diff --git a/cannon.lua b/cannon.lua
index f7bf0be..a9d2c46 100644
--- a/cannon.lua
+++ b/cannon.lua
@@ -61,7 +61,7 @@ local register_spacecannon = function(color, range, timeout, speed)
 
 		mesecons = {effector = {
 			action_on = function (pos, node)
-				spacecannon.fire(pos, color, speed)
+				spacecannon.fire(pos, color, speed, range)
 			end
 		}},
 
@@ -103,7 +103,7 @@ local register_spacecannon = function(color, range, timeout, speed)
 
 			meta:set_string("infotext", "Power: " .. eu_input .. "/" .. demand .. " Store: " .. store)
 
-			if store < spacecannon.config.powerstorage then
+			if store < spacecannon.config.powerstorage * range then
 				-- charge
 				meta:set_int("HV_EU_demand", spacecannon.config.powerrequirement)
 				store = store + eu_input
@@ -118,7 +118,7 @@ local register_spacecannon = function(color, range, timeout, speed)
 			local meta = minetest.get_meta(pos);
 
 			if fields.fire then
-				spacecannon.fire(pos, color, speed)
+				spacecannon.fire(pos, color, speed, range)
 			end
 		end
 
diff --git a/init.lua b/init.lua
index 6f4fc55..ac9d070 100644
--- a/init.lua
+++ b/init.lua
@@ -2,11 +2,16 @@
 spacecannon = {
 	config = {
 		-- technic EU storage value
-		powerstorage = 100000,
+		powerstorage = 10000,
 
 		-- charge value in EU
 		powerrequirement = 2500,
 
+		-- fuel item and count
+		power_item = "default:mese_crystal",
+		power_item_count = 1
+
+
 	}
 }
 
diff --git a/util.lua b/util.lua
index ef6aa84..34b9ad2 100644
--- a/util.lua
+++ b/util.lua
@@ -9,7 +9,31 @@ spacecannon.update_formspec = function(meta)
 		"list[current_player;main;0,5;8,4;]")
 end
 
-spacecannon.fire = function(pos, color, speed)
+spacecannon.fire = function(pos, color, speed, range)
+	-- check fuel/power
+	local meta = minetest.get_meta(pos)
+	local owner = meta:get_string("owner")
+
+	if meta:get_int("powerstorage") < spacecannon.config.powerstorage * range then
+
+		-- check inventory
+		local inv = meta:get_inventory()
+		local power_item = spacecannon.config.power_item
+		local power_item_count = spacecannon.config.power_item_count * range
+
+		if not inv:contains_item("main", {name=power_item, count=power_item_count}) then
+			minetest.chat_send_player(owner, "Not enough fuel to fire cannon, expected " .. power_item_count .. " " .. power_item)
+			return
+		end
+
+		-- use up items
+		inv:remove_item("main", {name=power_item, count=power_item_count})
+	else
+		-- use power
+		meta:set_int("powerstorage", 0)
+	end
+
+
 	local node = minetest.get_node(pos)
 	local dir = spacecannon.facedir_to_down_dir(node.param2)
 	local obj = minetest.add_entity({x=pos.x+dir.x, y=pos.y+dir.y, z=pos.z+dir.z}, "spacecannon:energycube_" .. color)