AEMO 100% renewable energy study: energy storage

[摘要] In July 2012, CSIRO was contracted by Australian Energy Market Operator (AEMO) to provide information on renewable energy supply, electricity generation opportunities and storage for the National Electricity Market (NEM) region of Australia. CSIRO was asked by AEMO to investigate a subset of technologies while other organisations have investigated the remaining renewable options.The information supplied to AEMO will be used by as part of a "100% renewable supply" project that the Federal Government has requested AEMO to undertake.AEMO divided the NEM region into 42 geographical 'polygons' of various sizes, and requested information on each renewable resource, likely energy supply and storage opportunity in each of the polygons.This report examines the opportunities for several storage technologies: solar thermal molten salt storage, biomass, biogas, compressed air energy storage (CAES) and batteries. In most cases the storage technology is available to be deployed in all polygons or is located with the relevant resource to which the technology is specific. The main exception is underground CAES which relies on a salt cavern as a storage vessel, limiting this particular form of CAES to one polygon. Note that pumped hydro storage was not within CSIRO's scope of work.Overall the report finds significant potential for storage and presents data and methodologies for determining their costs which are dependent on the scale of storage required - both in terms of hours and power level.Solar thermal molten salt storage has significant opportunities in all polygons, most notably those polygons in the western regions, where the resource is greatest. Because it is inherently difficult to separate the cost of storage from the cost of the rest of a solar thermal plant, costs have been calculated for each component of a solar thermal plant and the numbers of each of those components have been provided for two example plants, an 18 MW central receiver with 6 hours of storage and a solar multiple of 2 and a 100 MW central receiver with 6 hours of storage and a solar multiple of 1.8, per polygon. The first plant design is based the Australian Energy Technology Assessment (AETA) study (BREE 2012) and the second is based on the plant design used in solar thermal resource assessment undertaken by ROAM (2012b). Assuming that the plant fills and empties its storage on a daily cycle, it was possible to calculate the cost of energy storage for each plant type per polygon. The cost was found to be lower in regions with a greater resource. This is due to two reasons: the first is that because overall generation is greater, the cost of the storage part is offset by the cost of the non-storage part of the plant, which produces more energy and thus the cost as a function of energy is lower. The second reason is the cost of components is higher in the southern states of Victoria and Tasmania.Storage of biomass, where the output is electricity, is a particularly interesting case study as it needed to be defined separately from baseload biomass generation and from biomass used to produce biogas. This resulted in different harvesting, transport and storage practices being developed and costed for biomass storage, mainly so the available biomass per polygon could be stored onsite at the generation plant so it could be used on an as-needed basis. Two case studies were considered: the maximum where all of the biomass per polygon is used over four days. The second, representative case is where the biomass is used over 30 days. This is the rate at which the stock can be replenished. It was found that, because the biomass generation plant has a high capital cost, and as the plant is used at a low capacity factor, the cost of energy storage is dominated by the plant cost and is high compared to the other technologies.Biogas storage relies on the available biomass per polygon, where the biomass is converted using one of two different pat...

[发布机构] CSIRO

[学科分类] 地球科学(综合)