diff --git a/energy_storage/heatexchanger2.lua b/energy_storage/heatexchanger2.lua
index 967e26a..591acc8 100644
--- a/energy_storage/heatexchanger2.lua
+++ b/energy_storage/heatexchanger2.lua
@@ -283,7 +283,8 @@ techage.register_node({"techage:heatexchanger2"}, {
 				return "stopped"
 			end
 		elseif topic == "delivered" then
-			return -math.max(nvm.needed or 0, 0)
+			local data = power.get_network_data(pos, Cable, DOWN)
+			return data.consumed - data.provided
 		elseif topic == "load" then
 			return techage.power.percent(nvm.capa_max, nvm.capa)
 		elseif topic == "on" then
diff --git a/power/formspecs.lua b/power/formspecs.lua
index c014ab5..81fb87b 100644
--- a/power/formspecs.lua
+++ b/power/formspecs.lua
@@ -38,7 +38,7 @@ local function round(val)
 end
 
 local function calc_percent(max_val, curr_val)
-	return math.min(((curr_val or 0) * 100) / (max_val or 1.0), 100)
+	return round(math.min(((curr_val or 0) * 100) / (max_val or 1.0), 100))
 end
 
 -------------------------------------------------------------------------------