diff --git a/README.rst b/README.rst
index 41a18e02..edc8d255 100644
--- a/README.rst
+++ b/README.rst
@@ -8,6 +8,9 @@
  :target: https://mybinder.org/v2/gh/wind-python/windpowerlib/dev?filepath=example
 .. image:: https://img.shields.io/badge/code%20style-black-000000.svg
     :target: https://github.com/psf/black
+
+.. image:: https://img.shields.io/lgtm/grade/python/g/wind-python/windpowerlib.svg?logo=lgtm&logoWidth=18
+    :target: https://lgtm.com/projects/g/wind-python/windpowerlib/context:python
    
 Introduction
 =============
@@ -82,8 +85,14 @@ You can also look at the examples in the `Examples section <http://windpowerlib.
 Wind turbine data
 ==================
 
+The windpowerlib provides data of many wind turbines but it is also possible to
+use your own turbine data.
+
+Use internal data
+~~~~~~~~~~~~~~~~~
+
 The windpowerlib provides `wind turbine data <https://github.com/wind-python/windpowerlib/tree/master/windpowerlib/oedb>`_
-(power curves, hub heights, etc.) for a large set of wind turbines. Have a look at the `example <http://windpowerlib.readthedocs.io/en/stable/modelchain_example_notebook.html#Initialize-wind-turbine>`_ on how
+(power curves, hub heights, etc.) for a large set of wind turbines. See `Initialize wind turbine` in :ref:`examples_section_label` on how
 to use this data in your simulations.
 
 The dataset is hosted and maintained on the `OpenEnergy database <https://openenergy-platform.org/dataedit/>`_ (oedb).
@@ -94,9 +103,61 @@ To update your local files with the latest version of the `oedb turbine library
   from windpowerlib.wind_turbine import load_turbine_data_from_oedb
   load_turbine_data_from_oedb()
 
+If you find your turbine in the database it is very easy to use it in the
+windpowerlib
+
+.. code:: python
+
+    from windpowerlib import WindTurbine
+    enercon_e126 = {
+        "turbine_type": "E-126/4200",  # turbine type as in register
+        "hub_height": 135,  # in m
+    }
+    e126 = WindTurbine(**enercon_e126)
+
 We would like to encourage anyone to contribute to the turbine library by adding turbine data or reporting errors in the data.
 See `here <https://github.com/OpenEnergyPlatform/data-preprocessing/issues/28>`_ for more information on how to contribute.
 
+Use your own turbine data
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It is possible to use your own power curve. However, the most sustainable way
+is to send us the data to be included in the windpowerlib and to be available
+for all users. This may not be possible in all cases.
+
+Assuming the data files looks like this:
+
+.. code::
+
+    wind,power
+    0.0,0.0
+    3.0,39000.0
+    5.0,270000.0
+    10.0,2250000.0
+    15.0,4500000.0
+    25.0,4500000.0
+
+You can use pandas to read the file and pass it to the turbine dictionary. I
+you have basic knowledge of pandas it is easy to use any kind of data file.
+
+.. code:: python
+
+    import pandas as pd
+    from windpowerlib import WindTurbine, create_power_curve
+    my_data = pd.read_csv("path/to/my/data/file.csv")
+
+    my_turbine_data = {
+        "nominal_power": 6e6,  # in W
+        "hub_height": 115,  # in m
+        "power_curve": create_power_curve(
+            wind_speed=my_data["wind"], power=my_data["power"]
+        ),
+    }
+
+    my_turbine = WindTurbine(**my_turbine2)
+
+See the `modelchain_example` for more information.
+
 Contributing
 ==============
 
diff --git a/doc/getting_started.rst b/doc/getting_started.rst
index c4373330..e883612a 100644
--- a/doc/getting_started.rst
+++ b/doc/getting_started.rst
@@ -13,6 +13,9 @@ Getting started
 .. image:: https://img.shields.io/badge/code%20style-black-000000.svg
     :target: https://github.com/psf/black
 
+.. image:: https://img.shields.io/lgtm/grade/python/g/wind-python/windpowerlib.svg?logo=lgtm&logoWidth=18
+    :target: https://lgtm.com/projects/g/wind-python/windpowerlib/context:python
+
 Introduction
 =============
 
@@ -84,6 +87,12 @@ You can also look at the examples in the :ref:`examples_section_label` section.
 Wind turbine data
 ==================
 
+The windpowerlib provides data of many wind turbines but it is also possible to
+use your own turbine data.
+
+Use internal data
+~~~~~~~~~~~~~~~~~
+
 The windpowerlib provides `wind turbine data <https://github.com/wind-python/windpowerlib/tree/master/windpowerlib/oedb>`_
 (power curves, hub heights, etc.) for a large set of wind turbines. See `Initialize wind turbine` in :ref:`examples_section_label` on how
 to use this data in your simulations.
@@ -96,9 +105,62 @@ To update your local files with the latest version of the `oedb turbine library
   from windpowerlib.wind_turbine import load_turbine_data_from_oedb
   load_turbine_data_from_oedb()
 
+If you find your turbine in the database it is very easy to use it in the
+windpowerlib
+
+.. code:: python
+
+    from windpowerlib import WindTurbine
+    enercon_e126 = {
+        "turbine_type": "E-126/4200",  # turbine type as in register
+        "hub_height": 135,  # in m
+    }
+    e126 = WindTurbine(**enercon_e126)
+
 We would like to encourage anyone to contribute to the turbine library by adding turbine data or reporting errors in the data.
 See `here <https://github.com/OpenEnergyPlatform/data-preprocessing/issues/28>`_ for more information on how to contribute.
 
+Use your own turbine data
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It is possible to use your own power curve. However, the most sustainable way
+is to send us the data to be included in the windpowerlib and to be available
+for all users. This may not be possible in all cases.
+
+Assuming the data files looks like this:
+
+.. code::
+
+    wind,power
+    0.0,0.0
+    3.0,39000.0
+    5.0,270000.0
+    10.0,2250000.0
+    15.0,4500000.0
+    25.0,4500000.0
+
+You can use pandas to read the file and pass it to the turbine dictionary. I
+you have basic knowledge of pandas it is easy to use any kind of data file.
+
+.. code:: python
+
+    import pandas as pd
+    from windpowerlib import WindTurbine, create_power_curve
+    my_data = pd.read_csv("path/to/my/data/file.csv")
+
+    my_turbine_data = {
+        "nominal_power": 6e6,  # in W
+        "hub_height": 115,  # in m
+        "power_curve": create_power_curve(
+            wind_speed=my_data["wind"], power=my_data["power"]
+        ),
+    }
+
+    my_turbine = WindTurbine(**my_turbine2)
+
+See the `modelchain_example` for more information.
+
+
 Contributing
 ==============
 
diff --git a/example/modelchain_example.ipynb b/example/modelchain_example.ipynb
index f4b1f748..1b4dfa9e 100644
--- a/example/modelchain_example.ipynb
+++ b/example/modelchain_example.ipynb
@@ -288,7 +288,7 @@
    "source": [
     "# specification of wind turbine where power coefficient curve and nominal\n",
     "# power is provided in an own csv file\n",
-    "csv_path = 'data'\n",
+    "csv_path = ''\n",
     "dummy_turbine = {\n",
     "    'turbine_type': 'DUMMY 1',  # turbine type as in file\n",
     "    'hub_height': 100,  # in m\n",
diff --git a/example/modelchain_example.py b/example/modelchain_example.py
index acf85b8e..5619a668 100644
--- a/example/modelchain_example.py
+++ b/example/modelchain_example.py
@@ -10,27 +10,29 @@
 you need to specify your wind turbine, and in the last step call the
 windpowerlib functions to calculate the feed-in time series.
 
+Install the windpowerlib and optionally matplotlib to see the plots:
+
+   pip install windpowerlib
+   pip install matplotlib
+
+Go down to the "run_example()" function to start the example.
+
 SPDX-FileCopyrightText: 2019 oemof developer group <contact@oemof.org>
 SPDX-License-Identifier: MIT
 """
 import os
 import pandas as pd
+import requests
+import logging
+from windpowerlib import ModelChain, WindTurbine, create_power_curve
 
 try:
     from matplotlib import pyplot as plt
 except ImportError:
     plt = None
 
-from windpowerlib import ModelChain
-from windpowerlib import WindTurbine
-
-# You can use the logging package to get logging messages from the windpowerlib
-# Change the logging level if you want more or less messages
-import logging
-logging.getLogger().setLevel(logging.DEBUG)
-
 
-def get_weather_data(filename='weather.csv', **kwargs):
+def get_weather_data(filename="weather.csv", **kwargs):
     r"""
     Imports weather data from a file.
 
@@ -65,11 +67,16 @@ def get_weather_data(filename='weather.csv', **kwargs):
     """
 
     if "datapath" not in kwargs:
-        kwargs["datapath"] = os.path.join(
-            os.path.split(os.path.dirname(__file__))[0], "example"
-        )
+        kwargs["datapath"] = os.path.dirname(__file__)
+
     file = os.path.join(kwargs["datapath"], filename)
 
+    if not os.path.isfile(file):
+        logging.debug("Download weather data for example.")
+        req = requests.get("https://osf.io/59bqn/download")
+        with open(file, "wb") as fout:
+            fout.write(req.content)
+
     # read csv file
     weather_df = pd.read_csv(
         file,
@@ -95,7 +102,7 @@ def initialize_wind_turbines():
     that is provided along with the windpowerlib, as done for the
     'enercon_e126', or specify your own turbine by directly providing a power
     (coefficient) curve, as done below for 'my_turbine', or provide your own
-    turbine data in csv files, as done for 'dummy_turbine'.
+    turbine data in csv files, as done for 'my_turbine2'.
 
     To get a list of all wind turbines for which power and/or power coefficient
     curves are provided execute `
@@ -108,18 +115,19 @@ def initialize_wind_turbines():
            :class:`~.wind_turbine.WindTurbine`)
 
     """
+    # ************************************************************************
+    # **** Data is provided in the oedb turbine library **********************
 
-    # specification of wind turbine where data is provided in the oedb
-    # turbine library
     enercon_e126 = {
         "turbine_type": "E-126/4200",  # turbine type as in register
         "hub_height": 135,  # in m
     }
-    # initialize WindTurbine object
     e126 = WindTurbine(**enercon_e126)
 
-    # specification of own wind turbine (Note: power values and nominal power
-    # have to be in Watt)
+    # ************************************************************************
+    # **** Specification of wind turbine with your own data ******************
+    # **** NOTE: power values and nominal power have to be in Watt
+
     my_turbine = {
         "nominal_power": 3e6,  # in W
         "hub_height": 105,  # in m
@@ -133,25 +141,36 @@ def initialize_wind_turbines():
             }
         ),  # in m/s
     }
-    # initialize WindTurbine object
     my_turbine = WindTurbine(**my_turbine)
 
-    # specification of wind turbine where power coefficient curve and nominal
-    # power is provided in an own csv file
-    csv_path = os.path.join(os.path.dirname(__file__), "data")
-    dummy_turbine = {
-        "turbine_type": "DUMMY 1",
-        "hub_height": 100,  # in m
-        "rotor_diameter": 70,  # in m
-        "path": csv_path,
+    # ************************************************************************
+    # **** Specification of wind turbine with data in own file ***************
+
+    # Read your turbine data from your data file using functions like
+    # pandas.read_csv().
+    # >>> import pandas as pd
+    # >>> my_data = pd.read_csv("path/to/my/data/file")
+    # >>> my_power = my_data["my_power"]
+    # >>> my_wind_speed = my_data["my_wind_speed"]
+
+    my_power = pd.Series(
+        [0.0, 39000.0, 270000.0, 2250000.0, 4500000.0, 4500000.0]
+    )
+    my_wind_speed = (0.0, 3.0, 5.0, 10.0, 15.0, 25.0)
+
+    my_turbine2 = {
+        "nominal_power": 6e6,  # in W
+        "hub_height": 115,  # in m
+        "power_curve": create_power_curve(
+            wind_speed=my_wind_speed, power=my_power
+        ),
     }
-    # initialize WindTurbine object
-    dummy_turbine = WindTurbine(**dummy_turbine)
+    my_turbine2 = WindTurbine(**my_turbine2)
 
-    return my_turbine, e126, dummy_turbine
+    return my_turbine, e126, my_turbine2
 
 
-def calculate_power_output(weather, my_turbine, e126, dummy_turbine):
+def calculate_power_output(weather, my_turbine, e126, my_turbine2):
     r"""
     Calculates power output of wind turbines using the
     :class:`~.modelchain.ModelChain`.
@@ -161,7 +180,7 @@ def calculate_power_output(weather, my_turbine, e126, dummy_turbine):
     the default methods for the calculation steps, as done for 'my_turbine',
     or choose different methods, as done for the 'e126'. Of course, you can
     also use the default methods while only changing one or two of them, as
-    done for 'dummy_turbine'.
+    done for 'my_turbine2'.
 
     Parameters
     ----------
@@ -172,20 +191,14 @@ def calculate_power_output(weather, my_turbine, e126, dummy_turbine):
     e126 : :class:`~.wind_turbine.WindTurbine`
         WindTurbine object with power curve from the OpenEnergy Database
         turbine library.
-    dummy_turbine : :class:`~.wind_turbine.WindTurbine`
+    my_turbine2 : :class:`~.wind_turbine.WindTurbine`
         WindTurbine object with power coefficient curve from example file.
 
     """
 
-    # power output calculation for my_turbine
-    # initialize ModelChain with default parameters and use run_model method
-    # to calculate power output
-    mc_my_turbine = ModelChain(my_turbine).run_model(weather)
-    # write power output time series to WindTurbine object
-    my_turbine.power_output = mc_my_turbine.power_output
-
-    # power output calculation for e126
-    # own specifications for ModelChain setup
+    # ************************************************************************
+    # **** Data is provided in the oedb turbine library **********************
+    # **** ModelChain with non-default specifications
     modelchain_data = {
         "wind_speed_model": "logarithmic",  # 'logarithmic' (default),
         # 'hellman' or
@@ -206,17 +219,25 @@ def calculate_power_output(weather, my_turbine, e126, dummy_turbine):
     # write power output time series to WindTurbine object
     e126.power_output = mc_e126.power_output
 
-    # power output calculation for example_turbine
-    # own specification for 'power_output_model'
+    # ************************************************************************
+    # **** Specification of wind turbine with your own data ******************
+    # **** ModelChain with default parameter
+    mc_my_turbine = ModelChain(my_turbine).run_model(weather)
+    # write power output time series to WindTurbine object
+    my_turbine.power_output = mc_my_turbine.power_output
+
+    # ************************************************************************
+    # **** Specification of wind turbine with data in own file ***************
+    # **** Using "power_coefficient_curve" as "power_output_model".
     mc_example_turbine = ModelChain(
-        dummy_turbine, power_output_model="power_coefficient_curve"
+        my_turbine2, power_output_model="power_curve"
     ).run_model(weather)
-    dummy_turbine.power_output = mc_example_turbine.power_output
+    my_turbine2.power_output = mc_example_turbine.power_output
 
     return
 
 
-def plot_or_print(my_turbine, e126, dummy_turbine):
+def plot_or_print(my_turbine, e126, my_turbine2):
     r"""
     Plots or prints power output and power (coefficient) curves.
 
@@ -227,44 +248,55 @@ def plot_or_print(my_turbine, e126, dummy_turbine):
     e126 : :class:`~.wind_turbine.WindTurbine`
         WindTurbine object with power curve from the OpenEnergy Database
         turbine library.
-    dummy_turbine : :class:`~.wind_turbine.WindTurbine`
+    my_turbine2 : :class:`~.wind_turbine.WindTurbine`
         WindTurbine object with power coefficient curve from example file.
 
     """
 
     # plot or print turbine power output
     if plt:
-        e126.power_output.plot(legend=True, label='Enercon E126')
-        my_turbine.power_output.plot(legend=True, label='myTurbine')
-        dummy_turbine.power_output.plot(legend=True, label='dummyTurbine')
-        plt.xlabel('Time')
-        plt.ylabel('Power in W')
+        e126.power_output.plot(legend=True, label="Enercon E126")
+        my_turbine.power_output.plot(legend=True, label="myTurbine")
+        my_turbine2.power_output.plot(legend=True, label="myTurbine2")
+        plt.xlabel("Time")
+        plt.ylabel("Power in W")
         plt.show()
     else:
         print(e126.power_output)
         print(my_turbine.power_output)
-        print(dummy_turbine.power_output)
+        print(my_turbine2.power_output)
 
     # plot or print power curve
     if plt:
         if e126.power_curve is not False:
-            e126.power_curve.plot(x='wind_speed', y='value', style='*',
-                                  title='Enercon E126 power curve')
-            plt.xlabel('Wind speed in m/s')
-            plt.ylabel('Power in W')
+            e126.power_curve.plot(
+                x="wind_speed",
+                y="value",
+                style="*",
+                title="Enercon E126 power curve",
+            )
+            plt.xlabel("Wind speed in m/s")
+            plt.ylabel("Power in W")
             plt.show()
         if my_turbine.power_curve is not False:
-            my_turbine.power_curve.plot(x='wind_speed', y='value', style='*',
-                                        title='myTurbine power curve')
-            plt.xlabel('Wind speed in m/s')
-            plt.ylabel('Power in W')
+            my_turbine.power_curve.plot(
+                x="wind_speed",
+                y="value",
+                style="*",
+                title="myTurbine power curve",
+            )
+            plt.xlabel("Wind speed in m/s")
+            plt.ylabel("Power in W")
             plt.show()
-        if dummy_turbine.power_coefficient_curve is not False:
-            dummy_turbine.power_coefficient_curve.plot(
-                x='wind_speed', y='value', style='*',
-                title='dummyTurbine power coefficient curve')
-            plt.xlabel('Wind speed in m/s')
-            plt.ylabel('Power coefficient')
+        if my_turbine2.power_curve is not False:
+            my_turbine2.power_curve.plot(
+                x="wind_speed",
+                y="value",
+                style="*",
+                title="myTurbine2 power curve",
+            )
+            plt.xlabel("Wind speed in m/s")
+            plt.ylabel("Power in W")
             plt.show()
     else:
         if e126.power_coefficient_curve is not False:
@@ -278,10 +310,16 @@ def run_example():
     Runs the basic example.
 
     """
+    # You can use the logging package to get logging messages from the
+    # windpowerlib. Change the logging level if you want more or less messages:
+    # logging.DEBUG -> many messages
+    # logging.INFO -> few messages
+    logging.getLogger().setLevel(logging.DEBUG)
+
     weather = get_weather_data("weather.csv")
-    my_turbine, e126, dummy_turbine = initialize_wind_turbines()
-    calculate_power_output(weather, my_turbine, e126, dummy_turbine)
-    plot_or_print(my_turbine, e126, dummy_turbine)
+    my_turbine, e126, my_turbine2 = initialize_wind_turbines()
+    calculate_power_output(weather, my_turbine, e126, my_turbine2)
+    plot_or_print(my_turbine, e126, my_turbine2)
 
 
 if __name__ == "__main__":
diff --git a/example/data/power_coefficient_curves.csv b/example/power_coefficient_curves.csv
similarity index 100%
rename from example/data/power_coefficient_curves.csv
rename to example/power_coefficient_curves.csv
diff --git a/example/data/power_curves.csv b/example/power_curves.csv
similarity index 100%
rename from example/data/power_curves.csv
rename to example/power_curves.csv
diff --git a/example/turbine_cluster_modelchain_example.py b/example/turbine_cluster_modelchain_example.py
index ea0584bd..1d6cb953 100644
--- a/example/turbine_cluster_modelchain_example.py
+++ b/example/turbine_cluster_modelchain_example.py
@@ -25,6 +25,7 @@
 # You can use the logging package to get logging messages from the windpowerlib
 # Change the logging level if you want more or less messages
 import logging
+
 logging.getLogger().setLevel(logging.DEBUG)
 
 
@@ -202,10 +203,10 @@ def plot_or_print(example_farm, example_cluster):
 
     # plot or print power output
     if plt:
-        example_cluster.power_output.plot(legend=True, label='example cluster')
-        example_farm.power_output.plot(legend=True, label='example farm')
-        plt.xlabel('Wind speed in m/s')
-        plt.ylabel('Power in W')
+        example_cluster.power_output.plot(legend=True, label="example cluster")
+        example_farm.power_output.plot(legend=True, label="example farm")
+        plt.xlabel("Wind speed in m/s")
+        plt.ylabel("Power in W")
         plt.show()
     else:
         print(example_cluster.power_output)
diff --git a/example/data/turbine_data.csv b/example/turbine_data.csv
similarity index 100%
rename from example/data/turbine_data.csv
rename to example/turbine_data.csv
diff --git a/setup.py b/setup.py
index bd0a32ed..2a25ce00 100644
--- a/setup.py
+++ b/setup.py
@@ -6,22 +6,33 @@ def read(fname):
     return open(os.path.join(os.path.dirname(__file__), fname)).read()
 
 
-setup(name='windpowerlib',
-      version='0.2.1dev',
-      description='Creating time series of wind power plants.',
-      url='http://github.com/wind-python/windpowerlib',
-      author='oemof developer group',
-      author_email='windpowerlib@rl-institut.de',
-      license='MIT',
-      packages=['windpowerlib'],
-      package_data={
-          'windpowerlib': [os.path.join('data', '*.csv'),
-                           os.path.join('oedb', '*.csv')]},
-      long_description=read('README.rst'),
-      long_description_content_type='text/x-rst',
-      zip_safe=False,
-      install_requires=['pandas >= 0.20.0, < 0.26',
-                        'requests < 3.0'],
-      extras_require={
-          'dev': ['pytest', 'jupyter', 'sphinx_rtd_theme', 'nbformat',
-                  'numpy', 'matplotlib']})
+setup(
+    name="windpowerlib",
+    version="0.2.1dev",
+    description="Creating time series of wind power plants.",
+    url="http://github.com/wind-python/windpowerlib",
+    author="oemof developer group",
+    author_email="windpowerlib@rl-institut.de",
+    license="MIT",
+    packages=["windpowerlib"],
+    package_data={
+        "windpowerlib": [
+            os.path.join("data", "*.csv"),
+            os.path.join("oedb", "*.csv"),
+        ]
+    },
+    long_description=read("README.rst"),
+    long_description_content_type="text/x-rst",
+    zip_safe=False,
+    install_requires=["pandas >= 0.20.0, < 0.26", "requests < 3.0"],
+    extras_require={
+        "dev": [
+            "pytest",
+            "jupyter",
+            "sphinx_rtd_theme",
+            "nbformat",
+            "numpy",
+            "matplotlib",
+        ]
+    },
+)
diff --git a/tests/data/power_coefficient_curves.csv b/tests/data/power_coefficient_curves.csv
new file mode 100755
index 00000000..a3c70cc1
--- /dev/null
+++ b/tests/data/power_coefficient_curves.csv
@@ -0,0 +1,3 @@
+turbine_type,0,0.5,1,1.5,2,2.5,3,3.5,4,4.5,5,5.5,6,6.5,7,7.5,8,8.5,9,9.5,10,10.5,11,11.5,12,12.5,13,13.5,14,14.5,15,15.5,16,16.5,17,17.5,18,18.5,19,19.5,20,20.5,21,21.5,22,22.5,23,23.5,24,24.5,25,25.5,26
+DUMMY 1,0,,0,,0,,0,0,0.13,,0.38,,0.46,,0.48,,0.47,,0.44,,0.4,,0.36,,0.31,,0.26,,0.23,,0.2,,0.18,,0.14,,0.11,,0.1,,0.09,,0.07,,0.05,,0.04,,0.04,,0.03,,0
+DUMMY 2,0,,0,,0,,0.16,0.29,0.35,0.38,0.4,0.41,0.42,0.43,0.43,0.44,0.44,0.44,0.44,0.43,0.42,0.39,0.36,0.32,0.29,0.26,0.23,0.2,0.18,0.16,0.15,0.14,0.12,0.11,0.1,0.09,0.09,0.08,0.07,0.07,0.06,0.06,0.05,0.05,0.05,0.04,0.04,0.04,0.04,0.03,0.03,0,0
diff --git a/tests/data/power_curves.csv b/tests/data/power_curves.csv
new file mode 100755
index 00000000..85890d50
--- /dev/null
+++ b/tests/data/power_curves.csv
@@ -0,0 +1,3 @@
+turbine_type,0,0.5,1,1.5,2,2.5,3,3.5,4,4.5,5,5.5,6,6.5,7,7.5,8,8.5,9,9.5,10,10.5,11,11.5,12,12.5,13,13.5,14,14.5,15,15.5,16,16.5,17,17.5,18,18.5,19,19.5,20,20.5,21,21.5,22,22.5,23,23.5,24,24.5,25,25.5,26
+DUMMY 3,0,0,0,0,0,0,0,18000,34000,70000,10000,150000,190000,260000,330000,420000,510000,620000,740000,880000,1020000,1180000,1330000,1420000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,1500000,0,
+DUMMY 4,0,,0,,0,,0,,4000,,22000,,46000,,76000,,111000,,147000,,184000,,219000,,249000,,274000,,290000,,297000,,302000,,307000,,307000,,305000,,295000,,280000,,260000,,240000,,230000,,225000,0,
diff --git a/tests/data/turbine_data.csv b/tests/data/turbine_data.csv
new file mode 100644
index 00000000..0e9b9f9f
--- /dev/null
+++ b/tests/data/turbine_data.csv
@@ -0,0 +1,5 @@
+turbine_type,nominal_power
+DUMMY 1,4200000
+DUMMY 2,4200000
+DUMMY 3,1500000
+DUMMY 4,225000
diff --git a/tests/test_turbine_cluster_modelchain.py b/tests/test_turbine_cluster_modelchain.py
index 8a827978..463328b5 100644
--- a/tests/test_turbine_cluster_modelchain.py
+++ b/tests/test_turbine_cluster_modelchain.py
@@ -364,15 +364,20 @@ def test_heigths_as_string(self):
 
         # Convert data heights to str
         string_weather = self.weather_df.copy()
-        string_weather.columns = pd.MultiIndex.from_arrays([
-            string_weather.columns.get_level_values(0),
-            string_weather.columns.get_level_values(1).astype(str)])
+        string_weather.columns = pd.MultiIndex.from_arrays(
+            [
+                string_weather.columns.get_level_values(0),
+                string_weather.columns.get_level_values(1).astype(str),
+            ]
+        )
 
         # Heights in the original DataFrame are of type np.int64
-        assert isinstance(self.weather_df.columns.get_level_values(1)[0],
-                          np.int64)
+        assert isinstance(
+            self.weather_df.columns.get_level_values(1)[0], np.int64
+        )
         assert isinstance(string_weather.columns.get_level_values(1)[0], str)
 
         test_mc = tc_mc.TurbineClusterModelChain(
-            power_plant=wtc.WindTurbineCluster(**self.test_cluster))
+            power_plant=wtc.WindTurbineCluster(**self.test_cluster)
+        )
         test_mc.run_model(string_weather)
diff --git a/tests/test_wind_turbine.py b/tests/test_wind_turbine.py
index 4140911f..12af8763 100644
--- a/tests/test_wind_turbine.py
+++ b/tests/test_wind_turbine.py
@@ -22,7 +22,7 @@ class TestWindTurbine:
     @classmethod
     def setup_class(cls):
         """Setup default values"""
-        cls.source = os.path.join(os.path.dirname(__file__), "../example/data")
+        cls.source = os.path.join(os.path.dirname(__file__), "data")
 
     def test_warning(self, recwarn):
         test_turbine_data = {
@@ -114,10 +114,10 @@ def test_wrongly_defined_to_group_method(self):
     def test_create_unphysical_turbine(self):
         err_msg = "1/2rotor_diameter cannot be greater than hub_height"
         char = {
-           'hub_height': 80,
-           'rotor_diameter': 160,
-           'turbine_type': 'DUMMY 3',
-           'path': self.source
+            "hub_height": 80,
+            "rotor_diameter": 160,
+            "turbine_type": "DUMMY 3",
+            "path": self.source,
         }
         with pytest.raises(ValueError, match=err_msg):
             WindTurbine(**char)
diff --git a/windpowerlib/__init__.py b/windpowerlib/__init__.py
index a206ff5a..86aa5125 100644
--- a/windpowerlib/__init__.py
+++ b/windpowerlib/__init__.py
@@ -2,9 +2,10 @@
 __license__ = "MIT"
 __version__ = "0.2.1dev"
 
-from windpowerlib.wind_turbine import WindTurbine
-from windpowerlib.wind_farm import WindFarm
-from windpowerlib.wind_turbine_cluster import WindTurbineCluster
-from windpowerlib.modelchain import ModelChain
-from windpowerlib.turbine_cluster_modelchain import TurbineClusterModelChain
-from windpowerlib.wind_turbine import get_turbine_types
+from .wind_turbine import WindTurbine  # noqa: F401
+from .wind_turbine import get_turbine_types  # noqa: F401
+from .wind_turbine import create_power_curve  # noqa: F401
+from .wind_farm import WindFarm  # noqa: F401
+from .wind_turbine_cluster import WindTurbineCluster  # noqa: F401
+from .modelchain import ModelChain  # noqa: F401
+from .turbine_cluster_modelchain import TurbineClusterModelChain  # noqa: F401
diff --git a/windpowerlib/density.py b/windpowerlib/density.py
index 2630438d..4855a301 100644
--- a/windpowerlib/density.py
+++ b/windpowerlib/density.py
@@ -62,8 +62,13 @@ def barometric(pressure, pressure_height, hub_height, temperature_hub_height):
         http://www.dwd.de/DE/service/lexikon/begriffe/D/Druckgradient_pdf.pdf?__blob=publicationFile&v=4
 
     """
-    return ((pressure / 100 - (hub_height - pressure_height) * 1 / 8) * 1.225 *
-            288.15 * 100 / (101330 * temperature_hub_height))
+    return (
+        (pressure / 100 - (hub_height - pressure_height) * 1 / 8)
+        * 1.225
+        * 288.15
+        * 100
+        / (101330 * temperature_hub_height)
+    )
 
 
 def ideal_gas(pressure, pressure_height, hub_height, temperature_hub_height):
@@ -125,5 +130,8 @@ def ideal_gas(pressure, pressure_height, hub_height, temperature_hub_height):
             http://www.dwd.de/DE/service/lexikon/begriffe/D/Druckgradient_pdf.pdf?__blob=publicationFile&v=4
 
     """
-    return ((pressure / 100 - (hub_height - pressure_height) * 1 / 8) * 100 /
-            (287.058 * temperature_hub_height))
+    return (
+        (pressure / 100 - (hub_height - pressure_height) * 1 / 8)
+        * 100
+        / (287.058 * temperature_hub_height)
+    )
diff --git a/windpowerlib/modelchain.py b/windpowerlib/modelchain.py
index 57d9dfd4..128d3b77 100644
--- a/windpowerlib/modelchain.py
+++ b/windpowerlib/modelchain.py
@@ -144,7 +144,7 @@ def __init__(
         density_correction=False,
         obstacle_height=0,
         hellman_exp=None,
-        **kwargs
+        **kwargs,
     ):
 
         self.power_plant = power_plant
diff --git a/windpowerlib/power_curves.py b/windpowerlib/power_curves.py
index ef9eb138..00549a01 100644
--- a/windpowerlib/power_curves.py
+++ b/windpowerlib/power_curves.py
@@ -11,10 +11,15 @@
 from windpowerlib import tools
 
 
-def smooth_power_curve(power_curve_wind_speeds, power_curve_values,
-                       block_width=0.5, wind_speed_range=15.0,
-                       standard_deviation_method='turbulence_intensity',
-                       mean_gauss=0, **kwargs):
+def smooth_power_curve(
+    power_curve_wind_speeds,
+    power_curve_values,
+    block_width=0.5,
+    wind_speed_range=15.0,
+    standard_deviation_method="turbulence_intensity",
+    mean_gauss=0,
+    **kwargs,
+):
     r"""
     Smoothes a power curve by using a Gauss distribution.
 
@@ -159,7 +164,7 @@ def smooth_power_curve(power_curve_wind_speeds, power_curve_values,
         # Get standard deviation for Gauss function
         standard_deviation = (
             (power_curve_wind_speed * normalized_standard_deviation + 0.6)
-            if standard_deviation_method is "Staffell_Pfenninger"
+            if standard_deviation_method == "Staffell_Pfenninger"
             else power_curve_wind_speed * normalized_standard_deviation
         )
         # Get the smoothed value of the power output
diff --git a/windpowerlib/power_output.py b/windpowerlib/power_output.py
index 4db874b9..d254200c 100644
--- a/windpowerlib/power_output.py
+++ b/windpowerlib/power_output.py
@@ -9,9 +9,13 @@
 import pandas as pd
 
 
-def power_coefficient_curve(wind_speed, power_coefficient_curve_wind_speeds,
-                            power_coefficient_curve_values, rotor_diameter,
-                            density):
+def power_coefficient_curve(
+    wind_speed,
+    power_coefficient_curve_wind_speeds,
+    power_coefficient_curve_values,
+    rotor_diameter,
+    density,
+):
     r"""
     Calculates the turbine power output using a power coefficient curve.
 
diff --git a/windpowerlib/tools.py b/windpowerlib/tools.py
index 07ec376f..f033e6b5 100644
--- a/windpowerlib/tools.py
+++ b/windpowerlib/tools.py
@@ -22,6 +22,7 @@ class WindpowerlibUserWarning(UserWarning):
     >>> import warnings
     >>> warnings.filterwarnings("ignore", category=WindpowerlibUserWarning)
     """
+
     pass
 
 
@@ -187,9 +188,13 @@ def gauss_distribution(function_variable, standard_deviation, mean=0):
              New York, Cambridge University Press, 2011, p. 37
 
     """
-    return (1 / (standard_deviation * np.sqrt(2 * np.pi)) *
-            np.exp(-(function_variable - mean)**2 /
-                   (2 * standard_deviation**2)))
+    return (
+        1
+        / (standard_deviation * np.sqrt(2 * np.pi))
+        * np.exp(
+            -((function_variable - mean) ** 2) / (2 * standard_deviation ** 2)
+        )
+    )
 
 
 def estimate_turbulence_intensity(height, roughness_length):
diff --git a/windpowerlib/turbine_cluster_modelchain.py b/windpowerlib/turbine_cluster_modelchain.py
index b6309ac2..8f44f940 100644
--- a/windpowerlib/turbine_cluster_modelchain.py
+++ b/windpowerlib/turbine_cluster_modelchain.py
@@ -152,7 +152,7 @@ def __init__(
         block_width=0.5,
         standard_deviation_method="turbulence_intensity",
         smoothing_order="wind_farm_power_curves",
-        **kwargs
+        **kwargs,
     ):
         super(TurbineClusterModelChain, self).__init__(power_plant, **kwargs)
 
diff --git a/windpowerlib/wake_losses.py b/windpowerlib/wake_losses.py
index 77e46834..822efe7a 100644
--- a/windpowerlib/wake_losses.py
+++ b/windpowerlib/wake_losses.py
@@ -10,7 +10,7 @@
 import os
 
 
-def reduce_wind_speed(wind_speed, wind_efficiency_curve_name='dena_mean'):
+def reduce_wind_speed(wind_speed, wind_efficiency_curve_name="dena_mean"):
     r"""
     Reduces wind speed by a wind efficiency curve.
 
diff --git a/windpowerlib/wind_farm.py b/windpowerlib/wind_farm.py
index e7deb42d..aa806aa1 100644
--- a/windpowerlib/wind_farm.py
+++ b/windpowerlib/wind_farm.py
@@ -9,7 +9,6 @@
 from windpowerlib import tools, power_curves, WindTurbine
 import numpy as np
 import pandas as pd
-import logging
 import warnings
 
 
@@ -308,7 +307,7 @@ def assign_power_curve(
         standard_deviation_method="turbulence_intensity",
         smoothing_order="wind_farm_power_curves",
         turbulence_intensity=None,
-        **kwargs
+        **kwargs,
     ):
         r"""
         Calculates the power curve of a wind farm.
diff --git a/windpowerlib/wind_speed.py b/windpowerlib/wind_speed.py
index c620dd43..6bbe24b9 100644
--- a/windpowerlib/wind_speed.py
+++ b/windpowerlib/wind_speed.py
@@ -9,8 +9,13 @@
 import pandas as pd
 
 
-def logarithmic_profile(wind_speed, wind_speed_height, hub_height,
-                        roughness_length, obstacle_height=0.0):
+def logarithmic_profile(
+    wind_speed,
+    wind_speed_height,
+    hub_height,
+    roughness_length,
+    obstacle_height=0.0,
+):
     r"""
     Calculates the wind speed at hub height using a logarithmic wind profile.
 
diff --git a/windpowerlib/wind_turbine.py b/windpowerlib/wind_turbine.py
index 6ab1c52a..1c71aab9 100644
--- a/windpowerlib/wind_turbine.py
+++ b/windpowerlib/wind_turbine.py
@@ -101,7 +101,7 @@ class WindTurbine(object):
     >>> print(e126.nominal_power)
     4200000.0
     >>> # Example with own path
-    >>> path=os.path.join(os.path.dirname(__file__), '../example/data')
+    >>> path=os.path.join(os.path.dirname(__file__), '../tests/data')
     >>> example_turbine={
     ...    'hub_height': 100,
     ...    'rotor_diameter': 70,
@@ -123,7 +123,7 @@ def __init__(
         power_coefficient_curve=None,
         rotor_diameter=None,
         turbine_type=None,
-        **kwargs
+        **kwargs,
     ):
 
         self.hub_height = hub_height
@@ -176,7 +176,7 @@ def __init__(
                     self.rotor_diameter = float(turbine_data["rotor_diameter"])
 
         if self.rotor_diameter:
-            if self.hub_height <= 0.5*self.rotor_diameter:
+            if self.hub_height <= 0.5 * self.rotor_diameter:
                 msg = "1/2rotor_diameter cannot be greater than hub_height"
                 raise ValueError(msg)
 
@@ -378,7 +378,7 @@ def get_turbine_data_from_file(turbine_type, path):
     --------
     >>> from windpowerlib import wind_turbine
     >>> import os
-    >>> path=os.path.join(os.path.dirname(__file__), '../example/data',
+    >>> path=os.path.join(os.path.dirname(__file__), '../tests/data',
     ...     'power_curves.csv')
     >>> d3=get_turbine_data_from_file('DUMMY 3', path)
     >>> print(d3['value'][7])
@@ -409,6 +409,27 @@ def get_turbine_data_from_file(turbine_type, path):
         return wpp_df
 
 
+def create_power_curve(wind_speed, power):
+    """
+    A list, numpy.array, pandas.Series or other iterables can be passed to
+    define the wind speed and the power output. Make sure that the order is
+    not mutable because, values from both parameters will be used as value
+    pairs.
+
+    Parameters
+    ----------
+    wind_speed : iterable
+        A series of wind speed values in meter per second [m/s].
+    power : iterable
+        A series of power values in Watt [W].
+
+    Returns
+    -------
+    pandas.DataFrame
+    """
+    return pd.DataFrame(data={"value": power, "wind_speed": wind_speed})
+
+
 def load_turbine_data_from_oedb(schema="supply", table="wind_turbine_library"):
     r"""
     Loads turbine library from the OpenEnergy database (oedb).
@@ -502,7 +523,7 @@ def load_turbine_data_from_oedb(schema="supply", table="wind_turbine_library"):
         axis=1,
     ).set_index("turbine_type")
     # nominal power in W
-    turbine_data_df["nominal_power"] = turbine_data_df["nominal_power"] * 1000
+    turbine_data_df["nominal_power"] *= 1000
     turbine_data_df.to_csv(filename.format("turbine_data"))
     return turbine_data
 
diff --git a/windpowerlib/wind_turbine_cluster.py b/windpowerlib/wind_turbine_cluster.py
index 5507aecb..166ea64f 100644
--- a/windpowerlib/wind_turbine_cluster.py
+++ b/windpowerlib/wind_turbine_cluster.py
@@ -132,7 +132,7 @@ def assign_power_curve(
         standard_deviation_method="turbulence_intensity",
         smoothing_order="wind_farm_power_curves",
         turbulence_intensity=None,
-        **kwargs
+        **kwargs,
     ):
         r"""
         Calculates the power curve of a wind turbine cluster.