Demand side management: Benefits and challenges

In this paper, the major benefits and challenges of electricity demand side management (DSM) are discussed in the context of the UK electricity system. The relatively low utilisation of generation and networks (of about 50%) means that there is significant scope for DSM to contribute to increasing the efficiency of the system investment. The importance of the diversity of electricity load is discussed and the negative effects of DSM on load diversity illustrated. Ageing assets, the growth in renewable and other low-carbon generation technologies and advances in information and communication technologies are identified as major additional drivers that could lead to wider applications of DSM in the medium term. Potential benefits of DSM are discussed in the context of generation and of transmission and distribution networks. The provision of back-up capacity by generation may not be efficient as it will be needed relatively infrequently, and DSM may be better placed to support security. We also present an analysis of the value of DSM in balancing generation and demand in a future UK electricity system with significant variable renewable generation. We give a number of reasons for the relatively slow uptake of DSM, particularly in the residential, commercial and small business sectors. They include a lack of metering, information and communication infrastructure, lack of understanding of the benefits of DSM, problems with the competitiveness of DSM when compared with traditional approaches, an increase in the complexity of system operation and inappropriate market incentives.     

The potential of demand-side management in energy-intensive industries for electricity markets in Germany

This paper investigates the technical and economic potential of energy-intensive industries to provide demand-side management (DSM) in electricity and balancing markets through 2030. Increasing shares of renewables will lead to a rising demand for ancillary services at the same time that less conventional plants will be available to provide these services. This paper makes projections on the extent to which DSM from industrial processes can provide economic benefits in electricity markets with renewables by providing tertiary reserve capacity. Different industrial processes and their specific technical and economic properties are investigated and compared with other storage devices and electricity generation technologies. Based on an extension of an existing European electricity market model, simulations are used here to make long-term forecasts for market prices, dispatch and investments in the electricity markets through linear optimization.     

Quantifying the effect of renewable generation on day–ahead electricity market prices: The Spanish case

The penetration of renewable generation has grown since the electricity sector has been deregulated. To account for that, this paper proposes a methodology to estimate the downward effect of renewable generation participation upon the day-ahead electricity market prices, since such an effect is quite intuitive observing the merit order of the generating units. The European Electricity Market Matching Algorithm (EMMA) is currently based on Euphemia (Price Coupling of Regions), though there are several differences among countries across Europe. The new algorithm proposed uses market orders, which include aggregate hourly orders such as aggregate supply and demand curves. These orders are simple orders and the marginal price is affected by complex orders, especially by the minimum income condition (MIC) used in the Iberian Electricity Market and considered in our proposed algorithm. A case study of the Spanish day-ahead electricity market is evaluated for 2015, for which a daily generation sample is composed of 16 days in 2015. The sample is created following the characteristics of thermal production, renewable production and inframarginal production. The conclusions are drawn comparing the simulations of the real marginal prices and the new marginal prices after incorporating renewable generation participation into the aggregate demand curve at the maximum price.     

Optimal economic operation of microgrids considering combined heat and power unit,reserve unit,and demand-side management using developed adolescent identity search algorithm

In the present study, a method is proposed to solve the problem of economic load distribution in MGs, meet the challenges arising from the use of renewable sources periodically, ensure the stable performance of MGs, and minimize the operating cost of MGs considering combined heat and power (CHP) units and reserve system. Moreover, demand-side management (DSM) as a tool is employed to reduce the operating cost of the power system. Therefore, the proposed model for optimal operation of MGs using DSM is formulated as an optimization problem. Load shifting is considered as an effective solution in DSM. Minimizing the total operating cost of the system is considered as the objective function of this problem. Problem constraints include operating and executive constraints for load shifting. Finally, the model is solved using the developed adolescent identity search algorithm (AISA). In the developed model, Powell's local search operator is employed to improve the efficiency of searching for the optimal solution. Due to the existing uncertainties in load consumption and day-ahead market price, the method is presented as a scenario-based stochastic energy management problem. The results reveal the proposed method is highly efficient in solving the problem, and load management can improve economic indicators.     

Photovoltaic research and demonstration activities at New EnglandElectric

From 1985 onward, New England Electric has carried out and supported a wide range of research, development and demonstration projects related to the use of solar photovoltaic (PV) energy. This paper describes each project and summarizes performance to date. Several projects embody the concepts of distributed generation (DG) and demand-side management (DSM) as well as utilization of renewable energy. These residential and commercial grid-connected PV systems have reduced electrical demand at each site during the Company's summer peak hour from 1986 through 1993. In addition, during many of the hours around noon the residential systems have provided all of the energy for neighboring homes without PV systems. Transmission and distribution losses associated with the normal supply of energy to these sites was therefore minimized during these hours. On-site production of electricity via photovoltaics may also result in significant environmental benefits, particularly in summer, through displacement of energy from fossil-fueled peaking units. Other types of projects discussed include (1) a solar monitoring network, with simulation of electrical output for three types of PV systems, (2) a unique PV-assisted DC lighting system for a commercial building, (3) a large (100 kW) ground-mounted PV system, (4) a combination solar-PV and solar-thermal system, and (5) development of a single-module inverter     

Power sector of Oman—Today and tomorrow

In December 1999 the council of Ministers of Sultanate of Oman approved policies for the wholesale restructuring and privatization of the sultanate's electricity and related water sectors. The government started carrying out unbundling of the sector and setting up independent companies on a commercial basis. The companies are now shaping up for future electricity market. Beside these evolving structural changes, there would be a need to change their generation mix. Oman relies 100% on fossil fuel resources (mainly gas) for its power generation. However, Oman's natural gas supplies are largely committed and the country may become a net natural gas importer in the near future. Today, there is a great incentive for Oman to exploit renewable energy in order to face the changing environment and to guard against future trends. The electricity companies should investigate the renewable potential and work with Omani government and Authority for Electricity Regulation (AER) to establish policy support for large-scale renewable energy plants. Beside there is a huge potential for demand-side management and energy conservation which should be exploited for the benefit of the country and of the environment.     

Linking consumer energy efficiency with security of supply

Most modern energy policies seek to achieve systematic ongoing incremental increases in consumer energy efficiency, since this contributes to improved security of supply, favourable environmental outcomes and increased economic efficiency. Yet realised levels of efficiency are typically well below the most cost-effective equilibrium due to variety of behavioural and organisational barriers, which are often linked to information constraints. In addition efficient users are normally unrewarded for collective benefits to system security and to the environment, thus reducing the incentives for energy consumers to invest in efficiency improvements. This paper examines the dichotomies and symmetries between supply- and demand-side solutions to energy security concerns and reviews opportunities to overcome barriers to improved consumer efficiency. A security market is identified as a mechanism to promote both demand- and supply-side investments that support electricity system security. Such a market would assist in setting the optimal quantity of reserves while achieving an efficient balance between supply- and demand-side initiatives. It would also help to smooth overall investment throughout the energy system by encouraging incremental approaches, such as distributed generation and demand-side alternatives where they provide competitive value. Although the discussion is applicable to energy systems in general, it focuses primarily on electricity in New Zealand.     

Multi-objective optimization of a mixed renewable system with demand-side management

The 2001/77/CE European Commission Directive sets the target of 22% of gross electricity generation from renewables for the Europe, by 2010. In a scenario of large scale penetration of renewable production from wind and other intermittent resources, it is fundamental that the electric system has appropriate means to compensate the effects of the variability and randomness of the wind, solar and hydro power availability. The paper proposes a novel multi-objective method to optimize the mix of the renewable system maximizing its contribution to the peak load, while minimizing the combined intermittence, at a minimum cost. In such model the contribution of the large-scale demand-side management and demand response technologies are also considered.     

Consumption of electricity in Punjab: Structure and growth

Electricity has played a pivotal role in the development of Punjab economy. Of late there has been a steep rise in the demand for electricity in the state. The present study undertakes a holistic view of growth of demand for electricity in the state. The technique applied is multiple regression and secondary data is used for the purpose of analysis. The study concludes that demand for electricity in the state is price inelastic but income elastic for majority of consuming sectors. An important policy implication thereof is that price hike will be ineffective in regulating and managing demand unless price is varied in an hourly basis. Therefore, the state has to resort to other demand-side management (DSM) measures, such as improving efficiency of electricity use and its conservation. Considering the high income elasticity of electricity demand, sufficient electricity-generating capacity needs to be created, since demand is expected to grow at an accelerated rate in future. This calls for a comprehensive electricity policy. The study further concludes that in the long run, price-demand as well as income-demand relationship in case of electricity is likely to remain uncertain especially in the post-reform era.     

Electricity generation from renewable energy sources in Germany — Potentials, costs and implementation strategies

The objective of this paper is to analyse the technical potentials and the costs of renewable energy sources for electricity generation in Germany and to define and discuss possible strategies for a largescale implementation of such renewable sources into the German power generation system. Four renewable options are discussed: hydropower, windtechnical and photovoltaic electricity generation and the possible electricity production of biomass. First the technical potentials are identified for the present and future reference years. Then the specific costs are analysed, as well for the present and the future. Finally an exemplary implementation strategy is defined and discussed leading to a total renewable electricity generation in the year 2020 of about 86 TWh/a which would be a share of about 19 % of the total present electrical energy demand.     

Demand-side management by electric utilities in Switzerland: Analyzing its impact on residential electricity demand

In this paper, we use panel data from a survey conducted on 30 utilities in Switzerland to estimate the impact of demand-side management (DSM) activity on residential electricity demand. Using the variation in DSM activity within utilities and across utilities over time we identify the impact of DSM programs and find that their presence reduces per customer residential electricity consumption by around 5%. If we consider monetary spending, the effect of a 10% increase in DSM spending causes a 0.14% reduction in per customer residential electricity consumption. The cost of saving a kilowatt hour is around 0.04CHF while the average cost of producing and distributing electricity in Switzerland is around 0.18CHF per kilowatt hour. We conclude that current DSM practices in Switzerland have a statistically significant effect on reducing the demand for residential electricity.     

Hydrogen,ethylene and power production from bioethanol: Ready for the renewable market?

The economic sustainability of renewable based sources is a matter of debate and the technology is changing very fast. We here considered three examples of exploitation of bioethanol as renewable source: a) centralised hydrogen prodution; b) heat and power cogeneration (residential scale); c) ethylene production. Bioethanol can be a suitable starting material for the production of H₂, as fuel or chemical, or syngas. After designing the process and the implementation of kinetic expressions based on experimental data collected in our lab or derived from the literature, an economic evaluation and sensitivity analysis allowed to assess the economic sustainability of hydrogen production and purification by the steam reforming of bioethanol. The attention was mainly put on diluted bioethanol solutions, easy to purify and cost effective. The centralised hydrogen production from bioethanol was considered cost effective at least starting from diluted bioethanol from first generation crops. When dowscaling the hydrogen production and purification unit to feed a 5 kW fuel cell, the most undetermined item was the fuel cell cost, since no acclarate market price is still available.Finally, ethylene market is steadily increasing by ca. 4% each year due to economic growth. The demand for renewable ethylene, as well as the increasing oil price experienced in the recent past, suggested the development of alternative routes to ethylene. Based on the increasing availability of ethanol form renewable biomass, bioethanol-to-bioethylene processes have been recently designed, finding economic sustainability, at the moment, in Brazil.     

Strategies for a road transport system based on renewable resources – The case of an import-independent Sweden in 2025

When discussing how society can decrease greenhouse gas emissions, the transport sector is often seen as posing one of the most difficult problems. In addition, the transport sector faces problems related to security of supply. The aim of this paper is to present possible strategies for a road transport system based on renewable energy sources and to illustrate how such a system could be designed to avoid dependency on imports, using Sweden as an example. The demand-side strategies considered include measures for decreasing the demand for transport, as well as various technical and non-technical means of improving vehicle fuel economy. On the supply side, biofuels and synthetic fuels produced from renewable electricity are discussed. Calculations are performed to ascertain the possible impact of these measures on the future Swedish road transport sector. The results underline the importance of powerful demand-side measures and show that although biofuels can certainly contribute significantly to an import-independent road transport sector, they are far from enough even in a biomass-rich country like Sweden. Instead, according to this study, fuels based on renewable electricity will have to cover more than half of the road transport sector’s energy demand.     

Demand Matching Wind Power Generation With Wide-Area Measurement and Demand-Side Management

This paper outlines the benefits of combining wide-area monitoring and control systems with demand-side management applications for more effective network utilization. Besides a general overview of these two powerful technologies in combination, a technical architecture, and economic benefit in the context of power system operation is encouraged. A case, where a wind park's feed into a neighboring system and wind power generation's non-deterministic behavior caused expensive spot market energy purchase, demonstrates the impact of the proposed wide-area measurement system with ripple control for demand-side management. This example underlines application areas for some typical network configurations with decentralized power generation or dedicated corridors to neighbored systems. It further shows the potential of the proposed load-control scheme with respect to economic, ecological, and reliable power system operation against the background of increasingly decentralized and renewable generation units     

Storage and Demand Side Management as power generator’s strategic instruments to influence demand and prices

Classic storage utilisation is mainly based on charging/discharging strategies enabling a power generation company to generate revenues by buying electricity in low-price periods and selling it at higher prices. Within this paper another feasible way to gain arbitrage in storage utilisation is considered: Strategically increasing demand disregarding existing market prices. This means, charging electricity for storage is not only bought in low price periods, but in all periods where storage charging could influence demand so that market prices increase. This idea is expanded by focussing on another frequently discussed topic which could serve utilities for the same purpose: Automated Demand Side Management (DSM). By using data from Ontario’s electricity market and applying a particular storage and DSM strategy it is analysed to which extent a non-regulated dominant power generation company could influence hourly demand and corresponding prices. It turns out that both strategies analysed derive additional revenues for the dominant power generation company compared to a Business-as-Usual (BAU) case. The results provide an indicator of potential threats for misuse from particular storage or DSM utilisation. Therefore, especially in countries where DSM and/or storage applications are still in its fledgling stages, appropriate market surveillance has to be guaranteed.     

Scenarios for biofuel demands,biomass production and land use – The case of Denmark

The land potential for producing biomass for bioenergy purposes has been highly debated in recent years. The present paper analyses the possibilities and consequences for land use and agricultural production of biofuel production in Denmark based on domestic wheat and rape under specific scenario conditions for the period 2010–2030. The potential is assessed for a situation where policy targets for renewable energy carriers in the transport sector is reached using biofuels, and where second generation ethanol increasingly substitutes first generation ethanol.Three scenarios are developed and evaluated: a baseline, an alternative scenario allowing continuous growth in the now dominant livestock branch and a biofuel scenario assuming that efforts to achieve self-sufficiency in biofuel displaces part of the domestic production of fodder.Results show that the biofuel demand could be met in 2020; but only if current rape oil production is used to satisfy local bio-diesel demand. It would also imply that the Danish bio-diesel export currently supplying a minor part of the German fuel market would seize. In 2030, however, only about 60 percent of the biofuel demand would be covered by self-sufficiency. If biofuels were to displace animal production to make up for this, a reduction of the pig production between 10 and 20 percent would result. Efficiency increases across production branches would allow the animal production to continue un-affected if about half of the rape oil produced for other purposes is utilized.     

Financing solar thermal technologies under DSM programs: an innovative approach to promote renewable energy

A wide range of demand side management (DSM) options has been practiced so far in developed as well as in developing countries. However, solar thermal technologies have been left out from DSM programs considering them as supply side options. This study argues that a number of solar thermal technologies, which provide the same services as electric appliances, can be considered as DSM options and examines the possibility of promoting solar water heaters (SWH) under DSM programs in Thailand. The study found that installation of SWH in place of conventional electric water heaters (EWH) to meet hot water demand in the residential sector would be economically beneficial to the country as a whole. However, switching to SWH from EWH would be unlikely without having government interventions as there would be no incentives to individual consumers in doing so. If the government or state electric utilities provide funding to residential consumers through DSM programs for replacing their EWH by SWH, the total electricity generation in Thailand during the 2000–2015 period would decrease by 3.8 per cent. Moreover, promotion of SWH under DSM programs would cause 3.35 and 1.41 per cent reductions of total power sector CO₂‐ and NO_x‐emissions respectively, during the same period. This study also reveals that solar thermal technologies, especially the SWH, could be better options for DSM programs compared to the end‐use efficiency improvement options in Thailand. Copyright © 2000 John Wiley & Sons, Ltd.     

DSM演进历史的评析

DSM是一种广泛推行的能效管理技术和节能运作机制,自20世纪70年代开始至今,经历了20多年的实践在日趋完善,它主要应用在终端节电领域。DSM作为在市场经济体制基础上培植起来的一种能效管理和节能运作机制,要随市场经济体制的不断演进做相应的调整。DSM能够在政府法规和政策支持下,采取有效的激励和诱导措施,通过社会各方共同协力,达到节约能源和保护环境、实现能源与经济和环境协调发展的目的。从总体上看,我国的DSM还处于起步阶段,为把它纳入管理和运作轨道,还需要在借鉴国际经验的基础上探索适合自己的有效途径。     

Security of supply,energy spillage control and peaking options within a 100% renewable electricity system for New Zealand

In this paper, issues of security of supply, energy spillage control, and peaking options, within a fully renewable electricity system, are addressed. We show that a generation mix comprising 49% hydro, 23% wind, 13% geothermal, 14% pumped hydro energy storage peaking plant, and 1% biomass-fuelled generation on an installed capacity basis, was capable of ensuring security of supply over an historic 6-year period, which included the driest hydrological year on record in New Zealand since 1931. Hydro spillage was minimised, or eliminated, by curtailing a proportion of geothermal generation. Wind spillage was substantially reduced by utilising surplus generation for peaking purposes, resulting in up to 99.8% utilisation of wind energy. Peaking requirements were satisfied using 1550 MW of pumped hydro energy storage generation, with a capacity factor of 0.76% and an upper reservoir storage equivalent to 8% of existing hydro storage capacity. It is proposed that alternative peaking options, including biomass-fuelled gas turbines and demand-side measures, should be considered. As a transitional policy, the use of fossil-gas–fuelled gas turbines for peaking would result in a 99.8% renewable system on an energy basis. Further research into whether a market-based system is capable of delivering such a renewable electricity system is suggested.     

Flexibility in electric power planning: Coping with demand uncertainty

Future electricity demand is a key source of uncertainty facing electric utility system planners. Flexibility offers one way to cope. Making use of the flexibility measure proposed by Hobbs, Honious and Bluestein, we first discuss what factors are of importance for determining flexibility benefits of different utility resources when dealing with demand uncertainty. A multistage stochastic electric utility planning model is then used to compare the flexibility benefits of different electric utility resources for a representative utility, Ontario Hydro. In the absence of acid-gas (i.e. NO_x and SO₂) emission constraints, gas combustion turbines and demand-side management (DSM) were found to offer significant flexibility benefits, while nuclear generation has a large flexibility disbenefit. With acid-gas emission constraints in place, the flexibility benefit of gas combustion turbines is greatly reduced, while those of nuclear, DSM and gas combined-cycle generation all increase. A key finding is that flexibility benefits (or disbenefits) comprise a major portion of the total expected economic benefits of different utility resources in many cases. This result implies that analyses that neglect the effects of demand uncertainty may either dramatically underestimate or overestimate the expected economic benefits of different utility resources.