| dc.description.abstract | Since the liberalisation of the Dutch electricity market in 2004 large investments have been made to increase the installed capacity for producing electricity in the Netherlands. Especially in the harbours of Maasvlakte and Eemshaven large power plants were constructed. In both regions the Dutch Transmission System Operator (TSO) TenneT B.V. had doubts whether the available high voltage transmission lines in the regions could transport the electricity produced in those regions. If the production of electricity exceeds the maximum transport capacity it is called congestion. TenneT has a legal instrument to avoid congestion on lines in an area. This method of congestion management is called ' basic system redispatch' ; if too much electricity is produced in an area where congestion is expected, the excess of produced electricity in that area is ' redispatched' (replaced) to other power plants in the Netherlands. The question in this research is whether redispatch of power plants in Eemshaven has consequences on total CO2 and NOx emissions in the Netherlands. At Eemshaven the installed capacity consists of the RWE coal-fired power plant (1600 MWe), Nuon' s gas-fired Magnum power plant (1311 MWe), the gas-fired Eemscentrale power plant of GDF Suez (1800 MWe), TenneT' s high voltage direct current cable from Norway (700 MWe), and 183 MWe of wind turbines. Three steps were taken to give an answer to this question.
Firstly, the circumstances under which congestion in the northern part of the Netherlands is expected were determined. Especially in Eemshaven and Delfzijl it is expected that the amount of MWe installed capacity will rise. Under different scenarios it is investigated whether this rise in installed capacity will cause congestion on the transmission grid in the northern part of the Netherlands. In the different scenarios different combinations of electricity production by various power plants is modelled. The total amount of produced electricity is compared with the available transport capacity in the high voltage transmission grid in the northern part of the Netherlands. This led to the conclusion that the 380kV line between Eemshaven and Meeden is the first line whose capacity will be crossed in an n-1 situation (the outfall of one circuit in a line or one transformer in a combination of transformers). If the sum of import from Norway and production of power plants at Eemshaven is more than 3800 MWe, the line will reach its maximum n-1 capacity of 2635 MVA. All power plants at Eemshaven are in the area under influence of congestion management.
The second step was to define how likely it is that congestion will occur at Eemshaven. To determine this, merit orders for four possible future scenarios have been developed. Along with Residual Load Duration Curves an estimation could be made on the amount of time the power plants at Eemshaven would be producing under different load patterns and input variables (gas price, coal price, import and export values, amount of must-run CHP). One conclusion is that in a business as usual scenario, in rare occasions with extremely high electricity demand, around 124 MW of congestion is expected. In more extreme scenarios, with a lot of export, amounts of more than 1500 MW of congestion are expected. In the business as usual scenario the power plants that are redispatched at Eemshaven (Magnum turbines) are replaced by power plants with the same input fuel and building year. This means the redispatch, and thus congestion management, won' t have consequences for electricity prices or emissions. In the other three scenarios the power plants at Eemshaven that are redispatched are replaced by older power plants and/or power plants with another input fuel. Because of this differences in electricity prices and emissions can arise because of congestion management.
The consequences for emissions because of congestion management are determined in step three. The focus in this step is to determine whether redispatch of the expected congestion from the scenarios in step two had an effect on emissions of NOx and CO2. Only emissions of NOx and CO2 are chosen because it is most likely that gas-fired power plants are replaced by other gas-fired power plants in case of congestion management. Gas-fired power plants are expected to produce the peak electricity load. Since gas-fired power plants have no emissions of SO2 or particle matter (PM10) these to emissions are left out in this research. The business as usual scenario didn' t show an increase because redispatched power plants from Eemshaven were replaced by power plants with the same characteristics (building year, efficiency, emissions, etc.). In extreme scenarios the emissions of NOx and CO2 increased. However, the increases are relative small (not more than 1% of the total emissions). The maximum increase in CO2 emissions is 204 KtonCO2 per year starting from 2018. The maximum increase in NOx emissions is 184 tNOx per year. These increase are quite small compared to the total emissions of NOx and CO2 per year in the Netherlands by the energy sector. Congestion management therefore is not likely to have an effect on reaching NOx and CO2 emission reduction targets in the Netherlands. | |
