Integrating 300 GW of wind powerinto a single European electricity grid

(may 2008)

• Is there a limit to integrating wind?

“.. We do not think it is likely that there will be a technical limiton the amount of wind that may be accommodated as a result of short-therm balancing issues but economic and market factors will become increasingly important.”

• Contents

• Wind power as an answer to the European energy chellenge

• Wind power integration issues and points for action

• Recently launched actions: - Wind Energy Technology Platform - Integration study TradeWind

• Integrating 300GW of wind power in European power systems is feasible

Integrating 300 GW and more of wind power by the year 2030 into European power systens:• Feasible option for the electricity supply• Increases security of supply• Contributes to low and predictable electricity

prices• Environmentally sustainable

• What is needed to make large-scale integration happen?

• Power System Operation: Minor increase in additional balancing capacity.Power systems ahould become more flexible at all levels. Market rules need to be improved.

• Grid infrastructure: At macro-level a stronger interconnected transmission grid with extensions offshore.Transnational grid concept offshore.Smart grid approach at local level. High up in priority list (TEN-E). Socialisation of costs.

• Appropriate Grid Connection Codes: Grid codes developed in co-operation with stakeholders. As long as there is no single grid, there cannot be a single grid code.

• Single European Grid: The internal EU electricity market needs to be completed: European grid concept, more interconnection, framework to stimulate new investments, more effective unbundling, more competitiveness, efficient market rules.European regulator.

• Dedicated Research: Enhanced R&D efforts in co-operation with stakeholders (industry and TSO’s)

• Balancing in a system with wind power

Effect of wind power on scheduling reserves is small compared to the size of wind power capacity

Extra cost for consumer (reserve and back-up) at 100% wind penetration for Denmark less than 10% of the consumer price (Energinet study)

For Europe with 100% wind power the extra cost would be lower-thanks to beneficial effects of power exchange

• Grid codes and connection requirements for wind power

• Realities of today: - multitude of national grid codes and continuously

changing requirements - Wind turbines become smarter= capable for providing

grid support - Requirements are becoming more demanding e.g. for

voltage support (during FRT and island operation) in development, even for old technology.

- Requirements are not always technically and economically justifield – often inspired by Grid Code designed for high penetration levels

• Power system operation and market: recommendations

• Future power system design more flexible: Generation, operation of the system ( communication etc), demand side

management, storage. Distribution grids must be more actively managed.

• More interconnection to enable aggregation Better interconnetion reduces additional balancing by dispatchable plants

• More effective balancing and settlement procedures Balancing cost should reflect the aggregate imbalance The balance market rules to improve accuracy of forecasts and enable temporal and

spatial aggregation of wind power output forecast.Long gate-closure times should be reduced for variable output technologies-

• Curtailment of electricity production according to least-cost principles from a complete-system point of view.

As wind power is free, constraining of wind power should be the last solution and restrictd to a minimun.

• Harmonise methods for system studies to enable comparison

• Grid codes: recommendations

• Costly technical requirements should only be applied if their introduction is required for reliable and stable power system operation (= not at low power penetatrion levels).

• Development towards a single grid code should be done in a transparent and not-discriminatory way in co-operation between industry and the power sector. Process supervised by a European regulator ( green paper EC March 2006)

• R&D should continue to further improve the knowledge on dynamic interaction of system and wind power plants.

• EWEA initiative to co-ordinate input of wind industry in development of Grid Codes.

• Wind power benefits to security of supply

• Substitution of (imported)fuel burned in conventional (thermal) plants

• Replacement of conventional generation capacity ( wind powers capacity credit): between 35% and 10% WP capacity

• Technology diversification• Increase of price security – reduction of portfolio costs/risks by price stability

• Grid infrastructure upgrade: recommendations

• Large geographical spread of wind power should be encouraged a.o.through adequate interconnection.

• Cost of grid connection should be socialised as for allo other technologies.Grid connection charges should be fair and trasparent.

• Planning of grid infrastructure (interconnection, offshore, transnational reinforced grid) and planning of wind power projects should be co-ordinated on the European level ( Offshore action plan).Priority Interconnection Plan should take account of WP.

• Public Private Partnership and use of structural funds (e.g. via TENE) are recommended financing instruments.

• Studies needed to investigate transnational aspects of wind power integration to back up the priorities in grid reinforcement projects.

• Recommendation: proper standard for determination of capacity credit of wind power

• Proper standard – uniform method needed for determining wind power capacity credit for system adequacy evaluation and planning, to be used by TSO’s.

- In general . At present (low) levels of wind power penetration, the capacity credit of wind power is higher than the aggregated long-term average capacity factor.

• TradeWind results include• Quantified effects of distributed wind power feed-in on

continental and cross-border flows. In time steps until 2030, including uncertainties resulting from forecast errors

• European capacity credit of wind power (boosted by interconnection)

• Ranked recommendations for offshore and onshore grid upgrade; by investigating different scenarios looking at selected transmission corridors

• Survey of power exchange market rules and constraints• Proposals of solutions to facilitate maximum exchange of

wind electricity via markets resulting from extensive market simulations

• TradeWind: recent wind power integration study coordinated by EWEA

Objectives

• To develop recommendations for development of market rules and interconnector allocation methods to support wind power integration

• Scope Europe UCTE-NORDEL.GB Ireland and Island• Time horizon up to 2030• Based on a detailed study of future wind power scenario’s and

international market mechanisms• Targeted at relevant stakeholders (TSO’s, generators market parties, EU

and national policy frameworks)

Overview of an offshore windpark (Egmond aan see, NL)

• Project background• Electrical design• Environment, society, and economics• Summary

Why this windfarm?• Long-term ambitions of Dutch government - Offshore wind energy is an important national energy resource - Long history of use of wind power in the Netherlands - EU obligation to meet 9% of electricity use from renewable sources by 2010 - Ambition to develop up to 6000 MW of offshore windpower in NL

• Dutch governmenthas initiated a “demonstration project” - Identification of location, via Environmental Impact Assessment

- Creation of economical framework ( --> financial support)

- Public tender for developer/investors

• Shell and Nuon won the concession in 2002

Environmental and social aspects• Visibility from shore• Harm to animal species, regardless of whether they are

protected or not - Birds - Marine mammals (seals, harbour porpoise) - Fish - Benthos

• Shipping safety• These concerns have all been thoroughly addressed - Extensive environmental impact assessment - Independent monitoring programme - Formal “stakeholder group” including NGO’s to ensure integrity

Economics• Total construction costs are over EUR 200 Million• Financed by shareholders Shell (50%) and Nuon (50%)• Government financial support - Investment subsidy EUR27 million

- General fisical regulation EIA worth EUR 14 million

- Operational subsidy (EUR 97/MWh) during 10 years of production

• CO2 emissions reduction over 140 million Kg per jaar - Similar to CO2 emissions of 35,000 cars

• A good deal for Dutch consumers? - Costs for initial project are high, but expected to decreasse over time

- Net benefits to society are positive due to spinoffs

Summary• Windfarm Egmond aan Zee is highly Innovative power plant: - First offshore windfarm in the Netherlands - First windfarm with large (3MW) turbines in full sea and relatively deep

(20 mater) water - Largest windfarm in the Netherlands

• Offshore wind energy is one of great renewable energy resources in the Netherlands, and Shell and Nuon are working on new projects.

• Development of future offshore wind farms is besed on twin pillars of Innovation and investment.

• R&D remalns essential to address key growth questions - Reduced capital and operational costs - Improved technical reliability - Windfarms to meet ever-increasing demands from grid operators

Location

36 vestas V90 (3 MW) turbines : 108 MW10-18 Km offshore

38 kV AC offshore cables to an onshore subst.All cables are burled in the seabed (depth 1-

3meter)Step-up to 150 kV and connect to grid

The aim of the programme

To gain knowledge needed for implementation of 6000 MW wind energy at the North Sea.

(= 15% of present electricity demand in NL)

Wea@ Sea Targets• Reduce generation cost of offshore wind

energy: installation, opersation costs• Increase value of offshore wind electricity• Planning regulations, which favor wind energy• Outline for grid modifications

We@Sea Consortium’s Targets -Reduce generation costs of offshore wind energy and increase value of wind electricity

-Planning regulations which favor wind energy-Outline for grid modifications

Offshore projects in NL: Q7• E-Connection -> Evelop• 60 Vestas 2 MW V80 -> 120 MW• 23 KM from coast • 19-24 m water depth• Monopiles • Authorisation completed• Construction started ( Cables, Towers)• In operation mid 2007

We@Sea E= 26 million €• 0. integration & scenario’s 1,3• 1. offshore wind power generation 5,7• 2. spatial planning & environment 7,2• 3. energy transport & distribution 4,1• 4. energy market and financing 1,2• 5. installation, operation, maintenace & dismantling 4,3• 6. training, education, & dissemination of knowledge 0,7• 7. programme management 1,6

…. and some other projects1. Multi functional wind farm concepts ( e.g. mussel production)2. Very large rotor blades (PhD@Sea)3. Dedicated offshore wind turbine concepts (PhD@Sea)4. Design tools (structural dynamics, frequency domain analysis)5. Wind farm control strategies6. Sea floor morphology (PhD@Sea)7. Effects of wind farms on sea mammals, birds, benthos, fish8. Grid stability, balancing (and its economc consequences)9. Optimised integrated foundation and installation methods10.Offshore access technology (PhD@Sea)11.Port development12.O&M optimisation (incl. ’cost estimator’)

Why a national approach?1. NL has a strong offshore industry. Integrated approaches with

wind turbine industry needed.2. Spatial planning, environmental issues are region .3. Legal and policy issues are country specific (until EC directives

are in place).4. Energy market & financing issues are country apecific until EC

harmonisation is effective.5. For importing HiTech local expertise (training & education) is

needed.6. For maximising economic added value, highly specialised local

services ( installation, exploitation, maintenance & decommissioning, project design, financing, EIA, etc) need to be developed.

Why international co-operation?1. Risk profile of offshore is so high that full exploitation

of all available expertise is needed.2. To avoid unnecessary duplication and thus reduce

development cost. (R&D and testing infrastructure, pre-normative research, pre-competitive research, sharing grid connecting and transport capacity, results from atmospheric research, nature and environment)

3. Faster learning by sharing experiences

Some lessons learned• Bottom-up initiative is essential• Co-financing level too low (< 50%)• Demand based projects sometimes conflict

with highest scientific requirements• Regional programmes form an excellent basis

for international collaboration.

Integrating wind energyIn the EuropeanElectricity grid

Ronnie Belmans

Offshore Workshop, Delft, Oct 2006

Overview

• Synchronous areas in Europe - Cross-border flows • Transmission congestion - Loop flows• Wind power is a problem

Synchronous areas (1)Why create synchronous areas?

• Increas grid reliability and mutual support - Improved system frequency control to minimize major disturbances - Mutual support in case of emergencies - Sharing reserve capacities• Facilitate fuctioning of the electricity market - non-disciminatory domestic and cross-border access to the gridExample of direct benefits• Zone of 15 GW production capacity loses its largest unit 1 GW -isolated: needs to develop 1 GW in less than 5s to avoid collapse -As a part of UCTE it needs to develop its share of the largest UCTE unit, and thus 5% of 3GW, in 15-30s.

Synchronous areas (2)• Coordination and control of the electricity

flows - Interdependency of power flows - Interconnected systems share benefits and

problems• Problems on top of the above - Often different standards applied in control

zones

Interdependency of cross-border flows

• Cross-border flows even with balanced control zones

• Congestion on cross-border interconnections• Loop flows• Transit flow

Synchronous areas (3)Operational handbook (UCTE)

“Stronger interconnections require common and consistent understanding of grid operation and control and security in terms of fixed technical standards and procedures”

• Result of discussion between all involved TSO’s - Successor of past technical amd organizational rules and

recommendations• Unification and formalization of standards - To make the best possible use of benefits of interconnected

operation - To Keep the quality standards in the market environment

Overview• Synchronous areas in Europe - Cross-border flows • Transmission congestion - Loop flows• Wind power is a problem

Transmission Congestion• What is transmission congestion? - Congestion – when demand for transmission

capacity exeeds the available transfer capability

- Sources of congestion - Thermal line limits - System security (i.e. n-1) - Voltage stability issues

Types of congestion• Internal congestion - Congestion within a single control zone - Problem of individual TSO (but colleagues can help) - Handled on basis preferred by TSO• Cross-border congestion - Congestion between control zones - More than one TSO involved - Different market rules - Procedures difficult to agree upon - Much more complex problem

Internal congestion Causes

• Internal congestion is not new - Cheapest generation always given priority BUT - Central dispatch accounted for grid limitations• Under liberalized market things changed - Control zone network considered as copper plate - Market players do not care about limitations no incentive to “care” - Still the same rules-cheapest MWs get priority - If cheapest can not be dispatched: must run and pay

Internal congestionHow to handle it?

• Re-dispatching TSO pays some generator for increasing prodection, other for

decreasing it - Costs are socialized - considered as ancillary service - possibly organized as a market• Optimal line switching - Changing the network topology• load shedding - Switching off (interruptible) loads

Cross-border congestionCauses

• Different policies concerning energy sources• Nuclear – no nuclear, availability of natural gas,

coal lignite• Different policies concerning energy safety

• Choice to rely on import• Different fiscal rules

• Taxes, environmental regulation

Different energy prices

Cross.-border congestion – difficulties• More TSOs involved

• Different market rules• Coordination and cooperation issues

– Different languages/software systems– Confidentiality of data

• Interdependency of power flows– Allocation on one border influences all the other– Zonal network model

Loop flows

Cross-border power flows in European grid• Typical power flow pattern

• Countries structurally exporting or importing

• However:• Unstable productin strongly influences the pattern

– Wind generation

• Restrictions consist typically of several lines– What matters for the grid are individual lines flows!– This differs considerably from the physical “border capacity”

Cross-border congestion – difficulties Origin of loop flows

• Contract paths <> current path• Electrons do not read contracts

• Dispatch changes within a control zone• Cross-border exchange stay the same• Individual line power flows differ

• Wind generation• Significant but unstable energy source• Too few wind is bad

– Gradual production decrease

• Too much wind even worse!!– Instantaneously off-line

How dangerous can the loop flows be?• Unannounced wind power in the north Germany

• Actual event – Monday 27 Oct.2003, 18h00 – 20h00

• Very heavily loaded DE-NL border• 4550 MW total physical flows in the direction of NL

– 2380 MW more than scheduled

• Loss of n-1 security on 2 cross- border lines• Loss of n-1 security on phase shifting transformer

– Gronau (charged at 1250 MW)

• Risk for the blackout of Benelux

Overview• Synchronous areas in Europe - Cross-border flows • Transmission congestion - Loop flows• Wind power is a problem

Wind power is a problem • Large wind parks problematic for the network

• Unstable dispatch within a zone– Will there be wind ? Not too much?

• Unstable loop flows

• Benelux case – Positive correlation between loop flows and wind in Germany

» Up to 0.4– Loopflows almest entirely through BE and NL

Conflicting policies• Different policies put demands on grid

• System adequacy• Market facilitation• Connecting renewables (wind)

• Leads to conflicting policies nationally• But also internationally

1 grid expansion = 1 policy, not 3

Conflicting policiesInternationally• Countries tend to rely on import

• We do not need nuclear … we import it

• Screw your neighbors and install a wind park• Green policy neighboring country causes transits• Reducing grid potential for domestic policies

• CO2 measured at the power plant

Facilitating integration of wind power• Coupling wind power – hydro power

• Shorter gate closures (1h)• England & Wales since March 2001: 3.5 (NETA)• + Scotland since July 2002 : 1h (BETTA)

• Better short term wind predictions

Conclusions• Different challenges face EU electricity grid

• Sustainable energy requirements should take grid issues into account

• Wind power poses problems for the grid• Possible solutions

– Wind-water– Shorter gate closure– Better wind predictions