A method to mitigate the impact of cycling operation and carbon emissions

Published: 15 June 2021| Version 1 | DOI: 10.17632/mj7ss3m592.1
Amlan Chakrabarti


Geographical position of US 48 states has substantial distance from the equator in terms of latitude. Hence, the region makes substantial gains with the availability of daylight by adjusting their time in specific seasons. For large countries like USA, the geographic territorial distances in longitude justify multiple time zones. A mathematical model is available to split a territory in terms of multiple time-keeping zones of one-hour interval where area of each time-keeping zone is a function of hourly rise / fall of electrical power demand and longitude differential of its territory. Configuration of the time-keeping zones as a function of hourly rise and fall in demand is expected to result in higher reduction in daily differential in electrical power demand. In order to apply the model, it is required to have governance area wise hourly demand. US 48 states have a longitude differential of 60o. The four time zones across US 48 states make a rational time division of the geographical territory. It is essential to ascertain the benefits to justify any adjustment in these time zones. Investigations are necessary to determine the reduction in carbon emissions with adjustment of time zones for US 48 states. This work makes use of electric power demand data of USA as available from the API in USEIA website for the period from November 2018 to October 2019. This period covers one complete cycle of winter time and summer time. As state wise hourly demand figures are not available, the utility wise data has been used. In most cases, break-up of state wise hourly demand data for the utilities are available from their respective websites and USEIA. However, for MISO, SWPP and some smaller utilities, data are overlapping among multiple states. Sometimes, these states are in different time zones and shifting the demand by one or more hours would result in erroneously excess benefits. Hence, in all such cases, the demand has not been shifted and a pessimistic view has been taken. This analysis uses hourly demand data at the unit level of county or state. Hourly demand from Distribution System Operators (DSO) covers multiple states and is not suitable for this analysis. The aggregate demand data from all utilities used in this analysis was compared with the total hourly demand figures of US 48 states as available from USEIA API. The difference was found to be within 0.06% to 0.35% of total demand of US 48 states. This small difference in demand in utility level data is not expected to cause any change in the configuration of proposed adjustment in time zones for US 48 states. A reduction in the rise or fall of electrical power demand and flattening of electrical load curve shall reduce cycling operation of steam power plants and related carbon emissions. In addition, it shall result in optimized utilization of power plant capacity.


Steps to reproduce

Raw Data has been collected from USEIA website using their API. Hourly Demand Data for specific dates have been charted for all electric utilities, one sheet for each date. The sharpest rise or fall in hourly demand during peak / off-peak demand has been selected to configure the time zones for USA. Hourly Demands have been reconfigured in separate file using similar charts to work out changed total hourly demands for USA. Final savings based on the reconfiguration has been charted in Table 7.


Narula Institute of Technology


Electric Power Transmission