National Renewable Energy Laboratory, Harness Energy and National Centre for Atmospheric Research in May 2018 published a research report – Assessing the wind energy potential in Bangladesh: Enabling Wind Energy Development with Innovative Data Products. The study, funded by USAID, was done for the Bangladesh power division. Mahtab Uddin Ahmed spoke to the researchers – Mark D Jacobson, wind and water senior project leader of NREL, USA, Taj Capozzola, managing director of Harness Energy, USA and Jared A Lee, project scientist of NCAR, USA.
New Age: The NREL with NCAR and Harness Energy have provided the technical assistance in the ‘Wind Resource Mapping Project’ of the power division of Bangladesh funded by USAID. As part of that project you have conducted a study on wind mapping in Bangladesh. Can you please give a very brief description of that project for the readers?
Taj Capozzola: In total, we set up wind measurement stations at nine places in Bangladesh, with seven meteorological towers and a SoDAR (Sonic Ranging and Detection) moved between two other locations. The goal was to collect at least two years of data at the tower sites and 1 year of data at each of the SoDAR sites. But we had some weather and civil unrest that delayed deployment of the MET towers and SoDAR. However, we made sure we collected at least two years of data at each of the tower sites and at least 1 year of data at the SoDAR sites as originally planned. In the end, data was collected for minimum one year to maximum 40 months across the 9 measurement locations. The data we collected was then incorporated into the modelling efforts completed by the National Centre for Atmospheric Research and used to create the layers in NREL’s Renewable Energy Data Explorer tool. REDE is a web-based tool which is accessible to all and helps users understand the wind resource in Bangladesh along with other variables important to the overall wind industry. The data we have collected can be found in NREL’s RE-Explorer website with a GIS based tool which is accessible to all and which is very easy to visualise. One can find the wind resource data of Bangladesh for different heights, and by clicking at any point of the map and downloading the data for that 3km x 3km point.
New Age: In general, what technological changes took place in the last 15 years for wind mapping?
Mark D Jacobson: What is important to know I think is that we are trying to deliver more than a map. Fifteen years ago, typical wind resource assessments done with low resolution models (best available models at the time, but uncertainties were high) form. The end result was a static PDF maps on a piece of paper, and data on a server storage on a shelf and rarely used — as time passed these maps and data were of limited use. These early models were all performed at a low height (relative to the hub heights of ever evolving turbine technology) — model outputs of 30 or 40 or 50 meters off the ground. So this is the problem we are solving. Creating not maps, but data products that can graphically display a large data set to show not only the wind resource, but many other meteorological attributes at numerous heights to match current technology. Instead of 50-metre hub heights, turbines are now 80 meters, 100 meters and people are now looking at 120 meter, because the wind is stronger at that height. Additionally, by collecting measurements (via a MET tower or SoDAR) and using this data to inform the model, you can create a much more accurate data set than 15 years ago. It is a much more sophisticated approach.
New Age: What about the other areas of Bangladesh which are not covered by your survey?
Jared A Lee: Although data was collected from 9 places of the country, the model covers all the areas of the country. We worked with a numerical weather prediction model, or NWP model, which simulates atmospheric motions over a three dimensional grid. So for our model over Bangladesh, we have grid points every three kilometres in the model, and met towers were placed in 9 locations across the country. We used 62 vertical levels in the model. Then with those grid points the model simulated the whole atmospheric state to create the wind map of Bangladesh at different heights, including the wind speed at every grid point every few seconds, with the values of wind speed and other variables saved to an output file every hour. The model is complex and it assimilates all the publicly available atmospheric data for this part of the world and its neighbouring areas and the special data collected through the 9 met towers placed by Harness Energy on behalf of NREL. The model was corrected by the 3.5 years of observations collected through the met towers. And that gives us a best estimate of what is the state of the atmosphere, not only in the 9 points where the met towers were placed, but also throughout Bangladesh.
New Age: In Bangladesh, dominant discourse suggests that wind power potentiality is very low. Many experts and policy makers subscribe to that view. Do you think your recent mapping will change that view?
Mark D Jacobson: I don’t want to criticise anybody for the best available information at the time. Finding the resources to improve the assessment, like we have done here in Bangladesh is a common challenge. And staying current on the newest turbine technology that can take advantage of the specific ‘class of wind speed,’ is also difficult. It is a common issue all around the world. It happened in my own state Indiana, other parts of the United States and in other countries.
In Indiana, they had dated wind resource assessments and the model data output was at 50 meters. Therefore, there was no investment on wind power. Then new assessment completed, where measurements taken closer to the hub height of the newer turbine technology (approximately, five or six MET towers across the state of Indiana measured wind at 90-100 meters). From that tall tower data in Indiana they produced a new wind resource map, results were surprising. Almost overnight, 1500MW of wind power installed. We hope the same thing happens here in Bangladesh. Frequently, old projections made with 50-metre turbine technology and 15 years old models, you will not demonstrate enough wind. If you measure at higher elevation, using more sophisticated models and applying the improved efficiency of newer turbine technology the result would be changed.
For the US, one of our goals is now to open up the south east region. Previously little to no wind power had been developed here due to the class III winds and older wind speed projections. Now we have improved turbine technology, with higher hub heights and larger rotor diameters to take advantage of these class III lower wind speed sites. With more accurate data combined with newer technology, what was previously not developable in now developable.
New Age: How much wind speed per second is necessary at present according to the latest technology which is enough to run economically viable wind power plants?
Mark D Jacobson: The new turbines have a cut in speed around 3 metres per second. It means at 3 metres per second energy is starting to be produced. But it is the average wind speed and its distribution such as to that wind resource is economically viable is a big question. Therefore, 5-6 metres per second wind speed is typically viewed as the minimum wind speed needed for initiating a wind project. What is equally important to know here is that you can’t only look at the wind speed. You must look at what would be the general cost or average cost of power in that region. Our project has estimated the wind resource, but the next question to be answered is how much will it cost to install a wind project in Bangladesh? The cost of installing a wind power project and cost of transmission etc are important factors to consider here.
New Age: According to your mapping, which areas of Bangladesh has the highest potentiality of wind power?
Mark D Jacobson: You can see the details from the wind resource map in our RE-Explorer website at different heights. But I can tell you that on average we have demonstrated approximately 5 to 7 metres per second wind speed above 100-metre height, especially in the entire coastal belt of Bangladesh and in some part of the mid-east of the country. Not knowing the installation cost of wind in Bangladesh, but using the installation costs of neighbouring countries, we estimate that the wind is competitive. Even in some places of the coastal areas, we have got 6 metres per second at 30-metre hub-height. And in 160 metres almost the entire lower half of the country has wind speed from 5.89 metres to almost 8 metres per second.
New Age: What your study suggests about the potentiality of total wind power that can be generated in Bangladesh? Some research indicated that it is possible to generate at least 5,000MW wind power in Bangladesh in the coastal belt? What does your survey suggest?
Mark D Jacobson: We think, 5,000MW wind power is easily possible in Bangladesh, but again, with the caveat that we do not know what the installed costs will be yet (ie installation costs were outside of the scope of our study). However, using installed costs of other countries to represent what might be possible, we believe wind speeds in the 5.75 to 7.75 metres per second, could theoretically produce a total of ~34,000MW wind power (nearly twice the current demand in Bangladesh). This is a gross estimate of potential, applying no exclusion zones/filters for what land is and is not developable. Practically, the amount of developable potential might only be one third of this 34,000MW. But still that is significant opportunity for Bangladesh – more than 10,000MW and warrants further investigation. But again, understanding all of the key drivers for determining economics will be necessary – our study just focused on the quantifying and generally locating the wind resource.
New Age: What would be the cost per unit if we start generating wind power in these areas?
Mark D Jacobson: As I mentioned installation cost analysis was outside of our scope. There haven’t been any utility scale projects built in Bangladesh to compare against yet. Unique challenges relating to transporting components will probably drive costs higher. Economies of scale will be needed to drive costs lower. Beyond these general statements, I’d rather not comment further on future wind energy costs in Bangladesh.
However, when analysing the cost of wind energy in other countries with a similar wind resource, and using an average range of installation costs of $1,400-$2,000/KW, an estimated range of $0.05/KWH (Tk 4.23/KWH) to $0.116/KWH (Tk 9.82/KWH) has been realised. Bangladesh could be within that range or significantly higher, it depends on the construction costs and if a large enough project can be built to take advantages of scale. And lastly, it depends on the wholesale market you are competing within. The unsubsidised cost of energy should be the cost that wind energy is compared to.
Jared A Lee: And part of that production cost is also determined by economies of scale. So if you are putting in one turbine alone, then the cost of per turbine will be more expensive than it you built an entire wind park. So if you are putting more wind turbine at the same location, at the same area, at the same time, you are saving on cost. The more turbines you build in a given location in a farm the lower the construction of per turbine will be.
Mark D Jacobson: As an example, at the first project where I was involved in Montana, the price of that wind power was 2.9 cents per kilowatt hour and it was a 135 MW project, a good economies of scale to drive the cost of per turbine down and subsequently the cost of energy. The other part of any power project is the transmission line. Sometimes you may move away from a stronger wind speed in the coastal zone just to locate closer to a transmission line.
New Age: It has been reported that India is now to producing wind power at 4 cent per unit. Will it be possible for Bangladesh to produce wind power at similar rates in near future?
Mark D Jacobson: This gets back to the question of installation costs and whether the unique challenges of transporting turbine components and equipment can be solved to compare with India. That is all I’m comfortable saying at this point.
New Age: The price of renewable power is going down all over the world. Do you think the price will decline more in near future as the technology is advancing fast in this sector or it would face certain limit?
Mark D Jacobson: Yes, it is continuously going down all over the world. Turbine hub heights are getting higher to take advantage of stronger winds. For example, in Bangladesh the shear factor for wind is significant, which means in future, when 160-metre towers are built for wind turbines, the wind resource will be higher potentially decreasing the cost of future wind power more in Bangladesh.
New Age: To utilise the potentiality of wind power in Bangladesh what type of infrastructural and policy related developments are necessary?
Mark D Jacobson: The first recommendation is to open the access of data and procedures. Everyone should have access to the data so that there is increased competition which will drive down the prices with the best projects being built. Second, recommendation would be to look around the world and learn from the mistakes of other countries and not to repeat them. Many countries, including United States made some mistakes along the way, so try to learn from these if possible. Additionally, I would recommend that the transmission interconnection process be better understood. Another idea other countries have implemented is investing in infrastructure – both roads for transport of the components and improving the capacity of transmission grid. Investing in renewable is a good long term investment and a predictable power resource. Typically wind is sold in long term 20 contracts. Consumer will know price of power at year 5, 10 or 15 years. The 20 years contracts for power are a great way to create the predictability for within your power portfolio. One mistake some countries have made early in their career for procuring renewable power, was buying equipment from manufacturers without a reliable track record and or installers that don’t have experience in building successful projects. This is equally important to consider before investing money in renewable energy.
New Age: What is the potentiality about off-shore wind power in Bangladesh? What about the floating wind power technology?
Mark D Jacobson: Evaluating Off-shore wind was not a part of the NREL scope. That being said, expensive foundations and a marine transmission cable will be two of the cost challenges that all off-shore projects need to examine. Wind speeds are typically stronger and more steady for off shore projects, that is why many countries are evaluating this opportunity.
New Age: In your view, what is a better energy option for Bangladesh — coal, nuclear or renewable energy?
Mark D Jacobson: You know I have come from a renewable energy company. I have been working with wind projects over the last 15 years. I have been involved with wind projects which have cumulative capacity of more than 1,200MW. I have worked with both liberals and conservative, with people who like green energy and who like traditional energy. There is a way to bring all of these diverse parties together. Everyone has a different social barometer and a different bias. So if you focus on the social cost argument, one side will cheer, and the other side thy clinch. And if the goal is trying to bring both parties to a common position, then I believe you need to talk about economics – taka or dollars, you need to talk about the cost of energy. And I believe, renewable energy has a compelling story economically. It is frequently the low cost option when evaluating over the next 20 years. In 2016 and 2017, in the United States, the most MW installed in any technology was wind! More than gas, more than nuclear and coal! From my experience, a common language for all stakeholders, should be economics. Blended with other energy technologies, wind and solar should play a strategic role in the generation portfolio of many countries.