The Impacts of Wind Speed Trends and 30-Year Variability in Relation to Hydroelectric Reservoir Inflows on Wind Power in the Pacific Northwest

Abstract

In hydroelectric dominated systems, the value and benefits of energy are higher during extended dry periods and lower during extended or extreme wet periods. By accounting for regional and temporal differences in the relationship between wind speed and reservoir inflow behavior during wind farm site selection, the benefits of energy diversification can be maximized. The goal of this work was to help maximize the value of wind power by quantifying the long-term (30-year) relationships between wind speed and streamflow behavior, using British Columbia (BC) and the Pacific Northwest (PNW) as a case study. Clean energy and self-sufficiency policies in British BC make the benefits of increased generation during low streamflow periods particularly large. Wind density (WD) estimates from a height of 10m (North American Regional Reanalysis, NARR) were correlated with cumulative usable inflows (CUI) for BC (collected from BC Hydro) for 1979–2010. The strongest WD-CUI correlations were found along the US coast (r ~0.55), whereas generally weaker correlations were found in northern regions, with negative correlations (r ~ -0.25) along BC’s North Coast. Furthermore, during the lowest inflow years, WD anomalies increased by up to 40% above average values for the North Coast. Seasonally, high flows during the spring freshet were coincident with widespread negative WD anomalies, with a similar but opposite pattern for low inflow winter months. These poorly or negatively correlated sites could have a moderating influence on climate related variability in provincial electricity supply, by producing greater than average generation in low inflow years and reduced generation in wet years. Wind speed and WD trends were also analyzed for all NARR grid locations, which showed statistically significant positive trends for most of the PNW and the largest increases along the Pacific Coast.

Correlation analysis on wind and hydro resources with electricity demand and prices in New Zealand

“…A similar study by Cross [30] is based on wind speed data from meteorological towers at 10 m height and cumulative usable inflow data from hydro power stations. Cross estimated correlations during low and high inflow periods to determine whether wind speeds in different regions could be used for wind power development that had beneficial timing during periods in which the hydro power systems were under most stress.…”

“…Like in [29], but unlike in [28,30], the data represent actual or potential wind sites at possible hub heights, instead of weather stations at 10 m height. This is highly relevant for wind power assessment.…”

Wind trends analysis in southern South America from weather station and reanalysis data

“…Although this variable was less studied than air temperature or precipitation, the understanding of the SWS evolution is of great relevance for both productive activities and ecological preservation. Changes in WS regimes are important for coastal erosion (Dragani et al ., 2013; Knorr, 2013), air pollution potential (Gassmann and Mazzeo, 2000), forest and community infrastructure protection (Jungo et al ., 2002), surface energy balance (Rayner, 2007), building construction (Cechet and Sanabria, 2010; Cechet and Sanabria, 2012; Tapajós et al ., 2016), maritime activities (Caires and Sterl, 2005), and wind energy production (Barros, 1983; McVicar et al ., 2008; Cross et al ., 2015). Another important activity for which changes in SWS has a great impact is agriculture production, since it is a driver of evapotranspiration in agricultural systems (de la Casa and Ovando, 2016; Liuzzo et al ., 2016).…”