3,137 research outputs found
WHO PAYS FOR RENEWABLES? THE EFFECT OF DATACENTRES ON RENEWABLE SUBSIDIES. ESRI Research Bulletin 2019/11
Ireland faces several targets for renewable energy usage, across the heating,
transport and electricity sectors. These targets are set as a proportion of total
energy usage. In the case of electricity, 40% of electricity must be generated from
renewable sources by 2020. To meet this target, renewable electricity generation
is subsidised through the Public Service Obligation levy, which appears on all
consumers’ bills. The PSO is levied on residential consumers, commercial
consumers and large industrial consumers according to their contribution to peak
demand – the more the sector contributes to peak demand, the higher the
portion of PSO that they pay
Investment vs. refurbishment: incentivising the correct quantity and quality of electricity generators. ESRI Research Bulletin 2016/2/1
Electricity markets are increasingly moving from a design wherein firms are
compensated solely for the energy they provide (‘energy only’ markets) to one
where firms are also compensated separately for other costs incurred. One
example of a separate payment intended to compensate a firm for other costs
incurred is a capacity remuneration mechanism (CRM). CRMs are designed to
compensate firms for their fixed costs of capacity, or the cost of building the
power plant. In this way, CRMs help to ensure that sufficient electricity
generation capacity exists to provide sufficient generation during peak demand
hours, ensuring reliable supply
A Menu Approach to Revealing Generator Reliability Using a Stochastic Bilevel Mathematical Program. ESRI WP518. November 2015
Liberalised electricity markets often include a capacity remuneration mechanism to allow generation firms recover their fixed costs. Various de-rating factors and/or penalties have been incorporated into such mechanisms in order to award the unit based on the contribution they make to system security, which in turn depends on the unit's reliability. However, this reliability is known to the firm but not to the regulator. We propose an adaptation of menu regulation to design capacity payments based on a declaration by the firm of their reliability. We scale payments and penalties according to this declared reliability such that the firm's profit-maximising strategy is to truthfully reveal their reliability. We apply the methodology to an illustrative test system. Truth-telling is induced, increasing the efficiency of capacity payments while eliminating the requirement for the regulator to allocate resources to discovering reliability
Investment vs. Refurbishment: Examining Capacity Payment Mechanisms Using Mixed Complementarity Problems With Endogenous Probability. ESRI WP507. July 2015
Capacity remuneration mechanisms exist in many electricity markets. Capacity mechanism designs do not explicitly consider the effects of refurbishment of existing generation units in order to increase their reliability. This paper presents a mixed complementarity problem with endogenous probabilities to examine the impact of refurbishment on electricity prices and generation investment. Capacity payments are found to increase reliability when refurbishment is not possible, while capacity payments and reliability options yield similar results when refurbishment is possible. Final costs to consumers are similar under the two mechanisms with the
exception of the initial case of overcapacity
Does tiny-scale atomic structure exist in the interstellar medium ?
We report on preliminary results from the recent multi-epoch neutral hydrogen
absorption measurements toward three pulsars, B0823+26, B1133+16 and B2016+28,
using the Arecibo telescope. We do not find significant variations in optical
depth profiles over periods of 0.3 and 9--10 yr, or on spatial scales of 10--20
and 70--85 AU. The large number of non detections of the tiny scale atomic
structure suggests that the AU-sized structure is not ubiquitous in the
interstellar medium and could be quite a rare phenomenon.Comment: Accepted by ApJ Letters, 5 pages, 2 figure
Mindreading quality versus quantity:A theoretically and empirically motivated two-factor structure for individual differences in adults’ mindreading
Existing methods for studying individual differences in adults’ mindreading often lack good psychometric characteristics. Moreover, it remains unclear, even in theory, how mindreading varies in adults who already possess an understanding of mental states. In this pre-registered study, it was hypothesised that adults vary in their motivation for mindreading and in the degree to which their answers on mindreading tasks are appropriate (context-sensitive). These factors are confounded in existing measures as they do not differentiate between the frequency of mental state terms (MST), indicative of motivation, and the quality of an explanation. Using an innovative scoring system, the current study examined whether individual differences in adult undergraduate psychology students’ (N = 128) answer quality and / or quantity of explicit references to others’ mental states on two open-ended response mindreading tasks were separable constructs, accounted for by mindreading motivation, and related differentially to measures previously linked with mindreading (e.g., religiosity, loneliness, social network size). A two-factor and one-factor model both provided acceptable fit. Neither model showed significant associations with mindreading motivation. However, a two-factor model (with MST and response appropriateness loading onto separate factors) provided greater explanatory power. Specifically, MST was positively associated with religiosity and response appropriateness was negatively associated with religiosity, whilst the one-factor solution did not predict any socially relevant outcomes. This provides some indication that mindreading quantity and mindreading quality may be distinguishable constructs in the structure of individual differences in mindreading
Mindreading quality versus quantity:A theoretically and empirically motivated two-factor structure for individual differences in adults’ mindreading
Existing methods for studying individual differences in adults’ mindreading often lack good psychometric characteristics. Moreover, it remains unclear, even in theory, how mindreading varies in adults who already possess an understanding of mental states. In this pre-registered study, it was hypothesised that adults vary in their motivation for mindreading and in the degree to which their answers on mindreading tasks are appropriate (context-sensitive). These factors are confounded in existing measures as they do not differentiate between the frequency of mental state terms (MST), indicative of motivation, and the quality of an explanation. Using an innovative scoring system, the current study examined whether individual differences in adult undergraduate psychology students’ (N = 128) answer quality and / or quantity of explicit references to others’ mental states on two open-ended response mindreading tasks were separable constructs, accounted for by mindreading motivation, and related differentially to measures previously linked with mindreading (e.g., religiosity, loneliness, social network size). A two-factor and one-factor model both provided acceptable fit. Neither model showed significant associations with mindreading motivation. However, a two-factor model (with MST and response appropriateness loading onto separate factors) provided greater explanatory power. Specifically, MST was positively associated with religiosity and response appropriateness was negatively associated with religiosity, whilst the one-factor solution did not predict any socially relevant outcomes. This provides some indication that mindreading quantity and mindreading quality may be distinguishable constructs in the structure of individual differences in mindreading
The impacts of demand response participation in capacity markets. ESRI Research Bulletin 2019/10
Electricity demand varies over the course of a day or a year, with very high levels of electricity demand being seen for only a few hours per year. However, there must be sufficient electricity generation installed on the system to meet the total demand at these few hours per year, in order to avoid blackouts or brownouts, where electricity supply is disconnected for all or some customers, respectively. As electricity generation from variable renewable sources, such as wind and solar, increases, electricity market revenues decrease, which renders conventional generators less profitable. In order to ensure that there is sufficient conventional generation available to meet demand at the hours of highest demand per year, a separate market payment is made to generators, called a capacity payment
Contributors to the March Issue/Notes
Notes by Nicholas T. Tsiolis, Robert B. Devine, John A. Berry, John L. Towne, John H. Logan, Jr., August P. Petrillo, Richard A. Molique, and J. Frederick Meister
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