The outlook for Landsvirkjun’s water budget has worsened in the last few weeks as a result of historically low inflow levels to the Þórisvatn and Blanda Storage Reservoirs and unfavourable weather conditions, with prevailing north-easterly winds, low temperatures in the highlands and dry conditions in key areas. Last year was the second worst water year on record. Landsvirkjun was unable to fill all its storage reservoirs in the autumn of 2013, as a result of low precipitation and low temperatures in the highland areas throughout the spring and summer period. Unfortunately, the outlook for this water year could prove to be just as poor.
As reported earlier, Landsvirkjun has informed its energy intensive industry and wholesale clients of reductions to interruptible power, in accordance with current contract agreements. Projected energy curtailment was anticipated to be 260GWh or approx. 2% of the energy generated annually by Landsvirkjun.
Landsvirkjun is presently re-evaluating the need for curtailment in electricity generation as a result of these exceptional circumstances.
Landsvirkjun has gathered a large knowledge base with regard to the natural water sources utilised by the company throughout the last 50 years of operations. Water flow rates fluctuate between years and the company continually assesses any changes to the rivers’ behaviour as a result of changing weather conditions.
Projections developed by the company are based on historical data on water flow rates, throughout the last 55 years, corrected to reflect changes in temperature as a result of climate change. Of the last ten years unusually high proportion has had flow rates above average, with only the last year having flow rates well below average. Last year, inflow rates were close to the lowest prediction levels, as a result the Blanda and Þórisvatn Storage Reservoirs did not reach their full storage capacity.
Inflow rates so far this winter have been unusual. The water flow in the Tungnaá river has been lower than levels recorded in the last 55 years and the water flow in Blanda river has reached an all-time low.
Weather conditions this winter have been unfavourable. Weather conditions throughout February were unusual, as reported by the Icelandic Meteorological Office (www.vedur.is/um-vi/frettir/nr/2843. Unusually strong east and north easterly winds prevailed throughout the month. Precipitation was well below average in western Iceland and particularly dry in the inland areas of the northwest. February was the driest it has been in the past few decades (Reykjavík‘s driest February since 1966).
Iceland is not alone in experiencing these unusual weather conditions as reports of remarkable weather have been evident worldwide. The USA has experienced a rare dry spell across the west coast and cold weather has affected the rest of the country. Precipitation rates have been extremely high in the UK with levels reaching a 250 year high in some areas.
Landsvirkjun has always emphasised the importance of the long- term secure supply of energy and any measures executed by the company will be based on the lowest inflow predictions, despite indications that the situation could in fact be improving. There is hope that weather conditions could become more favourable; with low pressure systems across the country with warmer temperatures and precipitation. Such conditions could help to alleviate the situation.
Electricity in Iceland is generated without any interconnections to other national grids. Approximately 75% of all electricity generation is produced via hydropower which is highly reliant upon the water catchment areas utilised by the power stations. Water flows fluctuate between seasons and years. Storage reservoirs are utilised to compensate for fluctuations between seasons but the storage is generally not sufficient enough to compensate for fluctuations between the years. Low supply periods require alternative action and Landsvirkjun takes advantage of the degree of flexibility built into the company’s power supply contracts, allowing forvariations in the supply of energy to most of its clients. Intensive energy industries such as the aluminium industry allow for a 10% fluctuation and district heating plants have a dual system, enabling them to heat water with oil burners if electricity cut backs become a reality.
If these flexible supply contracts were not in place then the system would need to be designed in such a way that the energy supply would be guaranteed in all years; even during rarely experienced poor water years with extreme dry spells. Such a system would be considerably more expensive per energy unit. Clients can therefore secure lower energy prices through variable supply.
Landsvirkjun’s website shows the daily water levels at the Blanda, Þórisvatn and Hálslón Storage Reservoirs here.
News highlights can also be seen on Landsvirkjun’s website: