6,399 research outputs found

    The role of demand response in mitigating market power - A quantitative analysis using a stochastic market equilibrium model. ESRI WP635, August 2019

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    Market power is a dominant feature of many modern electricity markets with an oligopolistic structure, resulting in increased consumer cost. This work investigates how consumers, through demand response (DR), can mitigate against market power. Within DR, our analysis particularly focusses on the impacts of load shifting and self-generation. A stochastic mixed complementarity problem is presented to model an electricity market characterised by oligopoly with a competitive fringe. It incorporates both energy and capacity markets, multiple generating firms and different consumer types. The model is applied to a case study based on data for the Irish power system in 2025. The results demonstrate how DR can help consumers mitigate against the negative effects of market power and that load shifting and self-generation are competing technologies, whose effectivity against market power is similar for most consumers. We also find that DR does not necessarily reduce emissions in the presence of market power

    Analysing long-term interactions between demand response and different electricity markets using a stochastic market equilibrium model. ESRI WP585, February 2018

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    Power systems based on renewable energy sources (RES) are characterised by increasingly distributed, volatile and uncertain supply leading to growing requirements for flexibility. In this paper, we explore the role of demand response (DR) as a source of flexibility that is considered to become increasingly important in future. The majority of research in this context has focussed on the operation of power systems in energy only markets, mostly using deterministic optimisation models. In contrast, we explore the impact of DR on generator investments and profits from different markets, on costs for different consumers from different markets, and on CO2 emissions under consideration of the uncertainties associated with the RES generation. We also analyse the effect of the presence of a feed-in premium (FIP) for RES generation on these impacts. We therefore develop a novel stochastic mixed complementarity model in this paper that considers both operational and investment decisions, that considers interactions between an energy market, a capacity market and a feed-in premium and that takes into account the stochasticity of electricity generation by RES. We use a Benders decomposition algorithm to reduce the computational expenses of the model and apply the model to a case study based on the future Irish power system. We find that DR particularly increases renewable generator profits. While DR may reduce consumer costs from the energy market, these savings may be (over)compensated by increasing costs from the capacity market and the feed-in premium. This result highlights the importance of considering such interactions between different markets

    Examining the benefits of demand reduction policies for electricity. ESRI Research Bulletin, 2018/03

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    Many governments have adopted policies that provide incentives to increase the amount of electricity generated from clean and renewable sources. However, the availability of such sources, e.g., solar or wind energy, is unpredictable and varies throughout the day and seasons. To account for this variability electricity systems need to become more flexible, i.e., there must be measures in place to ensure that demand and supply are balanced when renewable sources are not available

    Cystomanometry – One of the Assessment Methods of the Urodynamic Indexes in Patients with Infiltrative Cervical Cancer

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    Aim: To evaluate contractile function of urinary bladder in patients with infiltrative cervical cancer after nerve-sparing radical hysterectomy (NSRH).Patients and Methods: Ninety patients with infiltrative cervical cancer were treated with nerve-sparing radical hysterectomy (n=45, NSRH group), or radical hysterectomy (RHE III) without preservation of pelvic autonomic plexuses (n=45, RHE group). Cystomanometry was carried out using urodynamic apparatus “Uro-Pro” by standard method.Results: Using cystomanometry, we have evaluated the main urodynamic indexes such as pressure upon bladder filling (P1), first vesical tenesmus pressure (P2); change of detrusor pressure upon change of bladder volume (P), volume of urinary bladder (V), and complience of urinary bladder wall (C) at preoperative period and postoperative period in both groups of patients. While at preoperative period P1 indexes did not differ significantly between the groups, after NSRH performance, P1 values were significantly higher than P1 values in the group of patients treated with RHE III (8,29±1,1 cm H2O versus 3,51±0,8 cm H2O (р<0,05)). P2 indexes in patients from both groups before and after surgical treatment differed significantly and were 6,82±0,4 cm H2O and 12,27±1,2 cm H2O (р<0,05) in NSRH group, and 5,44±0,6 cm H2O and 10,62±1,1 cm H2O (р<0,05) in RHE III group. The P value in both patients groups before and after the surgical treatments was significantly different, and demonstrated a gradual elevation of urinary bladder pressure, especially in the patients from RHE III treated group. Urinary bladder volume at preoperative and postoperative periods in NSRH-treated group remained practically unaltered (209,78±14,2 ml and 216,86±14,9 ml (р>0,5) respectively), while in the patients from RHE III-treated group after surgical treatment an urinary bladder volume significantly decreased from 188,4±10,5 ml to 161,9±9,8 ml (р<0,05). An analysis of compliance of urinary bladder wall (C) has shown that after surgical treatment in RHE group C value decreased by 75% while in NSE group this index decreased just by 25%.Conclusions: The data of urodynamic study evidence the better preservation of urinary bladder functions in patients with infiltrative cervical cancer after NSRH than in the patients treated with RHE III
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