Releasing wind farm equity via post-construction yield analysis

During pre-construction yield analysis, an extrapolated site wind regime is applied to a site model in order to produce estimated yield figures. However, once the site has been operational, many of the uncertainties involved in this modelling, such as electrical losses, wake losses, turbulence and power performance, may be resolved into measured operational parameters. This means that off-site anemometry may be directly related to power production on the site. In a post-construction yield analysis, the pre-construction figures are refined using actual operational data. This allows: a) The initial yield report figures to be reassessed in the light of wind farm performance, and b) The uncertainties associated with annual yield figures to be reduced and understood more fully. This increasing reduction in uncertainty allows improvements in financial modelling to take place over the operational life of the wind farm, releasing equity from the wind farm investmen

Subsidizing Public Inputs

Investment in research and development may (with some probability) lead to reductions in a firm’s production cost. If the production-cost savings associated with successful research and development is freely disseminated to other firms as soon as it is realized, too few resources may be allocated to this input. In such an environment, subsidies to the public input can lead to optimal input use. Four alternative subsidy instruments are considered in this paper. Two are incremental subsidies and the others are conventional level subsidies. One of the incremental subsidies and one of the level subsidies crudely capture characteristics of incentive mechanisms used in the United States and Canada. A laboratory implementation of these instruments generally confirms that incremental subsidies are inferior to level subsidies.

Long-Run Implications of Alternative Emission Trading Plans: An Experiment with Robot Traders

Two approaches to emmisions trading are cap-and-trade, in which an aggragate cap on emmisions is distributed in the form of permits, and baseline-and-credit, in which firms earn credits for emissions below their baselines. Theoretical considerations suggest the long-run equilibria of the two plans will differ if baselines are proportional to output, because a variable baseline is equivalent to an output subsidy. This paper reports on a laboratory environment designed to test this prediction. A computerized environment has been created in which subjects representing firms choose capacity and emission rates and participate in markets for permits or credits and for output. Demand for output is simulated. All decisions are tracked through a double-entry bookkeeping system. The timing of decisions was adjusted to avoid short-run instability. The paper reports the parameterization for an experiment with human traders and results of a simulated experiment using robots.

The vibration of rolling discs

The study presented is a fundamental investigation into the vibration of a rolling disc and an analysis of the sound which is then produced by the disc response. In order to characterise the disc's behaviour the free and forced vibration of a thin disc is analysed with the additional conditions which occur in rolling. These conditions include the geometric boundary conditions, the effect of the in-plane load, the change due to rotation of the disc and the effect of contact on the disc which in the first instance is modelled as a simple pinning constraint. Further in depth analysis is described for a more realistic model of the rolling contact including the effect of the contact stiffness and the creepage forces which may be present and simple contact models are proposed and corresponding responses predicted. Possible various sources of excitation are examined which cover the Rigid Body dynamics of the rolling disc, the effect of the contact model as a source of excitation and a preliminary consideration of the forces generated by contact of rough surfaces. An elementary representation is presented for the sound radiated by the rolling disc, assuming it is baffled, and its efficiency evaluated and the unbaffled disc radiation is also presented for a particular case

Amanda

"Amanda" is a stop-motion animated short film, shot in stereoscopic 3D. Using fairy tale themes, it tells the story of a young girl who is struggling to control her emotions. Lost in a dark swamp, she encounters a troll who catches and consumes her. She must eventually outwit him in order to return home

Baseline-and-Credit Style Emission Trading Mechanisms: An Experimental Investigation of Economic Inefficiency

Two approaches to emissions trading are cap-and-trade, in which an aggregate cap on emissions is distributed in the form of allowance permits, and baseline-and-credit, in which firms earn emission reduction credits for emissions below their baselines. Theoretical considerations suggest the long-run equilibria of the two plans will differ if baselines are proportional to output, because a variable baseline is equivalent to an output subsidy. This paper reports on a laboratory experiment designed to test the prediction in a laboratory environ- ment in which sub jects representing firms choose emission technologies and output capacities. A computerized environment has been created in which sub jects participate in markets for emission rights and for output. Demand for output is simulated. All decisions are tracked through a double-entry bookkeeping system. Our evidence supports the theoretical prediction that aggregate output and emissions are in- efficiently high under a baseline-and-credit trading plan compared to a corresponding cap-and-trade plan.