30 in the energy balance of an urban canyon (Toudert, 2005). The urban canyon is accountable for diurnal heat storage by the building materials of the canyon surfaces, the potential solar access inside the buildings and by implication (Toudert, 2005) and air movement.
The canyon ratio is the geometric descriptors of the system that are the average height of the buildings (or the canyon wall, H) and the width of the street (or canyon width, W) expressed in terms of H/W ratio or often referred as aspect ratio. (Oke, 1988) (Ahmed, 1995). H/W ratio is very much related to sky view factor of a canyon (Ahmed, 1995).
H1
H2
W
H W
H1 H2
W
Figure 2.6.c: Different Urban Canyon ((H1+H2)/W)
31 socialization, is the third factor. Again, the on-site produced energy from renewable sources including the sun, wind, and geothermal production, is considered as the fourth factor (Frenchman et al., 2010). Among them, operational energy is the main concern for this research. Operational energy includes heating, cooling, elevator operation, water pumping and lighting, which is commonly known as ‘electricity energy’. This research states ‘Energy’ for ‘Electricity Energy’.
The demand for electricity energy is increasing day by day in Bangladesh. The residential sectors consume more energy than other sectors, and this is the key contributor to greenhouse gas emission (Chen, Wang, & Steemers, 2013). In 2005, global energy demand was 29% in OECD countries (Organization for Economic Co- operation and Development) and 36% in non-OECD countries (Chen et al., 2013;
Taylor, Francoeur, d’Ortigue, Tam, & Trudeau, 2008). Even in Bangladesh, the residential sector consumes more amount of energy. In the DPDC area of Dhaka city, domestic category used 45% of total consumed electricity in April 2013(DPDC, 2013) (Figure 2.7.a). Again 87% customer were found in domestic category (DPDC, 2013) (Figure 2.7.a). This research has been focused on the residential energy consumption.
Figure 2.7.a: Electricity consumption percentage by various sector (April 2013) (Source: DPDC)
2.7.1 Present Scenario of Energy Consumption and Distribution
Electricity is a significant factor for a developing country like Bangladesh to develop its economy and the standard of living (Anam & Husnain-Al-Bustam, 2011). Electrical energy is produced by using the national resources. Bangladesh largely depends on natural gas and hydro power stations to generate a major portion of the power (Anam &
32 Husnain-Al-Bustam, 2011). But due to a high demand for rapid urbanization and elevated population growth, the country lags behind than its expected production capacity. A DPDC study found that, the current projected annual energy demand will be doubled by the year 2021 with consideration of 8.8% annual load growth (Source:
DPDC overview, January 2014, Dhaka Power Distribution Company Limited (DPDC)).
Figure 2.7.b: Projection of DPDC demands consideration 8.8% annual load growth.
((Source: DPDC overview, January 2014, Dhaka Power Distribution Company Limited (DPDC)).
The demand for electricity energy is increasing rapidly in Bangladesh. Due to the social progression and the upgradation of living standard in urban life, the energy consumption is growing rapidly. Urban life allows the excessive use of electrical devices to ensure sufficient lighting and thermal comfort in interior spaces. The rapid unplanned growth, inadequate breathing spaces between urban blocks, use of excessive cooling devices, indoor lighting system and modern appliances have been created additional loads on energy production.
Different government and non-government agencies are related with this energy sector in Dhaka. Different service departments are working under the guidance of Power Division, Ministry of Power, Energy & Mineral Resources (MPEMR), and these are -
1280 1393 1515 1649 1794 1951 2123 2310 2513 1600 1741 1894 2061 2242 2439 2654
2888 3142
0 500 1000 1500 2000 2500 3000 3500 4000
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Load
Year
Projection of DPDC Demand Considering 8.8% Annual Load Growth
MW MVA
33 for power generation Bangladesh Power Development Board (BPDB), Independent Power Producers (IPPs), Electric Generation Company of Bangladesh Ltd. (EGCB), for transmission, Power Grid Company of Bangladesh Ltd. (PGCB), for distribution, Bangladesh Power Development Board (BPDB), Dhaka Electric Supply Company Ltd.
(DESCO), Dhaka Power Division Company Ltd. (DPDC), Rural Electrification Board (REB), West Zone Power Distribution Company Ltd. (WZPDC), for formation stage, North Zone Power Distribution Company Ltd. (NZPDC), South Zone Power Distribution Company Ltd. (SZPDC), Central Zone Power Distribution Company Ltd.
(CZPDC) (Haque & Rahman, 2010).
For electricity power services, Dhaka city is divided into the north and south part, where the electricity is distributed by DESCO and DPDC accordingly. The Dhaka south has been divided into three parts and these are DPDC north, central and south.
These parts are served by 32 NOCs office under 16 circle offices.
2.7.2 Use of Energy in Urban Areas
Energy consumption usually do not consider the impact of urbanization which is one of the most significant global demographic trends in the coming decades (Jiang, 2009).
Cities are the focal point of energy consumption. The buildings and transports use a significant amount of energy, which are the two sectors, directly affected by urban planning (Steemers, 2003). So preparation of proper energy considering policies, designing planned and well-connected neighborhoods, designing built forms considering orientation and allowing green area should be some major considerations for contemporary practiced.
The energy is needed in urban areas for producing materials, construction and demolition of buildings, sites and streets. Buildings need energy for day to day functions like heating, cooling, using elevators, using water pump, lighting etc. Again the urban areas need energy for transportation to allow regular commute, everyday work, school and institutional activities, commercial activities, socialization etc. This is how, almost every sector of the urban area need energy.
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