Increase in Temperature - Essay Example

Literature Survey Alterations in weather conditions have a significant impact on the electrical industry as it affects the working of the power network as well as the consumption of electricity. Hor, Watson and Majitha, 2005, employing historical weather data for about fifteen years from the Meteorological Office of the United Kingdom and the British Atmospheric Data in combination with hourly electricity demand data from National Grid Transco created a demand regression model and using output from Global Circulation Models attempted to forecast future long-term monthly forecasts of electricity demand in the United Kingdom through their study. The authors found that temperature was the main driver in load forecasting. Increase in temperature was also found to affect the transmission of electric power negatively, by restricting the load carrying capacity of the transmission and distribution lines. They also found that in the United Kingdom the relationship between demand and temperature was inversely proportionate, due to the lower temperatures experienced in the United Kingdom. In summer though the general average demand was found to fall due to the lack of heating requirements, when temperatures exceeded twenty degrees Celsius demand increased, because of enhanced air-conditioning and cooling loads (Hor, Watson & Majitha, 2005) Among the several weather factors, temperature is the most influential weather factor that impinges on consumption of electricity. Rise in temperature in winter reduces consumption of electricity, because of lower demand for heating. High temperatures however, increase demand on electricity for air-conditioning and refrigeration requirements. The speed of prevailing winds may have some impact on air-conditioning and cooling from fans. There general effect of cooling from higher wind speed. Rainfall, relative humidity and are sunshine are three more factors that affects the demand of electricity. Wet conditions are increased during rainfall and enhanced relative humidity, increasing demands for heating in winter. In addition the cloud cover during rainy periods diminishes the heating effect of sunshine. The demand during extremes of heat and cold is non-linear with regard to temperature, but the model shows better forecasting of demand by the addition of these factors for the summer months (Hor, Watson & Majitha, 2005). Moving closer to the study area of the impact of weather on electricity consumption in Sacramento, California, Franco and Sanstad, 2005, studied the possible enhanced stress on the existing infrastructure of the California electric power system. For this purpose they employed recent data from sample locations around California, which included Sacramento to discern the relationship between temperature and electricity consumption as well as peak demand. Results obtained from this evaluation were then combined with new projections of regional climate change expected to impact on California. These new projections were obtained through the statistical downloading of recent global projections that were generated by two general circulation models. These results were used to provide the estimates of potential influence of future temperature changes on electricity consumption and peak demand in California. Data was downloaded from the Hadley A1Fi scenario for the locations of San Jose, Sacramento, Fresno, and Pomona, wherein the climate projections are provided for three periods of time consisting of 2005-2034, 2035-2064, and 2070-2099. These projections show the projected increase in average temperature of eight degrees Celsius starting from the historic period of 1961-1999 (forty degrees Celsius) and ending at the end of the century (forty-eight degrees Celsius). In addition the greater variability in maximum temperature to the extent of fifty percent is also projected, making for increase in temperature to become the feature of these locations over time (Franco & Sanstad, 2005). Hourly consumption data from California Independent System Operator (CAIISO) and daily temperature data from California Irrigation Management Information Service (CIMIS) was used to compute the demand for electric power in relationship to rise in temperature and the peak demand. At higher temperatures the predominant factor in increased demand for electric power was the use of air conditioners and other appliances for space cooling. Peak electric power demand occurs in these areas during summer due to rise in temperatures and it is possible to predict this demand based on maximum hourly temperatures. The relationship between the average daily temperature and daily consumption and in the CAIISO region during 2004 to 2005 and the relationship seen between the peak demand and average daily consumption were used to predict future consumption and demand as a function of expected future temperatures. Such calculations show that an estimated increase of 3.1% is forecasted for the period 2005 -2034, which translates into a cost factor of $930 millions in extra annual expenditure on electricity (Franco & Sanstad, 2005). The use of air conditioners for cooling spaces during increase in temperatures experienced is one of the main factors that increases the demand for electric and raises peak demand. Lillard and Aigner, 1984, conducted a study of six hundred randomly selected household in Southern California, for two years from 1979 onwards to evaluate time-of-day (TOD) consumption response to temperature and owning of air conditioners. Appropriate econometric methodology was employed by the authors to arrive at the estimates, which were then used on the data obtained by the study from California to arrive at the findings of the study. The study found that treating air-conditioner ownership as recursive would not cause a specification error and a corresponding bias. Customer variance and variation among customers with regard to their response to changes in average weekday temperature was found to be significant and made up for approximately sixty percent of the total variance seen with customers during any given month. The consumption pattern of consumer’s has a strong correlation from periods to period. In keeping with expectations the study found that the impact on use of air conditioners on peak period was in a wide range. In cool areas the effect was close to nil, while in hot areas and in hot months there was a very large effect. For a given price ratio in hot areas and in hot months the use of central air conditioning enhanced the proportion of electricity consumed by a definite percentage (Lillard & Aigner, 1984). Shade provided by trees in the proximity of houses among other factors has a cooling effect on the houses during summer, as shown from the evidence of earlier studies. Donovan and Butry, 2009, studied the effect of shade trees on randomly selected 460 single-family in Sacramento, to assess the value of shade trees in reducing the consumption of electricity. Aerial photography was used to collect data like crown area of the tree, distance from the house, and direction aspect relative to the house. A regression model was used to arrive at the results of the study. The study found that shade trees had a significant impact in reducing the use of electricity during summer. However the scale of reduced use of electricity depended on the location of the tree in respect to the house. Shade trees located appropriately not only reduce electricity use in summer time, but also reduce carbon emissions as a result of generating the excess electricity. Based on the location of the shade trees in respect to the house and the size of the shade trees it is possible to reduce the consumption of summertime electricity use in the range of 82 kWh to 457 kWh. Shade trees located south west quadrant of the house provides the maximum savings in summer time electricity use. Shade trees on the north side of a house are likely to increase summer time electricity use. However, even if tree saplings are given free of cost there is the cost of maintenance of the tree and to encourage planting of trees a subsidy in electricity charges should be given for planting trees in the south west quadrant of houses. In Sacramento planting of shade trees to derive benefits is not easy due to the constraints in space around houses and the availability of space in the south west quadrants for planting shade trees. This means that the planting of shade trees should be an integral component of planning of residential development and not subsequent to the development plans (Donovan & Butry, 2009). Literary References Donovan, G. H. & Butry, D. T. (2009). The value of shade: Estimating the effect of urban trees on summertime electricity use. Energy and Buildings, 41, 662-668. Franco, G. & Sanstad, A. H. (2005). Climate change and electricity demand in California. Climate Change, 87(Suppl.1), S139-151. Hor, C., Watson, S. J. & Majitha, S. (2005). Analyzing the Impact of Weather Variables on Monthly Electricity Demand. IEEE Transactions on Power Systems, 20(4), 2078-2085. Lillard, L., A. & Aigner, D. J. (1984). Time-of-Day Electricity Consumption Response to Temperature and the Ownership of Air Conditioning Appliances. Journal of Business & Economic Statistics, 2(1), 40-53. Read More