A couple of months ago, the fabulous folks at the Science Room invited me to chair a discussion on energy. It was going to be centred around the questions 'How can sustainability be measured?' and 'Is renewable energy sustainable in the long term?' - and there's a short recording of Phil discussing those questions with me afterwards, along with a transcript, below. The people who came were super engaged, and took the discussion down some really interesting turns - the diesel emissions scandal, and the importance of considering air pollution and other things in addition to climate change... the 'green'-ness of recycling (still better than landfill, but reduce and reuse first if you can)... Nikola Tesla's mad idea for transmitting electricity through thin air... putting solar panels in space (not that bad an idea, to get above the cloud cover - if only you could efficiently transmit the solar energy back to Earth)... mandating eco-labels the way food products now have those nutrition traffic light labels... taxation vs. moral persuasion... cancelling money as a proposed solution to unchecked growth... or moving to another planet... If only I could do justice to all those topics! Oh well. It was a fantastic event, I'm very grateful to the organisers for the opportunity, and I'd highly recommend the Science Room and similar events - to attend, or speak at - even if you don't think that's your sort of thing initially. OK, here's the recording and transcript:
Transcript Phil: Today you answered two questions, the first of which was 'How can sustainability be measured?' - so, if you could give our listeners your two cents on that? Susan: It's a great question 'cause it has both a technical side and a moral philosophical side. So, on the technical one, you would need to do a Life Cycle Analysis of whatever product or process you're looking at. So maybe the manufacture of a solar panel - you'd need to identify all the physical inputs and outputs of that - all the waste emissions from the manufacturing processes. Once you do that, you have a Life Cycle Inventory - all the substances going in and out - you need to know what effect does that have on the environment. The state of the art these days is to use a protocol or framework called ReCiPe, which defines 17 midpoint impacts - I won't go through them all, but they're things like climate change, acid rain, ozone depletion, ionising radiation - and so what the people who have worked on ReCiPe have calculated are conversion factors to go from any chemical substance emitted to how much that contributes to each of these 17 midpoint impacts. And then further, how much each midpoint impact contributes to the 3 endpoint impacts of damage to human health, natural ecosystems, and natural resources. A lot of that work has come from modelling studies and ecological and medical data, and that's all fed into how you calculate these endpoint impacts, given whatever product you start with. P: OK, so you mentioned during the event that there's - you had a question about, is that just manufacturing, or is that like the full life of the product, or afterlife of the product - if you could just quickly elaborate on that. S: For your Life Cycle Analysis, you need to define whether that's cradle-to-gate, meaning just for the manufacturing stage, or cradle-to-grave, which includes the operation phase. So for a solar panel that might include the emissions from fossil fuels that are displaced because you're getting your energy from solar rather than gas and coal or whatever. There's also cradle-to-cradle which includes the recycling stage. So which one you do really depends on the situation and what you want to compare exactly, but it's standard to always define which one you're looking at, whether it's cradle-to-gate, cradle-to-grave, cradle-to-cradle. P: Excellent, thank you. So the second question we received is sort of a follow-on: 'Is renewable energy sustainable in the long term?' So given what we've just discussed, can you summarise. S: Right. So with renewable energy, we're not going to run out of fuel. But there are other things that limits us. There's land usage, which is not actually that crucial when you consider less than 1 % of the land surface of the earth would need to be covered in solar panels to supply all the electricity needs of the world today. And before you get to that, you run into problems with - how do you fund that? P: That's a lot of Ikea flat-pack solar panels! S: Yeah, absolutely. I mean, there's so many other pressures on money, especially tax money. You need to fund health care, education. Is there enough for renewable energy? How much do you care about the environment compared to all these other things? And then there's also the material usage, because you need metals to make wind turbines, solar panels, batteries - and you need to keep replacing them over time as they wear out. We might get better at recycling as well. We might also invent new types of solar panels and batteries that use more abundant resources so that we don't have to keep extracting the rare and expensive ones, and so there's a lot of reason to be optimistic, but that's all on the supply side. When you look at our demand for energy, it's just been going up and up all through history and who knows, is it going to continue or will we ever be content and just plateau at a nice level of energy use that we can supply from what we have. So if we just keep on needing more energy, then that 1 % of land is not going to be enough. We're going to keep needing more, spending more money, digging up more out of the earth. And... we'll leave it at that. P: So to summarise - supply side, theoretically, with certain caveats, but demand is a major unknown and we have not much of an idea what's going to happen to that in future. S: I'm sure some people have ideas, come up with lots of scenarios. But yeah, I guess it's a "wait and see", really. P: Susan, thank you very much for taking the time to come in today and answer our questions. S: Thank you, Phil. With thanks to the Science Room organisers Jamal Kinsella and Phil Wiles, and to Dave Christensen for sound recording and editing. You guys rock!
1 Comment
25/4/2024 06:38:18 am
Reply
Leave a Reply. |
Susan's BlogIn which I scribble words about energy, the environment, climate change, and other science things. Views expressed here are my own and do not reflect those of the CDT staff or sponsors. Archives
August 2019
|