diff --git a/composer.json b/composer.json
index 0441a80..7b34d52 100644
--- a/composer.json
+++ b/composer.json
@@ -5,8 +5,9 @@
     "minimum-stability": "stable",
     "require": {
         "php": "^7.4",
+        "ext-json": "*",
         "holicz/simple-exception": "^1.1",
-        "thecodingmachine/safe": "^1.1"
+        "thecodingmachine/safe": "1.1"
     },
     "require-dev": {
         "phpstan/phpstan": "^0.12.18",
diff --git a/composer.lock b/composer.lock
index 5d0e540..4cf1df4 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "cf5da207b342941494d4612b6dfe25be",
+    "content-hash": "9a6f5f3cf45d4d416b9144ff31478945",
     "packages": [
         {
             "name": "holicz/simple-exception",
diff --git a/src/Adapter/PvgisAdapter.php b/src/Adapter/PvgisAdapter.php
index 08c505a..09399a8 100644
--- a/src/Adapter/PvgisAdapter.php
+++ b/src/Adapter/PvgisAdapter.php
@@ -15,6 +15,16 @@ final class PvgisAdapter
 {
     private const API_URL = 'https://re.jrc.ec.europa.eu/api/pvcalc?peakpower=1&pvtechchoice=crystSi&mountingplace=building&loss=1&outputformat=json&angle=35&lat=%s&lon=%s';
 
+    /**
+     * Multiplier to change the PVGIS result in order to get desired production
+     */
+    private float $multiplier;
+
+    public function __construct(float $multiplier = 1.0)
+    {
+        $this->multiplier = $multiplier;
+    }
+
     /**
      * @param string $latitude
      * @param string $longitude
@@ -43,15 +53,16 @@ public function getPvgisData(string $latitude, string $longitude): ElectricityPr
      * @return ElectricityProduction
      *
      * @throws InvalidResponseFormatException
+     * @throws StringsException
      */
     private function parsePvgisResponse(string $response): ElectricityProduction
     {
         try {
             $response = json_decode($response, true, 512, JSON_THROW_ON_ERROR);
 
-            $electricityProduction = new ElectricityProduction($response['outputs']['totals']['fixed']['E_m']);
+            $electricityProduction = new ElectricityProduction($this->multiplier * $response['outputs']['totals']['fixed']['E_m']);
             foreach ($response['outputs']['monthly']['fixed'] as $month) {
-                $electricityProduction->addMonthlyProduction($month['month'], $month['E_m']);
+                $electricityProduction->addMonthlyProduction($month['month'], $this->multiplier * $month['E_m']);
             }
         } catch (Exception $e) {
             throw new InvalidResponseFormatException(['response' => $response]);