By Debbie O'Hara
Many of us picture islands as pristine environments, destinations for vacation travel, even paradise. The reality, however, is that thousands of islands and other remote communities are struggling to keep up with their basic energy needs. They rely on expensive, dirty, diesel fuel systems for their electricity. It would seem that renewable energy solutions would be ideal replacements for these diesel systems, especially in the Caribbean islands where sun and wind are abundant. Unfortunately, when it comes to taking advantage of cleaner technologies, the costs are prohibitive. Land is at a premium in these island nations, so large solar farms are not always viable. Wind offers an alternative, but the costs of transporting large turbine components to smaller islands - with limited port and roadway infrastructure - creates big challenges.
How can we ease this pain for small islands and other remote communities, and provide them with viable, accessible, and affordable energy that will drive economic growth, while ensuring that both their economies and communities are less vulnerable to severe weather events?
It’s time to systematically eliminate the barriers for renewable wind energy. We have the knowledge and resources to create a solution that is:
- Less expensive to purchase
- Less expensive to transport to an island or remote location
- Easier to transport on limited roadways, often with sharp twists and turns
- Not dependent on a large, expensive crane to erect
- Less expensive to operate and maintain
In order to achieve all of the above, we need to:
- Eliminate the expensive nacelle and gearbox
- Eliminate large blades and subsequent over-sized shipping charges
- Make all components transportable in standard shipping containers
- Make the turbine self-erecting
- Eliminate the need for oil changes and gearbox repairs
This is not an impossible task. Rather than trying to adapt current wind technology to reach these goals, however, maybe it would make more sense to borrow from a different industry. Amusement rides may seem like a farfetched idea when considering options for clean energy, but the engineering involved in, say, a Ferris wheel, isn’t too different from what we see out on a wind farm. In fact, the technology has been around for ages.
The mechanics are fairly straightforward: Large Ferris wheels use two rubber truck tires that press up against the rim to turn the wheel. Instead of utilizing a heavy and expensive nacelle and gearbox, it’s possible to add a rim and utilize the drive tires. Additionally, we would eliminate the risk of fire and the expense associated with gearbox maintenance and replacement.
Rather than utilizing blades that stretch 100 feet, an alternative would be to use 20 five-foot blades (which would act as airfoils) on 64 spokes that extend from the hub to the rim. Each blade would individually pitch and customize their collective twist to current wind conditions, ultimately being more efficient than a larger blade with a permanent twist. An even greater advantage: all 1,280 blades can ship in a standard container.
In fact, all the components can be designed to ship in standard shipping containers. With the axle, rim segments, and tower segments all measuring less than 40 feet, transportation logistics are greatly simplified. Smaller sized components could be easily shipped to ports with limited access, to reach more remote locations lacking developed infrastructures.
Without the nacelle and gearbox, the turbine would be light enough to be lifted into place using a hydraulic cylinder. This cylinder would be a permanent installation that would offer an added advantage - it could be used to lower the turbine for maintenance, or in advance of severe weather.
Because this turbine model would be less expensive to purchase, install, and maintain, it would be an economically viable solution for stand-alone situations, ideal for distributed generation applications or mini/micro-grids. The rated capacity would be 800kW, but the more efficient design means the turbine would deliver a higher annual output of electricity. For example, in a wind regime of 7 m/s, the turbine would produce 3GW of electricity in a year’s time.
The flexibility of this turbine model has the potential to harness the world’s natural resources, making expensive diesel systems obsolete, and providing economic opportunity for remote communities in the Caribbean, Alaska, Canada, Sub-Saharan Africa, and any other place in the world hungry for affordable, accessible, and environmentally friendly energy.
Debbie O’Hara is Chief Marketing Officer at BarberWind Turbines, LLC, which offers low cost wind turbines for the mid-sized market.
BarberWind Turbines | barberwindturbines.com
Author: Debbie O'Hara