1. A method executable using at least one computer having at least one processor and memory located within a community energy management system (CEMS), the method comprising: receiving power supply data from a sensor of the CEMS at a first hierarchical control level of the CEMS, the power supply data comprising information of electricity supplied to a community by monitoring a feeder line from a local utility to the community, the community comprising a plurality of power consuming units at a second hierarchical control level of the CEMS, and each power consuming unit being a customer site, wherein each power consuming unit includes a plurality of power consuming appliances; dynamically sensing one or more time periods for which backup power is provided to the community based on the received power supply data indicating the feeder line from the local utility to the community is not adequately supplying power to the community, the backup power being from backup energy sources allocated to supply power to the entirety of the community; collecting at a second hierarchical control level of the CEMS during the one or more time periods, using appliance sensors associated with respective appliances in respective power consuming units, power consumption data indicative of individual consumption of electricity by the plurality of respective appliances in each of the plurality of power consuming units of the community; generating aggregated information at the second hierarchical control level, the aggregated information comprising the power consumption data aggregated to be indicative of power consumption of respective power consuming units; transmitting the aggregated information from the second hierarchical control level of the CEMS over a network to the first hierarchical control level of the CEMS; dynamically monitoring, at the first hierarchical control level, power consumption of respective power consuming units; estimating, at the first hierarchical control level of the CEMS, future backup power requirements of each of the power consuming units based on the aggregated information and a determination of backup power dynamically consumed by each of the plurality of power consuming units of the community during the one or more time periods for which backup power is provided to the community; receiving from the local utility a demand response command to reduce or turn off power consumption within the community; generating, at the first hierarchical control level of the CEMS, in response to the demand response command received from the local utility, a command for the second hierarchical control level of the CEMS to dynamically control further power consumption in individual power consuming units such that the backup power is allocated in accordance with community electricity usage objectives of the community, and individual priorities of respective power consuming units; and dynamically controlling, at the second hierarchical control level of the CEMS, individual power consumption of at least some of the plurality of appliances included in one or more respective power consuming units based on the command by passing the command through as an executable command to a respective appliance, or by generating at the second hierarchical control level of the CEMS, based on the command, a new executable command to the respective appliance.