Figure 1.12 Distributed Systems

Figure 1.12 Distributed Systems

Source: Author elaboration (Sebastian Moffatt). Note: Centralized, remote facilities with one-way networks may be transformed into distributed systems as shown in these two extreme examples of energy systems. In the centralized example, a remote facility services all end users in a one-way distribution network. In the distributed case, all buildings within a 5-kilometer radius are connected to a local heating and cooling plant, using low-temperature water to move heat or cooling from one location to another. Excess heat may be captured from local industrial processes, sewage, or large buildings such as the hospital and then shared at low cost. Local power generation is an option through the creation of a small electrical utility that offers waste heat for use in buildings or for the operation of a cooling system. Typically, such a combined system is able to raise overall effi ciencies from 55 percent to 80 percent. The on-site power may be used for local transit year-round. Flexibility is also enhanced because energy sources may be mixed to take advantage of market rates, local waste products, weather, new technology, and so on. Any excess electricity from the local utility may be offered to the regional grid and used for more effi cient load management and backup.

ty. After the water is used in the village, a heat pump draws thermal energy from the sewage and returns the heat to buildings that require space and water heating. When the sewage is eventually treated, the methane gas that is released is used to power the treatment facility. Is this a water system? A hydroelectric system? A gas-fi red electrical system? A district heating system? A sewage treatment system? Answer: all the above.

The photographs in fi gure 1.13, from a West Coast Environmental Law study, describe the integration of a trail system and other forms of infrastructure. Many possibilities exist for such multipurpose facilities and amenities (see fi gures 1.14–1.19). At some point, the integration of systems is most successful if it is, in fact, diffi cult to isolate any particular system from the others. The functional components of urban services are tightly woven into the fabric of the community at the most local scale.

Integrating forms with fl ows: Spatial planning and urban design

We now look at the possibilities for the application of a one-system approach in integrating urban form with urban fl ows. We consider land use, density, connectivity, proximity, green infrastructure, and other attributes of urban form and examine how a large portion of overall system effi ciency depends on integrating and coordinating these attributes with infrastructure systems.

Urban form, land use mix, density, connectivity, and proximity The integration of spatial planning and infrastructure system design represents the most signifi cant opportunity to enhance overall system performance. Urban form, land use mix, density, connectivity, and proximity all have effects on infrastructure performance. Yet, few land use plans are evaluated from this perspective. Planners and engineers sit in diff erent meetings at diff erent times and ask diff erent questions. Seldom do infrastructure concerns infl uence land use plans or vice versa. Despite this disconnect, the best time to consider ways to minimize infrastructure costs is during the early stages in land development processes.

In principle, spatial planning may contribute to lower infrastructure costs by increasing density and compactness and by locating development sites in close proximity to key facilities (box 1.4). The amount of linear infrastructure required for low-density, single-family