US008768528B2
`
`(12) United States Patent
`US 8,768,528 B2
`(10) Patent No.:
`Millar et al.
`(45) Date of Patent:
`Jul. 1, 2014
`
`(54)
`
`(75)
`
`ELECTRICAL THERMAL STORAGE WITH
`EDGE-OF-NETWORK TAILORED ENERGY
`DELIVERY SYSTEMS AND METHODS
`
`Inventors: Jessica Millar, Barrington, R1 (US);
`David A. Durfee, North Scituate, R1
`(US)
`
`(73)
`
`Assignee: VCharge, Inc., Providence, RI (US)
`
`( * )
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 403 days.
`
`...................... 307/38
`
`7/1996 Pugh et a1.
`5,534,734 A *
`7/1999 Broe
`5,927,598 A
`1/2003 Lacy ............................. 700/295
`6,510,369 B1 *
`4/2003 Leighton et a1.
`6,553,413 B1
`6,813,897 B1* 11/2004 Bash et a1.
`...................... 62/175
`7,142,949 B2
`11/2006 Brewster et a1.
`7,333,880 B2
`2/2008 Brewster et a1.
`8,019,697 B2 *
`9/2011 Ozog ............................ 705/412
`8,335,596 B2 * 12/2012 Raman et a1.
`................. 700/295
`2002/0038279 A1
`3/2002 Samuelson et a1.
`2002/0116139 A1*
`8/2002 Przydatek et a1.
`.............. 702/62
`700/286
`2004/0024494 A1 *
`2/2004 Bayoumi et a1.
`
`700/286
`2005/0165511 A1*
`7/2005 Fairlie ............
`.. 122/32
`2005/0279292 A1* 12/2005 Hudson et a1.
`.
`
`2006/0155555 A1*
`7/2006 Barsness et a1.
`705/1
`
`.................... 290/44
`2006/0279088 A1 * 12/2006 Miller et a1.
`
`(21)
`
`Appl. No.: 13/108,500
`
`(22)
`
`Filed:
`
`May 16, 2011
`
`(65)
`
`Prior Publication Data
`
`US 2012/0296479 A1
`
`Nov. 22, 2012
`
`Int. Cl.
`
`(51)
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`
`G05D 17/00
`G05D 23/00
`G01R 15/00
`G01R 13/00
`US. Cl.
`USPC ........... 700/295; 700/275; 700/276; 700/277;
`700/278; 702/57; 702/58; 702/59
`Field of Classification Search
`None
`
`See application file for complete search history.
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`(52)
`
`(58)
`
`(56)
`
`4,345,162 A *
`4,570,052 A *
`4,868,412 A
`5,042,081 A
`5,081,591 A *
`5,086,493 A
`5,201,024 A
`
`................ 307/39
`8/1982 Hammer et a1.
`2/1986 Smith ........................... 392/340
`9/1989 Owens
`8/1991 Steffes et a1.
`1/1992 Hanwayetal.
`2/1992 Steffes
`4/1993 Steffes
`
`............... 323/205
`
`100‘1
`
`120
`
`(Continued)
`OTHER PUBLICATIONS
`
`Millar et a1., “Baby Smart Grid; Concord Light”, 2009, 7 pages.*
`
`(Continued)
`
`Primary Examiner 7 Kavita Padmanabhan
`Assistant Examiner 7 Thomas Stevens
`
`(74) Attorney, Agent, or FirmiKuta IP Law, LLC;
`Christine M. Kuta
`
`(57)
`
`ABSTRACT
`
`A method and apparatus of controlling the electric power
`usage of electric thermal storage heaters and systems are
`based on: 1) current and recorded measurements local to the
`heater and building; 2) current measurements external to the
`heater and building; 3) forecasts communicated to the appa-
`ratus. The method also includes sending out communications
`about power use as well as various other local measurements.
`The apparatus has local controls on the electric thermal stor-
`age, including but not limited to the relays that control flow of
`power into the heating elements, a logic module that inte-
`grates the local controls, as well as communication channels
`that extend outside the building to entities capable of provid-
`ing automatic forecasts and potentially other types of infor-
`mation not available locally.
`
`10 Claims, 6 Drawing Sheets
`
`CONTROLLER
`
`COMM. DEV.
`
`DATA STORE
`
`
`
`105
`
`ETS SYSTEM
`
`
`ETS SYSTEM
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`
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`ETS SYSTEM
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`
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`Page 1 of 17
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`VOLTSERVER EXHIBIT 1025
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`VOLTSERVER EXHIBIT 1025
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`US 8,768,528 B2
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`Page 2
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`(56)
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`References Cited
`
`US. pATENT DOCUMENTS
`
`2007/0112694 A1
`2007/0177319 A1 *
`2008/0195255 A1 *
`2009/0093916 A1
`2009/0222143 A1
`*
`2010/0018228 A1 *
`ggigéggggigfi :1 *
`2010/0179704 A1 >x<
`2010/0179862 A1
`2010/0245103 A1*
`2011/0030753 A1*
`
`5/2007 Metcalfe
`8/2007 Hirst
`............................... 361/85
`8/2008 Lutze et a1.
`................... 700/291
`4/2009 Parsonnet et a1.
`9/2009 Kempton et 31.
`.
`1/2010 Flammang et a1.
`............. 62/115
`
`3/3818 gififilaireéf:1
`33373“;
`7/2010 020g ............................ 700/291
`7/2010 Chassin et a1.
`9/2010 Plaisted et al.
`................ 340/657
`2/2011 Weaver et al.
`................ 136/201
`
`2011/0106321 A1*
`2011/0175569 A1*
`2011/0238232 A1 *
`2012/0152511 A1*
`2013/0076033 A1*
`
`................ 700/286
`5/2011 Cherian et al.
`320/109
`7/2011 Austin .........
`
`700/291
`9/2011 Tomita et a1.
`.................. 165/202
`6/2012 Chang et al.
`3/2013 Zachary et al.
`................... 290/2
`
`OTHER PUBLICATIONS
`
`“Store Reneable Enerngourself’, New Energy and Fuel Magazine,
`,
`~
`2010 3 pages :1
`Daryanian, Bahman, et al., Automatic Control of Thermal Electric
`Storage (C001) Under Real-Time, PriCng, AUg. 1994, NYS EnergyR
`& D Authority, Albany, NY
`
`* Cited by examiner
`
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`U.S. Patent
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`Jul. 1, 2014
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`US. Patent
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`US. Patent
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`Jul. 1, 2014
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`Sheet 6 of6
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`US 8,768,528 B2
`
`400—\
`
`IMPLEMENT A HIERARCHICAL ENERGY
`
`DISTRIBUTION SYSTEM HAVING A
`PLURALITY OF LEVELS OF ENERGY
`
`ESTABLISH A THRESHOLD FOR TOTAL
`
`POWER CONTROL
`
`MANAGEMENT SYSTEMS
`
`
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`410
`
`CONTROL A LOWEST LEVEL OF THE HIERARCHICAL
`ENERGY DISTRIBUTION SYSTEM SUCH THAT EACH
`
`LOWEST LEVEL ENERGY MANAGEMENT SYSTEM
`
`DOES NOT EXCEED THE THRESHOLD FOR TOTAL
`
`POWER CONTROL
`
`FIGURE 6
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`Page 8 of 17
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`Page 8 of 17
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`US 8,768,528 B2
`
`1
`ELECTRICAL THERMAL STORAGE WITH
`EDGE-OF-NETWORK TAILORED ENERGY
`DELIVERY SYSTEMS AND METHODS
`
`BACKGROUND
`
`The Electric Grid
`
`The network over which electrical energy or power is dis-
`tributed is referred to as the electric grid. Generally, electrical
`energy is delivered from power plants to end users in two
`stages. These two stages are bulk transmission and local
`distribution. Bulk transmission, or “high voltage electric
`transmission,” is the transfer of electrical energy from gener-
`ating power plants to substations. The portion of the electric
`grid that is involved in bulk transmission is referred to as the
`transmission grid. Local distribution is the delivery of elec-
`trical energy or power from substations to end users. The
`portion ofthe electric gridthat is involved in local distribution
`is referred to as the distribution grid.
`Management ofthe power running through the electric grid
`is important both to efficient power delivery and to grid main-
`tenance. Electrical energy is difficult and expensive to store
`and therefore grid management is typically focused on sub-
`stantially continuously matching production with consump-
`tion. Reasons to manage the electric grid efliciently include
`the following: unused electrical production facilities repre-
`sent a less efficient use of capital (little revenue is earned
`when not operating) and by “smoothing” demand to reduce
`peaks, less investment in operational reserve will be required,
`and existing facilities will operate more frequently. Most
`noticeable to the electricity user is that failure to respond to
`changes in load in time can result in grid instability and grid
`failure.
`
`A common method of grid management is load manage-
`ment, which is the process of balancing the supply of elec-
`tricity with the load by controlling the load rather than con-
`trolling the output at the power plant. Examples of load
`management techniques include triggering circuit breakers
`and using timers. Residential and commercial electricity use
`often varies drastically during the day, and demand response
`grid management techniques attempt to reduce this variabil-
`ity based on pricing signals intended to influence end user
`behavior. Some load management techniques include predic-
`tive techniques and involve modeling based on past load
`patterns, weather and other factors.
`Conventional load management techniques have numerous
`flaws. These flaws include slow response time, as well as
`interference with customer experience. In some cases, the
`slowness is inherent. In some cases, the response time is
`limited by the age of the grid infrastructure. Predictive load
`management techniques may fail to compensate for some
`types of events.
`Further complicating grid management is the trend toward
`distributed power generation. Power from a larger number of
`sources complicates the matching process. Additionally,
`some power generation, such as wind power, is intermittent.
`There is a need for grid management methods and systems
`that are able to handle the complexities of distributed power
`generation including generation from intermittent sources,
`and that respond faster to irregular and unpredictable events
`in a way that is relatively transparent to the end users.
`2. Electric Thermal Storage Heaters
`Electric space heating accounts for a substantial minority
`of heating in commercial and residential living space. Within
`electric space heating, Electric Thermal Storage (ETS) heat-
`ers are currently a niche market, originally developed in
`Europe during World War II. ETS heaters had a period of
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`regionally-specific popularity in the United States during the
`1980’s and early 1990’s when utilities promoted them as a
`means to deal with anticipated nuclear generated electric
`energy at night.
`Conventional ETS heaters share the following basic archi-
`tecture. The ETS heater has a heat sink surrounded by an
`insulated housing. The heat sink is often made of some type of
`brick. The brick for example is a type of ceramic brick that
`can be heated to a high temperature. An example maximum
`temperature of this ceramic brick is 1200 degrees F. Some
`bricks, for example conductive bricks developed at Quebec
`Hydro, West Montreal, Quebec, Canada, are able to achieve a
`higher temperature.
`The ETS heater may further include at least one duct
`through the heat sink and housing to allow for surrounding air
`to be circulated past and heated by the heat sink. The ETS
`heater includes electric heating elements for generating heat
`and one or more fans for circulating air through the ducts. A
`room thermostat, that is, a thermostat for measuring the tem-
`perature of the space to be heated, is responsible for either
`directly or indirectly controlling operation of the fan. In the
`direct case, the ETS heater includes the room thermostat,
`which controls operation of the fan. In the indirect case, the
`ETS heater receives a heat call signal from the thermostat and
`uses that signal to control the fan. The ETS heater typically
`includes a second thermostat for measuring the temperature
`of the heat sink. In addition, the ETS heater in some imple-
`mentations receives signals from an outside temperature sen-
`sor which measures the temperature outside ofthe space to be
`heated. This temperature is typically the outdoor temperature.
`ETS heaters come in two types: room units and furnaces.
`The distinguishing factor between the two types is that fur-
`naces connect into central heating systems while the room
`units pump hot air directly into a room. The ETS furnaces
`further subdivide into whether they connect into air or water
`heating systems. Within these basic categories, there are also
`distinctions based on how much energy the heat sink can store
`and how much power the system can draw. The ETS heater is
`sometimes the sole heat source, sometimes primary, and
`sometimes supplemental. For example, ETS fumaces are
`sometimes used as supplements to heat pumps. In cases
`where room units provide the sole or primary heat for a
`building, the ETS heaters are often connected to a main con-
`troller by means of a system of low or high voltage wires.
`Sometimes an ETS system also controls other sources of
`heat. For example, an ETS furnace may be connected to a heat
`pump, and control when the heat pump is actuated.
`ETS heater units are often connected together into an ETS
`system: a central control unit receives signals external to the
`house, for example the outside temperature sensor signal and
`an “available/not available” signal, and relays these signals to
`the individual ETS heater units via some type of local com-
`munications network. The individual ETS heater units in the
`
`system typically receive input from separate room thermo-
`stats with each ETS heater unit responsible for heating a
`separate “zone” in the area to be heated. Accordingly, an ETS
`system can consist of a network of a single furnace, a furnace
`with one or more room units, or multiple room units.
`Most existing schemes for controlling the operation of the
`heating elements in ETS heaters involve establishing at each
`moment in time a current desired maximum tCDMDC and a
`current desired minimum tCDMm for the temperature of the
`heat sink. These temperatures may be a function of readings
`of outside temperature sensors, or they may be a function of
`both readings of outside temperature sensors and historical
`fanbehavior (which is linked to heat flow out ofthe bricks). In
`addition, there is a mechanism for determining that electricity
`
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`US 8,768,528 B2
`
`3
`is available for the ETS heateri“available” or “not avail-
`
`able.” In conventional ETS heaters, this “availability” mecha-
`nism does not take into account information from the particu-
`lar ETS heater. Examples include a timer, or an “offpeak/
`onpeak” signal sent by power line carrier signals (PLC) over
`the existing power lines from the utility. When electricity is
`available to the ETS heater, the ETS heater is not charging,
`and the current temperature tC is less than the current desired
`minimum heat sink temperature, then the ETS heater will
`begin to charge. Likewise:
`
`Electricifl Available
`
`Not charging
`
`Charging
`
`tC < tCDMl."
`TCDMl-n < tC < tCDMax
`tCDMm < tC
`
`Continue charging
`Start charging
`Continue not charging Continue charging
`Continue not charging
`Stop charging
`
`When electricity is not available, the ETS heater does not
`charge. Conventional ETS heaters typically have an emer-
`gency override feature that is often manually implementable.
`The above controls are implemented in conventional ETS
`heaters using a variety of methods including mechanical,
`electrical, and hybrid mechanical-electrical systems.
`The conventional control mechanisms for ETS heaters
`
`often result in significant and prolonged surges in the use in
`the first few hours ofa nightly off-peak “Electricity available”
`period, followed by minimal to low levels of charging in the
`middle of the night. This is far from ideal in terms of provid-
`ing cheap electricity from the point of view of the wholesale
`purchaser. From a grid management perspective, this is not a
`good method of flattening the load curve.
`In addition, conventional art is not capable ofbalancing the
`responsibility for guaranteeing a warm home while simulta-
`neously taking advantage of close to optimal charging pro-
`files. For example, although most ETS-heated homes in a
`small utility’s service area may need only to heat for three
`hours in a particular day, the utility cannot send out an “avail-
`able” signal limited to the cheapest three hours of that day
`because some ofthe homes may in fact need more energy than
`they can draw in those three hours.
`The heuristic control mechanisms described above become
`
`even less optimal in regions with increasing levels of non-
`carbon generation, where there can be dramatic and variable
`changes in supply and price.
`In conventional art, high penetration of ETS heaters on a
`circuit of an energy distribution system presents a challenge.
`There is no method that is both reasonably equitable and close
`to optimal for dealing with distribution-level constraints.
`Given that: 1) conventional residential ETS fumaces can
`charge at up to 45 kW; 2) conventional residential ETS fur-
`naces will often charge at an average of 4-6 kW over a week;
`3) and that average household electric loads are typically on
`the order of 1 kW, the issue of distribution constraints is
`important be addressed once penetration of ETS heating
`exceeds, for example, a couple percent.
`Some efforts have been made in the conventional art to
`address the issues associated with distribution constraintsi
`
`specifically, efforts to avoid the simultaneous activation of
`heater charging. For example, in many of the ETS heaters,
`there are either mechanical or electrical mechanisms for
`
`introducing some randomness in beginning to charge during
`a “charge available” cycle. In one implementation, thermal
`relays take variable amounts of time (up to 3-5 minutes) to
`turn heaters on, even though all the heater sites may be react-
`ing to the same sensed parameter. In some conventional heat-
`
`4
`
`ers, the heater operates on an internal 15 minute clock that
`occasionally resets. Thus, heaters of this type responding to
`the same signal will stagger over a 15 minute period. In
`addition, some heaters will charge at a more rapid rate in
`colder weather, taking advantage of inherently greater capac-
`ity on the lines when they are colder.
`There remains a need for a decentralized energy manage-
`ment solution that enables buildings with ETS heat to obtain
`electricity on a more efficient basis (i.e., without burdening
`the grid unnecessarily) and that likewise enables the grid
`operator to cost-effectively manage the balance of supply and
`demand. Further, there remains a need for an energy manage-
`ment system that includes management of distributed power
`generation including power from intermittent sources.
`
`SUMMARY
`
`The problems of managing ETS heating effectively and
`efliciently and of managing the electric grid including
`responding to irregular and unpredictable events are solved
`by the present inventions of an energy management system
`for ETS systems that incorporates control, measurement and
`communications devices, an ETS controller that is responsive
`to a number of data factors including present and future
`weather data, present and historical building data, and elec-
`tricity price, and a grid management system that responds
`quickly to unexpected or intermittent events.
`Additional embodiments include a grid management sys-
`tem that responds quickly and reliably to unpredictable and/
`or intermittent events, an ETS energy management system for
`a network of electric thermal heaters/heating systems, local
`homogenous market structure that can run on top of the ETS
`energy management system that can flexibly interface with a
`variety of grid management systems, ETS service network
`that provides performance data and repair information about
`individual heaters and ETS area networks, controller for an
`electric thermal heater/heating system.
`The controller on an individual ETS heater includes relays
`that control the charging of the elements that provide energy
`to the electric thermal storage heaters. It measures a number
`of quantities, including but not limited to time, power flowing
`into the heating elements of each heater, and temperature of
`the heat sink. The controller is part of the larger ETS energy
`management system, and includes the communications soft-
`ware and firmware in order to relay information to and from
`the larger system.
`The ETS energy management system includes control,
`measurement and communication devices for an electric ther-
`
`mal storage heating system. The energy management system
`charges the heating system based on forecasts of local
`weather and possibly other information created at a source
`external to the heated building and tailored to the location of
`the heated building. The additional information in various
`embodiments includes electricity price and price forecasts
`along with some measure of uncertainty, confirmation of
`commitments to purchase certain amounts of energy in par-
`ticular market instances, and current and historical data col-
`lected at the building by the energy management system. The
`energy management system (1) collects on-site data and off-
`site forecasted data and (2) processes this data to implement
`charging strategies for the ETS system, in such a way that the
`ETS system more optimally purchases energy while main-
`taining heating performance guarantees. The energy manage-
`ment system includes of a collection of electronics residing at
`each building having an ETS system to be controlled. The
`collection of electronics includes a controller connected to
`
`each heater and network devices connecting all the electron-
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`US 8,768,528 B2
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`5
`the electronics
`ics in an ETS area network. In addition,
`receive and transmit communications outside the building Via
`an external channel such as the Internet.
`
`The ETS energy management system measures and
`records a number of quantities: the measurements collected
`by the controllers in its ETS area network including quantities
`involving time, temperature, and electricity.
`The ETS energy management system performs computa-
`tions that involve making estimates of future energy require-
`ments for each ETS system in the energy management net-
`work over specific periods of time and under forecasted
`weather scenarios. The estimates of future energy require-
`ments are typically based on information collected by the
`energy management system both through the external chan-
`nel and from local measurements and calculations. The
`
`energy management system calculates estimations based on
`both historical data and forecasted data.
`
`Based on estimations of future energy use and other data
`such as externally or internally provided actual or forecasted
`prices for electricity markets, the ETS energy management
`system then activates the heating elements in the various
`heaters under control in a manner consistent with an energy
`purchase plan that optimizes some price-like objective func-
`tion subject to the constraints of maintaining the temperature
`of the heat sink within an acceptable range the estimation of
`future energy requirements is included implicitly or explicitly
`in this optimization. Such an ETS energy management sys-
`tem is capable of providing the ETS system with better per-
`formance than the existing art, for a range of performance
`metrics.
`
`The ETS energy management system is capable of inter-
`acting with a variety of larger grid energy management sys-
`tems. This larger system could employ typical direct load
`control regimes. Preferably, the larger system has a market-
`based, distributed control architecture.
`The present inventions together with the above and other
`advantages may best be understood from the following
`detailed description of the embodiments of the invention
`illustrated in the drawings, wherein:
`
`DRAWINGS
`
`FIG. 1 is block diagram of an embodiment of an energy
`management system according to principles of the inven-
`tions;
`FIG. 2 is a block diagram of an embodiment of an electrical
`thermal storage system according to principles of the inven-
`tions;
`FIG. 3 is a diagram of the data operations of the electrical
`thermal storage system of FIG. 2;
`FIG. 4 is a simplified state diagram illustrating how the
`present invention could be integrated into a decentralized,
`market-based pricing system;
`FIG. 5 is a block diagram of an embodiment of a hierarchy
`of energy management systems according to principles of the
`inventions; and
`FIG. 6 is a flow chart of the operation of a security system
`in the hierarchy of energy management systems of FIG. 5.
`
`DESCRIPTION
`
`An energy management system controls a network of elec-
`tric thermal heating systems. Each electrical thermal storage
`(ETS) heating system has one or more electric thermal heat-
`ers. The energy management system provides energy to each
`heating system based on present weather data and weather
`predictions, building data including historical data, electricity
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`price and energy availability, unexpected grid events, and
`heating system characteristics including current temperature
`and capacity. Each thermal electric heating system includes a
`controller and a network communications device that enables
`
`the heating system to be networked to other heating systems
`and with the energy management system. The energy man-
`agement system also has the ability to operate as part of a
`multi-building, multi-region grid control
`architecture
`enabling the grid to respond quickly to unexpected events and
`to absorb and store energy from intermittent sources.
`FIG. 1 shows an embodiment of an energy management
`system 100. The energy management system 100 includes a
`control system 120 controlling a plurality of ETS systems
`105. The energy management system 100 is connected to the
`electrical distribution and transmission grid 130 through the
`control system 120. The control system 120 includes a con-
`troller 122, a network communications device 124 and a data
`store 126. The data store 126 stores data used by the energy
`management system and the ETS systems 105. The data, in
`various embodiments,
`includes present weather data and
`weather predictions, building data including historical data,
`electricity price and energy availability, unexpected grid
`events, and heating system characteristics including current
`temperature and capacity. Only the data connections 132
`among the elements in FIG. 1 are shown. It should be under-
`stood that the control system 120 and ETS systems 105, 110,
`115 each draw power from the grid 130 and therefore also are
`connected to the grid 130.
`Each ETS system 105 in this exemplary embodiment, pro-
`vides heat for a building. Accordingly, one of the ETS sys-
`tems 105, in a first arrangement, is an ETS furnace system and
`the rest of the ETS systems 105 are configurations of standa-
`lone ETS heaters. One of skill in the art will understand that
`
`various configurations of ETS heaters in each ETS system are
`possible within the scope of the inventions. Further, the num-
`ber of ETS systems shown is merely exemplary. One skilled
`in the art will understand that the energy management system
`is capable of controlling a large number of ETS systems.
`In operation, the control system 120 manages the electrical
`energy provided to the ETS systems such that a minimum
`amount is provided in order for the buildings to be heated to
`a defined standard. In an alternative embodiment, the control
`system 120 manages and provides data used by the ETS
`systems to manage heat and power usage. The control system
`120 also operates to control the energy draw of each ETS
`system 105 such that the grid 130 is not overburdened and so
`that electricity costs at each ETS system 105 are minimized.
`The control system 120 further operates to control the energy
`draw of the ETS systems such that, as a network of energy
`stores, the ETS systems store energy from excess electricity
`on the grid that might otherwise be wasted. In addition com-
`munications enable the control system to become part of a
`larger distributed grid control architecture that can use the
`ability to rapidly change the power usage of the ETS in order
`to increase grid stability. As will be described below, the
`response of the control system 120 and networked ETS sys-
`tems to grid events is rapid and provides an improved method
`of grid management compared to conventional methods.
`Disclosed below are representative embodiments of meth-
`ods and apparatus for controlling the electrical power usage
`of ETS systems as described in the summary.
`FIG. 2 shows an embodiment of an ETS system according
`to one embodiment. The ETS system 200 of the present
`embodiment resides inside a building. In a first arrangement,
`the ETS system 200 functions to fulfill all ofthe heating needs
`ofthe building. In a second arrangement, the ETS system 200
`
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`US 8,768,528 B2
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`7
`is a supplemental heating system that runs in tandem with
`another heat source such as a heat pump.
`The ETS system 200 includes a plurality of ETS heaters
`206 in communication with a logic module 202 over a com-
`munications network 204 also referred to as the ETS area
`
`network. In one arrangement, the ETS heaters 206 are all
`stand-alone ETS heaters. In a second arrangement, one of the
`ETS heaters is an ETS furnace. Each ETS heater 206 includes
`
`a Resource Control and Metering Module (RCMM) 208.
`Each RCMM 208 may record measurements including but
`not limited to time, RMS current flowing into each of the
`heating elements of each heater, RMS voltage, power factor,
`one or more temperature measurements from within the heat
`sink in each heater, fan activation speed for moving heat out
`ofthe heat sink and into the building space, building tempera-
`ture in one thermally connected region, building thermostat
`settings.
`The logic module 202 is a piece of electronics that acts as
`the hub for the communications networkithe ETS area net-
`
`work 204. The logic module 202 stores measurements of
`outside temperature, time data from a local clock and, in some
`arrangements, building temperature, activation state of an
`alternate heat source and Global Positioning System (GPS)
`data. The logic module also stores data recorded and sent
`from each RCMM. The logic module may have a mechanism
`for adjusting the timestamp measurements
`for each
`RCMMithat is, estimating the degree to which an RCMM
`clock is uncalibratedias well as a mechanism for recalibrat-
`
`ing both its internal clock and the clocks ofthe RCMM’s. The
`logic module 202 communicates with the RCMMs 208
`within the building via the ETS area network 204 installed
`over low-voltage lines orpower-line carrier. Alternatively, the
`ETS area network 204 is a wireless network such as a Zigbee.
`Individual RCMMs 208 receive information from and send
`
`information to the logic module 202. In addition, the logic
`module 202 communicates to agents 210 outside the building
`via an external channel 212. The external channel 212 is, for
`example, an Internet connection. The external channel 212 in
`various embodiments is implemented using Ethernet, wire-
`less, or Zigbee combined with a smart-grid fiber-optic back-
`bone. In addition, the logic module 202 may receive commu-
`nications from standard utility communications mediums,
`such as radio and power line carrier. The ETS system is also
`connected to the transmission grid 214.
`The communications bandwidth of the external channel
`
`212 and the ETS area network 204 is typically large enough to
`support the following: each RCMM 208 receiving a power set
`point signal from the logic module 202 every 2-4 seconds, and
`sending all measurements made at each RCMM 208 back to
`the logic module 202 asynchronously within 10 milliseconds
`of a change in power as well as synchronously every 5 min-
`utes.
`
`The logic module 202 and the RCMMs 208 are applica-
`tion-specific integrated circuits, or general-purpose comput-
`ers, or other types of programmable controller known in the
`art. In an alternative embodiment,
`the ETS system 200
`includes more than one logic module 202 inside the building.
`The logic module 202 and the RCMMs 208 in various
`embodiments include sufficient electronics memory to store a
`certain amount of dataisuch as power use, energy levels in
`the heat sink, external temperature, and historical energy
`prices. The amount of data is sufficient to provide the means,
`via an estimation procedure carried out on the logic module,
`to more accurately assess future energy needs given specific
`weather conditions than are possible with factory settings that
`lack specific knowledge of the installation. The specific
`knowledge typically includes hourly weather, electrical
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