Power-to-gas and Power-to-liquids for Managing Renewable Electricity Intermittency in the Alpine Region

Large-scale deployment of renewable energy sources (RES) can play a central role in reducing CO2 emissions from energy supply systems, but intermittency from solar and wind technologies present grid integration challenges. High temperature co-electrolysis of steam and CO2, in the so-called power-to-gas (PtG) and power-to-liquid (PtL) configuration, could provide a path for utilizing the excess intermittent electricity from a power system by converting it into chemical fuels that can be directly utilized in other sectors, such as transportation and heating. The chemical fuels could also be used in the power sector during periods of deficit in supply. Here, we study the economic and engineering potential of PtG/PtL systems deployment as storage for intermittent renewable electricity and as a source of low-carbon heating and transportation energy among the different energy sectors in the Alpine region, using the BeWhere model, a geographic explicit cost minimization model. Preliminary results indicate large-scale deployment of the PtG/PtL technologies for producing chemical fuels from excess intermittent electricity is feasible, particularly when incentivized by carbon prices. In addition, large volumes of captured CO2, as much as 30 Mt CO2 /year are utilized in the synthesis of the chemical fuels, providing as much as 23% of liquid transportation fuels. In this context, it can be concluded that PtG/PtL technologies can enable greater integration of RES into the energy supply chain, with application worldwide

Negative Emissions on South East Asia: Renewable Energy Optimization with BECCS for Indonesia

Indonesia, on the one hand, is a tropical country with large biomass productivity and increasing oil and gas sector activities. On the other hand, it is the 3rd largest GHG emitter globally and some 90% of its emissions are generated from massive land-use change. However, Indonesia has also developed very ambitious climate targets aiming at up to 41% emission reduction by 2020. These targets need to be balanced with an envisaged GDP growth by 7% and projected 5 times higher energy consumption in 2050. To decrease its fossil fuel dependency and emissions, the government of Indonesia has decided to increase the renewable energy supply from 6% to 23% by 2025, along with a 100 percent electrification target by 2020. Furthermore, BECCS (i.e. the combination of forest based bioenergy with carbon capture and storage) is seen as a promising tool to bridge between the various future challenges Indonesia is facing and at the same time to deliver large quantities of negative emissions needed by the end of this century. But - irrespectively of Indonesia’s abundant resources to meet ambitious renewable energy and mitigation targets - there is lack of proper integrated planning, regulatory support, investment, distribution in remote areas of the Archipelago, and missing data to back the planning. To support the government of Indonesia in its sustainable energy systems planning, a geographic explicit energy modeling approach is applied. IIASA’s BeWhere Model identifies the optimal location of energy conversion sites based on the minimization of the supply chain costs. The model incorporates the existing fossil fuel-based infrastructures, and evaluates the optimal costs, potentials and locations for the development of renewable energy technologies (i.e. wind, solar, hydro, biomass and geothermal based technologies), as well as the development of biomass co-firing in existing coal plants. An optimally adapted renewable energy mix – vis-à-vis the competing fossil fuel based resources – is identified. In addition, the in situ BECCS capacity for different scenarios is assessed for Indonesia. Special focus is put on nature protection and cultural heritage areas, where feedstock (e.g., biomass harvesting) and green-field power plant sites will be limited – depending on the protection type and renewable energy technology. First results of the study provide indications on where, how and which technologies should be implemented. Moreover, the assessment indicates that the BECCS potentials vary substantially over the different scenario assumptions. Sustainable biomass feedstock production, energy demand and supply as well as competing industries and existing transport infrastructure are key to achieve an optimal BECCS solution. Clean energy access for all with special emphasis on remote areas and small islands in Indonesia turns out to be especially interesting from a socio-economic, emission savings and innovation perspective

Power-to-gas and power-to-liquid for managing renewable electricity intermittency in the Alpine Region

Large-scale deployment of renewable energy sources (RES) plays a central role in reducing CO2 emissions from energy supply systems, but intermittency from solar and wind technologies presents integration challenges. High temperature co-electrolysis of steam and CO2 in power-to-gas (PtG) and power-to-liquid (PtL) configurations could utilize excess intermittent electricity by converting it into chemical fuels. These can then be directly consumed in other sectors, such as transportation and heating, or used as power storage. Here, we investigate the impact of carbon policy and fossil fuel prices on the economic and engineering potential of PtG and PtL systems as storage for intermittent renewable electricity and as a source of low-carbon heating and transportation energy in the Alpine region. We employ a spatially and temporally explicit optimization approach of RES, PtG, PtL and fossil technologies in the electricity, heating, and transportation sectors, using the BeWhere model. Results indicate that large-scale deployment of PtG and PtL technologies for producing chemical fuels from excess intermittent electricity is feasible, particularly when incentivized by carbon prices. Depending on carbon and fossil fuel price, 0.15−15 million tonnes/year of captured CO2 can be used in the synthesis of the chemical fuels, displacing up to 11% of current fossil fuel use in transportation. By providing a physical link between the electricity, transportation, and heating sectors, PtG and PtL technologies can enable greater integration of RES into the energy supply chain globally

Combining expansion in pulp capacity with production of sustainable biofuels – Techno-economic and greenhouse gas emissions assessment of drop-in fuels from black liquor part-streams

Drop-in biofuels from forest by-products such as black liquor can help deliver deep reductions in transport greenhouse gas emissions by replacing fossil fuels in our vehicle fleet. Black liquor is produced at pulp mills that can increase their pulping capacity by upgrading some of it to drop-in biofuels but this is not well-studied. We evaluate the techno-economic and greenhouse gas performance of five drop-in biofuel pathways based on BL lignin separation with hydrotreatment or black liquor gasification with catalytic synthesis. We also assess how integrated biofuel production impacts different types of pulp mills and a petroleum refinery by using energy and material balances assembled from experimental data supplemented by expert input. Our results indicate that drop-in biofuels from black liquor part-streams can be produced for ~80 EUR2017/MWh, which puts black liquor on the same footing (or better) as comparable forest residue-based alternatives. The best pathways in both production routes have comparable costs and their principal biofuel products (petrol for black liquor gasification and diesel for lignin hydrotreatment) complement each other. All pathways surpass European Union's sustainability criteria for greenhouse gas savings from new plants. Supplementing black liquor with pyrolysis oil or electrolysis hydrogen can improve biofuel production potentials and feedstock diversity, but better economic performance does not accompany these benefits. Fossil hydrogen represents the cheaper option for lignin hydrotreatment by some margin, but greenhouse gas savings from renewable hydrogen are nearly twice as great. Research on lignin upgrading in industrial conditions is recommended for reducing the presently significant performance uncertainties

Hydropower production benefits more from 1.5°C than 2°C climate scenario

Hydropower plays an important role as renewable and clean energy in the world's overall energy supply. Electricity generation from hydropower represented approximately 16.6% of the world's total electricity and 70% of all renewable electricity in 2015. Determining the different effects of 1.5°C and 2°C of global warming has become a hot spot in water resources research. However, there are still few studies on the impacts of different global warming levels on gross hydropower potential. This study used a coupled hydrological and techno‐economic model framework to assess hydropower production under global warming levels of 1.5°C and 2°C, while also considering gross hydropower potential, power consumption and economic factors. The results show that both global warming levels will have a positive impact on the hydropower production of a tropical island (Sumatra) relative to the historical period, however, the ratio of hydropower production versus power demand provided by 1.5°C of global warming is 40% higher than that provided by 2°C of global warming under RCP6.0. The power generation by hydropower plants shows incongruous changing trends with hydropower potential under the same global warming levels. This inconformity occurs because the optimal sites for hydropower plants were chosen by considering not only hydropower potential but also economic factors. In addition, the reduction in CO2 emissions under global warming of 1.5°C (39.06×106 t) is greater than that under global warming of 2°C (10.20×106 t), which reveals that global warming decreases the benefits necessary to relieve global warming levels. However, the hydropower generation and the reduction in CO2 emissions will be far less than the energy demand when protected areas are excluded as potential sites for hydropower plants, with a sharp decrease of 40‐80%. Thus, government policy‐makers should consider the tradeoff between hydropower generation and forest coverage area in nationally determined contributions

Short-term solar and wind variability in long-term energy system models - A European case study

Integration of variable renewables such as solar and wind has grown at an unprecedented pace in Europe over the past two decades. As the share of solar and wind rises, it becomes increasingly important for long-term energy system models to adequately represent their short-term variability. This paper uses a long-term TIMES model of the European power and district heat sectors towards 2050 to explore how stochastic modelling of short-term solar and wind variability as well as different temporal resolutions influence the model performance. Using a stochastic model with 48 time-slices as benchmark, the results show that deterministic models with low temporal resolution give a 15–20% underestimation of annual costs, an overestimation of the contribution of variable renewables (13–15% of total electricity generation) and a lack of system flexibility. The results of the deterministic models converge towards the stochastic solution when the temporal resolution is increased, but even with 2016 time-slices, the need for flexibility is underestimated. In addition, the deterministic model with 2016 time-slices takes 30 times longer to solve than the stochastic model with 48 time-slices. Based on these findings, a stochastic approach is recommended for long-term studies of energy systems with large shares of variable renewable energy sources

Spatio-temporal Assessment of Integrating Intermittent Electricity in the EU Power Sector

The integration of solar and wind technologies into the energy supply system is becoming increasingly attractive as their costs per unit capacity drop and tight policies are being implemented against greenhouse gas emissions. However, their contribution to a power system is uncertain due to the intermittent nature of wind and insolation. Here, we investigate a power dispatch system that aims to supply the power demand of the EU based on low-carbon generation units enabled with expansion of biomass, solar, and wind energy. A spatially explicit techno-economic optimization tool simulates the EU power sector to explore policies for renewable energy deployment. Results show utility-scale deployment of intermittent electricity is feasible when incentivized with carbon tax. Expansion of transmissions capacity helps even-out intermittency of solar and wind technologies. Spatial assessment of bio-electricity potential (based on forest and crops residues) has small contribution to the optimal generation mix, limiting its effect as baseload

The role of oil palm biomass to meet liquid biofuels target in Indonesia

Indonesia aims at reducing the dependence on oil import by liquid biofuels consumption (i.e., biodiesel and bio-ethanol) in industry, transport and power sectors. The palm oil industry has played significant role in the development of biodiesel in the country producing crude palm oil (CPO) and palm fatty acid distillate (PFAD) based biodiesel. Opportunity exists for the industry to contribute to the development of bio-ethanol program by utilising the lignocellulosic biomass such as the empty fruit bunches (EFB). This study evaluates the potential of liquid biofuels production from oil palm biomass and the domestic demand for biofuels as per biofuel blending target set by the Indonesian government. The existing infrastructures as well as the investment opportunity of each type of biofuel are analyzed. While technology for biodiesel production is proven at large scale, the bio-ethanol production from EFB is not commercialized yet. The study shows that meeting the biodiesel blending target is at risk if Indonesia continues to solely reliance on the production of CPO and PFAD based biodiesel. Palm oil industry can produce nearly 7 billion litres biodiesel from CPO and PFAD in 2025 but the biodiesel domestic demand is 30% higher. The bio-ethanol program faces higher risk. EFB based ethanol through gasification and synthesis of alcohol can contribute to around 13% of the target in 2025, however the infrastructure is not ready yet. Feedstock diversification to produce liquid biofuels should be prioritized. We recommend a review of the current plan to a more achievable targets or prolong the timeline in order to secure domestic biofuels demand while continuing export. The study provides database for future modelling exercise on multi-period optimization study of palm biofuels supply chain in Indonesia in a geographically explicit way. © ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems

Meeting the bioenergy targets from palm oil based biorefineries: An optimal configuration in Indonesia

Biorefineries provide opportunities to improve the economic, environmental, and social performance of bio-based production systems. Prudent planning of plant configuration and localization is however of great merit to obtain maximum benefits from biorefineries. This study investigates optimal deployment of palm oil-based biorefineries on the two major islands of Indonesia, Sumatra and Kalimantan. In addition, the results of the optimal bioenergy (bioelectricity, biodiesel, ethanol) production are used to calculate the potential contribution of the palm oil industry according to the national bioenergy targets from 2020 to 2030. This work also offers a new perspective of analyzing the role of bioenergy in the palm oil industry in relation to meeting the bioenergy targets through the development of spatially explicit optimization model, BeWhere Indonesia. Results show that the palm oil-based biorefineries in Sumatra and Kalimantan can produce 1–1.25 GW of electricity, 4.6–12.5 bL of biodiesel, and 2.8–4.8 bL of ethanol in 2030. Significant efforts in terms of mobilization of resources and economic instruments are required to harness the full potential offered by the palm oil-based biorefineries. This study provides an important insight on how palm oil biorefineries can be developed for their enhanced roles in meeting global sustainability efforts