energy_required

  {
    type = "recipe",
    name = "science-pack-1",
    energy_required = 5,
    ingredients =
    {
      {"copper-plate", 1},
      {"iron-gear-wheel", 1}
    },
    result = "science-pack-1"
  },
  {
    type = "recipe",
    name = "science-pack-2",
    energy_required = 6,
    ingredients =
    {
      {"inserter", 1},
      {"transport-belt", 1}
    },
    result = "science-pack-2"
  },
  {
    type = "recipe",
    name = "science-pack-3",
    enabled = false,
    energy_required = 12,
    ingredients =
    {
      {"advanced-circuit", 1},
      {"engine-unit", 1},
      {"assembling-machine-2", 1},
    },
    result = "science-pack-3"
  },
  {
    type = "recipe",
    name = "military-science-pack",
    enabled = false,
    energy_required = 10,
    ingredients =
    {
      {"piercing-rounds-magazine", 1},
      {"grenade", 1},
      {"gun-turret", 1}
    },
    result_count = 2,
    result = "military-science-pack",
  },
  {
    type = "recipe",
    name = "production-science-pack",
    enabled = false,
    energy_required = 14,
    ingredients =
    {
     {"pumpjack", 1},
     {"electric-engine-unit", 1},
     {"electric-furnace", 1}
    },
    result_count = 2,
    result = "production-science-pack",
  },
  {
    type = "recipe",
    name = "high-tech-science-pack",
    enabled = false,
    energy_required = 14,
    ingredients =
    {
      {"battery", 1},
      {"processing-unit", 3},
      {"speed-module", 1},
      {"copper-cable", 30}
    },
    result_count = 2,
    result = "high-tech-science-pack",
  },