andromeda telematics - experts in the application of control networks

Local Action - Global Solution, a Strategy for a Sustainable City

Chris Glasow, Andromeda Telematics Limited

The Goal

The aim of this article is to propose an 'organic strategy' to provide a system that delivers both efficient use of resources at the local level and effective economic distribution of available resources at the city-wide level. This strategy must allow development and growth to mirror the 'chaotic' natural development of a city without imposing artificial constraints to that growth. In traditional energy management systems the inflexibility of the technology has precluded rapid and inexpensive expansion of the system to meet changing needs. With the advent of new technologies it is now possible to implement systems that will respond in an organic way to the needs of the users.

The key to this strategy is information. Without information it will not be possible to apply realistic controls or to ensure that people are aware of the impact of their actions. Ensuring efficient use of resources at the personal level will involve the forming of a gestalt of the conscious 'demand' decisions and 'embedded subliminal' control by 'intelligent' appliances using information about availability of resources provided by the utilities.

Being aware of the environmental impact of our actions should foster a responsible approach to environmental issues leading to a society empowered through the delivery of timely information to make a positive impact on the environmental well-being of their city.

The Structure

A city has many 'local events' operating at the personal demand level which impact each other in an unpredictable way. Currently these operate without any 'knowledge' of the impact on other local events or of the impact on utilities. In an environment of dense population where the supply and extraction processes are limited it is necessary to ensure that each of the utilities' systems are not overloaded and therefore wasteful of energy. There will be peaks in supply of water and waste removal as well as peak demands in electricity. Multiplied up these local events have a huge impact on the city, not only in demands but also in the environmental impact they have.

City Metabolism - Linear verses Circular

The city that uses linear processes has an environmental impact over a wide area of the planet: Water resources are wasted and polluted, toxic fumes pollute the air and sewage is discarded and pollutes. In a city that has circular processes the impact is felt over a small area because its needs are met by itself and by its own immediate environment. Likewise information flow should also be circular as only this way it will be possible to control or understand events in a 'circular metabolism' where each level of the city is adjusting to it's self like a constant servo loop. Where control is imposed from the top it will not be possible to respond in any dynamic way to the changes in society, only in an 'organic' system where each user has an impact on the whole and information and goals flow throughout the system will user demand be able to dynamically change the systems overall goals.

Top Down verses Bottom Up

An organic strategy enables each local event to modify and adapt to each users requirement in an efficient and timely way while providing information to other local events that can in turn respond to the processes around them. This also means that city-wide events are also able provide information throughout the system and ensure that any decisions being taken at the lower level will take into account the overall goals of the total system. In order to ensure the circular flow of information it is necessary to provide a distributed intelligence that will touch the points where the decisions on resource usage are made. This distributed intelligence must reside in the appliances that will use the resources, nodes will be not just part of the washing machine, but also the water tap and the toilet cistern. These nodes must be able to provide immediate advantages to the user, and wider advantages in providing resource management and control. Although each small node has a simple function its ability to interchange information with other nodes transforms the system into a complex system operating at many levels.

Available Technology

Technology is now available, Siemens AG's instabus EIB technology makes it possible to link products, devices or systems together.

Here is a simple example of how it works: A passive infra-red detector sensor detects that someone has entered the room and sends a message to the actuator controlling the room light. Meanwhile the sensor monitoring the ambient light in the room has also sent a message to the lamp actuator indicating the level of the ambient light, the actuator controlling the lamp would then decide, depending on the ambient light level to turn on the lamp, or even increase the lamp brightness to compensate for any low light. There is no 'master' system here, each bus device having a small amount of 'intelligence' makes it's own decisions based on the 'firmware' the designer has coded into it.

Using a distributed intelligence system the humble light switch takes on a new personality, it is now an access point into the network controlling your home, office or factory. For example, switch twice in succession and (assuming it's programmed to) and a message is sent to all the lamps to turn off, hold the switch down for two seconds and the building goes into 'night' mode, turning off the relevant lights and reducing the temperature in unoccupied rooms.

The Working Environment

In the working environment there is huge scope for energy savings, it is possible to control the lighting for whole buildings down to individual zones within an office. In this situation it would be possible to adjust lighting levels to the zones user requirement to take into account sun rotation around a building and sunset light levels. With the blinds being under control, they could be automatically rotated to reduce radiated heat and to reduce light levels. This would provide a continuous control from night conditions to full sunlight using only the precise amount of energy required.

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