pypsa-eur/scripts/build_renewable_profiles.py

#!/usr/bin/env python
"""Calculates for each network node the
(i) installable capacity (based on land-use), (ii) the available generation time
series (based on weather data), and (iii) the average distance from the node for
onshore wind, AC-connected offshore wind, DC-connected offshore wind and solar
PV generators. In addition for offshore wind it calculates the fraction of the
grid connection which is under water.

.. note:: Hydroelectric profiles are built in script :mod:`build_hydro_profiles`.

Relevant settings
-----------------

.. code:: yaml

    snapshots:

    atlite:
        nprocesses:

    renewable:
        {technology}:
            cutout:
            corine:
            grid_codes:
            distance:
            natura:
            max_depth:
            max_shore_distance:
            min_shore_distance:
            capacity_per_sqkm:
            correction_factor:
            potential:
            min_p_max_pu:
            clip_p_max_pu:
            resource:

.. seealso:: 
    Documentation of the configuration file ``config.yaml`` at
    :ref:`snapshots_cf`, :ref:`atlite_cf`, :ref:`renewable_cf`

Inputs
------

- ``data/bundle/corine/g250_clc06_V18_5.tif``: `CORINE Land Cover (CLC) <https://land.copernicus.eu/pan-european/corine-land-cover>`_ inventory on `44 classes <https://wiki.openstreetmap.org/wiki/Corine_Land_Cover#Tagging>`_ of land use (e.g. forests, arable land, industrial, urban areas).

    .. image:: ../img/corine.png
        :scale: 33 %

- ``data/bundle/GEBCO_2014_2D.nc``: A `bathymetric <https://en.wikipedia.org/wiki/Bathymetry>`_ data set with a global terrain model for ocean and land at 15 arc-second intervals by the `General Bathymetric Chart of the Oceans (GEBCO) <https://www.gebco.net/data_and_products/gridded_bathymetry_data/>`_.

    .. image:: ../img/gebco_2019_grid_image.jpg
        :scale: 50 %

    **Source:** `GEBCO <https://www.gebco.net/data_and_products/images/gebco_2019_grid_image.jpg>`_

- ``resources/natura.tiff``: confer :ref:`natura`
- ``resources/country_shapes.geojson``: confer :ref:`shapes`
- ``resources/offshore_shapes.geojson``: confer :ref:`shapes`
- ``resources/regions_onshore.geojson``: (if not offshore wind), confer :ref:`busregions`
- ``resources/regions_offshore.geojson``: (if offshore wind), :ref:`busregions`
- ``"cutouts/" + config["renewable"][{technology}]['cutout']``: :ref:`cutout`
- ``networks/base.nc``: :ref:`base`

Outputs
-------

- ``resources/profile_{technology}.nc`` with the following structure

    ===================  ==========  =========================================================
    Field                Dimensions  Description
    ===================  ==========  =========================================================
    profile              bus, time   the per unit hourly availability factors for each node
    -------------------  ----------  ---------------------------------------------------------
    weight               bus         sum of the layout weighting for each node
    -------------------  ----------  ---------------------------------------------------------
    p_nom_max            bus         maximal installable capacity at the node (in MW)
    -------------------  ----------  ---------------------------------------------------------
    potential            y, x        layout of generator units at cutout grid cells inside the
                                     Voronoi cell (maximal installable capacity at each grid
                                     cell multiplied by capacity factor)
    -------------------  ----------  ---------------------------------------------------------
    average_distance     bus         average distance of units in the Voronoi cell to the
                                     grid node (in km)
    -------------------  ----------  ---------------------------------------------------------
    underwater_fraction  bus         fraction of the average connection distance which is
                                     under water (only for offshore)
    ===================  ==========  =========================================================

    - **profile**

    .. image:: ../img/profile_ts.png
        :scale: 33 %
    
    - **p_nom_max**

    .. image:: ../img/p_nom_max_hist.png
        :scale: 33 %
    
    - **potential**

    .. image:: ../img/potential_heatmap.png
        :scale: 33 %
    
    - **average_distance**
    
    .. image:: ../img/distance_hist.png
        :scale: 33 %
    
    - **underwater_fraction**
    
    .. image:: ../img/underwater_hist.png
        :scale: 33 %

Description
-----------

This script functions at two main spatial resolutions: the resolution of the
network nodes and their `Voronoi cells
<https://en.wikipedia.org/wiki/Voronoi_diagram>`_, and the resolution of the
cutout grid cells for the weather data. Typically the weather data grid is
finer than the network nodes, so we have to work out the distribution of
generators across the grid cells within each Voronoi cell. This is done by
taking account of a combination of the available land at each grid cell and the
capacity factor there.

First the script computes how much of the technology can be installed at each
cutout grid cell and each node using the `GLAES
<https://github.com/FZJ-IEK3-VSA/glaes>`_ library. This uses the CORINE land use data,
Natura2000 nature reserves and GEBCO bathymetry data.

To compute the layout of generators in each node's Voronoi cell, the
installable potential in each grid cell is multiplied with the capacity factor
at each grid cell. This is done since we assume more generators are installed
at cells with a higher capacity factor.

This layout is then used to compute the generation availability time series
from the weather data cutout from ``atlite``.

Two methods are available to compute the maximal installable potential for the
node (`p_nom_max`): ``simple`` and ``conservative``:

- ``simple`` adds up the installable potentials of the individual grid cells.
  If the model comes close to this limit, then the time series may slightly
  overestimate production since it is assumed the geographical distribution is
  proportional to capacity factor.

- ``conservative`` assertains the nodal limit by increasing capacities
  proportional to the layout until the limit of an individual grid cell is
  reached.

"""
import logging
logger = logging.getLogger(__name__)
from _helpers import configure_logging

import matplotlib.pyplot as plt

import os
import atlite
import numpy as np
import xarray as xr
import pandas as pd
import multiprocessing as mp

import glaes as gl
import geokit as gk
from osgeo import gdal
from scipy.sparse import csr_matrix, vstack

from pypsa.geo import haversine
from vresutils import landuse as vlanduse
from vresutils.array import spdiag

import progressbar as pgb

bounds = dx = dy = config = paths = gebco = clc = natura = None
def init_globals(bounds_xXyY, n_dx, n_dy, n_config, n_paths):
    # global in each process of the multiprocessing.Pool
    global bounds, dx, dy, config, paths, gebco, clc, natura

    bounds = gk.Extent.from_xXyY(bounds_xXyY)
    dx = n_dx
    dy = n_dy
    config = n_config
    paths = n_paths

    if "max_depth" in config:
        gebco = gk.raster.loadRaster(paths["gebco"])
        gebco.SetProjection(gk.srs.loadSRS(4326).ExportToWkt())

    clc = gk.raster.loadRaster(paths["corine"])
    clc.SetProjection(gk.srs.loadSRS(3035).ExportToWkt())

    natura = gk.raster.loadRaster(paths["natura"])

def downsample_to_coarse_grid(bounds, dx, dy, mask, data):
    # The GDAL warp function with the 'average' resample algorithm needs a band of zero values of at least
    # the size of one coarse cell around the original raster or it produces erroneous results
    orig = mask.createRaster(data=data)
    padded_extent = mask.extent.castTo(bounds.srs).pad(max(dx, dy)).castTo(mask.srs)
    padded = padded_extent.fit((mask.pixelWidth, mask.pixelHeight)).warp(orig, mask.pixelWidth, mask.pixelHeight)
    orig = None # free original raster
    average = bounds.createRaster(dx, dy, dtype=gdal.GDT_Float32)
    assert gdal.Warp(average, padded, resampleAlg='average') == 1, "gdal warp failed: %s" % gdal.GetLastErrorMsg()
    return average

def calculate_potential(gid, save_map=None):
    feature = gk.vector.extractFeature(paths["regions"], where=gid)
    ec = gl.ExclusionCalculator(feature.geom)

    corine = config.get("corine", {})
    if isinstance(corine, list):
        corine = {'grid_codes': corine}
    if "grid_codes" in corine:
        ec.excludeRasterType(clc, value=corine["grid_codes"], invert=True)
    if corine.get("distance", 0.) > 0.:
        ec.excludeRasterType(clc, value=corine["distance_grid_codes"], buffer=corine["distance"])

    if config.get("natura", False):
        ec.excludeRasterType(natura, value=1)
    if "max_depth" in config:
        ec.excludeRasterType(gebco, (None, -config["max_depth"]))

    # TODO compute a distance field as a raster beforehand
    if 'max_shore_distance' in config:
        ec.excludeVectorType(paths["country_shapes"], buffer=config['max_shore_distance'], invert=True)
    if 'min_shore_distance' in config:
        ec.excludeVectorType(paths["country_shapes"], buffer=config['min_shore_distance'])

    if save_map is not None:
        ec.draw()
        plt.savefig(save_map, transparent=True)
        plt.close()

    availability = downsample_to_coarse_grid(bounds, dx, dy, ec.region, np.where(ec.region.mask, ec._availability, 0))

    return csr_matrix(gk.raster.extractMatrix(availability).flatten() / 100.)


if __name__ == '__main__':
    pgb.streams.wrap_stderr()

    configure_logging(snakemake)

    config = snakemake.config['renewable'][snakemake.wildcards.technology]

    time = pd.date_range(freq='m', **snakemake.config['snapshots'])
    params = dict(years=slice(*time.year[[0, -1]]), months=slice(*time.month[[0, -1]]))

    cutout = atlite.Cutout(config['cutout'],
                           cutout_dir=os.path.dirname(snakemake.input.cutout),
                           **params)

    minx, maxx, miny, maxy = cutout.extent
    dx = (maxx - minx) / (cutout.shape[1] - 1)
    dy = (maxy - miny) / (cutout.shape[0] - 1)
    bounds_xXyY = (minx - dx/2., maxx + dx/2., miny - dy/2., maxy + dy/2.)

    # Use GLAES to compute available potentials and the transition matrix
    paths = dict(snakemake.input)

    # Use the following for testing the default windows method on linux
    # mp.set_start_method('spawn')
    with mp.Pool(initializer=init_globals, initargs=(bounds_xXyY, dx, dy, config, paths),
                 maxtasksperchild=20, processes=snakemake.config['atlite'].get('nprocesses', 2)) as pool:
        regions = gk.vector.extractFeatures(paths["regions"], onlyAttr=True)
        buses = pd.Index(regions['name'], name="bus")
        widgets = [
            pgb.widgets.Percentage(),
            ' ', pgb.widgets.SimpleProgress(format='(%s)' % pgb.widgets.SimpleProgress.DEFAULT_FORMAT),
            ' ', pgb.widgets.Bar(),
            ' ', pgb.widgets.Timer(),
            ' ', pgb.widgets.ETA()
        ]
        progressbar = pgb.ProgressBar(prefix='Compute GIS potentials: ', widgets=widgets, max_value=len(regions))
        matrix = vstack(list(progressbar(pool.imap(calculate_potential, regions.index))))

    potentials = config['capacity_per_sqkm'] * vlanduse._cutout_cell_areas(cutout)
    potmatrix = matrix * spdiag(potentials.ravel())
    potmatrix.data[potmatrix.data < 1.] = 0 # ignore weather cells where only less than 1 MW can be installed
    potmatrix.eliminate_zeros()

    resource = config['resource']
    func = getattr(cutout, resource.pop('method'))
    correction_factor = config.get('correction_factor', 1.)
    if correction_factor != 1.:
        logger.warning('correction_factor is set as {}'.format(correction_factor))
    capacity_factor = correction_factor * func(capacity_factor=True, show_progress='Compute capacity factors: ', **resource).stack(spatial=('y', 'x')).values
    layoutmatrix = potmatrix * spdiag(capacity_factor)

    profile, capacities = func(matrix=layoutmatrix, index=buses, per_unit=True,
                               return_capacity=True, show_progress='Compute profiles: ',
                               **resource)

    p_nom_max_meth = config.get('potential', 'conservative')

    if p_nom_max_meth == 'simple':
        p_nom_max = xr.DataArray(np.asarray(potmatrix.sum(axis=1)).squeeze(), [buses])
    elif p_nom_max_meth == 'conservative':
        # p_nom_max has to be calculated for each bus and is the minimal ratio
        # (min over all weather grid cells of the bus region) between the available
        # potential (potmatrix) and the used normalised layout (layoutmatrix /
        # capacities), so we would like to calculate i.e. potmatrix / (layoutmatrix /
        # capacities). Since layoutmatrix = potmatrix * capacity_factor, this
        # corresponds to capacities/max(capacity factor in the voronoi cell)
        p_nom_max = xr.DataArray([1./np.max(capacity_factor[inds]) if len(inds) else 0.
                                  for inds in np.split(potmatrix.indices, potmatrix.indptr[1:-1])], [buses]) * capacities
    else:
        raise AssertionError('Config key `potential` should be one of "simple" (default) or "conservative",'
                             ' not "{}"'.format(p_nom_max_meth))

    layout = xr.DataArray(np.asarray(potmatrix.sum(axis=0)).reshape(cutout.shape),
                          [cutout.meta.indexes[ax] for ax in ['y', 'x']])

    # Determine weighted average distance from substation
    cell_coords = cutout.grid_coordinates()

    average_distance = []
    for i in regions.index:
        row = layoutmatrix[i]
        distances = haversine(regions.loc[i, ['x', 'y']], cell_coords[row.indices])[0]
        average_distance.append((distances * (row.data / row.data.sum())).sum())

    average_distance = xr.DataArray(average_distance, [buses])

    ds = xr.merge([(correction_factor * profile).rename('profile'),
                   capacities.rename('weight'),
                   p_nom_max.rename('p_nom_max'),
                   layout.rename('potential'),
                   average_distance.rename('average_distance')])

    if snakemake.wildcards.technology.startswith("offwind"):
        import geopandas as gpd
        from shapely.geometry import LineString

        offshore_shape = gpd.read_file(snakemake.input.offshore_shapes).unary_union
        underwater_fraction = []
        for i in regions.index:
            row = layoutmatrix[i]
            centre_of_mass = (cell_coords[row.indices] * (row.data / row.data.sum())[:,np.newaxis]).sum(axis=0)
            line = LineString([centre_of_mass, regions.loc[i, ['x', 'y']]])
            underwater_fraction.append(line.intersection(offshore_shape).length / line.length)

        ds['underwater_fraction'] = xr.DataArray(underwater_fraction, [buses])

    # select only buses with some capacity and minimal capacity factor
    ds = ds.sel(bus=((ds['profile'].mean('time') > config.get('min_p_max_pu', 0.)) &
                     (ds['p_nom_max'] > config.get('min_p_nom_max', 0.))))

    if 'clip_p_max_pu' in config:
        ds['profile'].values[ds['profile'].values < config['clip_p_max_pu']] = 0.

    ds.to_netcdf(snakemake.output.profile)