Harnessing river flows through the use of water wheels dates back thousands of years and is considered by many to be the first application of renewable energy technology. Technological advances over the past decade have broadened the potential for application of the technology, and the sector is now on the cusp of a major revival.
Hydrokinetic turbines capture energy in much the same way as a wind turbine, and, in fact, the next generation of river hydrokinetic turbines draws heavily on the lessons learnt from this more mature industry. As with wind power, the energy contained in a moving fluid – in this case water as opposed to air – is captured and converted to electricity.
Individual units come in a variety of sizes ranging from 5kW to as high as 2000kW, and they can be configured in arrays of much larger capacity – potentially hundreds of MW. There is no need for dams, impoundments, or river diversion, and baseload power can potentially be delivered in many locations. Latin America boasts a vast expanse of rivers, which are both deep and wide with strong current speeds during most of the year – in short, a world-class resource.
The Amazon River and its thousands of kilometers of tributaries are a case in point. So far, river technology has been deployed in the US, Canada, and Europe, where rivers are generally shallow. This limits the size of turbines that can be used. In Latin America, however, and particularly the Amazon, the rivers are of a different scale and allow for the deployment of larger individual units or large arrays.
What can be done to facilitate uptake in the region?
The sheer size of major rivers in the region and the strength of the resource certainly present some technical challenges – however, these are not insurmountable. Lessons learnt and experiences gained elsewhere, particularly in ocean application of these technologies, are highly transferrable. Perhaps a multifaceted program addressing the remaining technical, as well as social, economic, and ecological factors could be what is needed to trigger the construction of the next generation of damless hydropower in Latin America.
The IDB, via the Sustainable Energy for All Americas initiative, has commissioned a high-level study to assess the potential for generation at selected sites in Peru, Ecuador, and Brazil. The study draws on existing time-series hydrological data to analyze the depth and speed of the rivers and the variation of these two factors throughout the year. The study is ongoing, but preliminary conclusions suggest that both the scale and consistency of resource required for a large number of projects from 2MW to 100MW in scale with capacity factors in the range of 50% – 70% are available. Very promising indeed.
This would be welcome news for the estimated 10 million people that live mostly in urban areas along the banks of the river, as conventional renewable sources for electricity generation are very limited. Wind resources in the Amazon Basin are poor, and the potential for conventional dammed hydropower is limited due to geological and social challenges. To date, the only alternative is expensive diesel generation combined with some solar installation.
The potential is undoubtedly there. Realizing it, however, will take effort. Financing is certainly an important part of the puzzle, but more can be done to facilitate further resource assessment, as well as addressing some of the other logistical, environmental, and technical challenges.
The Amazon Basin is a challenging environment from many perspectives. However, if everything comes together, river hydrokinetic power might prove to be the distributed sustainable energy solution we have been looking for!