Interconnectors and RES
Arnis Staltmanis
AS AUGSTSPRIEGUMA TIKLS
Board member
04.07.2013 | www.ast.lv
Content

EU Strategy

The developments of generation capacity in Baltic
States

RES long term challenges

The projects in Baltic States towards 2050
10.05.2013 | www.ast.lv
EU milestones towards 2050
Electricity Highways 2050
 Large and intermittent wind
volumes in the northern
Seas.
 Large-scale solar in
southern Europe and
possibly in northern Africa.
 The Middle East along with
the developments in storing
and consuming electricity
and in decentralized models
of electricity generation.
Towards carbon-neutral
technologies in the future energy
mix
10.05.2013 | www.ast.lv
Drivers of Power System Evolution
 Security of supply
 Renewable energy integration
 Internal Market integration
10.05.2013 | www.ast.lv
Bulk power flows related to generation
connection
10.05.2013 | www.ast.lv
The developments of generation capacity in
Baltic States
Case B, optimistic
14.00
12.00
Not Clearly Identifiable Energy Sources
Hydro power (total)
Biomass
10.00
Solar
Offshore wind
8.00
Onshore wind
Mixed Fuels
Oil
6.00
Gas
Hard Coal
4.00
Lignite
Nuclear Power
2.00
0.00
2013
2015
2016
2020
10.05.2013 | www.ast.lv
The available capacity in Baltic States
Case B, optimistic
14.00
12.00
10.00
System Service Reserve
Outages
8.00
Maintenance and Overhauls
Non-Usable Capacity
6.00
Reliable Available Capacity
Load
4.00
2.00
0.00
2013
2015
2016
2020
The reliable available capacity is shown without market rules.
10.05.2013 | www.ast.lv
The developments of RES in Baltic States
2013
Not Clearly
Identifiable
Energy Sources
0%
Nuclear Power
0%
Renewable
energy sources
36%
Fossil Fuels
64%
Not Clearly
Identifiable
Energy Sources
1%
2020
Nuclear
Power
10%
Renewable
energy sources
40%
Fossil Fuels
49%
10.05.2013 | www.ast.lv
The RES long term challenges
•
•
•
•
•
•
•
Balancing the unpredictable renewable energy sources (RES) –
Wind, Sun and Biomass/Biogas.
High surplus by 2020 expected in the Nordic countries will need to
be transmitted to the Continental Europe.
Grid development may not be in time if RES targets are met as
scheduled, due to internal grid reinforcement restrictions.
Uncertainties regarding the market development on the EURussian border.
Large uncertainty regarding generator investments is a challenge
for grid development.
North - South flow direction in all the Baltic Sea countries.
Changing of power balance in Germany is significant
in the short term.
Wind energy – the most challenging
forecasted generation unit in grid operation
10.05.2013 | www.ast.lv
Where renewable energy interconnects
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Performance Expectations at Various
Connection Points in the Electric System
RES Connection
level
Interconnection
rules
System Integration
Concerns
Local and System
Values
Connection at
Distribution (DV)
Local connection
requirements
Feeder level issues,
such as power flows,
protection and voltage
impacts – issues related
to high penetration levels
Power, heat, load
control, quality and
Connection at
Transmission (HV)
National Grid Codes,
General requirement
for generation
connection
Understanding how to
plan and operate the
transmission grid and
other generation
resources based on RE
operating characteristics
reliability
Ancillary service
support to utility T&D
e.g. reserve capacity,
demand response,
deferral of expansions,
etc.
Variable energy
resources displace fuel
use and avoid
emissions
10.05.2013 | www.ast.lv
Concerns with Integrating Renewables
•
Penetration
• Affected by utilities' existing generation mix regulating capabilities, load
characteristics, resource availability, and correlations between system
load and resources
• Additional systems costs imposed by variability and uncertainty may go
up with increasing penetration
• Costs are moderate – up to 20-30% Penetration – and depend on
balancing authority and market structure
•
Infrastructure Capacity
• Lack of transmission capacity from stranded renewable resource
locations
•
Variable and Uncertain Generation
Solved by
• spatial diversity of the resource
• flexible conventional generation
• grid operations and control areas
• limited curtailment for extreme events
• load management
• sufficient AC interconnection capacity
• and at high penetrations possibly storage
Technical Concerns
Real but solvable
21.09.2012
2012.09 | www.ast.lv
RES Interconnection – Technical Concerns
Wind and Large Solar (Bulk System Connected Generation)
• Steady state and transient stability analysis
• Load/Generation Coincidence (Peak Load and Variability of
Source)
• Regulation Requirements
• Integration with Automatic Generation Control (AGC)
• Incorporation of renewable resource forecasting
• Examine current operating practice and new concepts to
enable high penetration;
• frequency responsive (create regulating reserves)
• demand side coordination
Most technical concerns at the bulk level have been solved
with modern wind turbines and grid codes
21.09.2012
2012.09 | www.ast.lv
RES Interconnection – Technical Concerns
Distributed Solar and Small Wind (Distributed Generation)
Issues listed above, plus
• Voltage and VAR Regulation
• Power Quality (Harmonics, Flicker, DC Injection)
• Unintentional Islanding
• Protection design and coordination (short circuit, recloser, etc.)
• Equipment grounding
• Load and generation imbalance
• Generation interaction with controllable loads (DSM)
• Storage and storage controls
Technical concerns at the distribution level have been
identified, but small RES have not been fully integrated into
planning and operations
21.09.2012
2012.09 | www.ast.lv
Solutions to Variable and Uncertain Generation
Wind diversity
• Spatial diversity of the resource
• Flexible conventional generation
• Sufficient AC interconnection capacity
• Grid operations and control areas
• Load management
• Limited curtailment for extreme events
• And at high penetrations possibly storage
21.09.2012
2012.09 | www.ast.lv
Energy Storage to Address RES Generation
Costs of More Wind Than Forecasted:
• Value of Day-Ahead contracts not
realised
• Day-Ahead Nominated Gas not used
• Power Plant Cycling
• Exports on AC interconnections
Costs of Less Wind Than Forecasted:
• Spot market electric purchases
• Greater “wear & tear” costs due to more
starts/stops than assumed in Retail rate
design
• Potential depletion of gas system pressure
due to higher than expected starts/usage
• Power Plant Cycling
• Imports on AC interconnections
10.05.2013 | www.ast.lv
Historical and Current Integration Activities
Regarding Large Wind Integration Studies
• A large amount of research has looked into the technical
concerns regarding integration of wind farms into the electrical
grid.
• Several studies have examined 20-30% penetration
• For large, diverse electric balancing areas, existing regulation
and load following resources and/or markets are adequate and
associated costs are low
21.09.2012
2012.09 | www.ast.lv
Historical and Current Integration Activities
Regarding Large Wind Integration Studies
• Moderate cost increases may be needed to account for
variability and uncertainty of wind resource (3-4% low to 7-10%
high)
• Largely dependent on local utility market design and
resource constraints
• State of the art forecasting can reduce costs
• majority of the value can be obtained with current state-ofthe-art forecasting
• additional incremental returns from increasingly accurate
forecasts
• Realistic studies are data intensive and require sophisticated
modeling of wind resource and power system operations
21.09.2012
2012.09 | www.ast.lv
Needs for Distributed Renewables
• Distributed renewable interconnection technologies with
advanced functionality
• Integration of renewable energy with dispatchable load and
storage
• Electric power systems technologies, controls, and operations
that enable high penetration of distributed renewable energy
systems
• Models for renewable energy systems that allow them to be
included in the planning and analysis tools
21.09.2012
2012.09 | www.ast.lv
The Long term challenges for transmission grid
The main objectives are:
1. increase of the security of supply;
2. increase of the competition in liberal electricity market;
3. development of the robust and reliable transmission system;
4. Baltic States integration in European power system;
5. RES integration.
External interconnectors:
 NordBalt –2016;
 Estlink2 – 2014;
 LitPol link – 2015.
Internal reinforcements in
2020 (LV, LT un EE):
 EE-LV 3rd
interconnection – 2020;
 Kurzemes ring, LV –
2018;
 Panevezis-MusaKlaipeda, LT – 2018;
 Harku-Sindi-Tartu, EE –
2018.
10.05.2013 | www.ast.lv
Conclusions
Interconnectors play cruicial role in order to meet EU RES targets
In order to have maximum benefit from interconnectors:
• forectasting methods has to be improved;
• opportunities given by smart grids has to be fully utilzed;
• new ways of effiecient energy storage has to be developed
10.05.2013 | www.ast.lv
Thank you for attention
2012.03.29| www.ast.lv
Latvian Transmission System Operator
AS AUGSTSPRIEGUMA TĪKLS
Dārzciema iela 86, Rīga, LV-1073
T: (+371) 67728353
F: (+371) 67728858
ast@ast.lv
22
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