Wave Energy Converter
=====================

SAM's wave energy converter (WEC) model uses an electrical power capture matrix to characterize the performance of the converter. This matrix can be generated by a time-domain numerical simulation model such as the open source `WEC-Sim <http://wec-sim.github.io/WEC-Sim/>`__ (Wave Energy Converter Simulation) MATLAB/SIMULINK model. The matrix maps electrical power capture to the significant wave height and peak period in the wave resource scatter diagram on the :doc:`Wave Resource <me_wave_resource>` page and should use the same bin size. The WEC modeling approach is consistent with the method described in LaBonte, A. et al. (2013). `Standardized cost and performance reporting for marine and hydrokinetic technologies <https://www.researchgate.net/publication/299410672_STANDARDIZED_COST_AND_PERFORMANCE_REPORTING_FOR_MARINE_AND_HYDROKINETIC_TECHNOLOGIES>`__. 11 pp. Proceedings of 1st Marine Energy Technology Symposium, Washington DC.

Unlike SAM's other performance models, the wave energy converter model does not perform a time series simulation of the system's performance so it does not generate hourly or subhourly time series results over the year like the other models.

You can either choose a wave power matrix from the wave energy converter library, or you can import the data from a text file or other program.

.. _weclibrary:

WEC Library
...........

SAM's wave energy converter library stores power matrix data and some descriptive information for different types of WECs.

WECS included in the library are based on open-source marine energy point designs as part of the Reference Model Project (RMP), sponsored by the U.S. Department of Energy (DOE). The included reference models are:

* Reference Model 3: Wave Point Absorber

* Reference Model 5: Oscillating Flap

* Reference Model 6: Oscillating Water Column

Related studies and supporting documentation for each reference model is located on the `DOE Reference Model Project website <https://energy.sandia.gov/technology-development/reference-model-project-rmp/>`__.

To choose an WEC from the library:

#. Click **Choose WEC from library**.

#. Click the item in the library.

SAM populates the power matrix table with data from the library and shows converter attributes in the table.

.. note:: You can select the data in the table by holding down the Shift key and using the up and down arrows to select the entire table. Then press Control-C (or Commad-C on a Mac) to copy the data to your clipboard.

Import WEC Power Matrix Data
............................

To model a WEC not found in the library, you can import its power matrix data from a file.

See the `SAM website <https://sam.nlr.gov>`__ for a sample WEC data file.

The WEC power matrix is a table of electrical power in kW for a range of significant wave heights in meters and wave energy periods in seconds with bins that match the wave energy resource scatter diagram on the :doc:`Wave Resource <me_wave_resource>` page. You can either type values into the table by hand, import data from a comma-separated (CSV) text file, or paste data from your computer's clipboard.

To import WEC power matrix data:

#. Click **Import WEC parameters**.

#. To import the data from a file, click **Import**.

#. To paste the data from the clipboard, click **Paste**. Paste works with tab-delimited data so you can paste from a spreadsheet program.

The file format for the WEC power matrix is as follows:

* Columns are separated by commas.

* Row 1 contains the peak wave energy period (Te) value in seconds for each bin. The first column of Row 1 is ignored.

* Column 1 contains the significant wave height (Hs) value in meters for each bin. The first row of Column 1 is ignored.

* The remaining data is the WEC electrical power output in kW for each Te, Hs pair.

.. image:: ../images/SS_MHKWave-WEC-file.png
   :align: center
   :alt: SS_MHKWave-WEC-file.png