Environmental assessment of future electricity mix - Linking an hourly economic model with LCA

open access

Abstract

Life Cycle Assessment (LCA) is an increasingly widespread method for the environmental accounting of products and services. Since almost all production processes use grid electricity, the environmental impact of power generation plays a key role in LCA. There is high potential both on a local and a regional scale for improving electricity generation to achieve decarbonisation goals in the near future. The environmental impact of electricity supply from the grid varies both in the short (intra-annual) and in the long term (over several years). This variation is usually highly simplified in current LCA practice, to yearly average or a specific year’s impact. In this paper, a method is presented for linking a detailed economic model and life cycle assessment to evaluate both intra-annual and long-term variation in the environmental impact of grid electricity. The model is applied for the case study of Hungary for three future scenarios. The “Decarbon” and “Delayed” scenarios include an emission reduction target of 94% for 2050 compared to 1990 for the EU with a less intensive support of renewables until 2035 in the “Delayed” scenario. The “No target” scenario sets no long-term goal for carbon-dioxide emission reduction. Our results show that in the next 30 years, 87% reduction is expected in the Global Warming Potential compared to 2018 in the Hungarian electricity mix if the decarbonisation of the grid is fulfilled. However, without support for renewable energy, only 30% reduction is foreseen. While the effect of intraannual variation is relatively low in the current fossil-based electricity market and in the “No target” scenario, its significance is expected to increase in the future with a change in the coefficient of variation to 77% from 10% by 2050. The results indicate that dynamic modelling of electricity taking into account variation due to cross-border trading and renewable penetration will influence the LCA results for products depending on their lifetime and pattern of electricity use.