AEB temporarily places a number of back up heat boilers. These heat boilers form a back up capacity of 30 MW, that AEB can use in case a lot of heat capacity is lost during a severe cold period. AEB does this because one of the turbines will be under maintenance for the coming period and because there is a chance that the Bio Energy Plant (BEC) will have to be shut down for about two weeks.
Normally, AEB has sufficient overcapacity to deal with several calamities at the same time. This is necessary, because AEB wants to be able to guarantee warm homes under all circumstances. During the recent overhaul it appeared that one of the turbines needs extra maintenance. This means that AEB can supply less heat. Moreover, during the testing of the Bio-Energy power plant it appeared that there is a small chance that the BEC will have to be shut down during the winter for a repair. Even without turbine 10 and the BEC, AEB can still supply sufficient heat. However, there is insufficient overcapacity to cope with the loss of another line during a harsh winter.
The BEC (Bio Energy Plant) is currently being tested under the leadership of the supplier. AEB has not yet taken over the plant. During the test phase, the plant is exposed to extreme conditions such as high temperatures, high pressure and sudden shutdown. This is done in order to detect and solve any teething problems and problems at an early stage. During these tests, leaks have occurred in one of the components. These leaks have now been rectified. The supplier investigates whether there is a structural problem and looks at possible solutions.
The part in which the leaks occurred is the "economizer". This is a heat exchanger that is used to extract residual heat from flue gas. The economizer consists of pipes through which water flows. There are about 4000 bends in these pipes. Water has leaked in eight of these bends. These bends have been replaced. For such a repair, the BEC has to be stopped for about two days. Replacing the economizer as a whole means a standstill of about two weeks. Whether this is necessary and desirable, and if so when, is now being investigated by the supplier. Although the chances are small, AEB wants to be prepared for a possible short-term standstill of the BEC during the winter.
The reserve heat boilers have been placed on the AEB site pending the permit. This is necessary in order to put the boilers into operation. The lead time for this permit is a few weeks. The boilers will be removed after the winter.