EWEA - The European Wind Energy Association

Introduction

A large contribution from wind energy to European power generation is technically and economically feasible. EWEA projects between 230 GW and 265 GW in 2020, of which between 40 GW and 55 GW would be offshore and 400 GW of total installed wind power capacity in Europe in 2030. This will result in a power generation in the same order of magnitude as the individual contributions from conventional technologies developed over the past century.

These large shares of electricity coming from wind - between 14.4% and 16.7% in 2020 and between 26.2% and 34.3% in 2030 - can be realised, while maintaining a high degree of system security in the power systems. The constraints of increasing wind power penetration are not inherently technical problems with wind technology per se. The barriers are mainly a matter of regulatory, institutional and market modifications, and should be dealt with in a broader power market context. Moreover, a re-orientation in the European power systems to take the characteristics of large-scale wind power into account is in line with the overall European policy objectives of sustainability, security of supply and competitiveness.

In order to properly assess the scope of integration of wind power, a system-wide approach should be adopted. Wind cannot be analysed in isolation from other parts of the power system - and all systems differ. The size and inherent flexibility of the power system are crucial aspects in determining the system’s ability to accommodate a high share of wind power. The role of a variable output power source, like wind energy, needs to be considered as one aspect of a variable supply and demand electricity system. The already established system reserves and balancing methods, available for coping with variable demand and supply, are in principle adequate for dealing with the additional variable supply of wind power, at penetration levels of up to around 20% of supply, depending on the nature of the system. For larger penetration levels, power systems need more flexibility, for example in generation and demand response, to accommodate the further integration of wind energy. In addition, transmission and distribution network infrastructure needs to be upgraded and extended to accommodate the increased power flows, to better distribute the geographically diverse wind resource, and to access the offshore wind resources.

The economic impacts of wind power integration are beneficial. Studies in the United Kingdom, Germany and the Nordic area as well as European system studies such as TradeWind and EWIS confirm that system integration costs for wind power, under the most conservative assumptions (low gas price compared to the current level, low to zero social benefit of CO₂) make up only a small percentage of the actual consumer price of electricity. In addition, wind power, by virtue of its relative price stability compared to fossil fuels, reduces portfolio generation costs. Therefore, wind and other zero fuel cost technologies have a positive effect on the overall energy mix.

The major challenges of wind power integration need to be addressed in the following main areas:

• Design and operation of the power system
• Grid infrastructure
• Connection requirements for wind power plants
• System adequacy and the security of supply
• Electricity market design

Finally, institutional and legal barriers to increased wind power penetration need to be addressed and overcome, in particular regulatory constraints posing barriers to grid development which occur mostly during the process of acquiring building permits as spatial planning licences.

Conclusions and recommendations in these areas are discussed below. 

System operation: power and energy balancing

Like any other form of generation, wind power will have an impact on power system reserves and will also contribute to a reduction in fuel usage and emissions. The impact of wind power depends mostly on the wind power penetration level, but also on the power system size, geographical area, generation capacity mix, the degree of interconnection to neighbouring systems and load variations.

When about 10% of total electricity consumption is produced by wind power, the increase in extra reserves is estimated at 2-4% of installed wind power capacity, assuming proper use of forecasting techniques. The consensus obtained from several national system studies is that the corresponding extra cost for secondary reserves is quite low, amounting to 1-3€/MWh (wind), typically less than 5% of generating cost at such a wind power penetration level. To be meaningful, these costs have to be compared to the reserve cost of other electricity generating technologies. However, such studies have not yet been conducted.

For the purposes of balancing, the qualities of wind energy must be analysed in a directly comparable way to that adopted for conventional plants. Balancing solutions involve mostly existing conventional generation units (thermal and hydro). In future developments of European power systems, increased flexibility should be encouraged as a major design principle (flexible generation, demand side management - possibly supported in the future by the uptake of Smart Grids -, interconnections, storage etc.), in order to manage the increased variability induced by renewables. Long gate-closure times should be reduced for variable output technologies. The balance market rules must be adjusted to improve accuracy of forecasts and enable temporal and spatial aggregation of wind power output forecasts. Curtailment of wind power production should be managed according to least-cost principles from a complete-system point of view.

Grid connection requirements and grid codes

It is evident that clear rules are needed to ensure that the power system operates efficiently and safely. In this respect, wind energy technology is evolving to keep up with ever stricter technical requirements. There are continuous changes in grid codes, technical requirements and related regulation, often introduced at very short notice and with minimum involvement of the wind power sector.

Grid codes and other technical requirements should reflect the technical needs for system operation and should be developed cooperatively between TSOs, the wind energy sector and authorities. Costly technical requirements should only be applied if they are based on a truly technical rationale and if their introduction is required for reliable and stable power system operation.

There is a need for a structural harmonisation of grid codes i Europe in order to avoid unnecessary costs for manufacturers and developers, to increase transparency, and to support the efficiency development of technical solutions. EWEA has consequently worked on such a structural harmonisation and published a first "Generic Grid Code Format" in December 2009.

Grid upgrades and costs are not an isolated wind power issue

The European grid infrastructure needs upgrading at national, cross-border and trans-European level, not only to accommodate increasing amounts of wind power cost-efficiently, but also in view of the rising demand for other generating technologies. A well-interconnected transmission network will enable the benefits of the continental wind resource to be reaped to the full. The fact that grid reinforcements benefit all system users also has to be taken into account. Therefore, an integrated approach to future decisions is needed, which should take the particularities of wind power technology, as well as those of other technologies, into account. In this respect, grid connection charges to cover the upgrade costs should be fair and transparent and competition should be encouraged.

The complex process of upgrading the grid systems requires short and long-term measures to enable a smooth integration of wind power. Short-term measures include the optimisation of the existing infrastructure and adaptation of management procedures. Reinforcement at critical transmission corridors, as identified within the TEN-E Guidelines, is also necessary in the short term. The outcome of studies at European level, like TradeWind and EWIS, should be used as a basis for the planning of the network reinforcements needed to accomodate future expected amounts of wind power. In the long term, a European Super Grid is proposed to accomodate large amounts of offshore wind power and to make full use of the continent-wide smoothing effects of wind power in synergy with electricity trade between Member States. This would improve the functioning of the emerging internal electricity market, similar to the way European gas pipelines have been constructed.

Adding wind power to the existing system contributes favourably to security of supply

Wind energy replaces energy produced by other power plants, which improves the energy adequacy of the power system. This is especially beneficial when wind is saving finite energy sources, such as gas, coal and oil, thus decreasing the effect of price volatility on the national economy. In addition to energy, wind power replaces conventional generating capacity. At low penetration rates, the capacity value of wind power is  in the order of its average power during times of peak load (20% of installed wind power capacity, depending on site conditions and wind power penetration in the system). The geographical aggregation of wind power at European scale has a strong positive effect on its capacity value. Finally, adding wind power to the existing system contributes favourably to the security of supply by virtue of technology diversification and indigenous production.

EWEA’s grid integration activities

EWEA published its first 20 year offshore network development master plan within the Offshore Report in September 2009 outlining a step by step approach to planning Europe's offshore grid in the Norther and Baltic Seas by 2030.

In the second half of 2010, EWEA will publish its analysis and recommendations concerning grid integration in a comprehensive report building on a previous EWEA grid report from 2006: Large scale integration of wind power in the European power supply, 2005. EWEA is currently working, in collaboration with its members and associated organisations, along the following main lines:

1. European Grid Code developments

EWEA has since 2007 a dedicated Working Group (WG GCR) in order to have a coherent influence of the wind industry on the process of development of Grid Code requirements in Europe. Its objective is to produce a common position from the wind power industry on a strategy towards the harmonisation of grid code requirements. The Working Group consists of representatives from wind turbine manufacturers, wind farm developers and operators, consultants, service providers and wind power associations. In December 2009, the WG published a first Generic Grid Code Template putting flesh on the bones on the harmonisation of Grid Code requirements for wind power. The WG recommends a structural harmonisation of Grid Code requirements on the short term, and is involved in a co-ordinated dialogue at European level with relevant stakeholders (TSOs, regulators, European Commission).

2. Grid infrastructure upgrade

EWEA monitors the development of European policy (TEN-E revision, upcoming EC Infrastructure package and key deliverables of ENTSO-E such as the 10-year network development plan and provides input based on analysis of technical and policy aspects. Within the TradeWind project (see below), EWEA participates in the working group for onshore and offshore grid development of the European Coordinator. Within the TradeWind project (see below) EWEA prepared recommendations for network upgrade measures to enable the integration of the wind power scenarios up to 2030. Furthermore, through participation in ongoing consultations from the European Energy Regulators and ENTSO-E, EWEA monitors and facilitates the communication of developments, new proposals and results, with respect to new technological and also policy-related developments in the area of transmission and distribution grids.

3. European Electricity Market (legislation, regulation)

EWEA closely follows development of the legislative and regulatory framework governing the functioning of the Internal Electricity Market. Through the TradeWind study, EWEA has already developed well-founded research to assess the efficiency of the market rules and to recommended where necessary improvements to enable an efficient trade of wind power in the markets. Furthermore, EWEA has analysed in its Economics of Wind Energy report in March 2009 financial and economic aspects of wind energy, from the very basic cost of wind energy as it leaves the farm to the effect large amounts of wind energy in the electric system have on the power price.

4. System integration studies

Following on the TradeWind study from 2009, EWEA keeps track of the progress and results of national and international studies on large scale wind power integration. This includes cooperation with the EWIS project and participation in the IEA task group 25.