## 4.4 Wind power

The module distinguishes between onshore and offshore wind generation.

The supply curves for wind are provided by the National Renewable Energy Laboratory (NREL), see the reference paper by Euret et al. (2016, forthcoming) and (Arent et al. 2012). The curves provide the maximum amount of capacity which can be installed in each region as a function of four factors:

1. capacity factor / full load hours (onshore and offshore) (wind_class in the model) - Nine classes: 9%, 20%, 24%, 28%, 32%, 36%, 40%, 44%, 48%
2. distance from load centres (onshore only) (wind_distance in the model) - Three classes: near (0-50 miles), transitional (50-100 miles), far (100-5000 m)
3. distance from shore (offshore only) (wind_distance in the model) - Three classes: near (5-20 nautical miles), transitional (20-50 nautical miles), far (50-100 nautical miles)
4. sea depth (offshore only) (wind_depth in the model) - Three classes: shallow (0-30 m), transitional (30-60 m), deep (60-1000 m)

The following table summarizes the main parameters for wind power:

Parameter Onshore wind Offshore wind
Global capacity 63 GW (2005) 0 GW (2005)
194 GW (2010) 3 GW (2010)
420 GW (2015) 11 GW (2015)
Base year investment cost 1467 USD/kW 2641 USD/kW (shallow)
2861 USD/kW (transitional)
3081 USD/kW (deep)
Lifetime 30 years 30 years
O&M cost {25,30} \$/kW 2 $$\times$$ onshore
Learning rate 10% 13%
Cross learning 80% 80%
Floor cost 500 USD/kW 900 USD/kW

The capacity is fixed up to the year 2015 in order to allow the model capturing the strong growth which has been taking place in recent years.

Investment costs are the same in all regions and decline over time through a learning-by-doing process (learning-by-researching is not modelled). The decline rate depends on the cumulative capacity installed worldwide and on the learning rate. The cross learning parameter indicates the share of the installed capacity of wind onshore (offshore) which is accounted for to calculate the cost reduction of wind offshore (onshore). As in the case of Solar, the standard equations of the energy module also apply for wind, only that now the variables are specifically defined per capacity factor classes, distance from load centres, and in the case of off-shore, the distance from the shore and depth.

### References

Arent, Douglas, Patrick Sullivan, Donna Heimiller, Anthony Lopez, Kelly Eurek, and others. 2012. “Improved Offshore Wind Resource Assessment in Global Climate Stabilization Scenarios.” National Renewable Energy Laboratory.