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The challenge of getting renewable energy into our power networks

The challenge of getting renewable energy into our power networks
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Renewable energy is on the rise around the world, but many experts say it will always remain the minority partner in our total energy mix, mainly because it is a question of reliability: you cannot always promise the sun and the wind. When there is a freezing storm across a continent, for example, it is the traditional power sources that we will rely on, not renewables. The same goes for the needs of big industry that consume massive amounts of energy on a regular basis. But there is also the question of how to integrate renewable energy sources into our power networks or national grids in an effective and competitive way. And what about the issue of storing renewable power, so it can be held in reserve and used when it is needed, not only when the sun is shining or the wind is blowing. Euronews reporter Seamus Kearney discussed some of these issues with Dr. Susan Krumdieck, a mechanical engineering professor at the University of Canterbury in Christchurch, New Zealand. She is also the director of the Advanced Energy and Material Systems Laboratory, an interdisciplinary research group. Seamus began by asking her what was a key issue in the future for those countries that want to increase their use of renewables.

Dr. Susan Krumdieck: “The power systems that we have were designed specifically to work with large-scale generation at one end and consumption at the other end. Renewables don’t work quite like that; they’re put in at different places and they come and go intermittently, so the design of systems with renewables in it really has to be done by the engineers, not by the politicians. There are a lot of countries that have the initiative to increase their renewable generation, but it’s really important that that be done not for political reasons or in political ways. The system was engineered really specifically to work the way it does now and renewables integrated into the system is a big engineering problem that needs to be handled technically, and it probably is going to require a lot of research as well.”

Seamus Kearney: “Do you believe that we can actually achieve that, in technical terms and in terms of research and development? Do you see a bright future for renewables? And are countries going to be able to meet their targets and even go beyond them?

Dr. Susan Krumdieck: “There’s no reason why we shouldn’t reach for targets of very high renewable penetration. The idea of doing that, there is nothing inherently wrong with it. The issue that we have to deal with is that the renewable system – a system that relies on renewables – is different than a system that relies on coal or fossil fuels. Fossil fuels are available on demand, when you need them, and renewables are available when they’re available. So you have to actually reengineer the system, the way that it moves the electricity around, and most importantly, you have to rework how the demand is structured, and the signals about what’s available and what’s not, and what the costs are, and what they are at any given time. That all now has to be built into the system if it’s going to rely a lot on renewables.”

Seamus Kearney: “What about this issue of being able to store the power, so it’s not direct usage. At the moment it’s going into the grid and it’s direct usage, but people talk about the need to have research into storing the power so it can be stuttered and spread out over time. What are your thoughts on that?

Dr. Susan Krumdieck: “The power systems that we’re using now, that are based on fossil fuels or even hydro – things that we can control the rate at which we put power into the grid, to follow the loads and match what the demand is at any given time – those systems really don’t have a lot of storage in them. The main reason is that storage is very expensive, especially on a large scale. When you start talking about renewables, electricity that really is available when it comes, not when you need it necessarily, one way to deal with the intermittency is to think about storing the electricity and using it later. And really the issue is cost and volume. The amount of electricity that you can store in a battery is really quite limited. And the cost that it adds to store the electricity and then take it back out is pretty impressive. That’s why even though we have batteries that we can use to do that with, we don’t see a lot of that on the grid because the electricity is not worth that much more when there are many other ways that we can deal with that intermittency than storing it. We can deal with how we actually are demanding the electricity.”

Seamus Kearney: “And this question of countries, power companies or cities having an energy mix, where we have a small part wind, etc., but other sources still being used. What are your thoughts on the fact that renewables are coming in as just another of the energy sources?”

Dr. Susan Krumdieck: “The energy mix on a grid really hasn’t developed historically in a way set by policy. It’s developed by what is most available and most reliable at the lower source. That is how we have historically got the energy mix that we have. Now we have policy-driven decisions about energy mix, which are much different than engineering decisions about energy mix. So what it means really is a lot more research is needed, and a lot more development and a lot more ingenuity into how you make a grid like that work. If you think about somebody who lives off-grid, for example; what they have is their own micro-grid; they’re generating power, they may be storing it, and if you look at the decisions that they make about how to use electricity, when to use electricity, they put a lot of effort into looking at how much they’ve got at any given time, before they make decisions about what they’re going to do. And when they make decisions about what size appliances they’re going to buy they take into consideration how much it’s going to cost them to get big enough batteries or big enough solar panels to run those. So that kind of thinking is really what we’re going to have to do if we’re going to get that energy mix with much more renewables and much less carbon. It’s not impossible, it’s just that we have to recognize that you can’t just make policy decisions and not actually do all of the reengineering that we need to do to get that system to work.”

Seamus Kearney: “And then of course there’s the question about energy savings, energy efficiency and smarter use of energy. Where does that come into the equation when we’re talking about renewables?”

Dr. Susan Krumdieck: “A lot of discussion, and maybe with some regulation, is aimed at energy efficiency, savings and conservation, and that’s actually key to getting a system that works with renewables. When you think about what you’re willing to spend for electricity, it’s really what you’re willing to spend for the services that you get. And we want to get those services without as much coal and gas, but we are thinking in terms of historically having that coal and gas and having very low-cost electricity. The thinking changes when your electricity is very expensive. So there’s a problem with our perception of how things are, and in my research area part of what we’re working on is to really understand how new products and new systems and new communications can be used to actually transition away from our historical experience of being able to use however much electricity we want, at any time we want, and not having a very big bill for that. And to transition more to like what someone who’s off-grid does, where they buy the amount of power generation that is commensurate with the services that they value the most. So it’s sort of a whole different economy that goes along with a whole different power generation system when it’s running on renewables.”