Magnus Korpås

Balancing Market Integration in the Northern European Continent: A 2030 Case Study

Increased production flexibility will be needed for the operation of a future power system with more uncertainty due to an increased share of uncontrollable generation from renewable sources. Wind energy is expected to cover a large portion of the future renewable generation. In this paper, a comparison is carried out between two balancing market models, simulating a non- and fully-integrated northern European market in a future 2030 scenario. Wind power is modelled based on high resolution numerical weather prediction models and wind speed measurement for actual and forecasted wind power production. The day-ahead dispatch and balancing energy markets are settled separately. First, the day-ahead market is modelled with simultaneous reserve procurement for northern continental Europe. Available transmission capacity is taken into account in the reserve procurement phase. In a second step, the balancing energy market is modelled as a real-time power dispatch on the basis of the day-ahead market clearing results. The results show the benefit of balancing market integration for the handling of variable production. Cost savings are obtained from balancing market integration due to less activation of reserves resulting from imbalance netting and increased availability of cheaper balancing resources when integrating larger geographical areas.

The Potential of Integrating Wind Power with Offshore Oil and Gas Platforms

Offshore wind technology has developed rapidly and an offshore wind farm has the potential to power nearby offshore platforms in the future. This paper presents a case study of integrating a 20 MW wind farm which addressed the theoretical challenges of integrating large wind turbines into a stand-alone oil and gas platform grid. Firstly, the operational benefits of the 20 MW wind power integration were quantitatively assessed with regard to the fuel gas consumption and CO2/NOx emissions reduction. Secondly, the electrical grid stability after integration of the 20 MW wind power was tested by nine dynamic simulations that included: motor starts, loss of one gas turbine, loss of all wind turbines and wind speed fluctuations. Thirdly, the maximum amount of the wind power available for integration was identified by simulating critical operational conditions and comparing these to the governing standards. Integration of an offshore wind farm to an oil and gas platform is theoretically possible, but has not been proven by this study and many other operational and economic factors should be included in future feasibility studies.

Analysis of grid alternatives for North Sea offshore wind farms using a flow-based market model

Offshore wind farms are gradually being planned and built farther from the shore. The increased integration of wind power, also onshore, and the demand for improved power system operation give rise to a growing need for transnational power exchanges. Grid connection is a critical factor for successful large scale integration of offshore wind power. In this paper a comparison study between two different grid building strategies for offshore wind farms in the North Sea is presented for the 2030 medium wind scenario of the TradeWind project [1] (302 GW installed wind capacity). These two strategies are: i) A strategy based on radial wind farm connections to shore and point-to-point interconnections between countries, called radial grid; ii) A strategy based on the use of offshore nodes to build an HVDC offshore grid, called offshore grid. The comparison addresses different power system aspects, such as the total socio-economic benefit associated with each strategy, power exchanges between countries, offshore wind power utilization, grid congestions and utilization of HVDC cable capacity. We find that the offshore grid gives a total benefit over the economic lifetime of the grid for the European interconnected power system of 2.6 billion Euro compared with the radial grid. Our results show that even for moderate amounts of installed wind capacity, the offshore grid strategy is better than the radial one, assuming the future European power system will have a large penetration of offshore and onshore wind power.

Balancing of Wind Power Variations Using Norwegian Hydro Power

This paper addresses the role of Norwegian hydro power to provide balancing power to a future wind dominated European power system. Two power market models, one simplified and one detailed are used to model possible responses of Norwegian hydro power to a wind driven exchange pattern for various amounts of exchange capacity. The case analysed assume a 2030 scenario for wind generation in Europe and an increase in exchange capacity between Norway and Europe from 2300 MW to 5800 MW. We find that the generation constraints and the exchange capacity, and not the aggregated reservoir size, are the most important limiting factors for the amount of balancing the Norwegian hydro power system can provide.

Impact of system power losses on the value of an offshore grid for North Sea offshore wind

Grid connection is a critical factor for the integration of large scale wind power. This factor is even more important in the framework of transnational power exchange which is a way to improve power system operation. In this paper a comparison study has been carried out between two different grid building strategies for offshore wind farms in the North Sea using the 2030 medium wind scenario from the TradeWind project [1]. These strategies are i) radial and ii) meshed grid configuration. The paper has considered active power losses for both strategies and capture the effect of losses on different power system aspects, such as the total soci-economic benefit associated with each strategy, offshore wind power utilization, power exchange between the grid points, grid bottlenecks and utilization of HVDC connections. Using a meshed grid compared to radial there will be a total benefit of 2.7 billion Euro over the economic life time of the grid. However this benefit will be increased by 0.3 billion Euro by taking into account the grid losses for both cases. The results shows the benefit of using meshed offshore grid for future European power system with a large penetration of off- and onshore wind power.

Value of combining hydrogen production with wind power in short-term electricity markets

This paper presents a methodology for optimizing the operation of a hydrogen (H2) production plant in combination with stochastic generators, such as wind turbines, in short-term power markets. The method finds the optimal contracted power exchange with the market before gate-closure and produces an optimal operational plan. The method takes into account probabilistic wind forecasts, spot market prices and expected costs of balancing power. The value of combined operation is shown through a general case study. Results show that combining controllable H2 production with wind power can cost-effectively reduce a substantial share of the power imbalances resulting from wind forecast uncertainties. The operation of the H2 plant is also very dependent on the variations in the hourly spot price. A strategy that simply seeks to minimize the imbalance leads to a much greater imbalance reduction, however at the expense of a higher H2 production cost.

Planning and Operation of Large Offshore Wind Farms in Areas with Limited Power Transfer Capacity

At many locations with excellent wind conditions the wind farm development is hindered by grid issues. Conservative assumptions are often applied that unnecessarily limits the wind power installation. This paper shows that significantly more wind power can be allowed by taking proper account of the wind power characteristics and facilitating coordinated power system operation. A systematic approach is developed for assessing grid integration of wind farms subject to grid congestions. The method is applied to a case of connecting offshore wind farms to regional grid with hydro generation (380 MW) and loads (75–350 MW). The tie to the main grid is via a corridor with limited capacity (420 MW). With conservative assumptions (i.e. no changes in scheduled hydro generation or control of wind power output) the wind power installation is limited to 115 MW. The system operation is simulated on an hourly basis for multiple years taking into account the stochastic variations of wind speed and hydro inflow as well as the geographical distribution of wind farms. The simulation uses a control strategy for coordinated power system operation that maximises wind penetration. By using the developed methodology the wind power capacity can be increased from 115 MW to at least 600 MW with relatively little income reduction from energy sales compared to a case with unlimited grid capacity. It is concluded that coordinated operation allows for the integration of surprisingly large amounts of wind power. In order to realize the increase in transfer capability, it is essential to take account of the power system flexibility and the stochastic and dispersed nature of wind power. The presented methodology facilitates this and represents a rational approach for power system planning of wind farms.