Short-Term Reduction of Peak Loads in Commercial Buildings in a Hot and Dry Climate

abstract: A major problem faced by electric utilities is the need to meet electric loads during certain times of peak demand. One of the widely adopted and promising programs is demand response (DR) where building owners are encouraged, by way of financial incentives, to reduce their electric loads during a few hours of the day when the electric utility is likely to encounter peak loads. In this thesis, we investigate the effect of various DR measures and their resulting indoor occupant comfort implications, on two prototype commercial buildings in the hot and dry climate of Phoenix, AZ. The focus of this study is commercial buildings during peak hours and peak days. Two types of office buildings are modeled using a detailed building energy simulation program (EnergyPlus V6.0.0): medium size office building (53,600 sq. ft.) and large size office building (498,600 sq. ft.). The two prototype buildings selected are those advocated by the Department of Energy and adopted by ASHRAE in the framework of ongoing work on ASHRAE standard 90.1 which reflect 80% of the commercial buildings in the US. After due diligence, the peak time window is selected to be 12:00-18:00 PM (6 hour window). The days when utility companies require demand reduction mostly fall during hot summer days. Therefore, two days, the summer high-peak (15th July) and the mid-peak (29th June) days are selected to perform our investigations. The impact of building thermal mass as well as several other measures such as reducing lighting levels, increasing thermostat set points, adjusting supply air temperature, resetting chilled water temperature are studied using the EnergyPlus building energy simulation program. Subsequently the simulation results are summarized in tabular form so as to provide practical guidance and recommendations of which DR measures are appropriate for different levels of DR reductions and the associated percentage values of people dissatisfied (PPD). This type of tabular recommendations is of direct usefulness to the building owners and operators contemplating DR response. The methodology can be extended to other building types and climates as needed.Dissertation/ThesisM.S. Architecture 201

Assessing the time-sensitive impacts of energy efficiency and flexibility in the US building sector

The building sector consumes 75% of US electricity, offering substantial energy, cost, and CO2 emissions savings potential. New technologies enable buildings to flexibly manage electric loads across different times of day and season in support of a low-cost, low-carbon electric grid. Assessing the value of such technologies requires an understanding of building electric load variability at a higher temporal resolution than is demonstrated in previous studies of US building efficiency potential. We adapt Scout, an open-access model of US building energy use, to characterize sub-annual variations in baseline building electricity use, costs, and emissions at the national scale. We apply this baseline in time-sensitive analyses of the energy, cost, and CO2 emissions savings potential of various degrees of energy efficiency and flexibility, finding that efficiency continues to have strong value in a time-sensitive assessment framework while the value of flexibility depends on assumed electricity rates, measure magnitude and duration, and the amount of savings already captured by efficiency

Dynamic Pricing, Advanced Metering, and Demand Response in Electricity Markets

Presents an overview and analysis of the possible approaches to bringing an active demand side into electricity markets. Part of a series of research reports that examines energy issues facing California

Kysyntäjouston ohjausstrategioiden optimointi suomalaisissa kaupungin omistamissa kiinteistöissä

The entire energy business from producers to energy end-users is currently undergoing major reforms due to more and more ambitious targets for climate change mitigation measures and energy efficiency of buildings stemming from various international agreements and dwindling of conventional fossil fuel resources. Both supply and demand side measures are required to tackle the issues at hand and much work has already been done in regards to developing and increasing renewable energy generation and demand side energy efficiency. Demand response is a more novel demand side action which targets reducing energy demand during peak demand hours, which in turn can reduce the need for expensive peak production and contribute to increasing the stability of the grid when system reliability is jeopardized. In practice, demand response means that energy use is changed from its typical patterns when it is beneficial from the relevant parties’ point of view. This thesis investigates heat load reduction potential for demand response purposes in typical Finnish city-owned district heated buildings. The potential is analyzed for three different types of buildings individually (office, school and apartment building) and on a city scale for a certain city located in southern Finland by creating building energy models for example buildings in the simulation software IDA ICE and optimizing demand response control strategies in the optimization software MOBO. MOBO is used to determine an optimal combination of controls for these strategies in terms of maximum direct cost saving potential resulting from reduced energy consumption. The optimizations are conducted for a few different example days in winter and in spring, and for a single three-hour-long demand response event on these days. Furthermore, the district heat producer’s point of view is regarded by using hourly marginal cost based district heat pricing as one of the minimized objectives in the optimizations. Hourly heat production costs and marginal costs before and after demand response implementation are calculated for the studied city in a previously developed MATLAB simulation model. The results of the simulations and optimizations indicate that heat load reduction potential for demand response in individual buildings is 50-80% for a single demand response event during the day and depending on the building type. On a city-scale, the achieved heat load reduction is 59 MW or 60-70% of the original heat demand at most, which accounts for approximately 10% of the heat demand of the entire city at the time.Energiateollisuus ja energiajärjestelmät tuottajista loppukäyttäjiin ovat tällä hetkellä keskellä merkittävää uusiutumista ja suuria muutoksia johtuen yhä kunnianhimoisemmista kansainvälisistä ilmastotavoitteista ja jatkuvasti tiukkenevista kansallisista energiatehokkuusmääräyksistä. Muutokset koskevat sekä tuottajia että kuluttajia, ja paljon työtä on jo tehty liittyen uusiutuvien energiamuotojen kehittämiseen ja käytön lisäämiseen sekä kuluttajapuolenkin energiatehokkuuteen. Kysyntäjousto on eräs vähemmän yleistynyt kuluttajapuolen toimintamalli, jolla pyritään vähentämään energiankulutusta kulutuspiikkien aikana, jolloin myös kalliin huipputuotannon tarve vähenee, ja parantamaan tarvittaessa systeemin tasapainoa sen ollessa uhattuna. Käytännössä kysyntäjousto tarkoittaa energiankäytön hetkellistä muuttamista normaalitilanteesta sen ollessa kysyntäjoustoon osallistuvien osapuolten kannalta edullista. Tässä diplomityössä tutkitaan kaukolämmön kysyntäjoustopotentiaalia lämmitystehon pienentämisen kannalta tyypillisissä Suomen kaupunkien omistamissa kiinteistöissä. Potentiaalia tutkitaan kolmessa erilaisessa rakennuksessa (toimisto, asuinkerrostalo ja koulu) yksitellen sekä koko kaupungin tasolla eräässä Etelä-Suomen kaupungissa. Esimerkkirakennuksista luodaan energiasimulointimallit IDA ICE – ohjelmalla, jonka jälkeen MOBO-optimointityökalulla määritetään erilaisista talotekniikkaohjauksista koostuva optimaalinen kysyntäjoustokombinaatio, jolla voidaan saavuttaa suurimmat energiankäytön vähenemisestä johtuvat kustannussäästöt kiinteistönomistajan sekä kaukolämpöyhtiön kannalta. Optimointitapaukset tehdään esimerkinomaisille talvi- ja kevätpäiville, joina kumpanakin toteutetaan yksi kolmen tunnin pituinen kysyntäjoustojakso aamupäivän aikana. Kaukolämmön tuottajan näkökulmaa pyritään tuomaan esille käyttämällä yhtenä optimoitavan tekijänä kaukolämmön kuluttajahintana käytettäviä lämmöntuotannon tuntikohtaisia marginaalikustannuksia. Tuntikohtaiset tuotantokustannukset ja marginaalikustannukset ilman kysyntäjoustoa ja sen kanssa määritetään MATLAB simulointimallia hyväksi käyttäen. Simulointien ja optimointien tulosten perusteella kaikilla kolmella rakennustyypillä on selvää tehonleikkauspotentiaalia kysyntäjoustotarpeisiin. Yksittäisille rakennuksille tehon alenema yksittäisen kysyntäjouston aikana on 50-80% alkuperäisestä kaukolämpötehosta. Koko kaupungin tasolle skaalattuna tämä tarkoittaa yhteensä maksimissaan 59 MW:n kaukolämpötehon leikkausta, joka on 60-70% alkuperäisestä näiden rakennustyyppien koko kaupungin omistaman rakennusmassan tehosta ja yhteensä noin 10% koko kaupungin kyseisen hetken kaukolämmön tarpeesta

High-Performance Integrated Window and Façade Solutions for California

The researchers developed a new generation of high-performance façade systems and supporting design and management tools to support industry in meeting California’s greenhouse gas reduction targets, reduce energy consumption, and enable an adaptable response to minimize real-time demands on the electricity grid. The project resulted in five outcomes: (1) The research team developed an R-5, 1-inch thick, triplepane, insulating glass unit with a novel low-conductance aluminum frame. This technology can help significantly reduce residential cooling and heating loads, particularly during the evening. (2) The team developed a prototype of a windowintegrated local ventilation and energy recovery device that provides clean, dry fresh air through the façade with minimal energy requirements. (3) A daylight-redirecting louver system was prototyped to redirect sunlight 15–40 feet from the window. Simulations estimated that lighting energy use could be reduced by 35–54 percent without glare. (4) A control system incorporating physics-based equations and a mathematical solver was prototyped and field tested to demonstrate feasibility. Simulations estimated that total electricity costs could be reduced by 9-28 percent on sunny summer days through adaptive control of operable shading and daylighting components and the thermostat compared to state-of-the-art automatic façade controls in commercial building perimeter zones. (5) Supporting models and tools needed by industry for technology R&D and market transformation activities were validated. Attaining California’s clean energy goals require making a fundamental shift from today’s ad-hoc assemblages of static components to turnkey, intelligent, responsive, integrated building façade systems. These systems offered significant reductions in energy use, peak demand, and operating cost in California

System-level key performance indicators for building performance evaluation

Quantifying building energy performance through the development and use of key performance indicators (KPIs) is an essential step in achieving energy saving goals in both new and existing buildings. Current methods used to evaluate improvements, however, are not well represented at the system-level (e.g., lighting, plug-loads, HVAC, service water heating). Instead, they are typically only either measured at the whole building level (e.g., energy use intensity) or at the equipment level (e.g., chiller efficiency coefficient of performance (COP)) with limited insights for benchmarking and diagnosing deviations in performance of aggregated equipment that delivers a specific service to a building (e.g., space heating, lighting). The increasing installation of sensors and meters in buildings makes the evaluation of building performance at the system level more feasible through improved data collection. Leveraging this opportunity, this study introduces a set of system-level KPIs, which cover four major end-use systems in buildings: lighting, MELs (Miscellaneous Electric Loads, aka plug loads), HVAC (heating, ventilation, and air-conditioning), and SWH (service water heating), and their eleven subsystems. The system KPIs are formulated in a new context to represent various types of performance, including energy use, peak demand, load shape, occupant thermal comfort and visual comfort, ventilation, and water use. This paper also presents a database of system KPIs using the EnergyPlus simulation results of 16 USDOE prototype commercial building models across four vintages and five climate zones. These system KPIs, although originally developed for office buildings, can be applied to other building types with some adjustment or extension. Potential applications of system KPIs for system performance benchmarking and diagnostics, code compliance, and measurement and verification are discussed

Preliminary design study of a baseline MIUS

Results of a conceptual design study to establish a baseline design for a modular integrated utility system (MIUS) are presented. The system concept developed a basis for evaluating possible projects to demonstrate an MIUS. For the baseline study, climate conditions for the Washington, D.C., area were used. The baseline design is for a high density apartment complex of 496 dwelling units with a planned full occupancy of approximately 1200 residents. Environmental considerations and regulations for the MIUS installation are discussed. Detailed cost data for the baseline MIUS are given together with those for design and operating variations under climate conditions typified by Las Vegas, Nevada, Houston, Texas, and Minneapolis, Minnesota. In addition, results of an investigation of size variation effects, for 300 and 1000 unit apartment complexes, are presented. Only conceptual aspects of the design are discussed. Results regarding energy savings and costs are intended only as trend information and for use in relative comparisons. Alternate heating, ventilation, and air conditioning concepts are considered in the appendix

Advanced Control Technologies and Strategies Linking Demand Response and Energy Efficiency

This paper presents a preliminary framework to describe how advanced controls can support multiple modes of operations including both energy efficiency and demand response (DR). A general description of DR, its benefits, and nationwide status is outlined. The role of energy management and control systems for DR is described. Building systems such as HVAC and lighting that utilize control technologies and strategies for energy efficiency are mapped on to DR and demand shedding strategies are developed. Past research projects are presented to provide a context for the current projects. The economic case for implementing DR from a building owner perspective is also explored