Abstract:Recent modelling studies suggest a decline of long-distance trade in energy carriers in future global renewable energy systems, compared to today's fossil based systems. In contrast, we discuss four important drivers of trade in such systems.
“…The role of electrolysis-based hydrogen in energy and electricity systems has been widely investigated in previous work, and several recent reviews show the important role of hydrogen in a future decarbonized energy world [3,4,20]. In particular, electrolyzers have been shown to increase the share of renewables in power systems such as in Europe [21], a sub-region in Norway [22], California [23], and Japan [24].…”
Hydrogen produced from renewable electricity can play an important role in deep decarbonization of industry, such as primary steel-making. However, adding large electrolyzer capacities to a low-carbon electricity system also increases the need for additional renewable electricity generation which will mostly come from variable renewable energies (VRE). This will require hydrogen production to be variable, unless sufficient flexibility is provided by other sources. Existing sources of flexibility in hydro-thermal systems are (a) hydropower and (b) thermal generation. However, increasing the flexibility of hydropower generation may have negative consequences for river ecosystems and the use of fossil and non-fossil fuels in generation may increase if thermal power is increasingly used to balance short-falls in wind power during electrolyzer operation. We assess here for our Swedish case study the utilization of electrolyzers with a dispatch model, assuming that additional VRE generation matches the additional electricity demand of hydrogen production on average. The flexibility of hydropower and thermal generation is restricted in four scenarios, and we run our model for 29 different weather years to test the impact of variable weather regimes. We show that (a) in all scenarios, electrolyzer utilization is above 60% on average, (b) the inter-annual variability of hydrogen production is very high if thermal power is not dispatched for electrolysis, (c) this problem is aggravated if hydropower flexibility is also restricted, and therefore (d) either long-term storage of hydrogen, backup hydrogen sources, or additional flexibility measures may be necessary to guarantee continuous hydrogen flows, and (e) adding wind power and electrolysis decreases the need for other backup flexibility measures in the system during climatic extreme events.
“…The role of electrolysis-based hydrogen in energy and electricity systems has been widely investigated in previous work, and several recent reviews show the important role of hydrogen in a future decarbonized energy world [3,4,20]. In particular, electrolyzers have been shown to increase the share of renewables in power systems such as in Europe [21], a sub-region in Norway [22], California [23], and Japan [24].…”
Hydrogen produced from renewable electricity can play an important role in deep decarbonization of industry, such as primary steel-making. However, adding large electrolyzer capacities to a low-carbon electricity system also increases the need for additional renewable electricity generation which will mostly come from variable renewable energies (VRE). This will require hydrogen production to be variable, unless sufficient flexibility is provided by other sources. Existing sources of flexibility in hydro-thermal systems are (a) hydropower and (b) thermal generation. However, increasing the flexibility of hydropower generation may have negative consequences for river ecosystems and the use of fossil and non-fossil fuels in generation may increase if thermal power is increasingly used to balance short-falls in wind power during electrolyzer operation. We assess here for our Swedish case study the utilization of electrolyzers with a dispatch model, assuming that additional VRE generation matches the additional electricity demand of hydrogen production on average. The flexibility of hydropower and thermal generation is restricted in four scenarios, and we run our model for 29 different weather years to test the impact of variable weather regimes. We show that (a) in all scenarios, electrolyzer utilization is above 60% on average, (b) the inter-annual variability of hydrogen production is very high if thermal power is not dispatched for electrolysis, (c) this problem is aggravated if hydropower flexibility is also restricted, and therefore (d) either long-term storage of hydrogen, backup hydrogen sources, or additional flexibility measures may be necessary to guarantee continuous hydrogen flows, and (e) adding wind power and electrolysis decreases the need for other backup flexibility measures in the system during climatic extreme events.
“…In more recent years the rapid expansion of variable renewable power sources has spurred a renewed vision about intercontinental connections, see Battaglini et al [2], Chatzivasileiadis et al [3] and the EU Commission [4]. There are several potential reasons for a pan-continental grid, some of which are of a more political nature, such as international cooperation [5], or that it is claimed to be part of China's geo-political strategy [58]. Others argue that a global renewable grid would strengthen the global economy [8].…”
Section: Introductionmentioning
confidence: 99%
“…For sensitivity scenarios, see below. 8%/5% (onshore wind/solar PV plants) of remaining5 land is available for wind/solar exploitation -'High': 16%/8% (onshore wind/solar PV plants) of remaining land is available for wind/solar exploitation In order to investigate the effect of the supergrid option under several technological futures, we run the base scenarios (rows 1-4, shaded in…”
Long distance transmission within continents has been shown to be one of the most important variation management strategies in renewable energy systems, where allowing for transmission expansion will reduce system cost by around 20%. In this paper, we test whether the system cost further decreases when transmission is extended to intercontinental connections. We analyze a Eurasian interconnection between China, Mid-Asia and Europe, using a capacity expansion model with hourly time resolution. The model is constrained by an increasingly tighter global cap on CO2 emissions in order to investigate the effect of different levels of reliance on variable sources. Our results show that a supergrid option decreases total system cost by a maximum of 5%, compared to continental grid integration. This maximum effect is achieved when (i) the generation is constrained to be made up almost entirely by renewables, (ii) the land available for VRE farms is relatively limited and the demand is relatively high and (iii) the cost for solar PV and storage is high. The importance of these two factors is explained by that a super grid allows for harnessing of remote wind-, solar-and hydro resources as well as management of variations, both of which are consequential only in cases where dispatchable resources are limited or very costly. As for the importance of the cost for storage, it represents a competing variation management option, and when it has low cost, it substitutes part of the role of the supergrid, which is to manage variations through long-distance trade. The cost decrease from a Eurasian supergrid was found to be between 0% and 5%, compared to the cost in the case of continental-scale grids. We conclude that the benefits of a supergrid from a techno-economic perspective are in most cases negligible, or modest at best.
“…shows high potential for land-based carbon mitigation 4,5 . Brazil, the largest ethanol producer from sugarcane globally, has put in place a series of policies, such as the National Biofuels Policy (RenovaBio) or the current proposal for a credit subsidized COVID- 19 Emergency Program to Support the Brazilian Sugar-Energy Sector (Peasse). These policies aim to safeguard the contribution of sugarcane ethanol toward the renewable energy targets of Nationally Determined Contributions (NDCs) and generate new incentives for biofuel production and technological innovation 2,6 .…”
Biofuels are currently the only available bulk renewable fuel. They have, however, limited expansion potential due to high land requirements and associated risks for biodiversity, food security, and land conflicts. We, therefore, propose to increase output from ethanol refineries in a land-neutral methanol pathway: surplus CO2-streams from fermentation are combined with hydrogen from renewably powered electrolysis to synthesize methanol. We illustrate this pathway with the Brazilian sugarcane ethanol industry using a spatio-temporal model. The fuel output of existing ethanol generation facilities can be increased by 42%-49% or ~100TWh without using additional land. This amount is sufficient to cover projected growth in Brazilian biofuel demand in 2030. We identify a trade-off between renewable energy generation technologies: wind power requires the least amount of land whereas a mix of wind and solar costs the least. In the cheapest scenario, green methanol is competitive to fossil methanol at a carbon price of 80EUR/tCO2
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.