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hello and welcome to technically speaking a podcast where scientists and engineers come together to chat about a common interest share knowledge and satisfy some curiosity i'm Ghalia and in this episode i'm joined by Antonia and Laura to talk about the electricity grid and the challenges to using renewable energy only we'll get all into that in a moment but i think first laura you have a few things you want to rave and celebrate about yeah yeah so we've been
doing this for just over a year now we had to we had our one year anniversary recently and to celebrate it amongst other things we did a reddit ask me anything which i thought was uh very entertaining and i really enjoyed it we've never done one before so there was like a team of us on zoom talking to each other saying do you want to answer that question how should we answer that one do we even try and answer that one or do we just let other people talk around it so i think we have
to thank all of the people that were involved in that and asked some really smart questions and not voted and people that then listen to the episodes as a result and sonya do you have any particularly memorable moments from the reddit ama there was quite a few really interesting ones there was someone who was trying to get back into learning and shared her story and that was really really cool there was a lot of lovely people talking about what it means to to
try and help with women and diversity in their fields and then of course there was someone who specifically asked me how do we use water and gravity to generate electricity or no water pressure they said and i try to pick it back to basics and i think i think we might have got somewhere maybe we made a perpetual motion machine that's good was anything in particular that you couldn't answer we tried to answer all the questions that were about science and there were quite a lot of questions about
being female or women scientists and engineers and our experiences of that and i know a lot of women experience a lot of bias in their industries i think we're quite a fortunate team and that we're not aware of any specific bias against us because of our gender but we don't talk about that a lot in this podcast we tend to focus on the science and engineering yeah yeah i think it was just kind of important to highlight it in that podcasting is listened mostly by
male people and created by mostly male people and then the industries we work in are male dominated i mean some people were talking about the biological sciences and them having more female people we're all in the uh physical science and engineering generally and it's not such an even split it's biased towards one way yeah we were recently talking just about have we ever had a female team leader or female project manager or female technical lead and i think in my experience i i've never had
a female technical lead or like a manager in that sense so it is quite shocking to be honest i've been in the industry a bit too long now for that not to be the case to bring it back to some of the more sciency engineering questions we got a lot of questions like who makes the best sandwich and why does seagulls keep stealing my fries well you need to science this yes 100 come up with some criteria for the best sandwich so it was a good mix of questions about science engineering in
the female side of it as well which was uh quite fun another thing we've got going on as a celebration is we now have team t-shirts tell us more so they've got a logo on the front and they have some code on the back that one of our team wrote which is sort of a definition of the podcast written in python as you do i feel like if you did try and execute it it might not always produce this podcast but at least you kind of have somewhere to start off yeah and we actually have a few t-shirts
and a few bags as well going spare so we made more than there are in the team at the minute so if anyone listening to this would like one please get in touch with us and we'll send you some more details garlic i think it's time to hand back over to you so we can talk about electricity and renewables yes i agree so on the on the topic of celebration it is british science week this week so in light of our discussion that we're about to have i thought it'd be good to mention michael faraday he is
a british scientist and he's had a huge contribution to the way in which we live and that's mainly around the study of electromagnetism which includes things like using a changing magnetic field to produce an electric current given efforts needed to adapt the grid to renewables and reduce the nation's carbon footprint to help mitigate climate change this is particularly relevant right now one interesting thing about michael faraday is that there is a memorial piece for him in elephantine
castle which is close to where i live in london and inside that there is an electrical substation for the northern and bakerloo line so if anyone's going through london or travels on the northern bakerloo line and happens to travel through elephant and castle remember michael faraday because that's apparently where he was born and raised and we were just looking at um female engineers and scientists that had quite a valuable contribution to the electricity or electrical field and
given most of those breakthroughs with during the victoria era and there are not many known women engineers or scientists working in the field at the time but we thought we would mention one her name is hertha erton she was an expert on the subject of electrical arcs and she was the first elected female member of the institute of electrical engineers and that was in 1899.
so antonia tell me why you're interested in ledger's grid about hertha erson we wanted to find someone because it's also international women's day on the day that we're recording this yeah on the daily record yeah david recording garlia's sister was looking over her shoulder as she was preparing for today and was like i can't believe you're not mentioning a woman yeah but yeah back on to the topic of electricity i work in the energy sector and advise uh different companies
about how they can reach net zero and often something that comes up is renewable energy and can they install solar panels on their roof and yeah that's great from their perspective but then things that i was reading before was for the national grid renewables are quite different in the way that they work compared to you know our conventional methods using a steam turbine so that was something that you know we don't really see on in a general view we just hear about oh let's renewables and
the actual generation technologies and actually the grid is kind of the backbone of it all okay laura i know you have a very different background so what does the grid mean to you why is it interesting for you it's not something i've ever thought about in a lot of detail you hear about the need to balance the grid and making sure there's enough supply to meet demand but i think for me i've not ever experienced um a blackout or a brownout because of not having enough power generation or
electricity generation and i think that's in a way that's quite surprising i was never so good at learning this stuff in school for some reason electronics was not my thing i think i've actually learned more about it from using particle accelerators then i have from teachers in school which is probably a weird way of learning about electricity all right enough i mean we all take different routes from my personal perspective i'm going to be very honest with you both
electricity and understanding the grid is never something i understood when i was at school um and even till this day i'm not in any way familiar with it all so before we start and delve into this perhaps it would be good if we could provide some definitions mainly for me to understand but everyone else is listening so what do we actually mean by the electricity grid like what is this so you have generators and often in the past it was big coal plants and they might be near
coal mines or far away from people because of the emissions from coal so it's not necessarily where we live so we have a transmission network that's at a higher voltage than we need and it'll come to a more local distribution network and again that's a little bit lower voltage and then we have substations and they distribute it to businesses and homes uh and that's what everyone calls the grid when i first think of a grid i thought of underground assets so things like traveling
underground but i guess to get from the generation part to the substations is that where the pylons are used so they're the ones that high voltage above ground and then to get to a house it's everything below ground is that right there's there's still some cabling that happens over over okay too but you know there are actually really big cables the interconnectors that we exchange electricity with ireland and france and somewhere else in europe we we have a few what we call interconnectors
they're huge cables that are buried under in the sea okay thanks for laying that out let's go back to basic this whole thing is all about power right so yeah power one way to think about it is how much energy you have per second one of the really funny ways i think of it is instead of electrons in cables it's like delivery people and getting deliveries okay you've changed my whole perspective on life right now because i always struggle with just imagining electrons just like hitting each other
so now i'm gonna just imagine them as delivery packages okay i'm with you so far yeah i'm gonna like also say this is from a direct current a dc perspective because that is where we're gonna start with okay let's say the battery where power comes from or the energy comes from the warehouse the distribution hub the more delivery drivers you have per second you're gonna get more deliveries that's a really nice way of describing it because i said near the start this
was something that always confused me in school and like in the last few years i've been working in a building that has particle accelerators and we do experiments with it and i i learned about currents in terms of the beam of particles that you're accelerating towards your sample and you know how many particles or how many ions you've fired it because you can measure the beam current so that's what i understand of current it's how many ions per second or how many electrons per second if you're
talking about an electrical circuit which i guess is the packages that you're talking about and then the voltage is pretty much how fast you can accelerate the particles so what's the energy that they're traveling at when they reach the maximum speed that you're giving them yeah from a more technical perspective it's potential difference that because of particle attraction the stronger the difference the faster a parcel is going to go from negative to positive but if we're talking about the
analogy of delivery driving it's like the speed limit of the road that they're traveling on generally they're going to match the speed limit to be fair your analogy is probably more understandable than mine because mine only really makes sense if you use a particle accelerator i was going to say laura could you give me a bit more information oh you don't really want to it's a bit off topic fair enough you start off with something that generates ions at one end and then you accelerate
them towards something they're attracted to and there are various things you can do to this but it's pretty much what antonio was describing where you have that potential difference that thing they want to accelerate to i should say that most of the stuff i'm working on was in a vacuum and in an actual electrical circuit it will probably be a little bit different so yeah maybe we don't use particle accelerators to explain how the electricity i think that's a good way for some
people you know why knock it i ended up looking at the gcse revision stuff that bbc bite size does i feel like anyone that's in school will probably notice better than we do this is a simple definition of power right the school children know better than i do it turns out so use your analogy i guess of packages what's power then if i'm talking about delivery drivers let's say power is how many patches you can deliver at an instant in time so yeah i guess most
people in school would know the equation is um power is voltage times current and i guess you learn about this by constructing a simple circuit with probably a light bulb connected to a battery and the electrons just run around that circuit but i i guess the grid is probably a little bit more complicated and quite a few people in the victorian area probably had a big part to play in how it was created i mentioned faraday at the start he discovered electromagnetic induction in
1831 which is the principle used by power stations that use steam to turn a turbine and so ultimately generate electricity and so from what i've read there was a lot of development of electricity generation between the 1880s to about the 1920s that's what i was reading we sort of had an idea to record this episode a while ago and i did a lot of reading to try and get my head around it apparently there was this huge argument about whether alternating current or direct current could be used
but alternating current was chosen because transformers could be used to change the voltage and the currents whereas with direct current it would be a little bit more complicated um an alternating current is where there's an oscillation so electrons move back and forth in the circuit i'm not entirely sure what that means for using transformers but the transformers mean that we can step the voltage up to up to 400 kilovolts apparently which reduces power loss over long distances so when
you're transmitting the energy along power lines and then you can drop it down to something that's apparently a safer voltage to use of 240 volts is what we use in the uk fun fact from what i've read when you're talking about batteries they're all direct current so it means that the alternating current must be converted if you want to charge your mobile phone or your electric vehicle and that apparently leads to a power loss which to me doesn't sound like a good thing so to get this correct
then so we have ac current to get the electricity or gets the energy to us and then within our homes we use dc no so we still use ac at home it's only for specific applications where we have to use dc apparently most appliances use dc but they'll convert it once it gets to that particular appliance okay antonio was talking about steam turbines they all generate alternating current yes so the whole idea about what michael faraday found was the way that the generators turn is how it generates the
current and that switches the poles and then you get the current going one way and then back another way and it happens at a specific frequency what's really funny is before we came to a standard there was so many different frequencies and voltages used that you'd basically could have an appliance that wouldn't work in another part of london because there was 10 different standards i just can't imagine going to a shop at one end and then going back to your house and
being confused while your electrical appliance wasn't working or you'd have to use some sort of adapter or transformer so that you had your correct energy supply no it sounds like it would have been so complicated and you can't just like borrow some light bulbs from your friends say because their power supply is different you mentioned that it used to be different in europe and i think that might explain why i managed to break um a minidisc player about 20
years ago when i was on holiday i wasn't really aware of this and it had an internal battery and i charged it up and then it would no longer work it must have done something with that battery that meant it would no longer hold the charge oh sad times yeah it's not a thing now thankfully well is that the case anywhere so that's why we have adapters it's not just for the shape of the plug but also it will transform it into the correct voltage and frequency for our appliances if you want to know
if something has a transformer which would be changing the output you can hear a little hum when it's connected if it's really inefficient okay i unders i can see these delivery drivers coming in and out and like they're on the speed limit and i get the powers just like how many drivers there are and then i understand that there's ac and dc so then how does that kind of all then relate to the grid because the grid was basically made up of steam turbines we found one of the most efficient ways to
run them was between 3000 or 3600 rpm and rpm is revolutions per minute or 50 turns per second that's 50 hertz and so that's the prevailing electric grid frequency across the world either 50 or 60 hertz because of these generators and we call that synchronous because if you imagine we have a network of all these generators connected by the national grid if one's spinning faster than the other then it will equal out but it will kind of be weird at one end yeah i'm
saying spinning way faster than the other and eventually the way that electrons would go they would kind of tend towards the easiest path so it would just mean like someone would have flickering light bulbs and someone else would have way too bright light bulb it's a path of fleece resist yeah yes i remember that now it's all coming back to me i'm telling you when you said they were most efficient at a particular frequency okay when i was reading into this from what i could tell 50 hertz was
picked because it was the lowest frequency at which old light bulbs wouldn't flicker back in victorian times it was you know those incandescent light bulbs have a filament that heats up um and then it starts to glow as it gets warm but anything lower than 50 hertz meant that the filament had time to cool down between each cycle which sounds like a thing we don't necessarily need now because i don't think a lot of people use incandescent light bulbs but there we go and apparently back in the
late um 1800s early 1900s when the grid was being developed you wanted turbine to spin at as low a frequency as possible because of limits on what you could do with the mechanics and the materials apparently the turbines could maybe tear themselves apart at very high frequencies obviously you've got steam at pressure turning this turbine quite a high frequency for something that's actually quite massive and then you've got that magnetic field being generated which
then induces the currents in the coils around it and i can see if you're spinning i guess maybe magnets originally that would have been really heavy there's a limit to how fast you can make that thing turn without doing damage yeah and i guess the more moving parts you have and the more they're used it just wears down faster so they probably would try to get away with spinning it as little as possible and generating enough to keep the lights on literally yeah i'd imagine so and i
think things have changed a bit since technology's obviously moved on they don't use magnets anymore they create electromagnets using electricity get your head around that one oh faraday how did they start that off if there's no electricity to begin with that's obviously one of those things that you have to build up starting with a grid that's maybe not so efficient and then improving it you were talking about voltages in different parts of the world and i keep hearing that the usa is very
different such that it took a kettle from the uk it would take forever to actually boil is that all throughout the us i don't know i don't know if that's true i've never really tested this maybe we need a trip to the us we have to validate this you have to do our own experiments so we said power equals voltage times current and we want to deliver the same power so we'd have to change the current or the voltage in the us they've changed the voltage so that would do something
to your current but i guess there would also be limits to it because otherwise you would have really thick cabling in order to do that or there is some fail safe in your equipment to make sure it doesn't run over current and so it probably blows all our fuses all the time so instead we have some adapter to make sure it doesn't so it just means we get less power delivered because our appliances weren't designed to work at 120 volts they were designed to work at
240. oh so is all of the usa 120 volts in industrial settings they use higher voltages to run a big equipment so then does that affect anything else in the grids like the frequency at which the alternating current alternates are i think they've gone for a different frequency as well i was reading they run at 60hz don't know why i think countries just choose different ones so is it the frequency that's particularly important to how the grid is run or is it the
voltage or the current or something else i think yes everything lots of things frequency is a good indicator of how much is being drawn from the grid and whether we've matched the generation to the demand if you imagine these turbines are spinning at a certain speed and if there's more energy being used that's going to need more energy than what the turbine is powering so the frequency of you know the oscillations will slow down if we go back to your particle
accelerate we are taking more particles off we've got more deliveries taken away and so you're just not going to get as many deliveries in that time the reviewer electrons totally yeah on the grid yeah we've just taken them out so then you need to dispatch more delivery drivers does that mean at different times of the day do we like pump more electricity into the grid to meet different demand peaks one of the classic national grid explanations is tea time or at least tea time in the
north when everyone gets home after work between like four and seven there's that kind of peak of energy being used so it's turning on the lights turning on kettle start cooking watch tv all that kind of stuff and that's when they usually ramp up generation or bring on other energy from like importing it or from storage is their reaction to a peak in demand quite instantaneous is it quite easy to just do because we're going back to laura's point like we've
never really have outages here in the uk so is it quite instantaneous or do we just have a really resilient infrastructure around that in part there's a lot of planning that comes into it you know we had an episode about weather forecasting the weather kind of dictates it if we're having a colder weather then we would anticipate more energy being used or if there are certain events then again that could be either a drop in energy demand or increase in energy demand kind of
depends what type of event it is but mostly it can really vary sometimes we do have a more instantaneous response if it's not anticipated the frequency will have dropped but increasingly with renewables there might be times when we have more energy than we needed and then we have to actually find a way to make sure that the grid doesn't have too much electricity going for it yeah more than it was expected or designed for it's a good point and a good segue into
renewables why is it not that easy first to just be able to use the grid as it is and just use renewable energy the term inertia comes to mind okay with a turbine like laura said before they're really big heavy pieces of kit so when we see there's a drop in demand you can simply you know reduce the flow of the steam going to the seam turbines and then slowly you would have less electricity being generated but it's not a sudden stop which doesn't necessarily happen with renewables because they're
just electrical energy instead of you know that physical kinetic energy then you could end up having suddenly loads of electricity to none and then that could be really bad for a stability point of view if we go back to the simple light bulb circuit if you had those variable resistors where you'd slide it across and you can see like the light bulb getting brighter and dimmer yeah instead you would kind of have a sudden on off and that gives people less time to react can we not generate energy
at peak times and store it or it does the storage require a lot of space yeah we have some capacity for storage so pumped hydro storage we've been using that for at least a century i think because it's quite a simple having a pump and you have again potential in the form of gravity during the cheaper times for generating energy you would pump the water up at a higher reservoir so it kind of is storing it as potential energy and then when you need the energy you release the valve and the water
flows down and pushes turbines so we do have some capacity for storage it's just not quite at the rate of which our renewables are coming online because we've kind of used a lot of the key places for hydro and there is kind of a physical limit to how much we can install before we have to start creating artificial reservoirs so when you say it's cheaper that's when there aren't a lot of people using electricity so at night when people are asleep but you still need some sort of generating
capacity because if there wasn't any electricity throat going through the grids i can't imagine the whole thing would shut down you need to keep those turbines turning is a really funny one the grid it needs to be in balance there can't be too much generation over what is demanding it's it's if we were delivering parcels but no one was actually needing them you just get a stockpile but all the electrons would kind of crash together and kind of overheat the cables and then you know
fire ah so with the steam turbines obviously we can control that because that's an entirely sort of a closed off process that people have created with renewables so with wind and solar you're limited by how strongly the sun is shining if it's shining at all because you said electricity is cheaper at night so it's definitely not shining then um or the wind's blowing though you have this sort of almost uncontrollable influx of electricity was that a challenge for managing the grid and
keeping it at that 50 hertz that's the funny thing a lot of people say renewables are unreliable it's not unreliable it's intermittent or kind of not within our control we can't say i demand more electricity so the sun must shine more we don't have control over that so we have to use other means basically to to match supply to demand we can have control on that those aspects a little so as we have more electronics we can actually decide when we want to do things like we don't have
to charging cars at a particular time of day we can set software up to set it to do it at a certain time things like that when i worked um so a sewage treatment plant it's quite energy intensive and we were doing it really for cost reasons but when we kind of would stop using things that weren't urgent or needed but kind of high energy intensive at certain times of the day and we put them on when it was the cheapest so yeah you can kind of manage i mean this is quite like a
big on a big industrial scale and you can manage i guess your electricity consumption throughout the day and it was cheaper to do that you can see you've got renewables if we forecast it's a really sunny day because the weather forecast is always accurate in the last episode does that mean you guys would all just run to work and be turning things on to get your intensely energy consuming plant up and doing its thing yeah and then you can't enjoy the sunshine bummer [Laughter]
yeah but sometimes people just need to do things at a certain time before christmas the wind wasn't blowing that much and the places we import electricity from also funnily enough did not have as much wind as us either so we had to use gas a lot more because it is that kind of controllable we can choose what flow rate or gas we use so that's why having other technologies is really good in terms of diversity in the news very recently a lot of people don't like russia right now which
is where we get a lot of our gas from so our prime minister is hatching a plan to make our electricity supply and our energy supply more widely a bit more resilient against geopolitical forces be interested to see what he comes up with because it sounds like we need some form of electricity generated from turning turbines i mean i worked in the nuclear industry a long time so that seems like the obvious answer to me yeah i think the difference though is we don't turn
nuclear plants on and off on a day-to-day basis we kind of plan it months in advance for a shutdown or maintenance they're often planned with times of low demand um i didn't work on the power generation side i should say so i only understand in very general terms but it sounds like from what you're saying you need that inertia in the grid so you need something that use steam turbines but then renewables wind and solar are very attractive for different reasons so i wonder what that
means for the future of renewables what does a resilient grid look like that's an interesting thing we've actually started making what one article called green turbines but essentially they are flywheels they're really heavy pieces of kit that are generally metal and we store all that extra energy as rotational energy they are really low friction so they kind of just keep spinning when we need it again we sort of tap in back into that rotational energy and use that to generate
electricity again and they can be quite efficient and we actually use that kind of technology in regenerative braking all right at least mechanically driven regenerative braking some is electrical you're regenerative braking in uh vehicles so in cars and lorries and things yes right they tend to yeah the the flywheels because they're so heavy tend to be mostly used in large vehicles rather than passenger cars yeah i think you mentioned this in our um episode about how was engineering
affected our lives a few months ago so um yeah so it sounds like you're sort of saying they do what a steam turbine would do that steam turbines have that inertia they're the big rotating things yeah but as well as sort of um mechanical ways we also have some electronic ways of sort of mimicking inertia in the uh frequency they're called grid-forming converses they kind of create electronic inertia again it comes back to the electromagnets instead of shutting off
immediately it kind of stays in the circuit because of induced induced magnetic fields so we're still using faraday's findings in some way just in a different way yeah and there are some other little bits of circuitry like capacitors and this is where my limit is we're essentially saying that because we have this old victorian electricity grid we're kind of limited with what we can do so i wonder what could we do if we were doing it from scratch based on what
little we know about how the grid works is this where we're going to look at some like movie that we've watched recently and try and mimic that world if only i could think of one i wonder if maybe using direct current would be more sensible in having just like local power generation so i can imagine like every community having its own power plant of some kind you know like new homes are often built with solar panels on the roof and that supplies direct current and your
appliances use direct current so you don't have to convert it so maybe there are fewer losses so your home is more efficient up to a point you're still limited by the sun shining so you need a secondary form of electricity supply i was saying that alternating current was chosen because we could use transformers and we could have really large voltages that were good for long power lines so if you don't need those long power lines maybe everything can be dc um or marvel
i think that makes sense but i would then just kind of be worried so i know energy production is privatized but the network is held by the government is that correct no that is still a private company okay they are um heavily regulated by off gem okay and there is sometimes talk about the future of that as a whole it it's surprising because in other countries they do have states or provinces which look after their own local grids and sometimes they're not actually better than private companies
because private companies are still the ones doing the job if you have your local council trying to control a grid they might not have all the expertise they have to go elsewhere yeah and because they're public sector sometimes they get overcharged because they don't have the expertise so it's a bit of a bit of a toss-up sometimes between privatization and public so i get laura's point it might be more efficient but then i was just going to talk about allocation of funds if one place is full
of rich people and they can hire lawyers and whatever that they might get a lot more funding to make sure that their parts are maintained a bit more but i guess it depends if it's privatized and it's regulated there's a specific level of service which they have to provide so you're both engineers here and you're talking about sort of the social and business aspects i'm just a scientist and i want to know how to use the science to the best advantage for my community
that's the fun thing about engineering now is we're still learning new things but inherently we have to consider the application for the people geographically even in the uk we don't have all the generation where we live offshore wind is great but we don't all live offshore i live very close to sea though so i'm fine at the conclusion of this is that laura is okay laura's a scientist she wants the most efficient way of doing this forget about everything else and antonio wants to live in a marvel
world i'm glad we reached those conclusions so this sounds like a good place to leave before we dive too far off topic thank you very much both for teaching me some basics of electricity and how that relates to the grid and i guess some of the concerns that we have with going completely renewable and the need for it to be diverse so we've sort of refreshed our memory of high school physics to help us understand our electricity supply which i think made us all feel a bit like our understanding
was a bit sketchy but then we have recovered from that i think we're okay we talked about the history of the national grid and why we have alternating current that operates at 50 hertz laura wants that now to be dc we'll see where that goes and how this is important for monitoring whether supply meets demand and why comparatively new technology like wind and solid doesn't always fit in with our victorian era electricity grid because it doesn't have that inertia and i guess
in our utopia worlds we all have our different ways of thinking so thank you very much both of you if you'd like to find us on twitter encounter conversation or leave us a comment on the episode thank you very much the views expressed in this podcast belong entirely to the person that said them they do not represent any industry or organization if you enjoyed listening to these views it would really help us out if you could rate us leave a review and tell a friend this podcast was
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