Rain shortage may pose threat to the power grid

The water reservoirs of Public Power Corporation (PPC) hydroelectric plants run the risk of drying out, as rainfall this winter has been minimal. On June 1 of last year the water reserves at hydroelectric plants amounted to 2,800 GWh. Today the equivalent reserves are estimated at just 1,200 GWh, which is very worrying as more than half of the inflow period has already lapsed. «The period of water inflow starts from October and lasts until May. Until January, we had an inflow of close to nothing,» said Giorgos Leris, director of steam and hydroelectric plant operation at PPC. The reduction of water reserves restricts the operation of hydroelectric plants and poses a serious threat to the stability of the power grid in Greece. Top officials from PPC and the Power Transmission System Operator (DESMHE) have warned the Development Ministry about the increased chances of a blackout in the peak hours of the summer. The problem also threatens farms of some 5,000 square kilometers watered by the same reservoirs, as well as the water supply of up to 2.5 million people in central and western areas of the country, such as Arta, Preveza, Lefkada, Agrinion and Karditsa. Development Minister Dimitris Sioufas has also sent a warning signal to his colleagues at the Public Works Ministry, Giorgos Souflias, and at the Ministry of Agricultural Development, Evangelos Bassiakos, who are also involved. In a letter last month, he invited the other two ministers to discuss the emerging problem. Sioufas believes that priority must be placed on securing the reliability of the power system, which is closely associated with the operation and performance of PPC’s hydroelectric plants. This year is even more risky as the possible energy imports from Bulgaria will be less due to the closure of the two nuclear reactors at Kozloduy. Consequently, the operation of the hydroelectric plants in Greece is more important than ever. Insufficient energy DESMHE officials note that for the first time the country’s electrical system is facing a great threat of a blackout in the peak hours of this summer due to the lack of energy sufficiency. Greece has not been in such a dire situation since 1996, they argue, adding that the blackout of 2004 was due to instability problems in the system and not due to insufficiency. The total installed power reaches 11,097 megawatts, from which about 3,000 MW are produced at PPC’s hydroelectric units. In 2006, with demand peaking at 9,665 MW, hydroelectric plants contributed 850 gigawatt-hours in the summer period (June-August), while the stability of the system relied on imports of 1,000-1,300 MW. Special measures were also taken for major industries to cut down on consumption along with the banning of irrigating fields from 11 a.m. to 3 p.m. by ministerial decision. Officials at DESMHE also estimate that the peak this summer will reach 10,200-10,300 MW, raising the issue of sufficiency. Furthermore, imports from neighboring countries will not only be limited this year but will also be more expensive. Prices have already risen far higher than last year, and soar at peak hours. Crucially, this also raises questions about PPC’s thermal plants: «Last year the thermal plants were unreliable,» the DESMHE officials suggest, referring to the failures noted at the plants of Megalopolis and Ptolemaida over the key summer period. From PPC’s side, however, the head of the general directorate for production, Avraam Mizan, stresses that «there is a maintenance program under way for the thermoelectric plants, so that in June they will all be available for the grid.» All officials, including Sioufas himself, make no secret of their concern about the response of the grid this summer. The long period without rain this winter has exacerbated the situation. The new question on the table now will concern the management of water resources.