In both the Antwerp and the Hamburg port area, companies were interviewed in order to investigate the potential and financial value of the flexibility of the electricity consumption related to their production process. The next figure shows which companies were analysed in the Hamburg harbour.
Detailed case-studies in the Antwerp and Hamburg harbour areas identified a huge potential for reduction of energy costs and integration of renewables. We present three smart examples:
Sludge processing plant
A new facility processes In the Antwerp harbour, a facility has been built for processing of sludge from the Scheldt river. The electric pumping installations of this facility have an uptake of several Megawatts. The flexibility found in the process is exceptional: several MW’s of flexibility during long periods of time. The buffers can store sludge for a long period, which makes the facility well suited
for local wind balancing. The installation can save up to 15% on its energy costs. And it could contribute substantially to balancing the local power grid (negative reserve capacity).
Exploiting this flexibility requires organisational and personnel measures like introducing a 16 or 24 hour shift. A new contract has to be negotiated between the company and subcontractors in order to remove that barrier, and achieve a valid business case.
Cold stores in the Antwerp and Hamburg harbours
Cold stores for deep frozen products can deliver flexibility by varying the temperature of the warehouse. In cold stores for exotic fruits, temperature limits appeared to be very tight. Wider temperature limits introduce flexibility, but influences the quality of the cargo, which is unacceptable. Some case studies show that flexibility can be used exploiting the differences between day- and night-tariff, which could yield a cost reduction of 9%. In general cold stores showed substantial flexibility, but there are operational constraints, imposed upon by the refrigeration system (low insulation level and/or an undersized system). The best option exploiting potential flexibility of cold stores seems to be to install a wind turbine on the local estate. In that case a cost reduction of 15% is within reach. These are profitable business cases. Research in another cold store company showed less potential for savings, caused mainly by a lower insulation level and less powerful refrigeration system. In a cold store for exotic fruits, temperature limits appeared to be very tight. Wider temperature limits introduce flexibility, but may influence the quality of the company’s core activities. The management finds this unacceptable. For the same reason, flexibility available in charging the forklifts of the company could not be made available: forklifts have to be ready for unloading the next vessel the moment it arrives. Charging during “off peak” hours reduces costs, but the management does not want to risk the company’s core business.
Chemical production plant
A large industrial company in the Hamburg harbour recently installed a large gas powered Combined Heat and Power Plant to cover the lion’s share of the heat demand. From a grid point of view the company is a net power producer, since the CHP plant generally produces more electricity than is consumed. As the earlier used gas boilers are still operational, there is a large flexible potential (by regulating down the CHP temporarily and covering the heat demand using the boilers). This is a prime example of ‘negative’ flexibility, where the facility (at the request of the grid operator) increases its power consumption in periods of excess supply.
By turning down the CHP the production of electricity can be reduced by several MW, for periods from a few minutes to several hours. Reaction time of the CHP is rather fast, and sufficient for the provision of tertiary or even secondary reserve capacity. There is a clear business case for this provision of (negative) reserve capacity, and the company is working on that now. The amount of flexibility could be increased even more if electric heaters would be installed to temporarily cover heat demand when the CHP is turned down, instead of gas boilers. This could double the now available flexible load.