SMA Solar Technology AG How PV Inverters Support Electrical Grid Stability Integration of solar power into the electrical grid

Overview  Renewable Energy (RE) and photovoltaic (PV) power in Germany  Present & future plans  Tools for grid management  Generation control  Frequency control  Voltage control  Dynamic grid support (“fault ride through“) 2

3 Renewable Energy capacities in Germany Origin: Branchenprognosse Stromversorgung 2020, Bundesverband Erneuerbare Energien e.V. Berlin Jan  Renewable Energies will replace a significant part of conventional power plants Electricity mix in 2020 in Germany: Renewables will cover 47% of the supply

4 Renewable Energy Targets in EU Origin: Eurean Photovoltaic Association, Paris

5 Ambiguous goal of EPIA: 12% photovoltaic in Europe by 2020  European PV industry (EPIA) has set their goal at 12% of all electric energy consumption in Europe in Origin: 1 EPIA (European Photovoltaic Industry Association) Press Release, Valencia, 4 September 2008  Approx GWp PV-power must be installed in Germany (> 350 GWp in Europe) by 2020!  This is approximately equivalent all currently existing conventional power plants in the UCTE region

6 How much PV-power supports the German grid?  PV power is peak load power!

7  More than 50 GWp of PV-power can be connected without problems  local generation: no new transmission lines neccessary  no additional storage neccessary!  PV must be integrated into grid management  SMA inverters meet all requirements for static and dynamic grid support  Large scale grid integration of PV can be done! Consequences for grid integration of PV

Tools for grid management  Generation control  Frequency control  Voltage control  Dynamic grid support (fault ride through) 8

9 Tools for grid management: Generation control  Manage temporary generation/load imbalance conditions in local grid sector  Limit power generation via remote control and SMA Power Reducer Box to e.g. 100%, 60%, 30% or 0% of maximum power  Already put into practice by DSOs in Vattenfall control zone (small picture, green area)  Available for all SMA inverters of SC, SMC and STP series.

10 Tools for grid management: Frequency control  Momentary reduction of generated power depending on frequency  in case of emergency  in case of generation/load imbalance  to avoid instability  Available for all SMA inverters of SC, SMC and STP series. Quelle: Erzeugungsanlagen am Mittelspannungsnetz. BDEW, Entwurf Dezember ,0550,251,2 f in Hz P PMPM 50,9 Frequency raises up to 50.9 Hz Power is reduced to 28% of P M Power stays constant until frequency is below Hz Back to MPP

11 Tools for grid management: Voltage control  Feed-in of active power has influence on voltage (voltage rise)  Voltage rise can be compensated via feed-in of reactive power  Available reactive power modes:  cos Phi = const.  Q = const.  cos Phi (P)  Q(V)  Available with SMA inverters of SC xxxHE-11, SC xxxCP, STP and SMC 1 series  Influence on dimensioning of inverters! _______________ 1 cos Phi = const. only

12 Tools for grid management: Dynamic grid support (fault ride through) source: German technical guideline for generating plants connected to the medium voltage grid. BDEW, June 2008  Generating facility must not disconnect during voltage fault!  Required behavior:  above „Grenzlinie 1“ stable operation  between „Grenzlinie 1“ and „Grenzlinie 2“ may disconnect in accordance with grid operator  below „Grenzlinie 2“ and below 30% V nom may disconnect

13 Tools for grid management: Full dynamic grid support source: German TransmissionCode 2007  Provide reactive current during voltage fault  Limits the influence of voltage faults (dips) in transmission lines on the grid  Prevention of  simultaneous disconnection of large generating facilities  blackouts!  Available with SMA inverters of SC xxxHE-11 1, SC xxxCP, STP and SMC 1 series  No influence on dimensioning of inverters _______________ 1 limited dynamic grid support only (no reactive current during fault)

14 Summary: The role of photovoltaic energy in power generation > PV and SMA inverters provide ideal conditions for grid integration > local generation, close to consumer > provides peak load power > In Germany integration of more than 50 GWp is possible! > Grid stabilization has to go hand in hand with the expansion of photovoltaic power plants > Requirements must be adjusted to plant size and voltage level ! > The integration of renewable energy sources into grid management allows for the unlimited access of RE to the grid!

15 Contact: Hakki Karacaoglan SMA Solar Technology AG Sonnenallee Niestetal Phone Fax