis position (pb5), the spar beam comprises a first fibre reinforced element including electrically conductive fibres, such as carbon fibres, and extending parallel to the spar beam axis, wherein the first fibre reinforced element is positioned between the conductive beam sheath and the spar beam axis and is configured to structurally connect the first and second blade sections. <EOS>