Showcase Antwerp

The goal of the Antwerp showcase is to facilitate the generation and application of renewable energy in harbour regions. The first aim of our research in the Antwerp harbour is to identify industries that can provide a flexible demand for energy. In close cooperation with the Antwerp Port Authority, VITO selected different companies that operate cooling and freezing facilities and a project for the dewatering and recycling of sludge. For the 5 companies the potential flexibility were analyzed and estimated.

Based on the flexibility of 4 of the screened companies we conducted a cluster analysis, consisting of a combined company flexibility analysis, and refer to the valorisation of a Virtual Power Plant (VPP). During our research we discovered an important source of flexibility:  the potential flexibility of a cluster of refrigerated containers (reefers).

Demand response audit, a methodology

Vito developed a methodology, to quantify the amount of flexibility of processes. It is a combination of plan of approach and a set of mathematical analysis tools. This produces an accurate insight in the revenues which can be gained by optimum usage of the available flexibility.

Identification of flexibility
In a first step the presence of flexibility in an installation or company is screened. Flexibility requires a combination of specific properties of the installation. Typically a combination of “direct” or “indirect” storage (energy or products) and a certain amount of overcapacity of the installation results in flexibility. Flexibility is a quite new concept and is not easily recognized in standard energy audits. For that reason a detailed technical screening of the installations is required in close cooperation with the technical people of the company.

Quantification of the flexibility
Flexibility contains aspects of “time”, “energy”, “power” and “frequency” which are related. During the quantification step the technical properties of the installation are translated into values which are independent of the type of installation.

Valorisation of the flexibility
Depending on the type of flexibility, the specific properties of the installation and the wishes of the company a number of business cases are selected and calculated. This allows the selection of the business case where the present flexibility results to the highest added value.

Exploitation of the flexibility
Depending on the valorisation scenario and the specific properties of the installation, the complexity of a system for the exploitation of the flexibility may differ. In some cases simple manual settings changes are sufficient, in other cases complex self learning algorithms may be needed in order to achieve optimal results.

In alphabetic order the case studies of the companies are described:

Case study: Amoras

Amoras luchtbeeldProject description: The Port of Antwerp is located about 70 km from the North Sea on the river Scheldt. In order to keep the Port of Antwerp competitive, continuous dredging of the river and in the docks is needed, in order to give ships with more draught access to the Port of Antwerp. In the docks on the right bank, this results every year in more than 1.000.000 m³ (± 500.000 tons dry matter) of dredged material which has to be processed. AMORAS is the name of a facility which was recently built as a sustainable solution for the dewatering of sludge.

What we have done

Quantification of the flexibility

AMORAS has 2 different locations in the Port of Antwerp: quay 536 in the docks and the ‘Bietenveld’. At quay 536 the sludge is accepted in a first buffer: the underwater cell. The sludge is dredged again with an electric cutter and on land a coarse sieving and desanding takes place before the sludge is pumped to the second location. At the ‘Bietenveld’, the sludge arrives in a second big buffer: the thickening pools. From the second buffer the sludge is pumped in to the mechanical dewatering installations for final processing and storage.

In a first technical screening, it was immediately clear that the AMORAS facility has a huge potential for the exploitation of flexibility. Both locations have huge buffers, which can store sludge for days up until weeks. The pump installation, which is responsible for the transport of the sludge from the first location to the second, has a capacity which is significantly higher than the capacity of the mechanical dewatering installation. The combination of large buffers and overcapacity are perfect ingredients for the presence of flexibility and a simplified model of the Amoras installations was made for further simulations.

In the simulations, 2 scenarios were compared:

  • Scenario 1: the AMORAS installations are operated in the same way as they are operated nowadays, but in combination with a wind turbine.
  • Scenario 2: the flexibility within the Amoras installations is used in such a way that a maximum of wind energy is used.

Findings

  • Amoras has a huge flexibility in “time”, “power” and “energy” and is well suited for local wind balancing. Present operational constraints must be investigated in order to achieve a valid business case.
  • Due to the large buffers and due to the large overcapacity of the pump installation, simulations showed that it is possible to operate the pump installation completely on wind energy. Without optimization, 60% of the produced wind energy can be used in locally.
  •  In case the flexibility is used in an optimal way, almost 80% of the wind energy can be used locally. This results in an overall energy cost reduction of almost 20% .
  • During the feedback discussions with Amoras the following concerns for the actual exploitation of the flexibility were raised:
    • o   The pumping installations cannot be operated without staff: currently, the pumping installations are operated only during the traditional office hours.
    • o   The operation of the Amoras installations requires the availability of staff. Although the amount of staff needed is limited, full exploitation of the present flexibility requires staff during the night and weekend. This has a significant social impact on the working conditions of the staff.
    • o   The daily operation of the Amoras facilities is outsourced to an external company who is responsible for e.g. staff. They have to deal with the operational/practical consequences i.e. costs of the exploitation of flexibility, but are not financially rewarded under present contract.

Recommendations

  • Further investigation on the organisational and operational consequences of exploiting the flexibility. After Vito conducted the DRA, an assigment from Amoras was recieved to futher examine the technical and organisational consequences of exploiting the flexibility. See also overall conclusions and recommendations.

 Reports and more information

 

Case study: Borealis

Borealis antwerpProject description: Borealis is a world player in the production of chemicals and innovative plastics. The Borealis facility in the Port of Antwerp (production site Kallo) produces polypropylene pellets. The production process consists of 3 major steps: a dehydrogenation process for the conversion of propane to propylene, a polymerization process for the conversion of propylene into polypropylene powder and an extruder section for the conversion of polypropylene powder into pellets. The electrical energy consumption is sizeable and characterized by a very constant demand. Borealis has a direct connection to the high voltage network of Elia, the Belgian transmission system operator. For the e-harbours project, it is very interesting to have a company as Borealis in its portfolio because it represents a typical “process industry” facility, known for its large energy consumption and very constant energy demand. Consequently, it is expected that not much flexibility can be found in this type of plants. The Borealis case allows validating this assumption.

What we have done

Power consumption analysis

In a first phase, the power consumption profile of Borealis was investigated based on quarter hourly measurement data which confirms the extreme constant power consumption. Nearly no daily day/night pattern nor seasonal patterns were visible. The typical power variations are just a few percent of the total power consumption. In the technical discussions with Borealis, however, flexibility was identified and it was decided to make a simplified model of the Borealis production process.

Quantification of the flexibility

With the model it was shown that power consumption can be controlled within +4% and -6% for a significant amount of time, without major consequences for the production process. In this case the flexibility is “lossless”: this means that using the flexibility does not result in extra energy consumption. Reductions up to 16% are theoretically possible, but the impact on the production process is significantly higher and the usage of the flexibility is not “lossless”: this means that using the flexibility results in extra operational costs.

With the model several case studies/scenarios were calculated:

  • Standard energy contract: Under the assumption that Borealis has a standard energy contract (contract details were not provided), it was shown that the available flexibility might reduce the energy consumption costs with  0.5%.
  • Local wind energy optimization: In this case the optimal usage of locally installed wind power was analyzed. The power consumption of Borealis is so large that locally generated renewable energy can always be used locally, and that flexibility is not needed in order to improve local power usage.
  • Belpex energy optimization: In this case it was assumed that all energy was bought on the Belgian day ahead power exchange. Optimal use of the flexibility results in a reduction of the energy consumption costs of 1%.

Findings

  • The search for flexibility in a company like Borealis shows that it is possible to find flexibility in the process industry although they strive to a high level of continuity in their processes.
  • Based on the extremely constant power consumption profile, it was expected that the flexibility within Borealis was limited. However, the present flexibility is significantly higher than expected.
  • Borealis has a large flexibility in “power”, but limited in “time” which gives limited possibilities for local wind balancing. The flexibility could be exploited in other ways, but present operational constraints prevent exploiting flexibility at this moment, or should be examined further.
  • At this moment, there is no business case: As the case studies show, the flexibility can be used to reduce the energy costs, but the gains are limited compared to the total energy consumption of the entire plant.

 Recommendations

  • The flexibility could be exploited in other ways, but operational constraints prevent exploiting flexibility at this moment, or should be examined further. Possibly on the reserve market.

Reports and more information

  • Media exposure
    • na
  • Contacts
    • Showcase leader:
      •  Fred Kuijper, fred.kuijper(at)vito.be, VITO
    • Researchers:
      • Jef Verbeeck,
      • Annelies Delnooz,
      • Davy Geysen.
  • Partners
    • borealis_logoBorealis
 Case study: Luiknatie

LuiknatieProject description: Luiknatie offers services ranging from maritime logistics, handling and storage of various goods to traditional land logistics offering customers complete solutions for import and export. One of the activities of Luiknatie is temperature controlled storage. Luiknatie has a cold store facility in the Antwerp harbour with 3 storage cells for cooling and 7 for deep-frozen products. It has a quite broad portfolio of products for deep freezing, including chemical products which are not temperature critical.

What we have done

Power consumption analysis

The power consumption of Luiknatie shows a typical cold store seasonal variation. The power consumption during the summer months is typically 20-30% higher compared to the winter. The analysis shows a typical day pattern with increasing power consumption from the morning to the early afternoon. In the late afternoon the power consumption decreases till 22:00h. At that time the night tariff starts and Luiknatie actively makes use of the cheaper energy price for deeper cooling. Furthermore we observed that the energy consumption is relatively “flat” during the weekends indicating that weekend activity is limited. The weekend is also used for deeper cooling of the cargo.

Quantification of the flexibility

For the Luiknatie case it was difficult to make an accurate estimate of the present flexibility, especially because it is a mixed cooling and deep freezing storage facility. The temperature margins for cooling are typically small and for that reason cooling is not considered as a source of flexibility. Based on the installed compressor power and the discussions with the operational people at Luiknatie, the present flexibility was estimated as a percentage of the total power consumption. Based on these estimations, a simplified cold store model was made for further simulations.

For Luiknatie, 4 scenarios were compared:

  • Scenario 1: Simulations with a standard contract and without wind turbine.
  • Scenario 2: Simulations with a standard contract and with wind turbine.
  • Scenario 3: Simulations with Belpex prices and without wind turbine.
  • Scenario 4: Simulations with Belpex prices and with wind turbine.

For each scenario, 4 simulations were performed: a reference simulation with a constant temperature of -20⁰C in the cells, a simulation with a temperature between -20⁰C and -22⁰C, a simulation with a temperature between -20⁰C and -25⁰C and a simulation where the temperature must be lower than -20⁰C.

Findings

  • The simulations with a standard contract and without wind turbine show a theoretical cost reduction of 3.5% in case a realistic temperature window of 5⁰C is used. Simulations show that the cost reduction nearly doesn’t change anymore in case the temperature window is further increased. In combination with a wind turbine the theoretical cost reduction increases to 12.4%. This is partially caused by the fact that 6.1% more energy is bought from the wind turbine but mainly due to a 35% reduction of the energy bought during the expensive day tariff and a significant reduction of the peak power consumption which is penalized in the energy contract.
    • The simulations with Belpex prices show a theoretical cost reduction of 4.2%. In combination with wind, the cost reduction is limited to 8.7%. This is caused by the fact that the price difference between the Belpex prices and wind is smaller than in the simulations with a standard contract. Further, there is no peak penalty in the contract. The main profit is made in the simulations with a standard contract by means of a peak power reduction.
    • Cost reduction is significantly and especially in case of a standard contract in combination with a wind turbine a decent profit can be realized by means of a demand side management system.

Recommendations

  • The detailed analyses show that the results for very similar companies differ significantly and an individual screening is mandatory for a proper quantification of the flexibility of each individual case.
  • As Luiknatie is planning an update of their control system, an additional and more detailed examination is recommended to make an inventory of the business case. Combining both efforts is recommended.

Reports and more information

  • Media exposure
    • na
  • Contacts
    • Showcase leader:
      •  Fred Kuijper, fred.kuijper(at) vito.be, VITO
    • Researchers:
      • Jef Verbeeck,
      • Annelies Delnooz,
      • Davy Geysen.
  • Partners
  • Map

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Case study Norbert Dentressangle

NorbertDentressangleProject description: Norbert Dentressangle is an international company with a base in Antwerp from where they offer customers a broad range of handling and logistic services to maritime related cargo flows moving through the port of Antwerp. Norbert Dentressangle can provide activities as freight management and transport, warehousing and distribution, terminal operations, short sea and deep sea shipping, stuffing and stripping of containers and all related administration. One of the divisions is the Fresh division, focusing on storage and distribution of temperature controlled perishable products. A new 162.000m3 temperature controlled storage facility was built in 2008 split up in 5 storage cells for cooling and 4 for deep-frozen products. The flexibility, present in this cold store facility was investigated during the e-harbours project.

What we have done

Vito

Power consumption analysis

The power consumption data shows some variation in the energy consumption from month to month, but not as much as expected.  This is probably due to the high insulation level of the building and a significant activity in cooling where the goods flows are higher and the cooling capacity depends more on the temperature of the incoming goods.

The analysis shows as well that there is nearly no activity during the weekends and the energy consumption is typically double as high during the day compared to the nights. Norbert Dentressangle  has a standard energy contract with higher energy prices during the day compared to the night and weekend. Nevertheless, the power consumption data shows that Norbert Dentressangle  does not use this price difference actively to reduce the energy consumption bill.

Quantification of the flexibility

Cold stores are well known the presence of flexibility, but the quantification is not easy. The present flexibility heavily depends on the insulation level of the building, the total thermal capacity of the stored goods, the activity in the building, the temperature of the goods arriving and their storage time. The presence of detailed log data helped to develop a relatively simple approach in order to achieve a simplified cold store model from the power consumption data. This cold store model was used for further simulations.

In the simulations, 4 scenarios were compared:

  • Scenario 1: Simulations with a standard contract and without wind turbine.
  • Scenario 2: Simulations with a standard contract and with wind turbine.
  • Scenario 3: Simulations with Belpex prices and without wind turbine.
  • Scenario 4: Simulations with Belpex prices and with wind turbine.

For each scenario, 4 simulations were performed: a reference simulation with a constant temperature of -20⁰C in the cells, a simulation with a temperature between -20⁰C and -22⁰C, a simulation with a temperature between -20⁰C and -25⁰C and a simulation where the temperature must be lower than -20⁰C.

Findings

  • The simulations with a standard contract show a theoretical yearly cost reduction of 9%. The cost reduction is calculated as the difference between the total yearly cost of the reference simulation and the simulation where the temperature must be lower than -20⁰C. In practice, most of the cost reduction can be achieved with a temperature window of 5⁰C.
  • In combination with wind energy, the results are even better: by means of intelligent control, the amount of energy bought in day tariff can be reduced with 60 to 70%, also in night tariff the reduction goes up to 40%. This results in a global yearly cost reduction of 15%. It is important to note that also here, the cost reduction is calculated as the difference between the total yearly cost of the reference simulation and the <-20⁰C simulation both with the presence of a wind turbine. The 15% is purely realized by the optimization.  In all simulations, a big part of the cost reduction is achieved due to a reduction of the peak power consumption which is penalized in the energy contract.
    • The simulations with Belpex prices show a theoretical cost reduction of 11% calculated in the same way as mentioned in the previous paragraph. Even with a smaller temperature window of 2°C, a cost reduction of 7.3% can already be achieved. This is caused by the higher volatility of the Belpex prices. There are more opportunities within a day to buy energy at lower prices. In combination with wind, the cost reduction is limited to 10.8%. This is caused by the fact that the price difference between the Belpex prices and wind is smaller than in the simulations with a standard contract. Further, there is no peak penalty in the contract. The main profit is made in the simulations with a standard contract by means of a peak power reduction.
    • The facility consists of a well insulated building with a powerful refrigeration system. In combination with wind energy, the maximum power of the refrigeration can be used efficiently in order to buffer and exploit cheap wind energy. The modern infrastructure is perfectly suited for local wind balancing. Theoretical energy cost reductions up to 15% can be achieved in a local wind balancing case.

Recommendations

The preconditions Vito has used for the simulations, was part of a discussion with the technical staff of Norbert Dentressangle: does exploiting day-night scenario´s really lead to a higher efficiency of their cold store?

Reports and more information

 

Case study: Sea Invest

Sea invest VrasenedokProject description: SEA-invest is one of the world’s largest terminal operators for dry bulk, fruit and liquid bulk and is active in 25 ports worldwide. SEA-invest has multiple activities in the Port of Antwerp. For the e-harbours project the discussions have taken place with the SEA-invest Fruit and Food Division. SEA-invest Fruit and Food Division mainly focuses in Antwerp on storage and riping of exotic fruits (e.g. bananas, pineapples, etc.). SEA-invest Fruit and Food Division has cold stores of all sizes, all focusing on cooling (-1°C …+14°C range). Generally, cold stores are known for their flexibility but typically temperature margins are wider in cold stores for freezing compared to cooling.

What we have done

Power consumption analysis

In a first screening, the power consumption profiles of the 8 connection points (locations) were investigated.  All locations show a typical day/night pattern with higher consumption during the day time and a lower consumption during the night and the weekend. There are no indications that there is an “active” use of the lower energy prices during the night or the weekend.  The power consumption during the night is typically 20 to 30% lower than during the day. Over the year the power consumption shows a typical seasonal variation: power consumption is 20-25 % lower in the winter compared to the summer. This behaviour is typical for cold stores while general power consumption is higher during the winter compared to the summer

The 8 locations can be mainly organized into 3 groups: storage facilities used as backup solution, manual operated terminal, and automated terminals.

  • Manual operated terminal: In the manual operated terminal, the power consumption is 30 to 40% lower during the night compared to the day. During the weekend the power consumption drops even with 50-60% compared to the typical day consumption. Every week day, the power consumption is maximum between 18:00h and 21:00h, most probably because forklifts are connected for charging. Quite remarkable is the increase of the average power consumption from Monday to Wednesday, on Thursday and Friday the power consumption decreases again.
  • Automated terminals: In the automated terminals, the power consumption is also lower during the night compared to the day, but the difference is limited to 10-15%. Also the differences between the weekend and weekdays are smaller.

Quantification of the flexibility

The results of the power consumption analysis were discussed with SEA-invest in order to identify the presence of flexibility. Several options for flexible consumption and production were addressed:

  • Temperature margins cold store: In a cold store, more flexibility can be achieved in case wider temperature margins can be used..
  • Forklift charging: The power consumption analysis shows that fork lift charging represents a significant part of the power consumption of a manually operated terminal.
  • Harbour cranes: SEA-invest has several diesel harbour cranes.
  • Reefers: SEA-invest has connection points for refrigerated containers (reefers).  Reefers have a typical on/off power consumption profile.

Findings

The discussions and investigations at SEA-invest Fruit and Food Division did not result in a concrete quantification of flexibility. SEA-invest already pays a lot of attention to the reduction of energy consumption. The constraints set by the company are so tight that insufficient flexibility is available to create a valid business case. This conclusion was confirmed by another external energy audit (BECO). For that reason, the remaining flexibility was considered too low and didn’t justify further analysis.

Nevertheless, the discussions with SEA-invest resulted in an important conclusion: “The exploitation of flexibility should not influence security, quality or continuity of the company’s main activities.”

This conclusion is nicely illustrated within SEA-invest with the following 2 examples:

  • Temperature limits in cold stores for exotic fruits are very tight and are integral part of the quality control process. Wider temperature limits introduce flexibility, but may harm the quality of the company’s core activities which is unacceptable.
  • Charging forklifts has a high priority in order to be ready for unloading the next vessel which arrives. Charging during the “off peak” hours results in a cost reduction, but may harm the continuity of the company’s core activities which is unacceptable.

Recommendations

  • The discussion with SEA-invest resulted in 2 new ideas for finding flexibility: reefers and harbour cranes.

Reports and more information

 

Case study: Refrigerated containers

ReefercontainersProject description: A lot of the refrigerated goods are transported in refrigerated containers, often called ”reefers” . Reefers need electric power for cooling and freezing their cargo, typically a reefer has an electric peak power of 10 to 15 kW. They have an excess in cooling capacity because they need to be able to maintain the temperature of the cargo even in extreme temperature conditions. Therefore they can be a potential source of flexibility, using them to cool to a lower temperature in order to delay the energy consumption afterwards. Looking at the global picture, for example in the harbour of Antwerp, it has a total of 5.000 connection points meaning that 5.000 reefers can be connected to the grid simultaneously. Because of the large number of reefers available in the harbour and their substantial energy consumption, we analyzed their theoretical and practical flexibility.

What have we done

First we made a theoretical estimation of the available flexibility potential of the reefers in the harbour of Antwerp. In 2012 a total of 480.000 reefer TEU were handled, dividing by 1.8 results in 266.666 reefers on a yearly base. The average connection time at the terminal is 3 to 4 days, so in total they remain in the harbour for 1.066.664 days which comes down to 2900 reefers/day present in the Antwerp harbour. Taking into account that 50% of them are operating in freezing mode, it is too critical to vary the temperature in cooling mode because the cargo requires a very specific temperature, a total of 1450 reefers are available counting up to 14.5 to 21.7 MW of flexibility. More important than the flexibility in power,  is to identify the time shift potential of this power. Therefore simulations were conducted to calculate this potential; the results showed that the average temperature in a well insulated reefer increases with 1⁰C per 5 hours in an outside temperature of 20°C when the reefer is switched off. Taking a temperature window of 5⁰C this leads to a delay in consumption of 24 hours. To check these numbers in practice, a reefer was fitted with temperature sensors to measure the influence of increasing temperature windows on the shift of the energy consumption.

Findings

One of the most important goals of the experiment was identifying how long the energy consumption of a reefer can be delayed, taking into account the technology available in a conventional reefer. This implies that, in order to delay the energy consumption, we can only rely on changing the freezing set point of the reefer. In our experiment we changed the set point from -22°C to -17°C (DT = 5°C) to see what the effect was on the temperature variation inside the reefer and thus its flexibility. This resulted in the reefer switching off for 6 hours, which is 4 times less than the 24 hours which were calculated in the simulations. One of the major causes for this difference is the degraded insulation of the used reefer, which was already over 10 years old. However, these 6 hours of flexibility, together with an air temperature window of 5°C, is still sufficient to exploit the flexibility on the day-ahead market or for local balancing purposes with regards to wind and/or solar production.

In order to really exploit the available flexibility some issues still need to be tackled. Every reefer should be fitted with a bi-directional communication system to enable remote control of the set point temperature. Currently a lot of new reefers are already fitted with such a system but the conversion will only be conducted gradually.

Another big challenge to start using the available flexibility is convincing all the stakeholders in the total transportation chain of the need to do so. For example the terminal operator wants to use the demand side flexibility to lower its energy bill, however this will have an impact on the cargo temperature so the owner of the cargo needs to agree and needs to have an incentive to do so. On the other hand there is also the leasing company of the reefer which needs to agree because the switching behavior in an active demand response system can have negative impact on the lifetime of the compressor etc.

It goes without saying that all stakeholders in the transportation chain need to agree and need to be fairly incentivized for the flexibility offered.

Apart from these technical and economic boundaries, it should be noted that the boundaries of the temperature window are decided by the owner of the cargo. It is of utmost importance that all rules with regards to food regulations are met at all times. Within these rules the carrier can offer a lower price for transportation if a specific temperature window is offered by the cargo owner.

Recommendations

A huge amount of flexibility is present because of the large number of reefers available in the harbour of Antwerp. The time shift capacity of this flexibility is sufficient to exploit it on the day-ahead market or for local balancing purposes with regards to wind and/or solar production. However before being able to use the flexibility, the above mentioned technical and economic barriers need to be tackled first.

Reports and more information

  • Reports

 

Clusteranalysis

Project description: The cluster analysis consists of a combined company flexibility analysis and refers to the valorisation of a Virtual Power Plant (VPP), based on the flexibility of all the screened companies within the Antwerp Showcase. The need to cluster flexibility into a VPP is acknowledged in function of managing the flexibility of small flexible energy sources to enable them to participate in the market. The valorisation of the potential of a VPP is performed for 4 of the individually assessed companies, being:

  • Borealis: The electrical energy consumption is sizeable and characterized by a very constant demand. Compared to the other investigated companies the largest amount of flexibility, in terms of ‘power’ was detected here.
  • Amoras:  The combination of large buffers and overcapacity are perfect ingredients for the presence of flexibility. Compared to the other companies which were subjected to the flexibility analysis, the largest amount of flexibility was found here in terms of both ‘time’ and ‘energy’.
  • Norbert Dentressangle: Given the fact that the temperature margins for cooling are typically small, only freezing is considered as a source of flexibility. From the comparative analysis it is clear that the flexibility of this company is present, but limited compared to the flexibility in the large facilities of Borealis and Amoras.
  • Luiknatie :Flexibility potential shows similarities to the case of Norbert Dentressangle.

What we have done

The analysis of the cluster flexibility is a complementary study to the individual company assessments. In order to valorise the flexibility of the cluster, it can be commercialized in different ways. Looking at the identified business strategies for smart energy networks within deliverable 3.4, there is a multitude of opportunities for flexibility. For the selected cluster in the Antwerp harbour two business strategies were selected, being:

Trade on the wholesale market

Significant amounts of energy are traded on energy exchange markets. Due to the variable price on these energy markets, the presence of flexibility can be used for energy cost reduction. Aggregated VPP clusters can use the different electricity wholesale markets to buy and sell electricity on the short and long run. On the short term spot market, the Day-ahead market (DAM) provides standardized products to sell and purchase electricity to be delivered the day after. In principle, in this business scenario the inventoried flexibility is optimally allocated to the hours where it is most profitable, meaning the lowest Day-ahead market prices.

Offer reserve capacity

In case BRP’s are not able to maintain the system balance, the transmission system operator (TSO) has reserve capacity in order to restore the balance. Customers can offer their flexibility directly to the TSO for balancing purposes of the total system control area.

The reason for selecting these specific business cases can be found in the fact that, in contrast to some other business strategies, there are already incentives available for offering flexibility onto these markets.

The reserve capacity system is divided into three stages, being primary, secondary and tertiary control.

  • Primary control is the first stage of reserves, used to rule out system imbalances. The principle of this business scenario is to use flexibility in times primary reserves are called upon. The Belgian TSO, Elia, offers a set payment to grid users willing to provide primary reserves. Thus, for the primary reserves there is only an availability fee considered and no separate remuneration for actually providing/activating this type of reserves. It should be noted that the provision of primary reserves is subjected to certain technical requirements. Only limited facilities are in the ability to meet these strict requirements. Within the cluster analysis it is assumed that all of these requirements are met.
  • Secondary control is dispatched after about 30 seconds to relieve the primary reserve in case of on-going imbalances, and to normalize the system frequency after a deviation. In this case the flexibility is optimally used in times when secondary reserve capacity is called upon. Secondary reserves can be asked for in two directions:
    • R2- reserves: activated downward regulation reserve, in this case the VPP cluster is asked to consume more and buys electricity from the TSO.
    • R2+ reserves: activated upward regulation reserve, in this case the VPP cluster is asked to consume less (or generate more electricity) and gets paid for this service by the TSO.

Secondary reserves is a service which entails specific technical requirements for the relevant facility. It is assumed within the cluster analysis that the technical requirements are fulfilled.

  • Tertiary control is the third stage of reserve capacity, which ensures that sufficient secondary control reserve is always available, and such reserve is distributed appropriately among the available sources. In this case the flexibility is offered to the TSO as part of the tertiary reserves. In parallel to the secondary reserves, the service of tertiary reserve capacity can be offered bidirectional:
    • R3- reserves: activated downward regulation reserve, in this case the VPP cluster is asked to consume more and buys electricity from the TSO.
    • R3+ reserves: activated upward regulation reserve, in this case the VPP cluster is asked to consume less (or generate more electricity) and gets paid for this service by the TSO.

Tertiary reserves are also subjected to certain technical requirements. It is assumed within the cluster analysis that the technical requirements are fulfilled.

Quantification of the flexibility

AMORAS has 2 different locations in the Port of Antwerp: quay 536 in the docks and the ‘Bietenveld’. At quay 536 the sludge is accepted in a first buffer: the underwater cell. The sludge is dredged again with an electric cutter and on land a coarse sieving and desanding takes place before the sludge is pumped to the second location. At the ‘Bietenveld’, the sludge arrives in a second big buffer: the thickening pools. From the second buffer the sludge is pumped in to the mechanical dewatering installations for final processing and storage.

In a first technical screening, it was immediately clear that the AMORAS facility has a huge potential for the exploitation of flexibility. Both locations have huge buffers, which can store sludge for days up until weeks. The pump installation, which is responsible for the transport of the sludge from the first location to the second, has a capacity which is significantly higher than the capacity of the mechanical dewatering installation. The combination of large buffers and overcapacity are perfect ingredients for the presence of flexibility and a simplified model of the Amoras installations was made for further simulations.

In the simulations, 2 scenarios were compared:

  • Scenario 1: the AMORAS installations are operated in the same way as they are operated nowadays, but in combination with a wind turbine.
  • Scenario 2: the flexibility within the Amoras installations is used in such a way that a maximum of wind energy is used.

Findings

Trade on the wholesale market

After exploiting the cluster flexibility for trading purposes on the wholesale market, the individual effects on the electricity cost of the relevant contributors can be identified. The largest relative profits, in comparison to the total electricity bill, can be seen at Norbert Dentressangle with a profit share of 20,50%. The largest absolute profit originates from Borealis, however the relative profit only accounts to 1,70 % of the total electricity cost. The remaining relative profit shares of Amoras and Luiknatie are respectively 16,19% and 9,29%.

Offer reserve capacity

Taking the specific features of the different reserve capacity products into account an evaluation can be made of the cluster performance within each business case (primary, secondary and tertiary control). When comparing the potential profit with the total electricity expenses within the primary reserves market, Luiknatie reaches the  highest relative share, being 13,98%. On an absolute basis, Borealis receives the largest profit, nevertheless the relative profit share only accounts 2,62%. Amoras and Norbert Dentressangle obtain a profit share of respectively 7,46% and 7,14%.

For the secondary reserves (both R2- and R2+), Borealis gains, by far, the most profit within this reserve product category, in absolute terms (looking at both the availability remuneration as the activation remuneration). Relatively spoken, with a percentage of 58,27%, Amoras reaches the highest profit share compared to their total electricity cost. The remaining relative profit shares of Norbert Dentressangle and Luiknatie are respectively 17,25% and 15,17%.

Finally, the tertiary reserves capacity market is assessed. For this reserve market product, comparative results can be found to the secondary reserves market. Again Borealis records the highest absolute profit, however only reaching a profit share of 0,85% in relation to the total electricity cost. On a relative basis, Amoras, with a 25,51%, performs the best. The remaining relative profit shares of Norbert Dentressangle and Luiknatie are respectively 7,36% and 3,73%.

Comparative analysis

As all the relevant business scenario calculations are performed, a comparative analysis can be made. Through the comparative study on business scenarios it is clear that the VPP cluster reaches the highest profit when the available flexibility is used on the secondary reserves market. The least profit can be expected when the relevant cluster offers the flexibility on the tertiary reserves market. This is inter alia due to the fact that tertiary reserve capacity is not frequently called upon.

  • Amoras has a huge flexibility in “time”, “power” and “energy” and is well suited for local wind balancing. Present operational constraints must be investigated in order to achieve a valid business case.
  • Due to the large buffers and due to the large overcapacity of the pump installation, simulations showed that it is possible to operate the pump installation completely on wind energy. Without optimization, 60% of the produced wind energy can be used in locally.
  • In case the flexibility is used in an optimal way, almost 80% of the wind energy can be used locally. This results in an overall energy cost reduction of almost 20% .
  • During the feedback discussions with Amoras the following concerns for the actual exploitation of the flexibility were raised:
    • The pumping installations cannot be operated without staff: currently, the pumping installations are operated only during the traditional office hours.
    • The operation of the Amoras installations requires the availability of staff. Although the amount of staff needed is limited, full exploitation of the present flexibility requires staff during the night and weekend. This has a significant social impact on the working conditions of the staff.
    • The daily operation of the Amoras facilities is outsourced to an external company who is responsible for e.g. staff. They have to deal with the operational/practical consequences i.e. costs of the exploitation of flexibility, but are not financially rewarded under present contract.

 

Recommendations

Further studies on a variety of business models, as identified within deliverable 3.4, can be elaborated. In this manner the exploitation of the VPP flexibility for other purposes can be examined.

  • Further investigation on the organisational and operational consequences of exploiting the flexibility. After Vito conducted the DRA, an assigment from Amoras was recieved to futher examine the technical and organisational consequences of exploiting the flexibility. See also overall conclusions and recommendations.

 

Reports and more information

Reports

Articles

 

 

 

 

 

 

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