Challenge: A Cold Wind Blows: Seeking Smaller, Ruggedized Wind Turbines for the Arctic

Challenge Statement

The Department of National Defence and the Canadian Armed Forces (DND/CAF) are seeking ruggedized wind turbines for the Arctic to reduce the reliance on diesel fuel generated power.

Background and Context

The demand for electrical power and space heating in the Canadian Subarctic and High Arctic is fulfilled almost exclusively with diesel-fired generators. The DND/CAF is seeking to reduce petroleum-generated electrical energy consumption in the North in order to minimize operational, logistical, but as importantly, to reduce the environmental burden. Wind turbines, are already in limited use in the North, but there are major hurdles to overcome before they can be fully exploited as a source of alternative energy.

Canada's far North and Arctic region is characterized by seasonally frozen ground and deep snow, rugged terrain, permafrost, and extreme temperatures that can reach -60º C in the High Arctic. The High Arctic and Subarctic also experience frequent high winds (80-120 km/hr). Wind turbine designs are needed that are ruggedized and able to withstand this harsh arctic climate and terrain. Very high ultraviolet (UV) radiation, extreme cold and wind severely impacts the durability of designs. Very strong arctic winds may destroy the turbines and composite materials (e.g., plastic, Kevlar) become fragile in the cold. Furthermore, ice-rimming of wind turbine blades also represents a significant problem that can affect turbine operations/efficiency.

Climate change is causing additional challenges for the structural design of arctic wind turbine foundations. Permafrost that has persisted for thousands of years is thawing and refreezing each season, causing existing buildings/foundations to sink, shift and crack. The design of a foundation must allow the turbine to remain level as well as account for the pressure to tip over due to the force of the wind interacting with the blades and rotor.

Typical wind turbines are absolutely massive in size, which significantly limits their potential use in remote and isolated northern locations given significant barriers related to transportation and installation. A typical unit that supplies 2-4 MW of energy have size dimensions that exceed 120 meters in height and have blades that are 80-90 meters long, which requires hundreds of tons of concrete for the base. The blades and shafts are typically made out of composite materials in order to limit their overall weight and reduce the logistical burden of lifting them during installation. A unit of that size is not as practical for most northern installations, and in any case, are designed to supply much more power than is necessary for the current challenge. A turbine that services one DND/CAF location only needs to have a power output of 10 kW to 500 kW.

Wind turbines are needed that have smaller MW capacities and are logistically manageable. Many DND/CAF locations exist in isolated locations or within small, arctic communities that have limited or no road access and must be reached by other means of transportation such as barges or heavy-lift aircraft. The roads that do exist tend to be built on ice in the winter months and have weight limits. Consequently, new designs must be modular to simplify transport by air, ship or ice road. Ideally, future designs would also make use of readily available parts or parts that are easy to manufacture in order to simplify the installation, maintenance and repair. Designs should also be easy to assemble by non-technicians using commonly available tools. New materials are needed that will similarly limit the burdens of installation, address durability concerns, and might further include radar absorbing materials (RAM) to mitigate interference with communications systems.

Desired Outcomes

Research, design concepts and technologies are sought that address the following:

• Wind turbines that have electrical generation capacities of 10 kW to 500 kW.
• Lightweight materials that can withstand the effects of very high UV radiation, extreme cold and extreme wind in the Subarctic and High Arctic;
• Materials and/or methods to mitigate ice-rimming of turbine blades;
• Materials which incorporate radar absorbing properties to limit interference with communications;

Additional Outcomes

• Approaches to wind turbine design and their foundations which account for climate change related impacts (i.e., melting permafrost);
• Modular wind turbine designs to facilitate ease of transport by air, ship or ice road;
• Designs that rely on readily available parts to simplify manufacturing and repairs; and/or
• Designs that are easy to re-assemble/maintain by non-technicians using commonly available tools.