Environmental consequences of different electricity generation mixes in Sri Lanka by 2050

Abstract

Electricity is considered the most versatile form of energy derived from commonly used primary source of energy; fossil fuels. Sri Lanka forecast 6.5% annual growth in the demand for electricity, where the recent generation mix (in 2016) comprised of 25% hydro power, 31% oil, 35% coal and 9% renewables, with continued growth in wind and solar energy systems. The national Energy Policy targeted to reach minimum 10% of the demand for gird electricity using non-conventional renewable energy by 2015, and the policy now is to use only renewable energy sources for electricity generation by 2050 through installing large scale wind, solar and biomass power plants. In the path to achieve this growth and transformation, the challenge is to use resources and materials with minimum environmental consequences and damages in construction, operation and deconstruction phases of power plants. This paper looks in to possible environmental consequences, based on life cycle analysis, arising out of different electricity generation mixes comprising thermal, hydro, wind and solar energy. The study shows that, in meeting the electricity demand in 2050 using either solar or wind power alone, or through a mix of the two, would have adverse environmental impacts on freshwater and marine ecotoxicity, urban land occupation, metal depletion, agricultural land occupation and natural land transformation, whereas hydropower adds impact towards water depletion too. It is evident from the results that, in Sri Lanka, future electricity generation mix between wind and solar energy has to be determined mainly considering the land occupation and metal depletion impact categories. Further, the results point to the essential need for a national integrated waste management policy in decommissioning power plants; existing fossil fueled power plants and new large scale solar and wind based power plants, to avoid more adverse environmental impacts associated with decommissioning of different types of power plants.