A method of measuring the amount of energy consumed from a water heater having a tank with two or more temperature sensors located a predetermined heights on or in the tank, the method including the step of; for each sensor, determining a corresponding volume of a segment of the tank, measuring the change of temperature at each temperature sensor, calculating the energy for the corresponding volume for each sensor, and summing the energy changes for all the sensors to determine the amount of energy consumed. The energy usage can be recorded with chronological information to construct a usage pattern which can be used for controlling the heater and for providing the user with details of energy usage. The system does not require the use of data derived from a flow meter.

A system and approach for developing a periodic water usage profile and demand for controlling a water heater. A mode may be selected for demand for a certain amount of water of a particular temperature range to be available for use from the water heater. Data on hot water usage may be collected and the usage profile and demand may be calculated from the data. The water heater may be programmed to operate in a certain fashion based on the usage profile and demand. A control knob may be on the water heater control to select a particular demand. Control of the water heater may be operated from a remote device connected in a wireless or wired fashion. An optimization program may be implemented in the control of the water heater for achieving one or more beneficial goals related to water heater performance and hot water production.

Systems and methods for storing power from distributed generation systems or other loads and sources that affect line voltage are disclosed. In embodiments, a water heater can be powered in a way that absorbs excess power from the grid by heating water when a controller senses excess power generation in the grid. Excess power generation can be sensed by either an increase in line voltage amplitude above a predetermined standard, or an increase in line voltage frequency above a predetermined standard.

A method of measuring the amount of energy consumed from a water heater having a tank with two or more temperature sensors located a predetermined heights on or in the tank, the method including the step of; for each sensor, determining a corresponding volume of a segment of the tank, measuring the change of temperature at each temperature sensor, calculating the energy for the corresponding volume for each sensor, and summing the energy changes for all the sensors to determine the amount of energy consumed. The energy usage can be recorded with chronological information to construct a usage pattern which can be used for controlling the heater and for providing the user with details of energy usage. The system does not require the use of data derived from a flow meter.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for metering water are disclosed. In one aspect, a method includes the actions of receiving, from a first meter that is connected to a first pipe, first audio data collected during a time period and first temperature data collected during the time period. The actions further include receiving, from a second meter that is connected to a second pipe, second audio data collected during the time period and second temperature data collected during the time period. The actions further include, based on the first audio data, the first temperature data, the second audio data, and the second temperature data, determining a first amount of material that has flowed through the first pipe during the time period relative to a second amount of material that has flowed through the second pipe.

The cogeneration system includes: a cogeneration apparatus which generates electric power using supplied fuel gas and supplies the electric power and heat; a heat accumulator which accumulates the heat supplied by the cogeneration apparatus; a controller which controls at least start and stop of the cogeneration apparatus; and a display unit that displays a remaining power generation duration which is a length of time for which the cogeneration apparatus can continue power generation. The controller further calculates the remaining power generation duration based on a remaining heat accumulation capacity which is a difference between (a) a maximum accumulable heat amount which is the amount of heat the heat accumulator is capable of accumulating and (b) a current accumulated heat amount that is the amount of heat currently accumulated in the heat accumulator, and causes the display unit to display the calculated remaining power generation duration.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for metering water are disclosed. In one aspect, a method includes the actions of receiving, from a first meter that is connected to a first pipe, first audio data collected during a time period and first temperature data collected during the time period. The actions further include receiving, from a second meter that is connected to a second pipe, second audio data collected during the time period and second temperature data collected during the time period. The actions further include, based on the first audio data, the first temperature data, the second audio data, and the second temperature data, determining a first amount of material that has flowed through the first pipe during the time period relative to a second amount of material that has flowed through the second pipe.

An operation plan correction unit is included which, after start of operation based on an operation plan, predicts a subsequent hot water supply load at a predetermined day on the basis of a hot water supply load result at the predetermined day, and changes a subsequent operation plan at the predetermined day generated by an operation plan generation unit, on the basis of the hot water supply load predicted again and a remaining amount of stored hot water in a hot water storage tank.

Appliances, such as hot water heaters, hot water heater controllers, and methods of operating such hot water heaters, that take into consideration the availability and capacity of alternative energy sources so that additional efficiencies can be realized by sensing the availability of an alternative energy source and adjusting the control algorithms used to control the use of the available electric power is provided.

Methods and compositions for controlling and monitoring residential and commercial pumping systems. Preferably, the controlling and monitoring functions include a remotely located controller component capable of displaying alerts and/or from which a user may input commands regulating the functioning of the plumbing system. In particularly preferred examples, the plumbing system is an on command hot water system in which hot water availability, use and energy efficiencies and conservation are monitored and maximized.