Impacts of Climate Change in Energy Infrastructure in Tropical Coastal Regions

Tropical regions contain approximately one-third of the total world population and they are highly vulnerable to the consequences of accelerated climate change. Extreme events such as very high heat index (heat waves) could affect the human health in different degrees, and changes in energy demands to mitigate these events will become crucial to protect the population. The Intra-America region is a tropical converging zone, defined as the area enclosed by 0°N to 30°N and 100°W to 60°W. This tropical region was used as case study to assess its climatology and the relationship between climate warming trend and energy demands. Recent reports for the region show a rapidly increasing sea surface temperatures (SSTs) at rates of 0.027oF per year. This warming trend is expected to result in higher energy demands for air conditioning system. NCEP reanalysis data was used to conduct heat index (HI), human discomfort index (HDI) and enthalpy climatology and for long term analysis over the period 1980-2013. HI was calculated using the National Weather Service method, whereas ASHRAE standard was used to set reference values in the HDI and enthalpy calculation. Enthalpy was estimated to determine how much energy is required to maintain indoor temperatures at human comfort levels. The heating, ventilation, and air conditioning (HVAC) energy was estimated on a per capita basis for each country and it refers to the energy required to bring temperatures and humidity to comfort levels. The Intra-America region climatology was divided into the early rainfall season (ERS) from April to July and the late rainfall season (LRS) from August to November. High HI values were observed in the Caribbean region during the ERS, but the LRS was characterized with the highest values. According with the NWS HI chart, during the LRS, the Greater Antilles were defined as an “extreme caution” region (average HI of 95oF), while Central America could be defined as a “caution” region with an average HI of 82 °F. In addition, it was found that the highest HDI was located in the Greater Antilles with an average value of 0.4, becoming the zone with most energy requirement for cooling. On the other hand, long-term HI averaged over the Intra-America region shows a continuously increasing trend of 0.11oF per year, indicating clearly that this region will require higher energy consumption for air conditioning system in order to keep population at comfortable levels. In addition, similar trends between the energy requirements for air conditioning system, and actual energy consumption were observed. In this way, climate change is linked to energy consumption requirements. When focusing in specific locations, the Island of Puerto Rico shows a HVAC increase of 0.02 GW per year in a direct relationship with the HI change of 0.011oF per year over the period 1980 to 2013. This trend suggest that higher energy will be required for air conditioning system, which contrasts the observed total energy consumption decrease. In the case of Dominican Republic, there is an HVAC increasing tendency of 0.072GW per year during this period. However the highest change was observed in Trinidad and Tobago with an increment of 0.79GW per year. At the same time, the total energy per capita consumption has increased in 130KW per year. In addition, in this country the HI index and enthalpy have increased in 0.01°F per year and 0.0019 BTU/lb per year respectively.