The most robust methods to determine the capacity contribution from intermittent sources combine load curve, variable generation profile, and dispatchable generators’ data to calculate any new inserted variable source’s capacity value in the power system. However, these methods invariably adopt the premise that the system’s dispatchable generators’ capacity is constant. That is an unacceptable limitation when the energy mix has a large share of hydroelectric sources. Hydroelectric plants are dispatchable sources with variable maximum power output over time, varying mainly according to the reservoirs’ level. This article develops a method that makes it possible to calculate the capacity value from renewable resources when the dispatchable generation units of an electric system have variable capacity. The authors apply the method to calculate the capacity value from solar and wind sources in Brazil as an exercise. By abandoning the hypothesis of constant dispatchable capacity, the developed approach is in principle extensible for other energy-limited resources, such as batteries and concentrating solar power (CSP). This can be a strategy to incorporate energy-limited capacity sources into the planning and operation models as reliable capacity sources.

Residual rights are the right to choose asset uses not specified in the contract. They are essential in situations of uncertainty. The current energy transition presents a greater variety of assets. Moreover, it is impossible to anticipate all relevant states that the assets and the environment can embody, making it impossible to optimize them contractually. Furthermore, there is consensus that the transition must occur quickly, which means high levels of investment in new specific assets. How should we distribute property rights to maximize social benefits in a context with specific and dispersed assets? Because of the complementarity between network and distributed resources, this article questions the premise that deverticalization is invariably beneficial to consumers and argues for the need to revise the concept of network and develop the regulatory implications of such a reconceptualization. We defend the need to evaluate alternative network concepts considering the technological repertoire available to operationalize them. When considering the technological repertoire available today, characterized by the competitiveness of information and communications technology (ICT) and distributed resources, we should recognize the inherently incomplete nature of the contracts signed between network operators and users.

Utilities, policymakers, regulators, free market, and prosumers share a common interest in understanding whether benefits associated with such increased of DERs outweigh costs. To dimension and qualify B/C relationship, there are intrinsic variables relative to DERs' technical-economic arrangement and standard mechanisms used for its compensation: NEM, feed-in policies, etc. Other side, DERs must be adjusted on established regulatory framework, tariff schemes and utility revenue models. In this article, these three ambits are analyzed including a Brazilian southeastern region user's case study connected to MV network with DG measured data. Thus, some guidelines are pointed for the comprehensive implementation of DERs from the perspective of those involved.

Desenvolvimento e Meio Ambiente addresses socioenvironmental issues

Given the ubiquitous nature of the laws of thermodynamics, it would be reasonable to expect that the divergence between strong and weak sustainability could be subjected to critical tests. That is, it should be possible to use the neoclassical production theory and the laws of thermodynamics to generate predictions able to question the empirical adequacy of the neoclassical research program in terms of sustainability. However, the current state of the debate normally suggests the opposite, that is, the currently available evidence is not sufficient to build refutations. Contrary to this prognosis, we argue that it is possible to build critical tests to evaluate the models in dispute using evidence already available. However, such a construction requires that the analysis of the sustainability be not restricted to the type of evidence traditionally used by such models. We argue that alternative theories must be explicitly used to give meaning to new types of evidence. Without the explicit mobilization of alternative theories to evaluate new types of evidence, critics of the orthodox theory dwell on an epistemological trap, in which the questioned research program determines what is or what is not scientifically meaningful. To illustrate the prospects of the methodological proposal presented here, we apply this approach to a particular neoclassical model - the Baumol's model -, which explicitly supports the ability to indefinitely continue the trajectory of economic growth triggered by the Industrial Revolution. The results refute the tested neoclassical model, demonstrate the need to distinguish between intensive and extensive substitution of natural resources, and corroborate the Geogescu-Roegen fund-flow model.