Micro Wind

Micro Wind

Project Drawdown defines micro wind as: electricity-generating 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 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 [1]

The total addressable market for micro wind is based on projected global electricity generation in terawatt-hours from 2020-2050, with current adoption [2] estimated from installed capacity figures at 0.007 percent (1.49 terawatt-hours) of global generation (WWEA, 2016).

Adoption Scenarios [3]

Impacts of increased adoption of micro wind from 2020-2050 were generated based on three growth scenarios derived from the evaluation of scenarios from four global energy systems models. [4] These three scenarios were assessed in comparison to a Reference Scenario where the solution’s market share was fixed at the current levels.

• Plausible Scenario: This scenario follows a high growth trajectory of total onshore wind adoption, where micro wind’s current share (0.22 percent) of total onshore wind is assumed to grow in parallel, capturing 0.048 percent of the market share in 2050.
• Drawdown Scenario: This scenario follows a medium growth trend derived from these same models, representing 0.033 percent of the electricity generation mix in 2050.
• Optimum Scenario: This scenario follows a medium growth trend derived from these same models, representing 0.035 percent of the electricity generation mix in 2050.

Financial Model

The financial inputs used in the model assume a weighted average installation cost of US$4,930 per kilowatt [5] with a learning rate of 14.5 percent, reducing the cost to US$3,387 in 2030 and to US$2,779 in 2050 (Hayward & Graham, 2013). An average capacity factor of 21 percent is used for micro wind, compared to 55 percent for conventional technologies such as coal, natural gas, and oil power plants.

Integration [6]

Through the process of integrating micro wind with other solutions, the total addressable market for electricity generation technologies was adjusted to account for reduced demand resulting from the growth of more energy-efficient technologies, [7] as well as increased electrification from other solutions like electric vehicles 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 the Plausible Scenario show that the net cost compared to the Reference Scenario would be US$36.12 billion from 2020-50, with approximately US$19.9 billion in savings from micro wind over the same period. Increasing the use of micro wind from 0.007 percent in 2014 to 0.048 percent of world electricity generation by 2050 would require an estimated US$49.3 billion in cumulative first costs. Under the Plausible Scenario, this solution has a reduced contribution to avoided emissions during 2020-2050 of just 0.2 gigatons of carbon dioxide-equivalent greenhouse gas.

Due to this integration and increased expectations from alternative solutions, both the Drawdown and Optimum Scenarios are less ambitious in the growth of micro wind technology, with impacts on greenhouse gas emission reductions over 2020-2050 of 0.1 and 0.12 gigatons, respectively.

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 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 21^st 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 make it hard to determine their true potential in this form.