天津近海风能资源的高分辨率数值模拟与评估

风能是可再生能源中发展最快的清洁能源,具有广阔的应用前景。近海地区由于风速较大,以及可利用面积大等优点,近海风电是未来风电发展中一种新的趋势,但海上气象要素直接观测困难,需要通过高分辨率数值模拟对其可利用性及开发潜力进行评估。本文利用MM5/Calmet模式模拟了天津沿海地区的较高分辨率（水平分辨率1km×1km、垂直分辨率10m）的风能资源分布状况,并结合实测数据对其模拟效果进行了评估。结果表明：该模式对天津沿海地区的年平均风速及风速的逐日变化趋势均具有良好的模拟能力,3个测风塔年平均风速的相对误差分别为7.11%、12.99%、6.14%,可为天津海上风能资源评估提供科学依据;利用风速大小年景分析得到天津沿m2,海且地有区效多小年时平数均长风,风能资资源源状分况布较状好况。,发现天津近海海域年平均风速在（6.6~7.0）m/s,平均风功率密度超过340w/m~2,且有效小时数长,风资源状况较好。

High-Resolution Numerical Simulation and Assessment of the Offshore Wind Energy Resource in Tianjin

Wind energy is a rapidly growing alternative energy source and has been widely developed around the world over the last 10 years. Offshore wind power generation is now becoming a new trend in the development of future wind power generation because wind tends to blow faster and be more uniform over offshore areas than on the land. Accurate assessment of wind energy resource is fundamental and valuable for wind energy developers and potential wind energy users because it allows them to choose a general area of the estimated high wind resource for more detailed examination. However, it is difficult to make direct observations from meteorological variables over offshore areas, which calls for numerical simulation with high resolution so as to derive the availability and potential of wind energy. The distribution of wind energy resources with 1 km horizontal resolution and 10 m vertical resolution in Tianjin coastal areas was simulated using the numerical model MM5 and Calmet to derive wind energy potential over the offshore areas. In addition, the simulation efficiency was determined by comparing observation data with three wind-measurement towers over the same period. Results show that the annual mean wind speed and trend of daily mean wind speed were simulated well, and the relative deviations between observations and simulated values at three wind measurement towers were 7.11%, 12.99%, and 6.14%, respectively. This suggests that the models are effective in assessing the offshore wind energy resource in Tianjin. The long time wind energy resource was obtained by comparing simulated year's and recent 20 years'mean wind speed. It was found that annual mean wind speed is (6.6~7.0)m/s, and annual mean wind power density is above 340w/m², which indicate that the offshore wind energy resource in Tianjin is exploitable and could be used for grid-connected power generation. The assessment shows that the MM5/Calmet model is capable of providing reasonable wind status, and can be widely used to explore wind energy resource potential, especially over offshore areas. This model could, however, not provide accurate strong wind days and time of presence of strong wind in this study area, which calls for further study to improve the simulation capacity of strong wind for the MM5/Calmet model.