How Unlikely Sources Could Change Energy Generation Worldwide
Energy is everywhere, whether it’s gasoline powering a car, a log burning in a fireplace or water flowing through a dam. But could energy also be harnessed from vibrations on a road, running shoes on pavement or devices embedded on the seafloor?
The answer is yes, and capturing it is no longer science fiction. As part of an ongoing series featuring IBM’s 5 in 5—five technological predictions that may become commonplace in the next five years—IBM Distinguished Engineer Harry Kolar envisions a world in which energy can be generated from any number of sources, including changes in room temperature and tidal forces.
Although still a few years off from large-scale practical use, Kolar describes how waves and tides could dramatically change how many regions around the world produce energy, giving them cheap, sustainable and source-independent ways to power their everyday lives.
Q. You mention in your 5 in 5 prediction that people may be able to charge their smartphones while jogging. Is this really possible?
A. People are making a number of applications in that area, including energy-generation devices and some scavenging devices for different types of systems—and not only for personal use. For example, there might be distributed systems that translate road vibrations into energy to charge batteries for sensors that monitor a bridge in a remote location. There are examples of people developing scavenging devices based on changes in room temperature as well. I don’t think they’re widely available yet, and we currently don’t see very large installations of any of that. They’re still in the development mode.
Q. How would that work in a wireless environment?
A. Well, there are inductively coupled devices, which are becoming more popular for use with handheld devices. You basically put your iPhone or iPad on a small platform that’s plugged into the wall, but there’s no physical plug between the device and the platform. Instead, inductive coupling is used to charge the battery. They’re not as efficient, obviously, as plugging the device into a wall, but they’re very convenient. The ultimate goal, though, is to have the distance between the device and the charging station expand over time, which is how the coupling of a running shoe and an electronic device would work. In general, though, it’s all about converting mechanical energy to electrical energy using generators.
Q. Which leads us to the bigger issue: How would this conversion apply to generating energy with waves and tides?
A. These are analogues to the wind-farm type approach except you’re using either wave motion to do the conversion or, obviously in the tidal energy conversion, devices that are actually submerged out of view sitting on the seafloor in particular areas where tidal currents are strong. Before doing either, however, we have to factor in the build cost of the associated machines, as well as the costs associated with operating them and connecting them to the electrical grid. If you look at the total equation, you have to be sure that you have high enough mechanical wave or tidal energy in particular areas to justify their deployment.
Q. Can modeling be used to deter-mine the effectiveness of wave or tidal forces in generating energy?
A. You do have to take measurements. Obviously, tidal activity is periodic and pretty well known, but in the case of waves, you need to use more sophisticated models. They can give you a rolling calculation for predicting waves based on weather conditions over a period of time.
I’m working on a wave-energy project on the west coast of Ireland. The Marine Institute of Ireland, which is supporting some of this wave-energy development, is working with another organization, the Sustainable Energy Authority of Ireland, at two wave-energy test sites. The Marine Institute actually runs fairly sophisticated wave models to predict wave heights, periods and detailed wave parameters to accurately characterize waves.
An interesting point is that one of the biggest groups of users of that data right now are hard-core surfers from around the world. They’ll actually look for surf conditions and show up in Ireland on short notice, flying in from places like Australia and South Africa to catch the bigger waves. So the models must be fairly accurate if these people are getting on airplanes on short notice and paying full boat for a ticket.
And that’s a very important piece of this. If you look at power from offshore winds, energy companies and the grid operators, because they have to balance the grid, they must try to accurately predict what the generation is going to be over a certain period of time or an exact number of days. And in many cases, they also have to figure out how to store that energy to manage the grid when the wind is blowing and they don’t need excess energy at that time. The same applies to ocean energy. Can you tell what’s coming and can you manage that in terms of generation input of a variable source that’s obviously triggered by the environment and not by somebody starting a power plant? It’s very important to include that modeling into the overall scheme of the operations of those sites and how they actually feed the grid, so grid operators have an idea of what they have on hand and what are the expected loads.
You want to look at the obvious things on the grid side, such as what’s going on in terms of weather. What’s the anticipated usage? What are other energy generators doing? Are they offline? Online? Do you have a balance or a mix of renewable resources? Do you have wind as well as wave energy?
Q. What are some of the other factors that must be explored?
A. Well, before anyone can do a deployment, you have to have a full site assessment. You have to determine what the seafloor looks like, what the coastal interactions will be when you start laying grid cables down. How will that affect sediment transport in the area? Will arrays of convertors alter the wave fields and possibly change the coastline? This is probably going to affect marine life as well, so you have to look at what’s going to happen with the electromagnetic fields from the actual grid cables. How will underwater noise affect these animals? Are there issues with anti-fouling paints used on the devices? You’re stacking up a number of environmental impact parameters
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