Renewable energy system controls
11625017 · 2023-04-11
Assignee
Inventors
- Aly Eldeen O. Eltayeb (Boston, MA, US)
- Benjamin Michael Jenkins (Durham, NH, US)
- Marco Ferrara (Boston, MA, US)
Cpc classification
Y04S50/14
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y04S10/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
G05B19/04
PHYSICS
G06Q30/0201
PHYSICS
G06Q40/04
PHYSICS
Abstract
Physical and/or financial instruments may optimally hedge the cash flow of one or more renewable energy generators based on a desired risk and return profile of renewable infrastructure investors. Baseline revenues may be determined based on forward-looking electricity market price scenarios corresponding to qualified market products intended for sale from the renewable energy generators. Risk and return metrics of cash flows of the renewable energy generators may be determined. At least one physical hedge and/or financial hedge may be added. The size and operation of the renewable energy generators along with any physical hedges, or financial hedges, or both physical and financial hedges, may be optimized across multiple market price scenarios of qualified market products to optimize investor-tailored risk and return utility functions.
Claims
1. A method to manage operation of a renewable power asset, comprising: operating one or more computing devices controlling or in communication with one or more control devices of a renewable power asset; identifying, by the computing device, one or more market products to be sold by the renewable power asset; generating, by the one or more computing devices, forward looking market price scenarios representative of the one or more market products; calculating, by the one or more computing devices, baseline revenues of the renewable power asset in the forward looking market price scenarios; determining, by the one or more computing devices, a first cash flow associated with the baseline revenues; determining, by the one or more computing devices, a second cash flow by adding at least one physical hedge into the first cash flow, wherein each physical hedge comprises a long duration energy storage system or a short duration energy storage system, and each physical hedge has attributes of a maximum rated power, a maximum rated stored energy, a round-trip efficiency, a self-discharge, a ramp-rate, a response time, a calendar degradation, a throughput degradation, a capital cost, an operating cost, and a decommissioning cost; optimizing, by the one or more computing devices, a size of the at least one physical hedge and an operational strategy of the renewable power asset; sizing the at least one physical hedge at the optimized size, and charging and discharging the at least one physical hedge based on the optimized operational strategy. controlling, by the one or more computing devices or the one or more control devices in communication with the computing device, the renewable power asset to generate and deliver power based on the optimized operational strategy; and wherein optimizing further comprises optimizing based on a mean-variance optimization of risk and return metrics using is a joint probability of (q.sub.RT=q.sub.RT,m; p.sub.RT=p.sub.RT,k) given a realized DA price, M is a number of possible renewable generation scenarios, indexed by 1≤m≤M, K is a number of possible RT price scenarios, indexed by 1≤k≤K, μ.sub.{tilde over (ϑ)} is defined as
is defined as (q.sub.RT,md.sub.RT−c.sub.RT−q.sub.Da−q.sub.X).sup.T.Math.p.sub.RT,k−δ.sub.RT,m,k−c.sub.PP.sub.ESS−c.sub.EE.sub.ESS.
2. The method of claim 1, further comprising holding the optimal size of a physical hedge as fixed at a size of an existing physical hedge associated with the renewable generator asset.
3. A method to manage operation of a renewable power asset, comprising: operating one or more computing devices controlling or in communication with one or more control devices of a renewable power asset; identifying, by the computing device, one or more market products to be sold by the renewable power asset; generating, by the one or more computing devices, forward looking market price scenarios representative of the one or more market products; calculating, by the one or more computing devices, baseline revenues of the renewable power asset in the forward looking market price scenarios; determining, by the one or more computing devices, a first cash flow associated with the baseline revenues; determining, by the one or more computing devices, a second cash flow by adding at least one physical hedge into the first cash flow, wherein each physical hedge comprises a long duration energy storage system or a short duration energy storage system, and each physical hedge has attributes of a maximum rated power, a maximum rated stored energy, a round-trip efficiency, a self-discharge, a ramp-rate, a response time, a calendar degradation, a throughput degradation, a capital cost, an operating cost, and a decommissioning cost; optimizing, by the one or more computing devices, a size of the at least one physical hedge and an operational strategy of the renewable power asset; sizing the at least one physical hedge at the optimized size, and charging and discharging the at least one physical hedge based on the optimized operational strategy. controlling, by the one or more computing devices or the one or more control devices in communication with the computing device, the renewable power asset to generate and deliver power based on the optimized operational strategy; and wherein optimizing further comprises: optimizing through a linear programming framework based on utility functions of risk and return metrics such that
=(q.sub.RT,m+d.sub.RT−c.sub.RT−q.sub.DA−q.sub.X).sup.T.Math.p.sub.RT,k−c.sub.PP.sub.ESSx.sub.EE.sub.ESS=d.sub.RT.sup.T.Math.p.sub.RT,k−c.sub.RT.sup.T.Math.p.sub.RT,k−q.sub.X.sup.T.Math.p.sub.RT,k−c.sub.PP.sub.ESS−c.sub.EE.sub.ESS+(q.sub.RT,m−q.sub.DA).sup.T.Math.p.sub.RT,k where q.sub.RT,m is a real time renewable generation forecast in an m.sup.th scenario, d.sub.RT is a real time optimal discharge schedule of the at least one physical hedge, c.sub.RT is a real time optimal charge schedule of the at least one physical hedge, q.sub.DA is a day ahead commitments, q.sub.X is a real time curtailment of renewable generation, p.sub.RT,k is a real time price forecast in a k.sup.th scenario, c.sub.P is a storage unit power cost amortized in an optimization horizon, P.sub.ESS is a rated power of the at least one physical hedge, c.sub.E is a storage unit energy cost amortized in the optimization horizon, E.sub.ESS is a rated energy of the at least one physical hedge, c.sub.RT is a real time optimal charge schedule of the at least one physical hedge, M is a number of possible renewable generation scenarios, indexed by 1≤m≤M, K is a number of possible RT price scenarios, indexed by 1≤k≤K, and J is a number of discretized time steps in the optimization horizon, indexed by 1≤j≤J; introducing an auxiliary optimization variable x and a unit returns r.sub.m,k such that
=x.sup.T.Math.r.sub.m,k; x.sub.3J+1=1; indexing scenarios to a variable t within a range of total scenario permutations, and expanding to components of x, r.sub.t such that {tilde over (ϑ)}.sub.t=x.sup.T.Math.r.sub.t=Σ.sub.1≤j≤3J+1x.sub.jr.sub.j,t; x.sub.3J+1=1; introducing an average return μ.sub.j at a given time step such that μ.sub.j
Σ.sub.1≤t≤Tw.sub.tr.sub.j,t; and configuring a linear programming goal and applying one of: a mean absolute deviation (MAD), a minimax, a conditional value risk (CVaR), a Gini mean difference (GMD), or a weighted conditional value at risk (WCVaR).
4. The method of claim 3, wherein configuring a linear programming goal further comprises configuring the goal to optimize subject to a minimum return constraint as expressed in
5. The method of claim 3, wherein configuring a linear programming goal further comprises configuring the goal to optimize based on minimizing dispersion while subject to a minimum return constraint as expressed in
6. The method of claim 3, wherein configuring a linear programming goal further comprises configuring the goal to optimize based relative to a no risk scenario as expressed in
7. The method of claim 3, wherein configuring a linear programming goal further comprises configuring the goal expressed in
λ is a risk tolerance factor, and
ρ(x) is defined as Dispersion; and applying one of the MAD, the minimax, the CVaR, the GMD, or the WCVaR further comprises applying one of: the MAD as expressed in
8. The method of claim 3, further comprising holding the optimal size of a physical hedge as fixed at a size of an existing physical hedge associated with the renewable generator asset.
9. A method to manage operation of a renewable power asset, comprising: operating one or more computing devices controlling or in communication with one or more control devices of a renewable power asset; identifying, by the computing device, one or more market products to be sold by the renewable power asset; generating, by the one or more computing devices, forward looking market price scenarios representative of the one or more market products; calculating, by the one or more computing devices, baseline revenues of the renewable power asset in the forward looking market price scenarios; determining, by the one or more computing devices, a first cash flow associated with the baseline revenues; determining, by the one or more computing devices, a second cash flow by adding at least one financial hedge into the first cash flow, wherein each financial hedge is any of a fixed for floating revenue swap, a fixed for floating renewable volume swap, or a fixed for floating price swap, applied in optimal amounts to revenues or components of revenues of the renewable power asset, and wherein each financial hedge has attributes of fixed revenues, fixed volumes, fixed prices, upper and lower bounds, and financial hedge premiums; optimizing, by the one or more computing devices, a size of the at least one financial hedge and an operational strategy of the renewable power asset; transacting, by the one or more computing devices, exchange of the at least one financial hedge at the optimized size through a financial transaction interface; controlling, by the one or more computing devices or the one or more control devices in communication with the computing device, the renewable power asset to generate and deliver power based on the optimized operational strategy; and wherein optimizing further comprises optimizing based on a mean-variance optimization of risk and return metrics wherein optimizing further comprises optimizing based on a mean-variance optimization of risk and return metrics using is a joint probability of (q.sub.RT=q.sub.RT,m; p.sub.RT=p.sub.RT,k), M is a number of possible renewable generation scenarios, indexed by 1≤m≤M, K is a number of possible RT price scenarios, indexed by 1≤k≤K, μ.sub.{tilde over (ϑ)} is defined as
is defined as
10. A method to manage operation of a renewable power asset, comprising: operating one or more computing devices controlling or in communication with one or more control devices of a renewable power asset; identifying, by the computing device, one or more market products to be sold by the renewable power asset; generating, by the one or more computing devices, forward looking market price scenarios representative of the one or more market products; calculating, by the one or more computing devices, baseline revenues of the renewable power asset in the forward looking market price scenarios; determining, by the one or more computing devices, a first cash flow associated with the baseline revenues; determining, by the one or more computing devices, a second cash flow by adding at least one financial hedge into the first cash flow, wherein each financial hedge is any of a fixed for floating revenue swap, a fixed for floating renewable volume swap, or a fixed for floating price swap, applied in optimal amounts to revenues or components of revenues of the renewable power asset, and wherein each financial hedge has attributes of fixed revenues, fixed volumes, fixed prices, upper and lower bounds, and financial hedge premiums; optimizing, by the one or more computing devices, a size of the at least one financial hedge and an operational strategy of the renewable power asset; transacting, by the one or more computing devices, exchange of the at least one financial hedge at the optimized size through a financial transaction interface; controlling, by the one or more computing devices or the one or more control devices in communication with the computing device, the renewable power asset to generate and deliver power based on the optimized operational strategy; and wherein optimizing further comprises: optimizing through a linear programming framework based on utility functions of risk and return metrics such that:
=(q.sub.RT,m−q.sub.DA−q.sub.X).sup.T.Math.p.sub.Rt,k−q.sub.H.sup.T.Math.(p.sub.RT,k−p.sub.H)−Σ.sub.s.sub.
=x.sup.T.Math.r.sub.m,k; x.sub.J+1+2(+2*S*N)=1; indexing scenarios to a variable t within a range of total scenario permutations, and expanding to components of x, r.sub.t such that {tilde over (ϑ)}.sub.t=x.sup.T.Math.r.sub.t=Σ.sub.1≤j≤J+(2*S*N)x.sub.jr.sub.j,t; x.sub.J+1+(2*S*N)=1; introducing an average return μ.sub.j at a given time step such that μ.sub.j
Σ.sub.1≤t≤Tw.sub.tr.sub.j,t; considering a hedge counter-party's cash flow to be
r.sub.H,k=q.sub.H.sup.t.Math.(p.sub.RT,k−p.sub.H)+Σ.sub.S.sub.
11. The method of claim 10, wherein configuring a linear programming goal further comprises configuring the goal expressed in
λ is a risk tolerance factor, and
ρ(x) is defined as Dispersion; and applying one of the MAD, the minimax, the CVaR, the GMD, or the WCVaR further comprises applying one of: the MAD as expressed in
12. The method of claim 10, wherein configuring a linear programming goal further comprises configuring the goal to optimize subject to a minimum return constraint as expressed in
13. The method of claim 10, wherein configuring a linear programming goal further comprises configuring the goal to optimize based on minimizing dispersion while subject to a minimum return constraint as expressed in
14. The method of claim 10, wherein configuring a linear programming goal further comprises configuring the goal to optimize based relative to a no risk scenario as expressed in
15. A method to manage operation of a renewable power asset, comprising: operating one or more computing devices controlling or in communication with one or more control devices of a renewable power asset; identifying, by the computing device, one or more market products to be sold by the renewable power asset; generating, by the one or more computing devices, forward looking market price scenarios representative of the one or more market products; calculating, by the one or more computing devices, baseline revenues of the renewable power asset in the forward looking market price scenarios; determining, by the one or more computing devices, a first cash flow associated with the baseline revenues; determining, by the one or more computing devices, a second cash flow by adding at least one physical hedge and at least one financial hedge into the first cash flow; optimizing, by the one or more computing devices, a size of the at least one physical hedge, a size of the at least one financial hedge, and an operational strategy of the renewable power asset; sizing the at least one physical hedge at the optimized size, and charging and discharging the at least one physical hedge based on the optimized operational strategy; transacting, by the computing device, exchange of the at least one financial hedge at the optimized size through an energy market exchange interface; controlling, by the one or more computing devices or the one or more control devices in communication with the computing device, the renewable power asset to generate and deliver power based on the optimized operational strategy; and wherein optimizing further comprises optimizing based on a mean-variance optimization of risk and return metrics using is a joint probability of (q.sub.RT=q.sub.RT,m; p.sub.RT=p.sub.RT,k), M is a number of possible renewable generation scenarios, indexed by 1≤m≤M, K is a number of possible RT price scenarios, indexed by 1≤k≤K, μ.sub.{tilde over (ϑ)} is defined as
16. The method of claim 15, further comprising holding the optimal size of a physical hedge as fixed at a size of an existing physical hedge associated with the renewable generator asset.
17. A method to manage operation of a renewable power asset, comprising: operating one or more computing devices controlling or in communication with one or more control devices of a renewable power asset; identifying, by the computing device, one or more market products to be sold by the renewable power asset; generating, by the one or more computing devices, forward looking market price scenarios representative of the one or more market products; calculating, by the one or more computing devices, baseline revenues of the renewable power asset in the forward looking market price scenarios; determining, by the one or more computing devices, a first cash flow associated with the baseline revenues; determining, by the one or more computing devices, a second cash flow by adding at least one physical hedge and at least one financial hedge into the first cash flow; optimizing, by the one or more computing devices, a size of the at least one physical hedge, a size of the at least one financial hedge, and an operational strategy of the renewable power asset; sizing the at least one physical hedge at the optimized size, and charging and discharging the at least one physical hedge based on the optimized operational strategy; transacting, by the computing device, exchange of the at least one financial hedge at the optimized size through an energy market exchange interface; controlling, by the one or more computing devices or the one or more control devices in communication with the computing device, the renewable power asset to generate and deliver power based on the optimized operational strategy; and wherein optimizing further comprises: optimizing through a linear programming framework based on utility functions of risk and return metrics such that
=x.sup.T.Math.r.sub.m,k;x.sub.3J+3+(2*S*N)=1 indexing scenarios to a variable t within a range of total scenario permutations, and expanding to components of x, r.sub.t, and equality contstraints such that {tilde over (ϑ)}.sub.t=x.sup.T.Math.r.sub.t=Σ.sub.1≤j≤3J+3+(2*S*N)x.sub.kr.sub.j,y; x.sub.3J+3+(2*S*N)=1; introducing an average return μ.sub.j at a given time step such that
r.sub.H=q.sub.H.sup.T.Math.(p.sub.RT,k−p.sub.H)+Σ.sub.S.sub.
18. The method of claim 17, wherein configuring a linear programming goal further comprises configuring the goal to optimize subject to a minimum return constraint as expressed in
19. The method of claim 17, wherein configuring a linear programming goal further comprises configuring the goal to optimize based on minimizing dispersion while subject to a minimum return constraint as expressed in
20. The method of claim 17, wherein configuring a linear programming goal further comprises configuring the goal to optimize based relative to a no risk scenario as expressed in
21. The method of claim 17, wherein configuring a linear programming goal further comprises configuring the goal expressed in
λ is a risk tolerance factor, and
ρ(x) is defined as Dispersion; and applying one of the MAD, the minimax, the CVaR, the GMD, or the WCVaR further comprises applying one of: the MAD as expressed in
22. The method of claim 17, further comprising holding the optimal size of a physical hedge as fixed at a size of an existing physical hedge associated with the renewable generator asset.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In the drawings, closely related figures and items have the same number but different alphabetic suffixes. Processes, states, statuses, and databases are named for their respective functions.
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DETAILED DESCRIPTION, INCLUDING THE PREFERRED EMBODIMENT
(10) In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown, by way of illustration, specific embodiments which may be practiced. It is to be understood that other embodiments may be used, and structural changes may be made without departing from the scope of the present disclosure.
Terminology
(11) The terminology and definitions of the prior art are not necessarily consistent with the terminology and definitions of the current invention. Where there is a conflict, the following definitions apply.
(12) A “computing device” refers to any one or all of cellular telephones, smart phones, personal or mobile multi-media players, personal data assistants (PDAs), laptop computers, personal computers, tablet computers, smart books, palm-top computers, wireless electronic mail receivers, multimedia Internet enabled cellular telephones, controllers, and similar electronic devices which include a programmable processor, memory, and circuitry configured to perform operations as described herein.
(13) A “server” refers to any computing device capable of functioning as a server, such as a master exchange server, web server, mail server, document server, content server, or any other type of server. A server may be a dedicated computing device or a computing device including a server module (e.g., running an application that may cause the computing device to operate as a server). A server module (e.g., server application) may be a full function server module, or a light or secondary server module (e.g., light or secondary server application) that is configured to provide synchronization services among the dynamic databases on receiver devices. A light server or secondary server may be a slimmed-down version of server-type functionality that can be implemented on a receiver device thereby enabling it to function as an Internet server (e.g., an enterprise e-mail server) only to the extent necessary to provide the functionality described herein.
(14) A processor refers to a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, within a computing device. A general-purpose processor may be a microprocessor, but, in the alternative, may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
(15) A computer network refers to a 3G network, 4G network, 5G network, local area network, wide area network, core network, the Internet, or any combinations thereof.
(16) A “renewable power asset” includes one or more renewable power generation assets and zero or more energy storage assets. A “renewable power asset” may also be referred to as a “node”.
(17) A “power generation system” includes one or more power generation sources and zero or more energy storage assets. The power generation sources may be renewable power generation assets or traditional non-renewable generation assets such as gas, coal, or nuclear. A power generation system may also be referred to as a “node”.
(18) A renewable power generation asset is a power generator using a renewable resource, such as, but not limited to, wind, solar, hydro, biomass, ocean thermal, and geothermal generators.
(19) A combined power generation, transmission, and storage system includes a power generation system with one or more energy storage assets, and one or more transmission facilities.
(20) An Energy Storage asset is equivalent to a bulk energy storage system.
(21) A bulk energy storage system is a short duration energy storage (SDES) or long duration energy storage (LODES), and may include one or more batteries.
(22) A Day Ahead Energy Market lets participants (energy generators and load serving entities) commit to buy or sell electricity one day before the operating day. The price committed is the Day Ahead (DA) price.
(23) A Real Time Energy Market lets participants (energy generators and load serving entities) buy and sell electricity during the course of an operating day, and balances differences between Day Ahead commitments and actual real-time demand. The price exchanged within the Real Time Energy Market is the Real Time (RT) price.
(24) In a regulated environment, also referred to as a regulated energy market, one entity owns and operates production, infrastructure, and delivery of electricity. Electricity pricing rates are set by public commissions and not a competitive market.
(25) An Operating Strategy is a mathematical/algorithmic framework for a renewable power asset.
(26) An Operating Schedule is an actual power output schedule for a renewable power asset; i.e., when to ramp-up, generate, and ramp-down for a generator; when to charge and when to output for a storage asset; when to transmit for a transmission asset.
(27) “Prediction” and “forecast” are used interchangeably herein.
(28) As used herein, the term “received” refers to information being acquired, obtained, or otherwise received, whether in response to a request for such information (i.e., initiated locally) or whether such information was sent from a remote computing device unsolicited (i.e., initiated remotely).
(29) A physical hedge is an energy storage system capable of charging (receiving power for storing) and discharging (outputting previously stored power). A physical hedge may be one or more long-duration energy storage systems (LODES), or one or more short-duration energy storage systems (SDES), or both one or more LODES and one or more SDES. A physical hedge has attributes of maximum rated power, maximum rated stored energy, round-trip efficiency, self-discharge, ramp-rate, response time, calendar and throughput degradation.
(30) A financial hedge is a contractually binding agreement applying to future financial aspects of revenues, volumes, or prices of energy produced by a renewable generator. A financial hedge may be any of a fixed for floating revenue swap, a fixed for floating renewable volume swap, a fixed for floating price swap, or any equivalent fixed for floating swap. A financial hedge may have attributes of fixed revenues, fixed volumes, fixed prices, upper and lower bounds (collars), and financial hedge premiums. A financial hedge may also comprise time-of-delivery variations, such as seasonal variation and/or peak/off-peak hour variations, to any of volume swaps, price swaps, and revenue swaps. A financial hedge can be sized, bought, and sold with financial intermediaries
(31) A market product is any of the services that may be provided by a combined power generation, transmission, and storage system. These include electrical energy, ancillary services, and capacity as a firm and dependable generation when required.
(32) Ancillary services are services and functions of an electric grid which facilitate and support continuous flow of electric power originating from generators and reaching consumers such that energy supply continually meets energy demand. Ancillary services include frequency control, frequency regulation, spinning reserves, non-spinning reserves, black-start, voltage control, and other equivalents.
(33) A qualified market product is a market product from a system which has shown it is capable of providing that market product.
(34) The following variables and operations are defined as used throughout the description. Bold notation indicates vector variables that span an optimization time horizon.
(35) .sup.T is to be a transpose operation.
(36) ⋅ is defined to be a scalar product operation.
(37) J is defined to be a number of discretized time steps in optimization horizon, indexed by 1≤j≤J.
(38) M is defined to be the number of possible renewable generation scenarios, indexed by 1≤m≤M.
(39) K is defined to be the number of possible RT price scenarios, indexed by 1≤k≤K.
(40) T is defined to be the number of total scenario permutations in given optimization, indexed by 1>t≤T.
(41) q.sub.DA is defined to be the DA commitments.
(42) q.sub.X is defined to be the RT curtailment of renewable generation.
(43) q.sub.RT is defined to be the RT renewable generation.
(44) q.sub.RT,m is defined to be the renewable generation forecast in the m.sup.th scenario.
(45) p.sub.RT, is defined to be a RT price.
(46) p.sub.RT,k is defined to be the RT price forecast in the k.sup.th scenario.
(47) (q.sub.RT,m−q.sub.DA−q.sub.X) is defined to be the deviation from DA commitments.
(48) δ.sub.RT,n,m,k is defined to be the RT penalties, which is a function of deviation from DA commitments and market prices. For example, penalties may be a multiplier of the absolute value of the deviation from DA commitments.
(49) γ.sub.m is defined to be a factor to bias optimization towards specific generation forecast scenarios.
(50) λ is defined to be a risk tolerance factor (with 0 being no risk aversion).
(51) is defined to be the Joint probability of (q.sub.RT=q.sub.RT,m; p.sub.RT=p.sub.RT,k) given a realized DA price.
(52) d.sub.RT is defined to be the RT optimal discharge schedule of a storage system.
(53) c.sub.RT is defined to be the RT optimal charge schedule of a storage system.
(54) SOC is defined to be the State of charge of storage system.
(55) (q.sub.RT,m+d.sub.RT−c.sub.RT−q.sub.DA−q.sub.X) is defined to be the deviation from DA commitments, including energy storage.
(56) P.sub.ESS is defined to be storage rated power.
(57) c.sub.P is defined to be storage unit power cost amortized in the optimization horizon.
(58) E.sub.ESS is define to be storage rated energy.
(59) c.sub.E is defined to be storage unit energy cost amortized in the optimization horizon.
(60) q.sub.H is defined to be a baseline hedge volume shape.
(61) p.sub.H is defined to be a baseline hedge price shape.
(62) q.sub.H,S,τ is defined to be a hedge volume shape perturbation in season s, time block τ; 0 otherwise.
(63) p.sub.H,S,τ is defined to be a hedge price shape perturbation in season s, time block τ; 0 otherwise.
(64) α.sub.S,τ is defined to be a multiplier of the hedge volume shape perturbation in season s, time block τ.
(65) δ.sub.S,τ is defined to be a multiplier of the hedge price shape perturbation in season s, time block τ.
Operation
(66) Systems, methods, and devices may enable planning, design, development, control, and ongoing maintenance of one or more renewable energy systems, including power generation, transmission, and/or storage systems, with or without long term financial contracts, to meet an optimized size and operational strategy.
(67) Referring to
(68) In power generation system 101, power generation sources 102 and bulk energy storage systems 104 may both be connected to one or more power control devices 110. Power control devices 110 may be connected to power grid 115 or other transmission infrastructure. Power control devices 110 may include switches, converters, inverters, relays, power electronics, and any other type devices that may serve to control the flow of electricity from, to, or between one or more of power generation sources 102, bulk energy storage systems 104, and power grid 115. Additionally, power generation system 101 may include transmission facilities 130 connecting power generation system 101 to power grid 115. As an example, transmission facilities 130 may connect between power control devices 110 and power grid 115 to enable electricity to flow between power generation system 101 and power grid 115. Transmission facilities 130 may include transmission lines, switches, relays, transformers, and any other type devices that may serve to support the flow of electricity between power generation system 101 and power grid 115. Power control devices 110 and/or transmission facilities 130 may be connected to plant controller 112. Plant controller 112 may be a computing device which may monitor and control the operations of power control devices 110 and/or transmission facilities 130, such as via various control signals. Plant controller 112 may control power control devices 110 and/or transmission facilities 130 to provide electricity from power generation sources 102 to power grid 115 and/or to bulk energy storage systems 104, to provide electricity from bulk energy storage systems 104 to power grid 115, and/or to provide electricity from power grid 115 to bulk energy storage systems 104. Power generation source 102 may selectively charge bulk energy storage system 104 and bulk energy storage system 104 may selectively discharge to the power grid 115. In this manner, energy (e.g., renewable energy, non-renewable energy, etc.) generated by power generation source 102 may be output to power grid 115 sometime after generation through bulk energy storage system 104.
(69) Power generation sources 102 and the bulk energy storage systems 104 may be located together or geographically separated from one another. For example, bulk energy storage system 104 may be upstream of a transmission constraint, such as co-located with power generation source 102, upstream of a portion of grid 115. In this manner, over build of underutilized transmission infrastructure may be avoided by situating bulk energy storage system 104 upstream of a transmission constraint, charging bulk energy storage system 104 at times of transmission shortage and discharging bulk energy storage system 104 at times of available capacity. Bulk energy storage system 104 may also arbitrate electricity according to prevailing market prices to increase the revenues to power generation source 102. In another example, bulk energy storage system 104 may be downstream of a transmission constraint, such as downstream of a portion of grid 115, from power generation source 102. In this manner, over build of underutilized transmission infrastructure may be avoided by situating bulk energy storage system 104 downstream of a transmission constraint, charging bulk energy storage system 104 at times of available capacity and discharging bulk energy storage system 104 at times of transmission shortage. Bulk energy storage system 104 may also arbitrate electricity according to prevailing market prices to reduce the final cost of electricity to consumers.
(70) Referring also to
(71) Referring also to
(72) Plant controller 112, or plant controllers 112A and 112B, may be in communication with computer network 120. Using connections to network 120, plant controller 112 may exchange data with network 120 as well as devices connected to network 120, such as plant management system 121 or any other device connected to network 120. Plant management system 121 may include one or more computing devices, such as computing device 124 and server 122. Computing device 124 and server 122 may be connected to one another directly and/or via connections to network 120. The functionality of computing device 124 and server 122 may be combined into a single computing device, or may split among more than two devices. Additionally, the functionality may be in whole, or in part, offloaded to a remote computing device, such as a cloud-based computing system. While illustrated as in communication with a single power generation system 101, plant management system 121 may be in communication with multiple power generation systems.
(73) Referring also to
(74) Plant management system 121 may interface with other computing devices connected to network 120, such as computing device 150. Using connections to network 120, plant management system 121 and computing device 150 may exchange data with one another. Alternatively, or additionally, computing device 150 may also directly connect to devices of plant management system 121. Plant management system 121 may provision one or more interfaces to other computing devices, such as computing device 150, enabling the other computing devices to interact with plant management system 121. As an example, plant management system 121 may provide a market interface enabling other computing devices, such as computing device 150, to be used to buy and/or sell shortfall and/or excess power generation of power generation system 101. The buying/selling of shortfall/excess may be controlled by plant management system 121 according to a cost strategy, such as a cost minimizing strategy, or a value strategy, such as a value maximizing strategy, that may inform operation of power generation system 101, especially bulk energy storage system 104. In this manner, bulk energy storage system 104 may be operated as a hedge against volatility of market prices. In other words, the ability of a market interface to sell and/or buy power generation capability through plant management system 121 may reduce the cost of supplying a load to consumers of the power from power generation system 101 or increase the market value of the power from power generation system 101 in a manner that optimizes the risk and return profile of the power generation system owner, operator, or investors.
(75) Given the various configurations illustrated in
(76) Referring also to
(77) The processor may receive 315 or acquire at least one forward-looking electricity market price scenario corresponding to each of the one or more identified market products intended for sale from the renewable energy system. Each forward-looking electricity market price scenario may be received from a vendor, a user-determined forecast, and/or any other source. Each forward-looking electricity market price scenario may be retrieved from a database, pre-loaded, input by a user, retrieved over a network, generated based on historical data, etc. Any forward-looking electricity market price scenario may be a Monte Carlo variation of best-guess baseline scenarios. The best-guess baseline scenarios may be determined based on historical patterns through techniques such as regression or machine learning. Additionally, or alternatively, the best-guess baseline scenarios may be determined based on fundamental analysis of cost-minimizing portfolios in future grids through techniques such as capacity expansion or production cost modeling simulations. The Monte Carlo variation may be generated based on correlated statistics calibrated with historical data. Additionally, or alternatively, the Monte Carlo variation may include known statistics of the underlying physical phenomena, such as renewable generator output, wind output, or solar output. Additionally, or alternatively, the Monte Carlo variation may include known statistics of the demand for electricity. Additionally, or alternatively, the Monte Carlo variation may include known statistics of the supply of electricity from a portfolio of generation and transmission assets.
(78) Alternatively, the processor may calculate the forward-looking electricity market price scenarios as forecasts of Day Ahead and Real Time energy prices. The forecasts may be generated as detailed in related co-pending application Ser. No. 16/892,942, naming inventors Benjamin Michael Jenkins, Aly Eldeen O. Eltayeb, and Marco Ferrara, filed Jun. 4, 2020, titled “Systems And Methods For Managing A Renewable Power Asset”, which is hereby fully incorporated by reference.
(79) The processor may determine 320 or receive one or more constraints on producing and/or supplying the identified market products imposed by market rules or physical infrastructure.
(80) The processor may determine 325 whether each market product is a qualified market product based on the forward-looking electricity market price scenarios and operational requirements modeled as mathematical constraints. If a market product falls within one or more of the constraints, it may be considered to be a qualified market product.
(81) The processor may determine 330 baseline revenues for each qualified market product from one or more corresponding forward-looking electricity market price scenarios.
(82) The processor may determine 335 a cash flow associated with the determined baseline revenues. The cash flow may have associated risk and return metrics. Risk metrics may include any of variance, standard deviation, downside spread from the median or mean value to an arbitrary downside value of the distribution of net present value, return on investment, and/or internal rate of return. Return metrics may include any of median or mean of the distribution of net present value, return on investment, and/or internal rate of return. LP computable risk and return metrics are detailed further below.
(83) Specific computable risk and return metrics may vary depending on what type of hedge is used. The hedge may be one or more physical hedges, or one or more financial hedges, or a combination of one or more physical hedges and one or more financial hedges. Once hedges are identified, the determined cash flow may be updated to account for the hedge, and an optimized size and operational strategy determined using computable risk and return metrics.
(84) The processor may receive 340 at least one physical hedge associated with the one or more renewable energy system. Any physical hedge may be received from a portfolio containing models, characteristics, structural specifications, and/or constraints of the at least one physical hedge, which may be stored in a database, pre-loaded, based on historical data, etc. Any physical hedge may be selected (i.e., identified) by a user working on or with the computing device housing the processor. Alternatively, any physical hedge may be identified from another source, such as a specification of a select renewable energy system. Each physical hedge may be a long-duration energy storage system (LODES) or a short-duration energy storage system (SDES) able to store and then provide electricity at various times. This enables shifting electricity from times of low market price to times of high market price, and providing electrical output in forms that conform with requirements of certain electrical products that are valuable when other electrical products are not. For example, a physical hedge may provide power output on demand to fulfill capacity obligations when renewable generation may suddenly and unexpectedly fall. Each physical hedge may have a maximum rated power, maximum rated stored energy, round-trip efficiency, self-discharge, ramp-rate, response time, calendar, and throughput degradation, as well as attributes of capital cost, operating cost, and decommissioning cost.
(85) The processor may determine 345 a second cash flow by adding the received physical hedge(s) into the previously determined cash flow. The processor may optimize 350 size and operational strategy of the renewable power generator combined with the received physical hedge(s), across generation, transmission, and storage of qualified market product. Such optimization may be to maximize investor-tailored risk and return utility functions as detailed through mean-variance optimization in Equation 1.
(86)
Where:
(87) (q.sub.RT,m+d.sub.RT−c.sub.RT−q.sub.DA−q.sub.X).sup.T .Math.p.sub.RT,k−δ.sub.RT,m,k−c.sub.PP.sub.ESS−c.sub.EE.sub.ESS
(88) Subject to storage system discharge, charge, and state of charge constraints, which can be readily implemented as it will be apparent to those skilled in the art:
d.sub.RT,j≤P.sub.ESS∀j
c.sub.RT,jP.sub.ESS∀j
(89)
0≤SOC.sub.j+1≤E.sub.ESS∀j
η.sub.dDischarge efficiency
η.sub.cCharge efficiency
(90) An alternative formulation for maximizing investor-tailored risk and return utility functions, which is suited for a linear programming framework with LP computable utility functions, may ignore penalties:=(q.sub.RT,m+d.sub.RT−c.sub.RT−q.sub.DA−q.sub.X).sup.T.Math.p.sub.RT,k−c.sub.PP.sub.ESS−c.sub.EE.sub.ESS=d.sub.RT.sup.T.Math.p.sub.RT,k−c.sub.RT.sup.T.Math.p.sub.RT,k−q.sub.X.sup.T.Math.p.sub.RT,k−c.sub.pP.sub.ESS−c.sub.EE.sub.ESS+(q.sub.RT,m−q.sub.DA).sup.t.Math.p.sub.RT,k Equation 2
(91) Introduce the auxiliary optimization variable
(92)
and the unit returns
(93)
Index scenarios to t and expand to components of x, r.sub.t:
(94)
Introduce average return at a given time step (average across scenarios):
(95)
(96) Different optimizations may be applied based on the LP goal expressed in
(97) Equation 6.
(98)
Equation 7 applies a mean absolute deviation (MAD), Equation 8 applies a minimax, Equation 9 applies a conditional value at risk (CVaR), Equation 10 applies a Gini mean difference (GMD), and Equation 11 applies a weighted conditional value at risk (WCVaR).
(99)
(100)
(101)
(102)
(103)
(104) Alternatively, the optimization may be subject to a minimum return constraint as specified in Equation 12. Again, different optimizations may be applied, such as MAD (Equation 13), minimax (Equation 14), CVaR (Equation 15), GMD (Equation 16), or WCVaR (Equation 17).
(105)
(106)
(107)
(108)
(109)
(110)
(111) As another alternative, optimizations may be based on minimizing dispersion while subject to a minimum return constraint as specified in Equation 18. Again, different optimizations may be applied, such as MAD (Equation 19), minimax (Equation 20), CVaR (Equation 21), GMD (Equation 22), or WCVaR (Equation 23).
(112)
(113)
(114)
(115)
(116)
(117)
(118) As another alternative, optimizations may be based relative to a no risk scenario as specified in Equation 24. Again, different optimizations may be applied, such as MAD (Equation 25), minimax (Equation 26), or CVaR (Equation 27).
(119)
(120)
(121)
(122)
(123) Referring also to
(124) The processor may determine 445 the second cash flow by adding the received financial hedge(s) into the previously determined cash flow. The processor may optimize 450 size and operational strategy of the renewable power generator combined with the received financial hedge(s), across generation and transmission of qualified market product. Such optimization may be to maximize investor-tailored risk and return utility functions as detailed through mean-variance optimization in Equations 28.
(125)
where:
(126)
(127) An alternative formulation for maximizing investor-tailored risk and return utility functions, which is suited for a linear programming framework with LP computable utility functions, may ignore penalties:
(128)
(129) By means of example, assume two seasons and two time blocks per day. Introduce the auxiliary optimization variable
(130)
and the unit returns r.sub.m,k
(131)
Index scenarios to t and expand to components of x, r.sub.t:
(132)
Introduce average return at a given time stamp (average across scenarios):
(133)
With this formulation, the same MAD, minimax, CVaR, GMD, or WCVaR optimizations may be applied to the maximization or minimization goals and constraints as in Equations 6-27. Additionally, the hedge counter-party's cash flow
(134)
is required to meet risk and return expectations, which may be formulated as additional LP computable constraints, as will be apparent to those skilled in the art.
(135) Referring also to
(136)
where:
(137)
Subject to storage system discharge, charge, and state of charge constraints, which can be readily implemented as it will be apparent to those skilled in the art:
d.sub.RT,j≤P.sub.ESS∀j
c.sub.RT,j≤P.sub.ESS∀j
(138)
b 0≤SOC.sub.j+1≤E.sub.ESS∀j
η.sub.dDischarge efficiency
η.sub.cCharge efficiency
(139) An alternative formulation for maximizing investor-tailored risk and return utility functions, which is suited for a linear programming framework with LP computable utility functions, may ignore penalties:
(140)
(141) By means of example, assume two seasons and two time blocks per day. Introduce the auxiliary optimization variable
(142)
and the unit returns r.sub.m,k
(143)
Index scenarios to t and expand to components of x, r.sub.t, add equality constraints:
(144)
Introduce average return at a given time stamp (average across scenarios):
(145)
(146) With this formulation, the same MAD, minimax, CVaR, GMD, or WCVaR optimizations may be applied to the maximization or minimization goals and constraints as in Equations 6-27. Additionally, the hedge counter-party's cash flow
(147)
is required to meet risk and return expectations, which may be formulated as additional LP computable constraints, as will be apparent to those skilled in the art.
(148) Should the physical or financial hedge already exist, the same optimizations may be performed as in Equations 1-4, and 28-33, or 34-39 while holding size of storage and/or parameters of financial hedges as fixed. Once optimized, any storage of the optimized size may be installed if not already present. Any optimally sized financial hedges may be automatically purchased through a financial transaction interface. Operational generation, transmission, and any storage may be directed by plant controller through operational schedules generated based on the optimized operational strategy.
(149) The various optimization frameworks detailed above may be implemented individually for a specific system and owner, operator, or investor. For example, a specific optimization for financial hedging may be selected and implemented in software for an owner, operator, or investor of a renewable generation asset with no related storage. A different optimization may be implemented in software for an owner, operator, or investor of a renewable generation asset adding storage as a physical hedge. Thus the software, and operation of the processor, may be customized to each system, owner, and owner preferences. Alternatively, multiple optimization frameworks may be implemented in software. Owner, operator, or investor selection between different optimizations may be in advance through a user interface selection or configuration setting, or multiple optimizations may be run and then selected between for ongoing system operation.
(150) With the optimized hedge sizing and operational strategy determined, they may be transmitted 355 for execution and operational control. Referring also to
(151) The processor may control 608 the operation of one or more renewable energy generation systems along with a physical hedge, or a financial hedge, or both a physical and financial hedge, according to the determined optimized size and operational strategy. The processor may direct the operation of a combined power generation, transmission, and/or storage system according to an operational plan or control algorithm that may be part of the operational strategy. In this manner, the combined power generation, transmission, and/or storage system may be operated to achieve the output goals. As examples, the combined power generation, transmission, and/or storage system may be operated according to an operational plan or control algorithm to discharge and/or charge a bulk energy storage system, may be operated according to an operational plan or control algorithm to output electricity to the grid from the power generation source and/or the bulk energy storage system, may be operated according to an operational plan or control algorithm to sell excess capacity to an electricity market, and/or may be operated according to an operational plan or control algorithm to buy capacity from an electricity market. Additionally, and/or alternatively, the determined optimized size and operational strategy may be used to design all or part of the renewable generation system, such as to size various aspects of the combined power generation, transmission, and/or storage systems.
(152) It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.