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| 1 |
ID:
166408
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| Summary/Abstract |
In 2015, ASEAN established a goal of increasing its renewable energy share in its energy portfolio from approximately 13–23% by 2025. Renewable electricity, especially intermittent and variable sources, presents challenges for grid operators due to the uncertain timing and quantity of electricity supply. Grid flexibility, the electric grid's ability to respond to changing demands and supply, now stands a key resource in responding to these uncertainties while maximizing the cost-effective role of clean energy. We develop and apply a grid flexibility assessment tool to assess ASEAN's current grid flexibility using six quantitative indicators: grid reliability, electricity market access; load profile ramp capacity; quality of forecasting tools; proportion of electricity generation from natural gas; and renewable energy diversity. We find that ASEAN nations cluster into three groups: better; moderately; and the least prepared nations. We develop an analytical ramp rate calculator to quantify expected load ramps for ASEAN in an integrated ASEAN Power Grid scenario. The lack of forecasting systems and limited electricity market access represent key weaknesses and areas where dramatic improvements can become cost-effective means to increase regional grid flexibility. As ASEAN pursues renewable energy targets, regional cooperation remains essential to address identified challenges. Member nations need to increase grid flexibility capacity to adequately prepare for higher penetrations of renewable electricity and lower overall system costs.
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| 2 |
ID:
166703
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| Summary/Abstract |
We present a computationally-efficient optimization model that finds the least-cost generation unit expansion, commitment, and dispatch plan to serve hourly electricity demand and ancillary service requirements. We apply the model to a case study based on data from the electricity market in Texas (ERCOT) to analyze the market and investment impacts of several incentive mechanisms that support variable renewable energy (VRE) investments and carbon emission reductions. In contrast to many previous studies, the model determines least-cost VRE investments under different cost and incentive assumptions rather than analyzing scenarios where VRE expansion is pre-determined. We find that electricity prices can vary significantly under different incentive mechanisms, even when comparable generation portfolios result. Therefore, the preferred incentive mechanism depends on stakeholder objectives as well as the prevailing electricity market framework. Our results indicate that a carbon tax is more system cost-efficient for reducing emissions, while production and investment tax credits are more system cost-efficient for increasing VRE investments. Similarly, incentive mechanisms that reduce electricity prices may increase the need for separate revenue sufficiency mechanisms (e.g. a capacity market) more than a policy that increases electricity prices. Moreover, the impacts on consumer payments are not always aligned with changes in system costs. Overall, the analysis illustrates the importance of considering electricity market impacts in assessing the economic efficiency of VRE and carbon incentive mechanisms.
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| 3 |
ID:
162915
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| Summary/Abstract |
This article studies the integration of variable renewable energy sources (RES) into power networks. The main goal is to confront the contents and trends of scientific literature with the eyes and projects of researchers on future topics and issues to be solved, especially in terms of the modeling of electrical systems. The analysis relies on a bibliometric study of the Scopus database on the topic and on an online survey sent to the corresponding authors of the identified papers. The paper analyzes the dynamics of publication, clusters of collaboration, and main topics studied. It then identifies potential research leads, among which unresolved challenges regarding technical aspects, markets and financing issues, and social aspects. The disparity of models and results is still a necessary evil as research is not mature enough to integrate in one model all the very complex parameters of VRE integration into power systems. There is a lack of recurrence, though, such as the impact of emergent technologies or the development of substitute low carbon-emitting technology (other than solar and wind), need to be addressed. The paper also advocates the need for a systemic vision, for both research and policymakers that goes beyond the sole power system.
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| 4 |
ID:
171479
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| Summary/Abstract |
The competitiveness of electricity sources is traditionally estimated by levelized cost of electricity (LCOE) compared to the average electricity price. However, the introduction of variable renewable energy sources (VREs) in power systems has evidenced that time, location and availability, are essential to set the marginal value of electricity sources. Overcoming the narrow view of costs for a broad value approach, the literature recognizes that the source comparison must consider the expected marginal value of each alternative, which evolves over time due to sources penetration and system development, changing static and dynamic integration costs. The paper presents the Brazilian experience as forerunner case study for the literature on systemic value, as the country has established a pioneering benefit-cost index (BCI) to compare different sources in centralized expansion auctions, which contracted 100 GW of installed capacity. The BCI analysis is based on hydro predominance, recognizing only static integration costs (backward-looking approach). Nevertheless, the Brazilian system is evolving towards higher short-term variability due to the loss of regularization of hydro reservoirs, limitations to hydropower expansion and VREs penetration. The expansion and operation of the power system are not sensitive to ongoing changes, neglecting dynamic integration costs, which must be incorporated in a forward-looking perspective.
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