Energy security impacts of a severe drought on the future Finnish energy system.

Finland updated its Energy and Climate Strategy in late 2016 with the aim of increasing the share of renewable energy sources, increasing energy self-sufficiency and reducing greenhouse gas emissions. Concurrently, the issue of generation adequacy has grown more topical, especially since the record-high demand peak in Finland in January 2016. This paper analyses the Finnish energy system in years 2020 and 2030 by using the EnergyPLAN simulation tool to model whether different energy policy scenarios result in a plausible generation inadequacy. Moreover, as the Nordic energy system is so heavily dependent on hydropower production, we model and analyse the impacts of a severe drought on the Finnish energy system. We simulate hydropower availability according to the weather of the worst drought of the last century (in 1939-1942) with Finnish Environment Institute's Watershed Simulation and Forecasting System and we analyse the indirect impacts via reduced availability of electricity imports based on recent realised dry periods. Moreover, we analyse the environmental impacts of hydropower production during the drought and peak demand period and the impacts of climate change on generation adequacy in Finland. The results show that the scenarios of the new Energy and Climate Strategy result in an improved generation adequacy comparing to the current situation. However, a severe drought similar to that experienced in 1940s could cause a serious energy security threat.

Recovery from acidification of Finnish lakes: regional patterns and relations to emission reduction policy.

The regional-scale response of Finnish headwater lakes to changes in acidifying deposition loads was studied using data from a national deposition monitoring network (19 stations), acidification monitoring lakes (163 lakes) and results of a statistically based national lake survey (873 lakes). Data from 1990 to 1999 were used for statistical trend analysis. A deposition model was used to assess changes in S and N deposition for the year 2010, assuming emission reductions according to two international agreements. The deposition of sulfate and H(+) showed statistically significant (Kendall-tau, P<0.05) decreasing trends at nearly all deposition stations. For N compounds, nearly all slopes were negative, but rarely statistically significant. Sulfate concentrations have declined in all types of small lakes throughout Finland in the 1990s (significant decline in 64-85% of the lakes in three different lake regions), indicating a clear response to S emission reductions and declined sulfate deposition. Base cation concentrations decreased in both deposition and lake water, especially in southern Finland, but to a lesser extent than sulfate concentrations. The median slope of the trend for Gran alkalinity in lakes ranged between 0.98 and 2.1 microeq l(-1) a(-1). Some 1400 (27%) of Finnish headwater lakes of size 4-100 ha were estimated to show statistically significant increases in Gran alkalinity (recovery). No large changes were observed in the lake water TOC concentrations. The reduction in S deposition is the main driving factor for the lake acidification recovery process in Finland. Deposition model calculations showed that further large reductions in S deposition beyond the 1999 level are not likely to occur by the year 2010, particularly for southeastern Finland. The mean estimated S deposition change by 2010 for the three lake regions in Finland was only between -0.9 and -6.6% for the two policy scenarios (UN/ECE Gothenburg protocol, EU NEC-directive), respectively. A slower acidification recovery of the lake ecosystems is, therefore, anticipated in the future.