1、4737 (RP-1146) Proposed Tools and Capabilities for Proact ive Mu I ti-Bu ild i ng Load Management : Part I-Customer Aggregation T. Agami Reddy, Ph.D., P.E. Member ASHRAE ABSTRACT Leslie K. Norford, Ph.D. Member ASHRAE This paper summarizes part ofthe workperformed under an ASHRAE research project en
2、titled “Building Operation andDynamiCs Within an Aggregated Load (RP -I I46), which was meant to (a) identijj situations and conditions under which aggregating individual building loads is attractive for managing total, multi-building load and (b) identiB and eval- uate operating and control strateg
3、ies for use in individual buildings that will reduce energy operating costs at the aggre- gate level by taking advantage ofthe diversity in demand among buildings. Research was done in two phases. Tasks undertaken aspart ofphase Iinvolved an extended background on electric utility aggregation, a det
4、ailed description of each of three case-study sites where multi-building load aggrega- tion and subsequent energy management strategies were performed, and a summavy of the lessons learnedfrom the above case studies. A previous paper by Reddy et al. (2004) described the Phase I results as well as th
5、e simulation case study to illustrate the benejts ofmulti-building load aggrega- tion and control. The second phase ofthe work consisted in formulating andproposing a list of 1 I tools that could be used by aggregators and their customers to alter the operation of buildings to control load. The obje
6、ctive ofthis paper is to provide a broad description of utility deregulation, list the types of issues faced by building owners and load aggregators, provide an overall description of the 11 proposed tools, and specijcally describe the functionality of Tools 1-4 neededfor assembling a portfolio of c
7、ustomers suitable for proactive aggregation. The companion paper by Norford and Reddy (2004) describes the functionality of Tools 5-1 I, which deal with optimal operation ofthe aggregate of buildings. INTRODUCTION The structure of the electric utility market and the complex relationship between supp
8、liers and consumers has undergone (and is undergoing) changes in recent years as a result of electric deregulation and real-time pricing schemes. This paper is one of the papers resulting fiom an ASHRAE research project entitled “Building Operation and Dynamics Within an Aggregated Load,” RP-1146 (R
9、eddy and Norford 2002), which was meant to (a) identify situations and condi- tions under which aggregating individual building loads is attractive for managing total, multi-building load and (b) iden- t and evaluate operating and control strategies for use in individual buildings that will reduce e
10、nergy operating costs at the aggregate level by taking advantage of the diversity in demand among buildings. Research was done in two phases. Tasks undertaken as part of Phase 1 involved an extended background and historical perspective on electric utility aggregation, a detailed descrip- tion of ea
11、ch of three case-study sites where load aggregation and subsequent energy management strategies were performed, and a summary of the lessons learned from the above case studies. The second phase of the work consisted in formulating and proposing a list of 11 tools that could be used by aggregators a
12、nd their customers to alter the operation of buildings to control load and a DOE-2 (Winklemann et al. 1993) simulation case study that consisted of aggregating three different building types (an office building, a hotel, and a retail store). The scope ofthe research was not to develop the tools to t
13、he extent that concerned load aggregators can use them. Rather, this research describes the functionality of these tools in a conceptual manner and provides relevant review of prior work and what future developments are needed for each of these tools. Due to economies of scale, the scope is limited
14、Agami Reddy is a professor in the Civil, Architectural, and Environmental Engineering Department, Drexel University, Philadelphia, Penn. Les Norford is principal at Tabors Caramanis and Associates, Cambridge, Mass. 02004 ASHRAE. 443 to larger commercial customers and not residential and small commer
15、cial customers. A paper by Reddy et al. (2004) described the phase 1 results as well as the simulation case study to illustrate the benefits of multi-building load aggregation and control. The objective of this paper is to provide a broad description of util- ity deregulation, list the types of issu
16、es faced by building owners and load aggregators, provide an overall description of the 11 proposed tools, and specifically describe the function- ality of Tools 1-4. Another paper by Norford and Reddy (2004) describe the functionality of Tools 5-1 1. OVERALL DESCRIPTION OF TOOLS + Power Producers B
17、ackground The goal of phase II was to identify tools or capabilities that could assist aggregators to better operate multiple build- ings, with the case studies from Phase I serving as typical strat- egies that could be used as initial starting points. Our evaluation of these case study sites (fully
18、 described in Reddy et al. 2004) was intended to contribute information on the current state of affairs relating to the control and management of multi-building groups. Deregulation has lowered commod- ity prices so substantially-at least in Pennsylvania-that building and site owners can easily save
19、 as much as 10% of their previous annual electric utility bill. This makes demand- limiting projects of a large scale prohibitive because, in many cases, the projects do not meet the financial payback threshold established by the building owners. Operational changes have also been shunned because th
20、ey often sacrifice comfort or profitability. Because the case studies did not reveal any strategies for operation of buildings, the principal investigators undertook to identifj the types of capabilities or tools that aggregators are likely to need in the future. These tools were largely identified
21、based on numerous discussions with about a dozen energy professionals with special expertise and working knowledge in this general area of utility deregulation and load aggrega- tion, as well as close input from the project monitoring sub- committee members, many of whom were knowledgeable in this a
22、rea. + Lorn1 Didnbtin Companies Powar Marketers Current and Future Scenarios Kahn (i 988), although somewhat dated, provides an excellent overview of how the electric utility industry moved from a growth-oriented environment into a period of instabil- ity, competition, and restructuring. Many specif
23、ic examples are used to first show how the industry worked when condi- tions were favorable and then highlight the complications that arose when the environment turned hostile. The book focuses on the broad strategic planning and organizational issues faced by the utility industry. The book predates
24、, and therefore does not address, the specific issues associated with utility deregu- lation. However, it tackles such issues as marginal and avoided costs, independent power production, demand-side utility programs, and comparison to other industries (such as tele- communications). I -1 A book edit
25、ed by Thumann (1999) is a compendium of several pertinent articles by professionals in this field, which provide practical advice to people responsible for purchasing energy. Lessons learned from deregulation in Scandinavia and England are presented, as well as an update of retail competi- tion in t
26、he U.S., brokenup by individual states. The role ofthe procurement professional, how energy legislation is likely to impact power marketing transactions, current happenings in electric utility deregulation, a ten-step program to successful utility deregulation for building owners, background on powe
27、r pools, as well as experiences with large-scale load aggregation and power purchase bidding for state facilities are some of the chapters contributed by experts in these areas. This book remains relevant despite the very recent changes in the dereg- ulation arena. The unfolding vista of utility der
28、egulation is leading to five distinct types of players, replacing the one entity-the regulated electric utility-that existed in the earlier environ- ment (see Figure i), 1. Power producers, which own the power generators and whose only responsibility is to generate the needed power and pump it into
29、the grid. Power exchanges, which provide a short-term or spot market for the sale of electricity by producers and its purchase by utilities or power marketers to supplement any bilateral, long-term contracts the utilities or marketers may have with producers. Local distribution companies (investor-o
30、wned or munici- pal), which physically own the power grid used to transmit and distribute electricity (electric wires, poles, switching stations, and transformers) and which have responsibility to maintain this infrastructure and serve customers. Local distribution companies typically charge a flat
31、rate for trans- 2. 3. L Power Exchanges i 1 il r“7- Customers U Figure 1 Various scenarios and players in the generation and consumption of electricity in buildings. 444 ASHRAE Transactions: Research mission and distribution, although congestion pricing for transmission will be used in the future. P
32、ower marketers, which contract with either power produc- ers or power exchanges to provide power to customers who choose not to buy it from the local utility. In a regulated electricity market, the local electric utility owned and maintained its own generators and provided an integrated service to i
33、ts customers (scenario 1 in Figure 1). Thus, the local utility combined the tasks of all four entities listed above. 5. Load consultants, a new player who emerged in the early days of deregulation (scenario 2 in Figure. 1). Because customers often lacked the knowledge to negotiate intelli- gently wi
34、th power producers, they relied on services offered by local load consultants. Such consultants usually catered to larger customers, who either had one building or several buildings that may or may not have been dispersed geographically. The load consultant essentially performed three tasks, as show
35、n in Figure 2. 4. Indmdual Pre-screening Customer Pre-screen the customers based on certain predeter- mined criteria to determine whether the customer is a potentially “good” client. Perform a load analysis based on the customers historic data, which could involve monthly billing data or hourly moni
36、tored data (if available, and if warranted). Negotiate a contract with a load-serving entity (LSE) on behalf of the customer in order to procure the needed power at the most favorable price. I contract Negotiation Load Atalis The term “load aggregators” when used in the current atmosphere typically
37、means load consultants. It is clear from the above discussion that currently load consultants behave as customer representatives who act on behalf of the interests of the customer(s) and negotiate with power marketers to get favorable rates due to bulk supply-side purchases. Their involvement is thu
38、s limited to the pre-contract stage, and they have minimal (or no involvement) once the contract is signed. As utility deregulation matures, these consultants are likely to become more proactive and provide active load management services to customers in order to better manage and control load. It i
39、s best to conceptualize proactive load management as “load control in response to variable rate pric- ing” (Gabel et al. 1998). Although this is a form of demand side management (DSM), it is perhaps wise not to use this terminology so as not to create confusion. About 20 years ago, DSM was a hackney
40、ed term, referring to any retrofit or oper- ational practice that a building owner could perform to save energy in a facility (Lee and Craven 2001). Usually these oper- ational practices involved at best some sort of passive load curtailment during the peak hours (with predetermined and nonvariable
41、rate pricing) by installing thermal storage systems, demand meters in certain equipment (such as chill- ers), and energy management and control (EMCS) systems for lighting load management. Figure 2 Services currently offered by load consultants. The shift toward proactive load management is being dr
42、iven by market forces. Electric utilities have strong incen- tives to offer real-time pricing (RTP) rates to encourage proac- tive demand energy management by customers. Peak electric load reduction decreases costs for generating, transmitting, and distributing power (Gabel et al. 1998). Further, RT
43、P shifts some of the risks historically bom by electric utilities (who hedge against them by building in safety margins in the quoted pricing) in delivering the needed power to the customers. Lower electricity charges when averaged over the year are the incentive to customers who accept shouldering
44、some of the risks during periods of high-priced spot-market power. A major challenge in achieving potential RTP savings is related to building controls. A large commercial building typi- cally has dozens or hundreds of heating, cooling, ventilating, lighting, and plug loads whose control setpoints,
45、starthtop schedules, and other operating parameters need to be properly managed to take full advantage of RTP rates (Gabel et al. 1998). As aresult, energy managers of large buildings are real- izing that proper load control can substantially benefit from an infrastructure of measurement and monitor
46、ing, data process- ing and analysis, and energy and demand reporting. Such services have been offered, over the last 15 years or so, by energy services companies (ESCOs). Further, the importance of this aspect has spawned several energy management soft- ware developers who are able to offer such com
47、prehensive services, either on a local basis or remotely through web-based platforms. In parallel with this trend, control companies are moving toward networking and interconnectivity of all HVAC equipment (as well as such other services as fire safety, build- ing access, lighting, elevator control)
48、. This effort is spurred by the ongoing development of such open protocols as BACnet (ASHRAE 1995) and LonTalk. These trends indicate the future emergence of local aggregators that would combine one or all of the above services (scenario 3 in Figure 1) and provide proactive load management in the bu
49、ilding or facility. This research is specifically targeted toward load aggregators who would like to offer services involving proactive control of a group of buildings (rather than a single one). Issues Pertinent to Building Owners and Load Aggregators This section briefly lists some of the pertinent issues and concerns from the perspective of individual building owners on one hand and proactive load aggregators on the other. ASHRAE Transactions: Research 445 The Building Owners Perspective a. Load aggregation How much am I going to save? What is my financial benefit in
