Now showing 1 - 10 of 20
  • Publication
    A rolling horizon approach for stochastic mixed complementarity problems with endogenous learning: Application to natural gas markets
    In this paper we present a new approach for solving energy market equilibria that is an extension of the classical Nash-Cournot approach. Specifically, besides allowing the market participants to decide on their own decision variables such as production, flows or the like, we allow them to compete in terms of adjusting the data in the problem such as scenario probabilities and costs, consistent with a dynamic, more realistic approach to these markets. Such a problem in its original form is very hard to solve given the product of terms involving decision-dependent data and the variables themselves. Moreover, in its more general form, the players can affect not only each others׳ objective functions but also the constraint sets of opponents making such a formulation a more complicated instance of generalized Nash problems. This new approach involves solving a sequence of stochastic mixed complementarity (MCP) problems where only partial foresight is used, i.e., a rolling horizon. Each stochastic MCP or roll, involves a look-ahead for a fixed number of time periods with learning on the part of the players to approximate the extended Nash paradigm. Such partial foresight stochastic MCPs also offer a realism advantage over more traditional perfect foresight formulations. Additionally, the rolling-horizon approach offers a computational advantage over scenario-reduction methods as is demonstrated with numerical tests on a natural gas market stochastic MCP. Lastly, we introduce a new concept, the Value of the Rolling Horizon (VoRH) to measure the closeness of different rolling horizon schemes to a perfect foresight benchmark and provide some numerical tests on it using a stylized natural gas market.
      455Scopus© Citations 26
  • Publication
    The impacts of demand response participation in capacity markets
    Demand Response is capable of reducing the total amount of generation capacity investment required to ensure electricity system security. We utilise this fact to devise a novel methodology to estimate the contribution of a load-shifting demand response resource to system adequacy. We then simulate an electricity market using mixed complementarity models to determine how the participation of demand response in capacity markets impacts on market outcomes. Demand response primarily affects the equilibrium outcome through the energy market, however demand response also reduces both equilibrium prices and consumer costs through its capacity market contribution. The effect is particularly pronounced when there is a high level of variable renewable generation and initial undercapacity. In the absence of demand response, increased wind generation leads to higher capacity prices as generators seek to offset depressed energy prices. However, we find that demand response's participation in the capacity market can combat these increased capacity prices. These results suggest that demand response participation in capacity markets can mitigate some of the market challenges of renewable integration, particularly that of the “missing money” problem.
      621Scopus© Citations 60
  • Publication
    Coastal blue space and depression in older adults
    This paper tests whether higher exposure to coastal blue space is associated with lower risk of depression using data from The Irish Longitudinal Study on Ageing (TILDA), a nationally representative longitudinal study of people aged fifty and over in Ireland. We contribute to the literature on blue space and health by (i) using scores from the Center for Epidemiologic Studies Depression Scale (CES-D) to measure depression outcomes (ii) using new measures of coastal blue space visibility (iii) studying the association in an older population (iv) using data from Ireland. Our results indicate that exposure to coastal blue space is associated with beneficial mental health outcomes: TILDA respondents with the highest share of sea view visibility have lower depression (CES-D) scores, while distance from coastline is not statistically significant when views and proximity are both included in the model. This finding supports the idea that the primary channel through which coastal blue space operates to reduce depression scores is visual rather than related to physical proximity.
      1126Scopus© Citations 79
  • Publication
    Inducing truthful revelation of generator reliability
    (Elsevier BV, 2017-05) ;
    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 reward 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 adopt a mechanism design approach for capacity payments based on a declaration by the firm of their reliability. The mechanism scales payments and penalties according to this declared reliability such that the firm's profit-maximising strategy is to truthfully reveal its reliability. A stochastic mixed complementarity problem (MCP) is used to model the interactions between the firms, and we apply this methodology to a test system using Irish electricity market data. Truth-telling is induced, increasing the efficiency of capacity payments while eliminating the requirement for the regulator to allocate resources to discovering reliability.
      345Scopus© Citations 2
  • Publication
    Liquefied natural gas and gas storage valuation: Lessons from the integrated Irish and UK markets
    (Elsevier, 2019-03-15) ;
    To guarantee European countries greater access to competitive energy sources, the European Union has identified new infrastructures as Projects of Common Interest (PCIs). This paper aims to evaluate the implications for consumers of new investments in liquefied natural gas (LNG) import capacity and gas storage capacity. We utilise a stochastic mixed complementarity problem model with daily timesteps, incorporating stochastic natural gas supply cost and demand scenarios. Therefore, we assess the expected benefits for consumers of a diversified natural gas supply, and their sensitivity to changing market conditions. We use the integrated UK-Ireland gas system, which represents an ideal framework to evaluate new energy routes. We underscore the complementary of LNG and gas storage investments to manage short-term peak loads and long-term seasonal loads, and reduce energy bills. This study has implications for decision- and policy-makers when addressing new gas infrastructure development and the flexibility of energy systems.
      619Scopus© Citations 16
  • Publication
    A simulation model for the management and expansion of extended port terminal operations
    This study introduces a discrete event simulation model for the analysis of bulk carrier unloading and material transport, storage and discharge at Europe’s largest alumina refinery, RUSAL Aughinish Alumina. With novel features such as the integration of additional unloading functionality, auxiliary infrastructure units, as well as efficient maintenance scheduling into the material processing chain, the model is used to predict and evaluate the performance gain in the port system in the context of long-term investment and planning scenarios. Promising strategic directions in terms of large scale performance indicators such as berth occupancy and costs have been identified.
      527Scopus© Citations 35
  • Publication
    Blockchain Electricity Trading Under Demurrage
    (IEEE, 2019-01-11) ;
    This letter proposes a novel demurrage mechanism for blockchain electricity marketplaces, whereby the redemptive value of energy-backed tokens declines with time. This mechanism is intended to reward organic price-responsive load shifting by incentivising the consumption of electricity when it is locally abundant. To demonstrate how such a demurrage mechanism might function in practice, this letter describes a mixed complementarity model of a notional token marketplace. These market simulations indicate that, in equilibrium and with rational actors, the demurrage mechanism creates price signals that temporally align the production and consumption of electricity.
      964Scopus© Citations 83
  • Publication
    Examining the benefits of load shedding strategies using a rolling-horizon stochastic mixed complementarity equilibrium model
    (Elsevier BV, 2018-06-01) ;
    As a result of government policies increasing the amount of electricity generated from fluctuating renewable sources in many countries, the requirement for flexibility in the corresponding electricity systems increases. On the demand side, load shedding is one demand response mechanism contributing to an increased flexibility. Traditionally, load shedding was based on rather static or rotational strategies, whereby the system operator chooses the consumers for load shedding. However, ongoing technological developments provide the basis for smarter and more efficient load shedding strategies. We therefore examine the costs and strategies associated with such mechanisms by modelling an electricity market with different types of generators and consumers. Some consumers provide flexibility through load shedding only while others additionally have the ability to generate their own electricity. Focussing on the impacts of how and to whom consumers with own generation ability can supply electricity, the presence of market power and generator uncertainty, we propose a rolling horizon stochastic mixed complementarity equilibrium model, where the individual optimisation problems of each player are solved simultaneously and in equilibrium. We find that a non-static strategy reduces consumer costs while allowing consumers to provide own generation to the whole market results in minimal benefits. The presence of market power was found to increase costs to consumers.
      337Scopus© Citations 14
  • Publication
    An auction framework to integrate dynamic transmission expansion planning and pay-as-bid wind connection auctions
    Competitive renewable energy procurement auctions are becoming increasingly prevalent. In a pay-as-bid auction, investors bid the price support required and receive that price if successful. Bidding strategy may be influenced by factors external to the auction, such as transmission expansion planning decisions. This may increase costs. In this paper, we show that integrating a pay-as-bid auction with transmission expansion planning may allow for closer total system cost minimisation over many time periods. This paper develops an auction mechanism and associated modelling framework to carry this out. The contributions of this framework are verified using a numerical example. Our results show that ignoring generation costs in transmission expansion planning can have economic consequences, while traditional pay-as-bid auctions can benefit from incorporating features associated with transmission expansion planning, such as multi-period optimisation. Full integration of both modelling frameworks can lead to efficiency improvements, both in terms of reduced investor rent-seeking and a more efficient deployment path.
      513Scopus© Citations 12