Chain wind siting to support contiguous siting of multiple farms

[crvernon]

Wind farms need to be connected networks of grid cells if the unit size is larger than the amount of MW that a grid cell can support is exceeded.

[jenniesrice]

The process of wind farm siting in CERF:

1. GCAM-USA provides total MW of new wind capacity for each state in each time step (actually, CERF converts GCAM-USA new wind energy to MW of new wind capacity)

2. CERF needs a new parameter with a constant assumed value for average wind farm capacity (in MW) that it will use to determine the number of new wind farms to be sited in each state. # new wind farms to site per state = Total new wind MW per state / average wind farm capacity (MW). This needs to be researched. Also, let's consider that perhaps at some point we will want this new parameter to vary by state (e.g., Wyoming only sites massive wind farms, Georgia wind farms are 1/5 the size of WY wind farms)

3. CERF needs a new parameter with a constant assumed value for average MW produced per 1 km grid cell. In other words, # grid cells needed per wind farm = Average wind farm capacity (MW) / average MW produced in each 1 km grid cell. For example, if the average wind farm is 20 MW and each 1 km can produce 4 MW, then CERF will need to designate 5 cells (shape TBD) as "sited" for each wind farm.

According to this site, https://css.umich.edu/factsheets/wind-energy-factsheet, "Large (>20 MW) wind projects require ~85 acres of land area per MW of installed capacity, but 1% or less of this total area is occupied by roads, turbine foundations, or other equipment; the remainder is available for other uses.9" Since a square km has 247 acres, this would mean about 3 MW per 1 km grid cell. This needs more research.

4. CERF needs to have an assumption for the shape of the average wind farm (e.g., rectangular or square). This will result in a standard wind farm footprint that CERF will use for the siting process. This needs to be researched.

5. CERF siting logic to be discussed more after we get the Nature paper done!

[kmongird]

USGS's wind farm database looks like a highly valuable resource for this task: https://eerscmap.usgs.gov/uswtdb/viewer/#4.56/38.78/-100.3

An alternative idea to establishing a single unit size and shape for wind and looking for suitable connected grid cells that match a specific layout could be to allow wind farms to be built within a range of unit sizes. It could start at a minimum threshold (e.g. 8 MW, 2 grid cells) and grow in any shape until it either (1) hits the maximum capacity allowed (e.g. 40 MW, 10 grid cells) or (2) runs out of connected, suitable grid cells.

This would eliminate the need to site wind farms in a specific shape, allow larger wind farms to be built in areas that have a large amount of available space, and allow small wind farms to still be built in areas that may have fewer connected grid cells available (e.g., Florida)