Analyzing Major Challenges of Wind and Solar Variability in Power Systems

Ambitious policy targets together with current and projected high growth rates indicate that future power systems will likely show substantially increased generation from renewable energy sources. A large share will come from the variable renewable energy (VRE) sources wind and solar photovoltaics (PV); however, integrating wind and solar causes challenges for existing power systems. In this paper we analyze three major integration challenges related to the structural matching of demand with the supply of wind and solar power: low capacity credit, reduced utilization of dispatchable plants, and over-produced generation. Based on residual load duration curves we define corresponding challenge variables and estimate their dependence on region (US Indiana and Germany), penetration and mix of wind and solar generation. Results show that the impacts of increasing wind and solar shares can become substantial, and increase with penetration, independently of mix and region. Solar PV at low penetrations is much easier to integrate in many areas of the US than in Germany; however, some impacts (e.g. over-production) increase significantly with higher shares. For wind power, the impacts increase rather moderately and are fairly similar in US Indiana and Germany

Economics of Nuclear Power and Climate Change Mitigation Policies

The events of March 2011 at the nuclear power complex in Fukushima, Japan, raised questions about the safe operation of nuclear power plants, with early retirement of existing nuclear power plants being debated in the policy arena and considered by regulators. Also, the future of building new nuclear power plants is highly uncertain. Should nuclear power policies become more restrictive, one potential option for climate change mitigation will be less available. However, a systematic analysis of nuclear power policies, including early retirement, has been missing in the climate change mitigation literature. We apply an energy economy model framework to derive scenarios and analyze the interactions and tradeoffs between these two policy fields. Our results indicate that early retirement of nuclear power plants leads to discounted cumulative global GDP losses of 0.07% by 2020. If, in addition, new nuclear investments are excluded, total losses will double. The effect of climate policies imposed by an intertemporal carbon budget on incremental costs of policies restricting nuclear power use is small. However, climate policies have much larger impacts than policies restricting the use of nuclear power. The carbon budget leads to cumulative discounted near term reductions of global GDP of 0.64% until 2020. Intertemporal flexibility of the carbon budget approach enables higher near-term emissions as a result of increased power generation from natural gas to fill the emerging gap in electricity supply, while still remaining within the overall carbon budget. Demand reductions and efficiency improvements are the second major response strategy

Towards a Better Understanding of Disparities in Scenarios of Decarbonization: Sectorally Explicit Results from the RECIPE Project

This paper presents results from a model intercomparison exercise among regionalized global energy-economy models conducted in the context of the RECIPE project. The economic adjustment effects of long-term climate policy aiming at stabilization of atmospheric CO2 concentrations at 450 ppm are investigated based on the cross-comparison of the intertemporal optimization models REMIND-R and WITCH as well as the recursive dynamic computable general equilibrium model IMACLIM-R. The models applied in the project differ in several respects and the comparison exercise tracks differences in the business as usual forecasts as well as in the mitigation scenarios to conceptual differences in the model structures and assumptions. In particular, the models have different representation of the sectoral structure of the energy system. A detailed sectoral analysis conducted as part of this study reveals that the sectoral representation is a crucial determinant of the mitigation strategy and costs. While all models project that the electricity sector can be decarbonized readily, emissions abatement in the non-electric sectors, particularly transport, is much more challenging. Mitigation costs and carbon prices were found to depend strongly on the availability of low-carbon options in the non-electric sectors.Decarbonization, Energy and Climate Policy

Managing power demand from air conditioning benefits solar pv in India scenarios for 2040

An Indian electricity system with very high shares of solar photovoltaics seems to be a plausible future given the ever-falling solar photovoltaic (PV) costs, recent Indian auction prices, and governmental support schemes. However, the variability of solar PV electricity, i.e., the seasonal, daily, and other weather-induced variations, could create an economic barrier. In this paper, we analyzed a strategy to overcome this barrier with demand-side management (DSM) by lending flexibility to the rapidly increasing electricity demand for air conditioning through either precooling or chilled water storage. With an open-source power sector model, we estimated the endogenous investments into and the hourly dispatching of these demand-side options for a broad range of potential PV shares in the Indian power system in 2040. We found that both options reduce the challenges of variability by shifting electricity demand from the evening peak to midday, thereby reducing the temporal mismatch of demand and solar PV supply profiles. This increases the economic value of solar PV, especially at shares above 40%, the level at which the economic value roughly doubles through demand flexibility. Consequently, DSM increases the competitive and cost-optimal solar PV generation share from 33-45% (without DSM) to ∼45-60% (with DSM). These insights are transferable to most countries with high solar irradiation in warm climate zones, which amounts to a major share of future electricity demand. This suggests that technologies, which give flexibility to air conditioning demand, can be an important contribution toward enabling a solar-centered global electricity supply. © 2020 by the authors

Time to act now? Assessing the costs of delaying climate measures and benefits of early action

This paper compares the results of the three state of the art climate-energy-economy models IMACLIM-R, ReMIND-R, and WITCH to assess the costs of climate change mitigation in scenarios in which the implementation of a global climate agreement is delayed or major emitters decide to participate in the agreement at a later stage only. We find that for stabilizing atmospheric GHG concentrations at 450 ppm CO2-only, postponing a global agreement to 2020 raises global mitigation costs by at least about half and a delay to 2030 renders ambitious climate targets infeasible to achieve. In the standard policy scenario—in which allocation of emission permits is aimed at equal per-capita levels in the year 2050—regions with above average emissions (such as the EU and the US alongside the rest of Annex-I countries) incur lower mitigation costs by taking early action, even if mitigation efforts in the rest of the world experience a delay. However, regions with low per-capita emissions which are net exporters of emission permits (such as India) can possibly benefit from higher future carbon prices resulting from a delay. We illustrate the economic mechanism behind these observations and analyze how (1) lock-in of carbon intensive infrastructure, (2) differences in global carbon prices, and (3) changes in reduction commitments resulting from delayed action influence mitigation costs.ou

Is atmospheric carbon dioxide removal a game changer for climate change mitigation?

The ability to directly remove carbon dioxide from the atmosphere allows the decoupling of emissions and emissions control in space and time. We ask the question whether this unique feature of carbon dioxide removal technologies fundamentally alters the dynamics of climate mitigation pathways. The analysis is performed in the coupled energy-economy-climate model ReMIND using the bioenergy with CCS route as an application of CDR technology. BECCS is arguably the least cost CDR option if biomass availability is not a strongly limiting factor. We compare mitigation pathways with and without BECCS to explore the impact of CDR technologies on the mitigation portfolio. Effects are most pronounced for stringent climate policies where BECCS is a key technology for the effectiveness of carbon pricing policies. The decoupling of emissions and emissions control allows prolonging the use of fossil fuels in sectors that are difficult to decarbonize, particularly in the transport sector. It also balances the distribution of mitigation costs across future generations. CDR is not a silver bullet technology. The largest part of emissions reductions continues to be provided by direct mitigation measures at the emissions source. The value of CDR lies in its flexibility to alleviate the most costly constraints on mitigating emissions

Weltklimagipfel in Kopenhagen: Welche Erfolgsaussichten hat ein globales Klimaabkommen?

Auf dem Weltklimagipfel in Kopenhagen im Dezember 2009 wird ein globales Klimaabkommen verhandelt. Können dort Strukturen geschaffen werden, die einen effizienten und kostengünstigen Klimaschutz ermöglichen? Entscheidend sei es, nach Meinung von Hubertus Bardt, Institut der deutschen Wirtschaft Köln, die Klimaschutzziele mit möglichst geringem Kostenaufwand zu erreichen. Möchte man international einen möglichst effizienten Klimaschutz betreiben, müssten die Maßnahmen zur Vermeidung von Treibhausgasemissionen an den Orten vorgenommen werden, wo dies je vermiedener Einheit am billigsten sei. Oftmals dürften diese Möglichkeiten in den Entwicklungs- und Schwellenländern liegen, während in den klimapolitisch aktiven Industrieländern preiswerte Vermeidungspotentiale bereits zu einem guten Teil ausgeschöpft seien. Ein neues internationales Klimaabkommen müsse also dazu beitragen, dass die global günstigsten Vermeidungspotentiale realisiert werden. Ottmar Edenhofer, Brigitte Knopf und Gunnar Luderer, Potsdam-Institut für Klimafolgengforschung, sehen eine sinnvolle Architektur der Klimapolitik hauptsächlich in drei Maßnahmen: 1) in einer Einigung über die Kohlenstoffmenge, die noch bis zum Ende des Jahrhunderts in der Atmosphäre abgelagert werden darf, 2) in der Verteilung der Emissionsrechte nach einem gerechten Schlüssel auf alle Nationen und 3) in der Schaffung der institutionellen Voraussetzungen für einen globalen Emissionshandel. Für Sabine Schlacke, Universität Bremen, scheint das "Ob" und "Wie" eines Post-Kyoto-Abkommens "derzeit mehr als ungewiss". Ein Scheitern der internationalen Verhandlungen könne aber durchaus auch die Möglichkeit eröffnen, über einen Systemwandel bei der internationalen Architektur des Klimaschutzes nachzudenken.Umweltabkommen, Internationale Umweltpolitik, Klimaschutz, Finanzierung, Welt

The economically optimal warming limit of the planet

Both climate-change damages and climate-change mitigation will incur economic costs. While the risk of severe damages increases with the level of global warming (Dell et al., 2014; IPCC, 2014b, 2018; Lenton et al., 2008), mitigating costs increase steeply with more stringent warming limits (IPCC, 2014a; Luderer et al., 2013; Rogelj et al., 2015). Here, we show that the global warming limit that minimizes this century's total economic costs of climate change lies between 1.9 and 2°C, if temperature changes continue to impact national economic growth rates as observed in the past and if instantaneous growth effects are neither compensated nor amplified by additional growth effects in the following years. The result is robust across a wide range of normative assumptions on the valuation of future welfare and inequality aversion. We combine estimates of climate-change impacts on economic growth for 186 countries (applying an empirical damage function from Burke et al., 2015) with mitigation costs derived from a state-of-the-art energy-economy-climate model with a wide range of highly resolved mitigation options (Kriegler et al., 2017; Luderer et al., 2013, 2015). Our purely economic assessment, even though it omits non-market damages, provides support for the international Paris Agreement on climate change. The political goal of limiting global warming to "well below 2 degrees" is thus also an economically optimal goal given above assumptions on adaptation and damage persistence. © 2019 Copernicus GmbH. All rights reserved

Development Without Energy? Assessing Future Scenarios of Energy Consumption in Developing Countries

We analyze the relationship between economic development and energy consumption in the context of greenhouse gas mitigation. The main contribution of this work is to compare estimates of energy thresholds in the form of minimum energy requirements to reach high levels of development with output projections of per capita final energy supply from a group of integrated assessment models (IAMs). Scenarios project that reductions of carbon emissions in developing countries will be achieved not only by means of decreasing the carbon intensity, but also by making a significant break with the historically observed relationship between energy use and economic growth. We discuss the feasibility of achieving, on time scales acceptable for developing countries, both decarbonization and the needed structural changes or efficiency improvements, concluding that the decreases in energy consumption implied in numerous mitigation scenarios are unlikely to be achieved without endangering sustainable development objectives. To underscore the importance of basic energy needs also in the future, the role of infrastructure is highlighted, using steel and cement as examples