Renewable energy has big co-benefits in reducing toxic mercury emissions

Maximising renewables cuts mercury pollution in Europe by 33%

Maximising renewable power generation could lead to substantial co-benefits from reduced mercury pollution, according to a new study.

The main source of mercury emissions in Europe is coal-fired power stations, which contribute about 60% of the total. Mercury is deposited onto land and then washed into rivers and lakes, entering the human food chain after accumulating in fish and seafood. It is highly toxic, causing damage to the brain and nervous system, especially in unborn children. Growing evidence of the harmful effects of mercury led to the adoption of the Minamata Convention on Mercury in January 2013 – a global treaty to control mercury emissions from gold mining, power stations and industry, and ban the use of mercury in many products.

The study, led by IIASA, looked at two future scenarios for Europe – a baseline, with no change from current policies on renewable energy or greenhouse gas emissions, and a Maximum Renewables scenario. Both scenarios assume that all currently planned air quality legislation is enacted. Under the baseline scenario, energy demand grows by 7% from 2005 to 2050, and the share of renewable energy grows from 6% to 16%. In the Maximum Renewables scenario, energy demand falls (due to efficiency measures) and the share of renewable energy grows to 58% in EU countries and 46% in non-EU European countries. Electricity generation is almost carbon-free, helped by imported solar power from North Africa which meets almost a quarter of electricity demand.

In the Maximum Renewables scenario, mercury emissions in 2050 fall by a third, from 145 tonnes in the baseline to around 100 tonnes. The cumulative saving from 2005 to 2050 is 1200 tonnes, with 63% of these savings being due to the increased share of renewable energy (displacing coal), and the rest being from increased efficiency and other changes in industrial activity. Mercury emissions from combustion of biomass and waste are expected to increase slightly, but this is far outweighed by the emission cuts from burning less coal.

As would be expected, the co-benefits are greater for countries that are highly dependent on coal-fired power generation, including Poland, Germany and Turkey. But much of the mercury deposited in Europe comes from outside the continent, so the paper concludes with a reminder that action is needed at a global level, not just in Europe.

Benefits of European Climate Policies for Mercury Air Pollution. Peter Rafaj, Janusz Cofala, Jeroen Kuenen, Artur Wyrwa and Janusz Zyśk. Atmosphere 2014, 5, 45-59; doi:10.3390/atmos5010045