diff --git a/basis/windturbine_lib.lua b/basis/windturbine_lib.lua
new file mode 100644
index 0000000..f52aa6f
--- /dev/null
+++ b/basis/windturbine_lib.lua
@@ -0,0 +1,84 @@
+--[[
+
+	TechAge
+	=======
+
+	Copyright (C) 2019-2020 Joachim Stolberg
+
+	GPL v3
+	See LICENSE.txt for more information
+	
+	Wind turbine helper function
+
+]]--
+
+local S = techage.S
+local P = minetest.string_to_pos
+local M = minetest.get_meta
+
+local function chat_message(player_name, msg)
+	if player_name then
+		minetest.chat_send_player(player_name, S("[TA4 Wind Turbine]").." "..msg)
+	end
+end
+
+-- num_turbines is the mx number of valid wind turbines. In the case of a tool
+-- it should be 0, in case of the rotor: 1
+function techage.valid_place_for_windturbine(pos, player_name, num_turbines)
+	local pos1, pos2, num
+
+	-- Check if occean (only for tool)
+	if num_turbines == 0 and pos.y ~= 1 then
+		chat_message(player_name, S("This is not the surface of the ocean!"))
+		return false
+	end
+	local node = minetest.get_node(pos)
+	if num_turbines == 0 and node.name ~= "default:water_source" then
+		chat_message(player_name, S("This is no ocean water!"))
+		return false
+	end
+	local data = minetest.get_biome_data({x=pos.x, y=-2, z=pos.z})
+	if data then
+		local name = minetest.get_biome_name(data.biome)
+		if not string.find(name, "ocean") then
+			chat_message(player_name, S("This is a "..name.." biome and no ocean!"))
+			return false
+		end
+	end
+	-- check the space over ocean
+	pos1 = {x=pos.x-20, y=2, z=pos.z-20}
+	pos2 = {x=pos.x+20, y=22, z=pos.z+20}
+	num = #minetest.find_nodes_in_area(pos1, pos2, {"air", "ignore"})
+	if num < (41 * 41 * 21 * 0.9) then
+		techage.mark_region(player_name, pos1, pos2, "")
+		chat_message(player_name, 
+				S("Here is not enough wind (A free air space of 41x41x21 m is necessary)!"))
+		return false
+	end
+	-- Check for water surface (occean)
+	pos1 = {x=pos.x-20, y=1, z=pos.z-20}
+	pos2 = {x=pos.x+20, y=1, z=pos.z+20}
+	num = #minetest.find_nodes_in_area(pos1, pos2, 
+			{"default:water_source", "default:water_flowing", "ignore"})
+	print(num, (41 * 41 * 0.9))
+	if num < (41*41 * 0.8) then
+		techage.mark_region(player_name, pos1, pos2, "")
+		chat_message(player_name, S("Here is not enough water (41x41 m)!"))
+		return false
+	end
+	-- Check for next wind turbine
+	pos1 = {x=pos.x-13, y=2, z=pos.z-13}
+	pos2 = {x=pos.x+13, y=22, z=pos.z+13}
+	num = #minetest.find_nodes_in_area(pos1, pos2, {"techage:ta4_wind_turbine"})
+	if num > num_turbines then
+		techage.mark_region(player_name, pos1, pos2, "")
+		chat_message(player_name, S("The next wind turbines is too close!"))
+		return false
+	end
+	
+	if num_turbines == 0 then
+		chat_message(player_name,  minetest.pos_to_string(pos).." "..
+				S("is a suitable place for a wind turbine!"))
+	end
+	return true
+end
diff --git a/init.lua b/init.lua
index 1bfa3b6..89582a7 100644
--- a/init.lua
+++ b/init.lua
@@ -84,6 +84,7 @@ dofile(MP.."/basis/assemble.lua")
 dofile(MP.."/basis/networks.lua")
 dofile(MP.."/basis/recipe_lib.lua")
 dofile(MP.."/basis/formspec_update.lua")
+dofile(MP.."/basis/windturbine_lib.lua")
 
 -- Main doc
 dofile(MP.."/doc/manual_DE.lua")
diff --git a/tools/repairkit.lua b/tools/repairkit.lua
index 548e449..f408ebc 100644
--- a/tools/repairkit.lua
+++ b/tools/repairkit.lua
@@ -199,15 +199,23 @@ local function read_state(itemstack, user, pointed_thing)
 		local hours = math.floor(time / 6)
 		local mins = (time % 6) * 10
 		if mins < 10 then mins = "00" end
+		
+		local number = techage.get_node_number(pos)
+		local node = minetest.get_node(pos)
+		local ndef = minetest.registered_nodes[node.name]
+		
+		if node.name == "default:water_source" then
+			local player_name = user:get_player_name()
+			techage.valid_place_for_windturbine(pos, player_name, 0)
+			return itemstack
+		end
+		
 		minetest.chat_send_player(user:get_player_name(), S("Time")..": "..hours..":"..mins.."    ")
 		local data = minetest.get_biome_data(pos)
 		if data then
 			local name = minetest.get_biome_name(data.biome)
 			minetest.chat_send_player(user:get_player_name(), S("Biome")..": "..name..", "..S("Position temperature")..": "..math.floor(data.heat).."    ")
 		end
-		local number = techage.get_node_number(pos)
-		local node = minetest.get_node(pos)
-		local ndef = minetest.registered_nodes[node.name]
 		
 		if ndef and ndef.networks then
 			local player_name = user:get_player_name()
@@ -291,6 +299,7 @@ minetest.register_tool("techage:end_wrench", {
 	on_use = read_state,
 	on_place = read_state,
 	node_placement_prediction = "",
+	liquids_pointable = true,
 	stack_max = 1,
 })