In 2014, NCAR embarked on a project with NREL and Harness Energy, funded by the U.S. Agency for International Development (USAID) and in partnership with the Government of Bangladesh (GOB), to assess and quantify the wind resource in Bangladesh. GOB has pledged that 10% of its national electricity generation will be from renewable sources by 2021, but no utility-scale wind farms yet exist in Bangladesh.
Figure 1: Transporting the sodar instrument via ox cart through a field to the platform near Rajshahi, Bangladesh. Photo credit: Harness Energy, and Fig. 20 in Jacobson et al. (2018).
NREL deployed one sodar (Figure 1) at two sites as well as seven meteorological observation towers (six to 80-m height, one to 60-m height) at locations throughout Bangladesh. Each site had at least 12 months of observations, and some sites had up to 43 months. The original project plan called for sodars and met towers to be deployed for two years, but poor weather, civil unrest, and other local challenges led to delays in removal of the observation equipment, which incidentally led to a longer, more robust wind resource assessment.
NCAR’s role was to use WRF® to assess the resource and to assimilate data from the new observational network to calibrate the models. The first step was to compare the wind resource from three separate historical reanalyses, which blend information from historical observations with models. The next step involved working closely with NREL to downscale and assimilate the observations using Four-Dimensional Data Assimilation (FDDA). NCAR assimilated the observations from the deployed sodars and met towers to compute, at 3.3-km grid spacing, 3.5 years of modeled wind speeds throughout the country to determine the best locations to deploy wind energy.
Figure 2. A detailed wind resource map for Bangladesh, with transmission lines and met tower locations overlaid. From Fig. ES-1 of Jacobson et al. (2018).
In 2018 the NCAR team completed both the WRF-FDDA runs and the validation of the WRF dataset. NCAR also demonstrated how self-organizing maps could be used to extend the 3.5-year, high-resolution WRF dataset to 15 years via dynamic downscaling of a coarse-resolution reanalysis. The NREL team used NCAR’s WRF dataset as the basis for their wind resource assessment, publicly viewable on NREL’s Renewable Energy Data Explorer (https://maps.nrel.gov/gst-bangladesh/). The model-driven wind resource at 120 m above ground level is shown in Figure 2.
Representatives from NREL, NCAR, and Harness Energy presented the final results at a workshop in Dhaka, Bangladesh, in May 2018 to the Minister of Power, Energy, and Mineral Resources and several other government officials. The workshop and its findings also generated local media attention (e.g., http://www.newagebd.net/print/article/43570). The project’s results are summarized in an NREL Technical Report (Jacobson et al. 2018), and a journal article is also planned.
