1. dena Grid Study II Integration of Renewable Energy Sources in the German Power Supply System from with an Outlook to 2025
Jaakko Iivanainen

2. Contents Introduction Areas studied Wind Grid Flexibility and Storage
Results

3. dena Grid Study II
Aim: To find solutions to fully integrate 39% RE suppy to the German grid by 2020
Securing supply
European energy market
Different approaches to improving and expanding the grid
Complete integration of RE by increasing flexibility
Storages
Demand side management
Improved wind forecast capablility
Balancing energy by wind or biomass

4. dena Grid Study II dena Grid Study II is based
20% of all energy from RE souces by 2015
850 km of new trasmission lines required
dena Grid Study I results incorporated in the Power Grid Expansion Act as priority projects
dena Grid Study II assumes that that the grid enhancements and expansion measures have been implemented

5. Areas studied All sections studied Main focus on:
Wind energy feed in time series
Transmission requirements
Flexibility and integration of renewables

6. Part I Generation of feed-in timeseries for wind
Time series of 15 minutes
based on historical data from a numerical weather model
consists of hourly values from 2004 to 2007
transformed to electrical wind power in 2020 using physical models
data pool of measurements from 83 wind farms was used to complete the weather model
1186 onshore grid nodes and 46 offshore wind farms
37 GW onshore wind capacity, 14 GW offshore wind
Results in 2200 full-load hours onshore and 4400 full-load hours offshore

7. Part I Generation of feed-in timeseries for wind
27% wind penetration was calculated
Extension of wind power in leads to reduced relative fluctuation of wind power across Germany
Reduces need for balancing power
The wind power time series of part I for the basis for grid calculations in part II and the balancing power calculations in part III

8. Part I Generation of feed-in timeseries for wind
Evaluation:
Wind measurement data is collected only from 4 consecutive years instead of recommended 8
The simulations correlate very well with measurements
The benchmark case for the study is the previous study
Reality might turn out to be very different
Properties of future wind turbines were assumed

9. Part II Effects on the grid and future development
Grid suggested in dena Grid Study I is examined
Larger feed of RE
Non-transmittable power
Optimization measures evaluated
Non-transmittable power in 70% of all borders
2015 grid inadequate in 2020

10. Part II Effects on the grid and future development
Increasing transmission capacity of overhead lines
Flexible line management (FLM)
Conductor temperature is monitored
Strong winds and low outdoor temperature allow up to 50% increase in current
High temperature conductors (TAL)
High temperature resistant aluminum
50% higher current than normal
Neither are considered economically viable

11. Part II Effects on the grid and future development
Integration solutions:
Integration via grid extension (version 000)
50% storage of non-transmittable power in the bottleneck region (version 050)
100% storage of non-transmittable power in the bottleneck region (version 100)
combined with:
Basic grid with standard transmission capacity (BAS)
Flexible line management (FLM)
High temperature conductors (TAL)
Total nine variants

12. Part II Effects on the grid and future development

13. Part III Increasing flexibility for the best possible integration of renewable energy
The wind energy forecast quality can be improved by approx. 45%
Demand side management potential taken into account in process industry and a few applications in domestic environments.
60% of the demand for positive balancing energy
2% of the negative balancing energy
Biomass plants have in principle the ability to do high power ramps
generally suitable for providing balancing power

14. Part III Increasing flexibility for the best possible integration of renewable energy
Pumped storage assumed to increase 1700 MW
Electricity storage would not relieve grid bottlenecks, when they behave in an economically optimal way.
Compressed air and hydrogen storage facilities will not occur in the simulation due to being uneconomical

15. Overall results

16. Assumptions and limitations
Properties of future wind turbines were assumed
Nuclear phase-out: 2020 nuclear capacity 6.7 GW
Might turn out different
Model-based economic optimization of conventional power stations in Germany
European market integration only limited by interconnector capacities
Photovoltaics 18 GW in 2020
40 GW in 2016
Assumed 8% reduction in net electricity consumption between and 2020

17. Thank you!