How To Improve the Urban Microclimate
11 June 2009 | Green News | No Comments
Improvement of the ambient microclimate in the urban environment involving the use of more appropriate materials, increased use of green areas, use of cool sinks for heat dissipation, appropriate layout of urban canopies, etc., to counterbalance the effects of temperature increase, is among the more efficient measures.An increase in the energy consumption in urban areas, because of the heat island effect, places great stress on utilities that have to supply the necessary additional load.
Construction of new generating plants may solve the problem but it is an unsustainable solution, is expensive and takes a long time. Adoption of measures to decrease the energy demand in urban areas, such as the use of more appropriate materials, increased plantation, use of sinks, etc., seems to be a much more resonable option. Such a strategy, adopted by the Sacramento Municipal Utility District(SMUD), has proved to be very effective and economically profitable.
It has been calculated that a megawatt of capacity is actually eight times more expensive to produce than to save. This is because energy-saving measures have low capital and no running costs, whereas the construction of new power plants involves high capitaland running costs. The optical characteristics of materials used in urban environments ans especially the albedo to solar radiation and emissivity to long-wavelength radiation have a very important impact on the urban energy balance. Use of cool materials (high-albedo materials) reduces the amount of solar radiation absorbed through building envelopes and urban structures and keeps their surfaces cooler. Lower surface temperatures contribute to decrease the temperature of the ambient air as the heat convection intensity from a cooler surface is lower. Such temperature reductions can have significant impacts on cooling energy consumption in urban areas, a fact of particular importance in hot climate cities.
Use of vegetation. Trees and green spaces contribute significantly to cooling our cities and saving energy.Trees can provide solar protection to individual houses during the summer period while evapotranspiration from trees can reduce urban temperatures.Trees also help mitigate the greenhouse effect, filter pollutant, mask noise, prevent erosion and calm thair human observers.In general, any tree, even one bereft of leaves, can have a noticeable impact on energy use.
Tags: ambient microclimate, building envelopes, cooling energy consumption, energy-saving measures, evapotranspiration from trees, green areas, heat dissipation, increased plantation, solar radiation absorbed, urban environment, use of cool sinks