Traffic turbines - a feasibility study for using horizontal turbines to generate power from roadside turbulence created by vehicles
Among the renewable and clean energy technologies, wind energy is one of the most efficient, costing 1–2 cents per kilowatt-hour after the production tax credit by governments12345. While natural wind speeds over various continents in the world span from 0 to 20 m/s, the Vertical Axis Wind Turbines (VAWT) placed on highway medians make it possible to utilize consistently higher wind speeds due to vehicle motion 6. Additionally, the energy generated out of these wind turbines is reported to increase multi-fold due to the shearing winds generated on both sides of the medians by the on-going traffic 3. Your task will be to optimize the positioning of turbines to achieve optimal results using criteria you deem to be important, such as output power, ease of installation/repair, proximity to consumers, additive effects from positioning etc., using real-life traffic, geographical and weather data, and subsequently investigate economic feasibility of implementation of this technology. Specific focus to Alberta terrains and regulations would help as well.
The idea of VAWTs is to harvest the untapped turbulence energy generated from vehicles in highways/roadways with ample traffic and speeds enough to generate profitable energy. The VAWTs suffer from inconsistency in vehicle speeds etc. and hence their outputs have a lot of factors that affect their performance. Some of these factors include: the amount of traffic and the speed of the traffic, the total time the wind energy is available (without traffic), seasons, locations and changing climatic conditions. These questions need to be answered to understand the long-term benefits of stationed vertical wind turbines.
We task the participants to quantify the effects of such factors and find an optimized setup of wind turbine for maximum profitability along the roadways. Here are a few areas of study:
- Choose your favorite traffic highway system anywhere in the world. It is interesting to have some examples from both the developed and the developing world, and varying climate conditions. The traffic system should have enough data on cars’ movement to make quantitative predictions. Collect traffic data on various part of highways during various times and seasons;
- Translate the traffic speeds into wind speeds using some hypotheses on the air motion around cars and available information in the literature;
- Study typical wind patterns in that part of the world from available literature and compute the net effect of traffic motion on the wind;
- Compute the optimal number and location of wind turbines along the highway to optimize either the power production, distance to the load point or utility grid etc, distance from neighboring city to minimize repair costs, or some combination of optimization goals;
- See if viable options can be reached which pay off the original turbine setup costs sooner than those estimated in literature (3.5 yrs to 10 yrs) and start generating profitable energy after that 5;
- If return to profitability on its own is not possible, estimate the amount of government support needed to implement the system, either in terms of tax benefits, direct cash injection or setting tariff rates. We expect the team to come up with the relevant information during the literature search. As a starting point, the teams can look at Ref. 7891011125 for interesting questions about the technical/economic feasibility.
There are some known issues that could be resolved with innovative ideas. For e.g., the cost issue of constructing long transmission lines from highways/remote roadways to the energy storage locations. This could be circumvented by constructing electric charging stations on the highways to charge electric vehicles, near to the wind turbine grids. A Tesla model 3 car takes 50-75KWh to get charged and each of these wind turbines are said to produce tens of thousands of KWh energy annually 36. So, at least on paper, few hundred of VAWTs in a local grid seem to be enough for electric vehicle charging stations, but that calculation ignores the cost of setting up and maintaining the VAWT systems and their maintenance, grid connection and electricity storage. It would be interesting if any recommendation can be done for the conditions ATCO’s charging stations are currently operating in 13. If VAWT technology is not feasible for providing power for charging stations, lower levels of energy generated can be sold for street/highway lighting that forms a significant portion of the city’s budgets 7. The team is welcome to propose its own way to economic feasibility of the project, or, alternatively, prove that no system of VAWT can ever be economically viable.
We advise to take caution and have conservative measures/weights for maintenance costs incurred due to replacements needed due to the turbine blade’s fatigue over the years of operation 14. Also, ice layers that build up in wind turbines in the North have disturbed the balance of turbine blades and created wobbling and vibration effects, eventually leading to breakage 15. So, areas with extreme temperatures/weather may be challenging from the possible spots for positioning. On the other hand, electricity costs may be substantially higher in these areas. Data collection and optimization: Traffic data over the years, for most highways, are available online for various countries/provinces. They can be collected from trusted government reports/Google maps data. Natural wind speeds data is also available from similar online resources. The formulation to translate both in terms of the local wind speeds is up to the team.
The wind turbine blade design choice, the country/region of position optimization are up to the team. The idea is not novel and has been implemented in a few countries so far. Inspirations from similar studies on those projects/patents can also be taken as reference. References to payback period studies have also been done 4. They predict the original and operational costs to be paid back within 6 months, 3.5 to 10 yrs depending on whichever turbine is chosen 341614. The basis of all these reports must be critically questioned from a scientific viewpoint, as some other authors say it is not feasible and larger turbines are preferred 1718. The cost and effects of large vs. these smaller turbines installable on highway medians should be distinguished using technical and scientific proof.
Quantitative results are needed to back up any of the claims. Please note that this is a feasibility study and does not need to prove it viable or not.
Ability to quickly grasp on technical details and skills required. Desired skills:
- knowledge of calculus of variations
- programming/coding experience.
Wind Turbines along highways, TU Delft thesis ↩︎