Synthesis of wind time series for network adequacy assessment

When representing the stochastic characteristics of wind generators within power system simulations, the spatial and temporal correlations of the wind resource must be correctly modelled to ensure that reserve and network capacity requirements are not underestimated. A methodology for capturing these correlations within a vector auto-regressive (VAR) model is presented, and applied to a large-scale reanalysis dataset of historical wind speed data for the British Isles. This is combined with a wind speed-to-power conversion model trained against historically metered data from wind farms on the Great Britain (GB) electricity system in order to derive a lightweight model for simulating injections of wind power across a transmission network. The model is demonstrated to adequately represent ramp rates, both at a site and network level, as well as the individual correlations between sites, while being suitable for network adequacy studies which may require the simulation of many years of operation

Managing regional security of supply : a case study from Scotland

Securing the supply of electricity to a region of a power system requires either generation capacity within that region, or transmission import capability coupled with generation elsewhere in the power system. The problem is one of co-optimising generation and transmission infrastructure. This paper begins by discussing changes in Great Britain (GB) regulator environment affecting the provision of regional security of supply: changes to the transmission charging regime; new regulatory arrangements including enhancements to the System Operator’s role, and the opening up of major new transmission projects to competition; and some limitations of the existing standard defining the methodology for calculating secure transmission capabilities. Scotland, as a region of the GB power system, provides an interesting case study in which to investigate the allocation of contributions to regional security of supply between transmission and various categories of generation. In particular, intermittent generation is currently ignored when calculating the level of transmission import capability required to maintain security of supply in a region, whilst it is considered in overall generation adequacy calculations at a system level. Whilst wind generation is not dispatchable, it is shown here that it does provide an additional source of generation availability that should be considered in studies into transmission import requirements. This paper uses historical data for Scottish generation availability from recent winters to investigate the likely impact of changes to the Scottish generation fleet on the need for secure transmission import capability into Scotland. It calculates transmission requirements based on the risk of requiring demand reduction within a region. Scenarios representing possible generation backgrounds in Scotland over the coming decade show that, measured in this way, wind generation can offset transmission import requirements by up to 25% of its installed capacity. The key conclusions of the paper are that a risk-based analysis of regional security of supply and transmission requirements can help allocate the true impact of different generators on the transmission import capability needed to secure supply to a region. Such a method can therefore be useful in informing the allocation of charges between parties and in developing planning standards to shape future investment in the system

An Independent Review of USGS Circular 1370: An Evaluation of the Science Needs to Inform Decisions on Outer Continental Shelf Energy Development in the Chukchi and Beaufort Seas, Alaska

Reviews the U.S. Geological Survey's findings and recommendations on Alaska's Arctic Ocean, including geology, ecology and subsistence, effect of climate change on, and impact of oil spills. Makes recommendations for data management and other issues

Flexible Transmission Network Planning Considering the Impacts of Distributed Generation

The restructuring of global power industries has introduced a number of challenges, such as conflicting planning objectives and increasing uncertainties,to transmission network planners. During the recent past, a number of distributed generation technologies also reached a stage allowing large scale implementation, which will profoundly influence the power industry, as well as the practice of transmission network expansion. In the new market environment, new approaches are needed to meet the above challenges. In this paper, a market simulation based method is employed to assess the economical attractiveness of different generation technologies, based on which future scenarios of generation expansion can be formed. A multi-objective optimization model for transmission expansion planning is then presented. A novel approach is proposed to select transmission expansion plans that are flexible given the uncertainties of generation expansion, system load and other market variables. Comprehensive case studies will be conducted to investigate the performance of our approach. In addition, the proposed method will be employed to study the impacts of distributed generation, especially on transmission expansion planning.

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process

The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system

Design criteria for flight evaluation. Monograph 4 - Control system evaluation

Methods and analyses for flight evaluation of control systems for multistage launch vehicle

Capacity credits of wind and solar generation: The Spanish case

This paper analyses the capacity credits (CCs) of renewable photovoltaic (PV), concentrated solar power (CSP) and wind technologies in the Spanish power system. This system has steadily increased the share of renewables, reaching a penetration level of over 30%. The predictions made by ENTSO-e suggest that this level will increase to 50% by 2030. Therefore, different scenarios are studied in this paper to investigate the evolution of renewable integration and assess the corresponding contributions to reliability. The assessment is performed using a sequential Monte Carlo (SMC) method considering the seasonality of renewable generation and the uncertainties related to renewable sources, failure issues and the maintenance of thermal-based units. The baseline for SMC is provided by historical annual time series of irradiance and wind power data from the Spanish system. In the solar case, these time series are transformed into power time series with models of CSP and PV generation. The former includes different thermal storage strategies. For wind generation, a moving block bootstrap (MBB) technique is used to generate new wind power time series. The CC is assessed based on the equivalent firm capacity (EFC) using standard reliability metrics, namely, the loss of load expectation (LOLE). The results highlight the low contribution of renewables to power system adequacy when the Spanish power system has a high share of renewable generation. In addition, the results are compared with those of similar studies.This work was supported by the University Carlos III of Madrid under project Feasibility of power systems with renewables (2009/00416/002

Meteorological data for RES-E integration studies: State of the art review

The ongoing growth of RES-E requires power system modellers to adapt both methodologies and datasets, in particular time series for electricity generation from wind and PV. Meteorological models are increasingly used for this purpose. This report provides on overview on the methodologies available and the approaches pursued by recent RES-E integration studies. Based on this review, recommendations for best practice are identified.JRC.F.6-Energy Technology Policy Outloo