Micro wind turbines atop a building.
Technical Summary

Micro Wind Turbines

Project Drawdown defines micro wind turbines as electricity-generating onshore wind turbines with capacity of 100 kilowatts or less. This solution replaces conventional electricity-generating technologies such as coal, oil, and natural gas power plants.

In recent years, attention has been given to large utility-scale wind turbines, though the micro wind market offers individuals a good opportunity to become more self-reliant and less dependent on the grid to serve their electricity needs. Small wind turbines remain more expensive than large turbines, especially if the objective is to produce electricity for the grid, since the electrical connection and maintenance are a much higher proportion of the capital value of a distributed system. However, small wind turbines can be integrated into urban infrastructure, such as building-mounted micro turbines.

The micro wind turbine market has been growing steadily over the past few years. Though it has thus far been concentrated mostly in the United States, China, the United Kingdom, and Germany, the increasing electrification of the developing world offers the industry phenomenal inroads for further expansion and development.

Methodology

This analysis models any wind turbine that is rated less than or equal to 100 kilowatts.

Total Addressable Market

The total addressable market for micro wind turbines is based on projected global electricity generation in terawatt-hours from 2020 to 2050, with current adoption[1] estimated from installed capacity figures at 0.008 percent (2.2 terawatt-hours) of global electricity generation.

Adoption Scenarios

Impacts of increased adoption of micro wind turbines from 2020 to 2050 were generated based on two growth scenarios. These were assessed in comparison with a Reference Scenario, in which the solution’s market share was fixed at the current levels.

  • Scenario 1: This scenario follows ambitious adoption trajectories of onshore wind adoption from IEA (2017) Energy Technology Perspectives 2DS and B2DS scenarios; IEA (2018) World Energy Outlook SDS; and Grantham Institute and Carbon Tracker (2017) strong climate mitigation policies with lower costs for solar photovoltaics and electric vehicles scenario using a medium growth trajectory. Micro wind turbines’ current share (0.22 percent) of total onshore wind is assumed to grow in parallel, capturing 0.04 percent of the market share in 2050.
  • Scenario 2: This scenario follows a high growth trend derived from the same above-mentioned scenarios estimated yearly adoption, representing 0.04 percent of the electricity generation mix in 2050.

Financial Model

The financial inputs used in the RRS model assume an average installation cost of US$6481 per kilowatt[2] with a learning rate of 9.7 percent, reducing the cost to US$4536 in 2030 and to US$3742 in 2050. An average capacity factor of 18 percent is used for micro wind, compared with 57 percent for conventional technologies such as coal, natural gas, and oil power plants.

Variable operation and maintenance costs of US$0.03 per kilowatt-hour and of US$127.3 per kilowatt for fixed costs are considered for micro wind turbines, compared with US$0.005 per kilowatt-hour and US$34.7 per kilowatt for the conventional technologies.

Integration

Through the process of integrating micro wind turbines with other solutions, the total addressable markets were adjusted to account for reduced demand resulting from the growth of more energy-efficient technologies,[3] as well as increased electrification from other solutions like electric cars and high-speed rail. Grid emissions factors were calculated based on the annual mix of different electricity generating technologies over time. Emissions factors for each technology were determined through a meta-analysis of multiple sources, accounting for direct and indirect emissions.

Results

The results for Scenario 1 show that the net cost compared with the Reference Scenario would be US$52.8  billion from 2020 to 2050, with negative savings of approximately US$19.9 billion over the same period. Increasing the use of micro wind turbines from 0.008 percent of world electricity generation in 2018 to 0.04 percent by 2050 would require an estimated US$78.5 billion in cumulative first costs. Under Scenario 1, this solution has a small contribution to avoided emissions during 2020–2050 of just 0.09 gigatons of carbon dioxide-equivalent.

Scenario 2 has a slightly  higher impact of the growth of micro wind turbines technology, with impacts on greenhouse gas emission reductions over 2020–2050 of 0.13 gigatons of carbon dioxide-equivalent.

NOTE: These estimates were based on a conservative capacity factor. Since wind power is proportional to the cube of the wind speed, higher wind speeds result in much higher power. Doubling the wind speed in this framework would result in an order of magnitude increase in the carbon savings.

Discussion

Because micro wind turbines are such an emerging technology, there is a lot of uncertainty around how the technology will grow. Advancements in the lifetimes of micro wind turbines are the type of benefit that take decades to creep into the marketplace. As such, their impact may not be felt until midway through the 21st century. The potential of building-integrated micro wind turbines is increasingly being explored to generate clean energy on site. However, at the moment, uncertainty about how factors such as low wind speeds, high levels of turbulence, noise, visual impact, and animal strikes influence the performance of micro wind turbines makes it hard to determine their true potential in this form.


[1] Current adoption is defined as the amount of functional demand (terawatt-hours) supplied by the solution in 2018.

[2] All monetary values are presented in 2014 US$.

[3] For example: LED lighting and high-efficiency heat pumps.