The theme for this week’s sustainability research is RENEWABLE
ENERGY
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Research in Details
Research #1
The role of biogas and biogas-derived fuels in a 100% renewable energy system in Denmark
Highlights
Biogas should be used directly when possible or in the form of biomethane.
Power, heat and industry benefit the most from using biogas and biomethane.
Transport should focus on electrification and liquid electrofuels.
Electromethane can be a solution for niche markets depending on its value streams.
Authors: Andrei David Korberg, Iva Ridjan Skov, Brian Vad Mathiesen
Date of publication: 15 MAY 2020
Summary
In this paper, we analyse the role of biogas and biogas-derived fuels in a 100% renewable energy system for Denmark using the energy system analysis tool Energy PLAN. The end-fuels evaluated are biogas, biomethane and electromethane. First, a reference scenario without biogas is created. Then biogas, biomethane and electromethane replace dry biomass-derived fuels in different sectors of the energy system. The results show that biogas and biomethane reduce dry biomass consumption by up to 16% when used for power, heat or industrial sectors. If biogas feedstock is free for energy purposes, this brings significant energy system cost reductions, but when the energy sector pays for the biogas feedstock, then savings are lower, in which case biogas and biomethane still reduce the energy system costs for use in power, heat or industrial sectors. Replacement of liquid bio-electrofuels for transport with biomethane shows slight cost reductions, but considerably higher costs when using electromethane. For power, heat, industry and partly transport, electromethane is economically unfeasible, independent of the dry biomass costs. Biogas should be used directly or in the form of biomethane. It is a limited resource dependent on the structure of the agricultural sector, but it can supplement other renewable energy sources.
Keywords: Biogas, Biomethane, Electromethane, Energy system analysis, 100% renewable Energy system
Research #2
Flexible electricity use for heating in markets with renewable energy
Highlights
Electric heating can contribute to decarbonization and provide flexibility for renewable integration.
Analysis of electric storage heaters for German 2030 scenarios with open-source electricity sector model.
Temporally flexible charging of storage heaters provides only small benefits.
Electric storage heaters not suited to align seasonal mismatch between renewables and heat demand.
Flexible power-to-heat generally fosters use of generation technologies with low variable costs.
Authors: Wolf-Peter Schill, Alexander Zerrahn
Date of publication: 15 MAY 2020
Summary
Using electricity for heating can contribute to decarbonization and provide flexibility to integrate variable renewable energy. We analyze the case of electric storage heaters in German 2030 scenarios with an open-source electricity sector model. We find that flexible electric heaters generally increase the use of generation technologies with low variable costs, which are not necessarily renewables. Yet making customary night-time storage heaters temporally more flexible offers only moderate benefits because renewable availability during daytime is limited in the heating season. Respective investment costs accordingly have to be very low in order to realize total system cost benefits. As storage heaters feature only short-term heat storage, they also cannot reconcile the seasonal mismatch of heat demand in winter and high renewable availability in summer. Future research should evaluate the benefits of longer-term heat storage.
Keywords: Power-to-heat, Electric heating, Renewable energy integration, Energy storage, Demand-side management, Decarbonization, Power system model
Research #3
A two-stage multi-criteria analysis method for planning renewable energy use and carbon saving
Highlights:
A two-stage multi-criteria analysis tool developed for renewable energy planning.
Technical, economic, and environmental criteria considered.
Economically, wind turbines and bioenergy prioritized for electricity and heat production.
The plan has 255 wind turbines, 23,497 PV panels, 2 bioenergy units, and 3382 GSHPs.
The plan has an annual carbon footprint of 109,629 ton CO2-eq.
Authors: Asam Ahmed, Setiadi Wicaksono Sutrisno, Siming You
Date of publication: 15 May 2020
Summary
Renewable energy use is critical for achieving climate change goals. It is essential to understand necessary to the priority, capacity, and number of units of renewable energy systems for generation planning. Multi-criteria analysis methods serve as an effective tool for planning renewable energy generation. In this work, a two-stage multi-criteria analysis method was developed to identify the priority and capacities, as well as the numbers of units of renewable energy technologies. Technical (capacity factor and power density), economic (benefit-to-cost ratio), and environmental (carbon dioxide equivalent emission) criteria were considered. The method was applied to plan Glasgow’s renewable energy use. It was found that the planned renewable energy use configuration consists of 255 units of wind turbines (3.6 MW each), 23,497 units of solar photovoltaic panels (11 kW each), 2 units of biomass combustion systems (2 MW each), and 3382 units of ground source heat pumps (22.5 kW each) corresponding to an annual carbon footprint of 109,629 tonnes carbon dioxide equivalent. Sensitivity analysis was also conducted to assess the impacts of weightings in technical, economic, and environmental criteria on the decision in the configuration of renewable energy use.
Keywords: Renewable energy, Decision tool, Multi-criteria analysis, Climate change, Energy storage
Research #4
Variations in the environment, energy and macroeconomic interdependencies and related renewable energy transition policies based on sensitive categorization of countries in Africa
Highlights:
Energy-environment-economy interdependencies are explored for panels of sensitively grouped African countries.
We find no long-run relationship in CO2 and GDP models for four panels.
Renewable energy contributes ∼40% of the ∼25QBtu total energy demand in 2030.
Energy investments of ∼US$3367.2 billion is required to achieve 100% renewables in 2030 for Africa.
The findings imply intensifying current renewable energy policies.
Authors: Amos Oppong, Ma Jie, Kingsley N.Acheampong, Mark A.Sakyia
Date of publication: 10 MAY 2020
Summary
The disparities in development levels of countries in Africa necessitate correspondingly sensitive categorization approaches because effective renewable energy-related (RER) decisions, policy-making, and subsequent implementation hinges on workable categorization indices. However, studies on sensitive categorization approaches for energy-environment-economy (3E) interdependencies for Africa is rare. This study uses a sensitive characteristic-driven approach to explore the interdependencies in 3E indicators for carbon dioxide (CO2) emissions, renewable energy consumption (REC), fossil fuel energy consumption, gross domestic product (GDP), population, and gross fixed capital formation in 39 African countries. Further, we forecast the dollar values of policy innovations necessary to facilitate the transition to 100% renewable energies for 2030. Using balanced data spanning 2000–2014, the empirical results from the panel vector error-correction model show long-run Granger causality in CO2 emissions, REC and GDP models for Africa, but no evidence of such relationship was found four sub-panels. The results depict varied individual unidirectional and bidirectional causalities among the variables in each panel. Evidence from variance decomposition analysis show that ∼93% of innovations required to achieve renewable energy-led Africa must happen in REC. Results from the high precision own-data-driven forecast puts total energy demand in Africa at ∼25QBtu in 2030 with ∼40% from renewables. Estimates of the dollar value of innovations depict that it would cost Africa ∼ US$3367.2 billion [in 2030 only] to transition to 100% renewables. We find RER investment (RERIs), in billion US$, ranging from 2.69 to 1274.12 for seven sub-panels. Yet, the panel of Moderate Lower Middle-Income Economies need not to make further investments because their existing REIRs could be enough to help the region reach 100% renewables by 2030. The findings herein imply that RER policies in Africa must be intensified to achieve 100% renewable energy target.
Keywords: Sensitive categorization of countries, Granger causality, Own-data-driven forecasting, Renewable energy transition policies, Renewable energy-related investments, One hundred percent renewables
Research #5
Integration of distributed renewable energy sources in Israel: Transmission congestion challenges and policy recommendations
Highlights
Congestion in the Israeli electric grid inhibits renewable energy integration.
Power reduction in conventional plants may promote renewable energy integration.
Optimal distribution of solar power plants may reduce line loads by tens of percent.
The traditional notion that peak demand is the worst case may be misleading.
Authors: Aviad Navon, Pavel Kulbekov, Shahar Dolev, Gil Yehud, Yoash Levron
Date of publication: May, 2020
Summary
This paper studies congestion in the Israeli transmission network due to integration of renewable energy sources, and suggests policies to address this problem. We show through an extensive set of simulations that several key lines are overloaded and therefore energy sources cannot be added without risking the system’s reliability. Moreover, additional renewable energy may be added by reducing production in conventional power plants at hours of peak solar power production. We also compare three scenarios of location and size of new solar plants, and show that the optimal distribution of these plants may reduce transmission line loads by several tens of percent. Lastly, this study demonstrates that line loads in areas with a high share of distributed renewable energy sources are not necessarily maximal during peak demand. As a consequence, the [Math Processing Error]N−1 and [Math Processing Error]N−2 contingency planning criteria should be updated accordingly. The paper concludes with policy recommendations for overcoming these problems, in order to promote integration of renewable energy sources in Israel.
Keywords: Energy policy, Renewable energy, Transmission system, Congestion, Israel