Alberto Dalla Riva: System Value of Wind Power - An Analysis of the Effects of Wind Turbine Design, MSc Thesis, DTU and Università degli Studi di Padova, 2016
Nowadays, the European power system is undergoing a radical change, as the increasing share of wind energy is posing operational and market integration issues. In countries with substantial wind penetration, the simultaneous production of large wind fleets is pushing electricity prices down in hours of high wind, reducing income for wind producers. As a consequence, market value of wind is dropping, potentially endangering future investments in the technology. Beside a number of other suggested mitigation measures, deploying a more system-friendly wind technology has been proposed as an alternative and more effective solution. This advanced technology is now available in the market and features increased hub heights and larger rotor diameters for the same rated power.
This thesis intends to assess the system impacts, the potential cost reductions and the market value projections of different wind turbine designs. Using an Economic Dispatch model named Balmorel, the development of the European power system and the market outcome until 2030 is simulated. In this framework, national targets and energy policies, as well as renewables roll-out and planned transmission expansion are taken into account in the model. With a particular focus on Germany, due to the large potential for onshore wind and the country's commitment to renewable energies, the deployment of different onshore wind technologies is simulated. Five technological scenarios are assessed with different levels of specific power and hub heights. A new way of modelling wind generation using aggregated regional power curves has been specifically proposed and used for this study.
The outcomes of the analysis show that reduced specific power has a higher impact in both the system and the electricity market compared to increased hub height. Deploying lower specific power in new installations shows a decrease in total system costs and other system advantages, such as reduced curtailment, lower fossil fuel production and less steep residual load duration curve. As for the market value, large differences across specific power technologies are resulting from the simulations. The adoption of turbines with a specific power of 400 W/m2 results in a market value of onshore wind dramatically lower than the average market price. In opposition, the reduction of specific power from 400 to 200 W/m2 shows an increase in the market value of 30% in Germany for the year 2030, with an onshore penetration level of 31%. This figure is higher when compared to previous works considering a green-field optimum system and robust across large variations in fossil fuel and CO2 prices. The site specific trade-off between increased levelized cost of electricity on one side and higher value on the other remains to be assessed.
The result of studies like the present one can provide policy-makers valuable information in order to design effective support schemes to drive the deployment of system-friendly wind technologies. At the same time, it could make project developers become more aware of the risks related to eventual collapse in the wind market value. Opting for economic design criteria when investing in wind power and shifting from a cost to a value perspective can have positive impacts for both private stakeholders and society as a whole.