There are two reasons for this enhanced value. First, wind plant output -- viewed as a negative load -- enables more water to be kept in the reservoirs. The efficiency of the water turbines, which increases with the head of water, goes up as a result. Second, there is a substantial wind induced heating load, so that the use of wind energy can reduce the amplitude of some of the winter peaks. According to study researcher Jacques Tellier, the synergies of wind and water power have received very little attention. Tellier's study considers a typical 950 MW hydroelectric plant with a 60% utilisation factor and installed wind capacity of 95 MW (nameplate).
A minimum 75% water reserve on November 1 of each year is required on the Hydro Quebec system. Throughout the three years of the study period, wind energy was seen as a negative load on the grid, allowing more water to be kept in the reservoir. The net effect increases the utility minimum reserve from 75 to 82%, on average. Under suitable assumptions on increase in demand and wind power penetration, a 15% increase in head increased available hydroelectric power by 27% of the installed wind power in the third year. This power increment adds directly to the recognised power capacity of a wind plant. According to a statistical study by Hydro Quebec, (Windpower Monthly, November 1994), this increased capacity would be about 55%.
Several scenarios were analysed to determine a level and rate of wind facility development. After a series of tests, it was determined that a penetration factor of 2% (wind/hydro capacity ratio) for the first year, 4% for the second and 6% the third year offered a balanced and realistic solution. The study was paid for by Hydro Quebec in 1995 as part of the public participation in the 1996-1999 Hydro Quebec Development Plan.