Understanding best practice regarding interruptible connections for wind generation: lessons from national and international experience

The aim of this study is to explore different practices for accelerating the integration of generating facilities to the electricity network using smart solutions. Case studies from Great Britain, Ireland and Northern Ireland and the Unites States were selected. The paper assesses and compares the different Principles of Access (POA) that have been implemented in these countries, such as Last-in First-out (LIFO), Pro Rata and Market-based. The social optimality of these approaches is also discussed. The paper also evaluates how the risk (regarding curtailment and investment) is allocated between parties (distributor network operators, generators and customers). Even though the cases are diverse, important findings and lessons have been identified which may assist UK distribution network operators to address the issue of increasing the connection of distributed generation while managing efficiently and economically energy exports from generators

Does Weather Have an Impact on Electricity Distribution Efficiency? Evidence from South America

This paper analyses the influence of weather variables on the efficiency of electricity distribution utilities in Argentina, Brazil, Chile and Peru. The data covers 82 firms that operate in the previously mentioned countries which represent more than 90 per cent of the distribution market of energy delivered for the period 1998-2008. The stochastic frontier analysis (SFA) is applied with a translog input distance function approach. A combination of cost and cost-quality models is proposed to create better discussions. Weather data are collected from 429 meteorological stations and lightning data (flash rate) are collected from 3,423 coordinates provided by NASA. A geographic information system (GIS) is used for locating the firms' service areas and for allocating their respective meteorological stations and coordinates. Results suggest that on average under cost models there is a significant increase in efficiency when weather is incorporated in the production function. Firms from Brazil and Peru are those which operate in less favourable weather conditions. Under the cost-quality models, on average the effect of weather is much lower. From this, it appears to be that firms have internalised the effects of weather and have adapted their networks with consideration to the environment in which they operate. A company-level analysis indicates that across models an important number of companies are affected by weather. Regulators are advised to make the case for the proper adjustments of efficiency scores when specific firms face important efficiency changes due to weather

Distributed Generation: Opportunities for Distribution Network Operators, Wider Society and Generators

This study explores and quantifies the benefits of connecting more distributed generation (with and without the use of smart connections) across different parties (Distribution Network Operators, wider society and generators). Different connection scenarios are proposed (with partial and full interruptible capacity quota, a mix of generation and different technology-specific curtailment levels) for integrating DG units in the constrained area of the March grid (East of England). This constitutes the trial area of the Flexible Plug and Play project, which is being implemented by UK Power Networks. The smart connection option is by far the preferred option across all the scenarios (higher NPV/MW). However, for some generators the results are very sensitive to the discount rate used (i.e. solar PV). The analysis of the distribution of benefits suggests that generators capture most of the benefits while DNOs and wider society capture much less benefit. A smart connection incentive, which recreates the benefits to DNOs from an earlier losses incentive, is proposed. In contrast with other societally desirable metrics which are usually incentivised or penalised, there is currently no direct connection between more DG MWs connected and DNO incentive payments. Our proposed smart connection incentive, by charging DG for smarter connection may help to distribute more efficiently the benefits for connecting more DG

Integrating Distributed Generation: Regulation and Trends in Three Leading Countries

We explore trends in the deployment and integration of distributed generation in Germany, Denmark and Sweden. In particular, we examine the regulation of renewable energy generation with a focus on grid access and connection mechanisms. The high rate of distributed generation penetration in these countries is the result of early support given to the expansion of renewable energy generation – mainly wind and solar - within their respective national policies. Germany and Denmark are the countries with the most sophisticated support schemes, which have shown changes over time. In terms of connections, Germany is the country with the most favourable connection regime. It provides not only priority connection but also priority use of the grid to generation units that produce electricity from renewable energy sources. Sweden guarantees equal treatment among different technologies (i.e. a non-discrimination principle) and is thus the least favourable. High connection costs have been observed, especially in Germany and Denmark. The costs of network upgrades are usually socialised across customers. The use of smart solutions combined with novel business models might allow more efficient use of the current distribution electricity infrastructure. Hence, integration issues should be taken into consideration in order to avoid expansion of distributed generation in a way that unnecessarily raises total system costs, via high connection costs

An evaluation of a local reactive power market: the case of Power Potential

This paper quantifies the benefits of introducing reactive power markets that promote the participation of distributed energy resources (DER) in a coordinated way, between the electricity system operator and the electricity distribution utilities. The contribution that DER could make by displacing conventional network assets in supplying reactive power support is evaluated in the context of a case study, the Power Potential (PP) project in Great Britain. We discuss the rising need for absorptive (leading) reactive power in the PP trial area, driven by the rapid connection of renewable generation in an area of low demand growth. A social cost benefit analysis (SCBA) is performed to quantify the net benefits, with sensitivities regarding bid prices, % of DER participation, time horizons. Price information from the PP live trial conducted between January and March 2021 is also used to evaluate the robustness of the SCBA and to estimate benefits using actual prices. Our results suggest that energy consumers could save from 8-21% of business as usual asset costs by 2050. The introduction of trial bid prices increases these savings by around 3% of business as usual asset costs out to 2050. Potential sources of additional benefits on top of those identified in the SCBA are also discussed