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

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

Who pays for renewables? Increasing renewable subsidisation due to increased datacentre demand in Ireland. ESRI WP566, June 2017

Demand from datacentres makes up a rapidly growing portion of electricity demand in Ireland. Increased demand in turn gives rise to increased renewable generation, mandated by government targets, and a corresponding increase in subsidisation levels. The current method of apportioning renewable subsidy costs may lead to consumers other than datacentres bearing this excess cost of subsidisation. This letter calculates the expected impact on these consumers

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

Focus drive mechanism for the IUE scientific instrument

A compact, lightweight mechanism was developed for in-orbit adjustment of the position of the secondary mirror (focusing) of the International Ultraviolet Explored telescope. This device is a linear drive with small (.0004 in.) and highly repeatable step increments. Extremely close tolerances are also held in tilt and decentering. The unique mechanization is described with attention to the design details that contribute to positional accuracy. Lubrication, materials, thermal considerations, sealing, detenting against launch loads, and other features peculiar to flight hardware are discussed. The methods employed for mounting the low expansion quartz mirror with minimum distortion are also given

Blockchain electricity trading using tokenised power delivery contracts. ESRI Working Paper No. 649 December 2019

This paper proposes a new mechanism for forward selling renewable electricity generation. In this transactive framework, a wind or solar farm may directly sell to consumers a claim on their future power output in the form of nonfungible blockchain tokens. Using the flexibility of smart contract code, which executes irrevocably on a blockchain, the realised generation levels will offset the token holders’ electricity consumption in near real-time. To elucidate the flexibility offered by such smart contracts, two ways of structuring these power delivery instruments are considered: firstly, an exotic tranched system, where more senior tokens holders enjoy priority claims on power, as compared against a simpler pro-rata scheme, where the realised output of a generator is equally apportioned between token holders. A notional market simulation is provided to explore whether, for instance, consumers could exploit the flatter power delivery profiles of more senior tranches to better schedule their responsive demands

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

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

Research notes: Significance of incompatibility reactions of Rhizobium japonicum strains with soybean host genotypes

Soybeans normally nodulate with Rhizobium japonicum and fix nitrogen in symbiotic association. However, several interactions, under genetic control, have been reported which result in ineffective nodulation or failure of the fixation process despite substantial nodule development. The recessive gene, rj1 , (Williams and Lynch, 1954) in homozygous mode, results in the exclusion from nodulation of a broad spectrum of Rhizobium jabonicum strains in soil culture

Juvenile River Herring in Freshwater Lakes: Sampling Approaches for Evaluating Growth and Survival

River herring, collectively alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis), have experienced substantial population declines over the past five decades due in large part to overfishing, combined with other sources of mortality, and disrupted access to critical freshwater spawning habitats. Anadromous river herring populations are currently assessed by counting adults in rivers during upstream spawning migrations, but no field-based assessment methods exist for estimating juvenile densities in freshwater nursery habitats. Counts of 4-year-old migrating adults are variable and prevent understanding about how mortality acts on different life stages prior to returning to spawn (e.g., juveniles and immature adults in lakes, rivers, estuaries, and oceans). This in turn makes it challenging to infer a link between adult counts and juvenile recruitment and to develop effective management policy. I used a pelagic purse seine to investigate juvenile river herring densities, growth, and mortality across 16 New England lakes. First, I evaluated the effectiveness and sampling precision of a pelagic purse seine for capturing juvenile river herring in lakes, since this sampling gear has not been systematically tested. Sampling at night in June or July resulted in highest catches. Precision, as measured by the coefficient of variation, was lowest in July (0.23) compared to June (0.32), August (0.38), and September (0.61). Simulation results indicated that the effort required to produce precise density estimates is largely dependent on lake size with small lakes (\u3c50 \u3eha) requiring up to 10 purse seine hauls and large lakes (\u3e50 ha) requiring 15–20 hauls. These results suggested that juvenile recruitment densities can be effectively measured using a purse seine at night in June or July with 10–20 hauls. Using juvenile fishes captured during purse seining in June–September 2015, I calculated growth and mortality rates from sagittal otoliths. Density, growth, and mortality were highly variable among lakes, and mixed-effects regression models explained 11%–76% of the variance in these estimates. Juvenile densities ranged over an order of magnitude and were inversely related to dissolved organic carbon. Juvenile growth rates were higher in productive systems (i.e., low secchi depth, high nutrients) and were strongly density-dependent, leading to much larger fish at age in productive lakes with low densities of river herring compared to high density lakes. Water temperature explained 56%–85% of the variation in juvenile growth rates during the first 30 days of life. Mortality was positively related to total phosphorous levels and inversely related to hatch date, with earlier hatching cohorts experiencing higher mortality. These results indicate the importance of water quality and juvenile densities in nursery habitats for determining juvenile growth and survival. This study encourages future assessments of juvenile river herring in freshwater and contributes to an understanding of factors explaining juvenile recruitment that can guide more effective and comprehensive management of river herring

Research Notes: Genetic Studies of Soybean Host Cultivar Interactions with Rhizobium Strains

Several genetic factors have been identified which govern specific nodulation response in soybeans. The RJ2 genotype, carried by the cultivars \u27Hardee\u27 and \u27CNS,\u27 conditions an ineffective response in specific combination with Rhizobium japonicum strains of serogroups c1 and 122. The ineffective response is characterized as the development of either cortical proliferations on the roots or rudimentary nodules, rather than normal nodules