05 mar 2020
Intelligent optimisation basis for reverse collection
The Netherlands is leading in recycling of household waste. Collecting waste using underground containers helps local authorities fulfill circular ambitions.
Reducing the amount of general waste while collecting more raw materials, such as plastic, paper and glass is one of reverse collection’s objectives. Citizens take their own general waste to underground containers, which are emptied on the basis of smart technologies and intelligent optimisation. Automated exchange of information about the levels of waste in underground containers allows the planning of optimum routes for emptying them. This means the collection of general waste can now be more closely matched to collection capacity. Besides the fact that fewer trucks are required, reducing the mileage driven means lower CO2 emissions. This helps local authorities achieve their sustainable goals and fulfil their circular ambitions. Moreover, the fact that local authorities are able to optimise the management and control of their waste collections means the underground containers also form a link in the IT infrastructure of smart cities.
Reverse collection yields more raw materials
The aim of reverse collection is to increase waste separation to 75 percent. This will reduce the annual amount of general waste from what was around 250 kg per inhabitant in 2014 to 100 kg in 2020. On balance, this will makes more reusable raw materials such as plastics and organic waste available. The aims are set out in the VANG Household Waste Implementation programme. The majority of local authorities – more than 90 percent – have set out measures for waste and raw materials in a plan. More than half of councils have set both general waste and separation targets. This is the result of an interim evaluation of the VANG Household Waste implementation programme. The evaluation also forecasts that the average annual amount of general waste in 2020 will be approximately 140 kg per person; still well above the 100 kg target.
Emptying underground containers on basis of smart technology and IoT
In practice, reverse collection means the frequency of door-to-door collection is reduced and underground containers need to be emptied more often. To prevent a rise in the number of trucks using the streets – a familiar nuisance to citizens – underground containers are only emptied when the ideal fill level has been reached. This is possible due to intelligent optimisation; a combination of smart technologies and IoT (the Internet of Things). The optimal routes for emptying the underground containers are calculated according to fill level data. As the containers only send a notification when the waste has reached a certain level, the collection route is planned differently every day. There are several ways of identifying how full a container is. For example, the system counts the number of times the access flap is opened, or it may use historical data on previously logged container content weights.
Sensors register fill level of underground containers
The use of sensors is another option available for logging the fill levels of underground containers. Around the clock, each sensor measures a series of parameters, including the level of waste in the container, and thus the amount deposited. The current fill level is used to predict when containers need to be emptied. As such, the optimal route can be calculated to limit the mileage driven and in turn minimise CO2 emissions. In other words, it produces the most efficient collection model. The system uses the information to generate optimised routes that are automatically forwarded to the planning department. The route instructions are then drawn up, scheduled and automatically forwarded to the dustcarts. Full containers are not the only ones to be emptied. For instance, using a series of complex algorithms, the system may recommend emptying a nearby container even if it is ‘only’ 75% full. Consequently, more efficient use is made of the available collection capacity.
Benefits of intelligent optimisation
Only emptying underground containers when the ideal fill level is reached is one of the major benefits of intelligent optimisation. Natasja Vemmer, Business Consultant at Omrin, sees the more logical planning of routes as another key plus point. ‘The work is shared more fairly among the drivers, and now they don’t have to drive over to the other side of town to empty an underground container that’s only half full,’ she says in an interview with AMCS. ‘Because it allows us to work more efficiently, we have a surplus vehicle every week, so we can add an extra route or use it for other work. Route optimisation also means fewer complaints from residents. Now we are able to see at a glance how full the containers are, so we know exactly when they need emptying. Consequently, we almost never arrive too late any more.’
When asked, Natasha comes up with another important point. ‘When our planner starts in the morning, he no longer has to check first which containers need emptying. That job, together with working out the optimum route for emptying the containers, has already been done for him. Not only does it save a huge amount of time, it takes the stress out of planning.’ What’s more, in practical terms, route optimisation means less work. This saves time, which means we can deploy people and equipment elsewhere. The environmental benefits are another important reason why many councils are optimising collection routes. The number of vehicle movements has fallen, which means we have been able to reduce the mileage driven and cut CO2 emissions, all of which reduces the impact on the environment. At the same time, intelligent optimisation is helping local authorities achieve their sustainable goals and fulfill their circular ambitions.