Modifiers matching electricity:

• natural,
• atmospheric,
• cosmic,
• municipal,
• cheap,
• extraneous,
• home,
• renewable,
• clean,

Simple categories matching renewable:

• polymer,
• energy,
• wood,
• material,
• tree,
• substance,
• source,
• plant,
• electricity,
• resource,
• waste,
• fibre,
• substrate,
• fiber,
• softwood,
• fuel,
• product,
• molecule,
• sugar,
• structure,
• tissue,
• elements,
• system,