Abstract:
An energy monitor that measures the amount of electricity consumed by an appliance and translates that measurement into the amount of carbon dioxide that was emitted into the atmosphere as a result of creating that amount of electricity.

Description:
[0001]    The present invention relates to a device that measures the amount of electricity consumed by an appliance and, based on the source of the electricity, calculates and displays the amount of carbon dioxide that was emitted into the atmosphere as a result of producing that amount of electricity. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electricity is generated in many different ways, with a wide variation in environmental impact. When electricity is generated through the burning of fossil fuels such as oil, natural gas, or coal, carbon dioxide is released into the atmosphere. Carbon dioxide, along with methane, nitrous oxide, and fluorinated gases, are called “greenhouse gases” and are associated with a number of adverse environmental effects, including global warming, unhealthy air quality, and acid rain. These adverse effects are not associated with energy derived from solar, wind, or geothermal sources. 
         [0003]    In view of the heightened awareness of the damage done to the environment as a result of the use of fossil fuels, the public has become more interested in the ways to reduce the emission of greenhouse gases. If people know the amount of destructive carbon that was emitted by the generation of the electricity needed to power their household appliances, they can make the decisions on which appliances to use, how often to use them, and whether to replace them with other appliances that have less of an adverse environmental impact. 
         [0004]    There are a number of software programs that estimate a “carbon footprint,” i.e., the measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide. See, e.g., www.carboncounter.org; www.carbonfootprint.com; and www.begreennow.com. These calculators factor in elements that characterize lifestyles, such as house size, type of car, miles traveled by air or road, to arrive at a number for a carbon footprint which depicts the relative impact on the environment such a lifestyle represents. These carbon footprints, while interesting, are merely approximations based on broad assumptions which may or may not hold true for any one individual or household. 
         [0005]    Energy monitors for household appliances are known in the art. For example, U.S. Pat. No. 6,095,850 discloses an electric adapter that displays various parameters of the electricity consumed by an appliance that has been plugged into the adapter. Also, U.S. Pat. No. 6,476,729 discloses a power monitoring module with a display unit which is placed on a power strip to display the power used by the appliances plugged into the strip. 
         [0006]    The prior art, however, does not reveal a device which can accurately indicate to a consumer, based on the source of electricity, how much carbon was emitted in the production of the electricity needed to run a particular appliance. Further, there is no disclosure of a device that can display the aggregate electricity consumption of multiple appliances. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is directed to an energy monitor which can display various electrical parameters of one or more appliances. Included among the parameters that may be displayed is an accurate reading of the amount of carbon that was emitted by the generation of the electricity used by the appliances. 
         [0008]    The energy monitor senses the amount of electricity that is drawn by an appliance and derives the number of watts being used by the appliance. A time base signal generator in the device measures the time during which the watts are being drawn to arrive at the number of kilowatt-hours used by the appliance. The number of kilowatt-hours are multiplied by the carbon dioxide emission rate for the specific power source from which the electricity is obtained to arrive at the weight of carbon dioxide that was released into the atmosphere by the generation of that amount of electricity. 
         [0009]    Generating electricity from fossil fuels such as coal, petroleum, and gas results in the emission of carbon dioxide into the atmosphere, while electricity generated from nuclear, wind, geothermal, or solar sources does not. Power utility companies in different parts of the United States use different fuel mixes to obtain electricity to supply to its customers. The Environmental Protection Agency lists the percentages of the fuel mix components, i.e., “power profiles,” for different cities on its website, for example: 
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 non-hydro 
                   
                   
                   
                   
                   
               
               
                   
                 renewables 
                 hydro 
                 nuclear 
                 oil 
                 gas 
                 coal 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 New York NY 
                 0.5 
                 0 
                 43.8 
                 20.2 
                 34.9 
                 0 
               
               
                 Los Angeles CA 
                 9.4 
                 17.7 
                 16.5 
                 1.2 
                 42.3 
                 11.9 
               
               
                 Washington DC 
                 1.2 
                 0.9 
                 38.3 
                 4.0 
                 9.6 
                 45.1 
               
               
                 Dallas TX 
                 1.3 
                 0.3 
                 11.9 
                 0.5 
                 47.5 
                 37.1 
               
               
                 Fairbanks AK 
                 0 
                 11.7 
                 0 
                 7.1 
                 69.4 
                 11.8 
               
               
                 Miami FL 
                 1.5 
                 0 
                 13.8 
                 17.9 
                 39.0 
                 26.2 
               
               
                 Chicago IL 
                 0.4 
                 0.7 
                 22.3 
                 0.4 
                 2.7 
                 72.8 
               
               
                 Boise ID 
                 2.3 
                 48.6 
                 3.3 
                 0.3 
                 10.8 
                 34.4 
               
               
                 National Avg 
                 2.1 
                 6.5 
                 19.3 
                 3.0 
                 18.8 
                 49.6 
               
               
                   
               
             
          
         
       
     
         [0010]    Carbon dioxide emission rates are calculated based on power profiles from generating units of U.S. electric plants. The carbon emission rate, i.e., pounds of carbon dioxide per kilowatt-hour, in different geographic regions in 1999 have been calculated to be 
         [0000]                                                New England   1.077           Middle Atlantic   1.058           East North Central   1.579           West North Central   1.746           South Atlantic   1.342           East South Central   1.470           West South Central   1.529           Mountain   1.542           Pacific Contiguous   0.435           Pacific Noncontiguous   1.393           U.S. Average   1.341                        
Data from “Carbon Dioxide Emissions from the Generation of Electric Power in the United States,” July 2000, Department of Energy, Washington D.C. 20585, Environmental Protection Agency, Washington D.C. 20460.
 
         [0011]    Accordingly, if consumers are interested in having a more accurate measure of the amount of carbon emitted into the atmosphere by their energy use, they will need to program their energy meter with the geographically-appropriate carbon dioxide emission rate. For customers not interested in such accurate numbers, the device may be programmed with the national average as the default. 
         [0012]    To use the device, the consumer plugs the appliance into the sensor portion of the meter. The sensor measures the electricity that is used by the appliance and transmits the data to a central processing unit which then sends the results of calculations to a display to indicate the pounds of carbon that were emitted. To enhance the accuracy of the information presented by the device, it may be equipped with an aging icon that can display how old the reading is. Should the consumer see that the icon indicates that the reading is old, the consumer may wait for the refreshed reading to better understand the his or her electricity use. 
         [0013]    In one embodiment, the device may be comprised of multiple sensors which can transmit information regarding multiple appliances to the receiver. The receiver can then present the information for each appliance individually or as an aggregate measure of electricity consumed and carbon emitted. 
         [0014]    One embodiment of the invention includes a wireless transmission from the sensor to the receiver. A second embodiment utilizes two components, a sensor and a receiver, that are tethered together by wires for the transmission of information. Yet another embodiment is a unit in which the sensor and receiver are integrated within a single housing, which also includes a display. 
     
    
     
       DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0015]      FIG. 1A  is a representation of a wireless embodiment of the present invention. 
           [0016]      FIG. 1B  is a circuit block diagram of a wireless embodiment. 
           [0017]      FIG. 2A  is a circuit block diagram of a tethered embodiment. 
           [0018]      FIG. 2B  is a representation of a tethered embodiment. 
           [0019]      FIG. 3A  is a circuit block diagram of an embodiment where the sensor, receiver, and display are integrated into a single housing. 
           [0020]      FIG. 3B  is a representation of the embodiment with components integrated into a single housing. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]      FIG. 1A  shows a wireless embodiment of the invention which consists of at least one energy sensor  10  and a display unit  11 . Sensor  10  is comprised of a housing  12  which has an outlet  13  formed thereon and an electrical plug  9  extending therefrom. An appliance having an electrical plug, such as e.g., a computer or toaster, is plugged into outlet  13  on housing  12  and sensor  10  is plugged into an electrical socket so that energy consumption of the appliance may be measured. Data relating to the electricity drawn by the appliance is transmitted wirelessly to display unit  11  for processing and display. Display unit  11  may be configured to receive data from multiple sensors and display cumulative data readings, or to display data received from individual sensors for individual appliance display, or to display individual and cumulative readings simultaneously. Display unit  11  may also be configured to display projections of electricity use or cost on user-selectable time periods, such as daily, monthly, or annual basis. 
         [0022]    A circuit block diagram of the circuit of the wireless embodiment of the inventive device is shown in  FIG. 1B . Circuit  100  is arranged on a circuit board inside sensor  10  and circuit  110  is arranged on a circuit board within display unit  11 . 
         [0023]    Current sensing circuit  14  and voltage sensing circuit  15  detect and measure the current and voltage levels of the electricity drawn by the appliance. This technology, including the various circuitry choices and components, is known to those skilled in the art. While the embodiments herein incorporate voltage detecting circuits, other configuration in which a constant voltage is programmed into the unit may also be employed. This type of configuration will be less costly to manufacture but will lower the accuracy of the readings. 
         [0024]    In a preferred embodiment, analog-to-digital converter  16  converts the analog current signal passing through current amplifier  18  into a digital signal; analog to digital converter  17  converts the analog voltage signal passing through voltage amplifier  19  into a digital signal. These signals are sent to control circuit  20  which also receives, transmits to, and processes data stored in memory  21  as well as data from time base signal generation circuit  22 . 
         [0025]    Control circuit  20  wirelessly transmits data relating to the current, voltage, phase angle, power, consumption since last transmission, and accumulated consumption to the control circuit  25  where it is further processed and the resulting data is stored in memory  32 . 
         [0026]    In setting up the inventive device for use, the user will obtain the carbon dioxide emission rate for the relevant geographic region and program that rate into the device using input unit  30 ; this data is sent to control circuit  25 . Other data, such as cost of electricity per kilowatt-hour, can also be obtained locally and entered into the system using input unit  30 . Control circuit  25  processes the data received from control circuit  20  with the data input by the user as well as data received from time base signal generation circuit  31  and memory  32  to calculate, inter alia, a value for the amount of carbon dioxide that was emitted into the atmosphere by the generation of the amount of electricity used by the appliance. Control circuit  25  sends that carbon amount value, as well as other data, to display  33 . 
         [0027]    The front panel  44  of display  33 , shown in  FIG. 1A  includes a screen  45 , such as an LED or LCD display, that indicates information such as the cost of electricity consumed, the number of the monitored sensor, and physical data such as voltage, current, kilowatt-hour, carbon emitted, elapsed time, evaluation period, aging icon, and low battery indicator. Input and selection devices, such as buttons  71 ,  72 , and  73 , are configured to input data through input unit  30  to control circuit  25  and to cycle the display through different values, e.g., to estimate future costs for different evaluation periods, to show different measured or calculated values of one sensor, to show cumulative values of multiple sensors, or to change the display to a different sensor or an auto-display function. The display unit can show the data received from an individual sensor  10  and an indication  78  on screen  45  will specify from which of the multiple sensors  10  the data is being drawn. 
         [0028]    Information relating to electricity drawn by the appliance can be shown on the screen in various configurations, one of which is shown in  FIG. 1A , where the total amount of pounds of carbon emissions is shown as a primary value  77 , and measured kilowatt-hours and elapsed time of measurement are shown as secondary values  74  and  75 . 
         [0029]    The system is continually reading the current and voltage, storing the values in memory  21  and memory  32 , while control circuit  20  processes the values and sends data to control circuit  25  which sends processed data to display unit  11 . While the display may be configured to show data in real time, in certain instances it may be more cost-effective to display periodic readings. To reflect that the data displayed is not in real time, but rather is being refreshed periodically, display screen  45  may be configured with an aging icon, such as the pie chart icon  79  as shown in  FIG. 1A , to indicate whether the reading is fresh (no pie sections) or old (full pie icon). 
         [0030]    Screen  45  may contain other icons, such as a coal plant icon  76  to indicate carbon emissions, used to clarify or emphasize the type of value on display. 
         [0031]    The device may be programmed to display projections of usage based on prior usage. Projections can be shown as the primary value  77  with an indicator  80  showing whether the projection is a daily, weekly, monthly, or yearly forecast. 
         [0032]    Data may be sent from a number of different sensors, as shown in  FIG. 1A , and data may be displayed individually from each sensor for a measure of the usage of one appliance, or cumulatively, e.g., measuring and adding together all the components on a home entertainment center. 
         [0033]      FIG. 2A  shows a circuit board diagram of a second embodiment of the present invention where the components, sensor  210  and display unit  211 , shown in  FIG. 2B , are tethered by a wire  212 . An appliance is plugged into outlet  231  on sensor  210 . Sensor  210  gathers the voltage and current signals drawn by the appliance, and transmits those signals, through wire  212  to display unit  211 . 
         [0034]    Circuit  201  is arranged on a circuit board inside energy sensor  210  and circuit  202  is arranged on a circuit board within display unit  211 . Current sensing circuit  214  and voltage sensing circuit  215  detect and measure the current and operating voltage level, respectively, of the electricity drawn by the appliance. 
         [0035]    In this preferred embodiment, analog-to-digital converter  216  converts the analog current signal passing through current amplifier  218  into a digital signal; analog to digital converter  217  converts the analog voltage signal passing through voltage amplifier  219  into a digital signal. These signals are sent to control circuit  220  which, in addition, receives, transmits, and processes data stored in memory  221  as well as data from time base signal generation circuit  222 . 
         [0036]    Control circuit  220  then sends data relating to the current, voltage, phase angle, power, consumption since last transmission, and accumulated consumption through the circuit to the display  225 . 
         [0037]    In setting up the inventive device for use, the user will obtain the carbon dioxide emission rate for the relevant geographic region and program that rate into the device using input and selection devices, buttons  271 ,  272 , and  273  shown in  FIG. 2B , to input unit  230  which then will be sent to control circuit  220 . Other data, such as cost of electricity per kilowatt-hour, can also be obtained locally and entered into the system using input devices  271 ,  272 , and  273 , to input unit  230 . Control circuit  220  processes the data received from voltage detecting circuit  215  and current detecting circuit  214  with the data input by the user as well as data received from time base signal generation circuit  222  and memory  221  to calculate, inter alia, a value for the amount of carbon dioxide that was emitted into the atmosphere by the generation of the amount of electricity used by the appliance. Control circuit  220  then sends that carbon amount value to display  225 . 
         [0038]    The front panel of display  211 , shown in  FIG. 2B  includes a screen  245 , such as an LED or LCD display, that indicates information such as the cost of electricity consumed, physical data such as voltage, current, kilowatt-hour, carbon emitted, elapsed time, and evaluation period. Buttons  271 ,  272 , and  273  can be configured to cycle the display through different values, e.g., to estimate future costs for different evaluation periods or to change the display to different parameters. Information relating to electricity drawn by the appliance can be shown on the screen in various configurations, such as total weight of carbon emitted, kilowatt-hours, cost, projected use or cost, etc., shown as a primary value  277 . 
         [0039]    The system is continually reading the current and voltage, storing the values in memory  221 , while control circuit  220  processes the data and sends processed data to display unit  211 . 
         [0040]    Screen  245  may contain other icons  281  to emphasize the type of value on display, such as a coal image, dollar sign, or electricity symbol. 
         [0041]    The device may be programmed to display projections of usage based on prior usage. Projections can be shown as the primary value  277  with a further icon  280  showing whether the projection is a daily, weekly, monthly, or yearly forecast. 
         [0042]      FIG. 3A  shows circuit board  301  of a further embodiment of the present invention where the sensors and display unit are contained within the same housing  310 , shown in  FIG. 3B . An appliance is plugged into outlet  331  on housing  310 . During operation of the appliance, voltage detecting circuit  314  and current detecting circuit  315  detect and measure the current and operating voltage, respectively, of the electricity drawn by the appliance. This technology, including the various circuitry choices and components, is known to those skilled in the art. 
         [0043]    In a preferred embodiment, analog-to-digital converter  316  converts the analog current signal passing through current amplifier  318  into a digital signal; analog to digital converter  317  converts the analog voltage signal passing through voltage amplifier  319  into a digital signal. These signals are sent to control circuit  320  which, in addition, receives, transmits, and processes data stored in memory  321  as well as data from time base signal generation circuit  323 . 
         [0044]    Control circuit  320  then sends data relating to the current, voltage, phase angle, power, consumption since last transmission, and accumulated consumption through the circuit to the display  325 . 
         [0045]    In setting up the inventive device for use, the user will obtain the carbon dioxide emission rate for the relevant geographic region and program that rate into the device using input and selection devices  371 ,  372 ,  373  to input unit  330  which then will be sent to control circuit  320 . Other data, such as cost of electricity per kilowatt-hour, can also be obtained locally and entered into the system using input devices  371 ,  372 ,  373 . Control circuit  320  processes the data received from voltage detecting circuit  314  and current detecting circuit  315  with the data input by the user as well as data received from time base signal generation circuit  323  and memory  321  to calculate, inter alia, a value for the amount of carbon dioxide that was emitted into the atmosphere by the generation of the amount of electricity used by the appliance. Control circuit  320  then sends that carbon amount value to display  325 . 
         [0046]    Housing  310  includes a screen  345 , such as an LED or LCD display, that indicates information such as the cost of electricity consumed, physical data such as voltage, current, kilowatt-hour, carbon emitted, elapsed time, and evaluation period. Buttons  371 ,  372 , and  373  may be configured to cycle the display through different values, e.g., to estimate future costs for different evaluation periods or to change the display to indicate different parameters. Information relating to electricity drawn by the appliance can be shown on the screen in various configurations, such as total weight of carbon emitted, kilowatt-hours, cost, projected use or cost, etc. 
         [0047]    The system is continually reading the current and voltage, storing the values in memory  321 , while control circuit  325  processes the data and sends processed data to display screen  345 . Screen  345  may contain other icons to emphasize the type of value on display, such as a coal image, dollar sign, or electricity symbol. 
         [0048]    The device may be programmed to display projections of usage based on prior usage. Projections can be shown as the primary value  377  with other icons showing whether the projection is a daily, weekly, monthly, or yearly forecast.