External costs of fossil electricity generation: Health-based assessment in Thailand

Airborne pollutants from fossil fuel burning in electricity generation potentially contribute a number of consequent environmental impacts. In order to indicate the actual costs of energy, a so-called external cost has become of growing concerns internationally. This study aims to evaluate the external costs related to human health degradation resulting from Thai electricity generation produced from fossil fuel which operated during the period from 2006 to 2008. Impact Pathway Approach (IPA) was applied in the analysis. The advections of the criteria pollutants (SO₂, NO_X, and PM₁₀) including secondary particulates (sulfate and nitrate aerosols) had been simulated using the CALMET/CALPUFF modeling system. Subsequently, the exposure-response functions (ERFs) were used to quantify the marginal damage to public health. Finally, costs of such damages were then estimated based on welfare economics. The results showed that the criteria pollutants caused significant damage to both premature mortality and morbidity. The average damage cost was totally about 600 million 2005 US$ annually which ranged between 0.05 and 4.17 US$ cent kWh⁻¹ depending on fuel types. It implies that the external costs are significant to the determination of electricity market price. With the damage costs being included, the electricity price will reflect the true costs of the generation which will be beneficial to the society as a whole.     

A study on a ventilation stack integrated with a light pipe

A theoretical and experimental study has been conducted on the performance of a vertical light pipe that also functions as an air flow stack for night ventilation. The rectangular light pipe of height 3 m and cross-section area 0.0625 m² surrounded by an air duct of total cross-section area 0.23 m² is situated above a room of height 3.8 m and floor area 9 m². Heat transfer from the hot water in the wraparound hot water jacket to the air in the duct is assisted by stainless steel fins. The ventilation of the room, due partly to the buoyancy of the air in the duct and partly to the wind effect, amounted to nearly 10 air changes per hour which is sufficient for passive cooling during cooler night periods. The light pipe has specular reflecting walls. It was found that the transmission of daylight through the light pipe in the middle of a partly cloudy day was sufficient for illuminating the room to general illumination level.     

Assessment of energy savings from the revised building energy code of Thailand

The government of Thailand legislated an Energy Conservation Promotion Act (ECP Act) in 1992 and set bye-laws that identify designated buildings (DBs) and detail mandatory requirements for energy conservation for DBs in 1995. An Energy Conservation Promotion Fund (ENCON Fund) was also created to fund energy audits on 1900 DBs. Recently the requirements and procedures for energy conservation in buildings have been revised where system performance requirements for building envelope, lighting, air-conditioning, and hot water generation are adopted. Moreover, the new building energy code (BEC) distinguishes different categories of DBs, provides credit for use of solar energy, and introduces a new option of whole building energy compliance. The authors develop building models from data obtained from energy audit reports and use them to estimate savings on energy and peak demand from future new buildings using forecasted energy and peak demand data from the Load Forecast Subcommittee, a panel tasked to forecast future electric load of Thailand. From a modest level of energy saving in the first year that the code is expected to be enforced, the level of saving rise to over 10% and 20% annually of requirement of target buildings in 6 and 12 years respectively.