Spatially explicit life cycle assessments reveal hotspots of environmental impacts from renewable electricity generation

Abstract

Renewable energy generation has great potential to reduce greenhouse gas emissions, however, it may exacerbate other environmental impacts, such as water scarcity, elsewhere in the supply chain. Here, we reveal a wide range of global environmental impacts of concentrated solar power, run-of-river hydropower, and biomass burning compared to classical coal-fired power: Spatially explicit life cycle impact assessment is used to evaluate their supply chains with respect to demand for energy, land, material, and water, greenhouse gas emissions, and impacts on human health and ecosystem quality with a focus on mining. Hotspot analyses in terms of location and type of impact show that there is no clear preference for any of the technologies, mainly because water consumption is often critical on-site. The examined concentrated solar power plant is the least suitable for a sustainable energy transition: Its spatial hotspots are spreading the furthest globally and may exceed those of coal combustion in number and severity. The presented methodology is the basis to mitigate such environmental hotspots.

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“…For the hotspot analysis according to Schomberg et al 2022 22 , a cut-off criterion was set so that only activities that contribute at least 1% to the overall result of a footprint are included in the analysis. For almost all footprints, the selected activities cover in total at least 61% and on average 80% of the total footprint result.…”

“…By using a regionalised data set for eight mining products and breaking down the SHIFTPHONE supply chain up to supplier level 3, this spatial coverage is already above the average of a standard LCA. Nevertheless, the spatial data is insu cient, why we supplement the spatial analysis of activities with an analysis of the type of activities 22 . Particularly affected by the lack of spatial data are the activity categories non-metal mining, diesel use, display production and transport.…”

“…4, according to SHIFT GmbH), but not the origin of the raw materials. By updating a dataset of Schomberg et al 2022 22 to ecoinvent 3.8, we are able to regionalise the supply chains of the mineral commodities aluminium, copper, coal, cement, iron and steel, lithium and phosphorus at mine site level. To make the number of mine sites globally manageable, single mine sites are clustered with respect to geology and regional water stress, resulting in ve mine sites per country that are added to ecoinvent 3.8 and linked to the existing datasets.…”

“…80% of world production are covered, respectively. The procedure is described in detail by Schomberg et al 2022 22 . Supply chains modeled using datasets include the most likely origin of a given mineral commodity in the global supply system unless more speci c information becomes available.…”

“…The land footprint is described by the total area of land occupied through the supply chain of the SHIFTPHONE in m 2 a. Here, no assessment is performed in the absence of a suitable method recommended by the Life Cycle Initiative 22 .…”