 Can you hear me? Okay Look at that. That's a wonder of technology, isn't it? Okay, and let's make sure that my slides are advancing so with a bit of luck you'll see some glorious high-quality animation So hi everyone. Thank you so much for being here. I really do appreciate it Liz and I are absolutely gutted that we can't be there in person COVID as it turns out sucks. I want to Really thank Johnty and the entire AV crew for arranging this at the last minute. I really really appreciate it So thanks everyone there Because I'm not there to drink club marty with you if you've got any questions or comments, please at me I'm at Eden on Twitter. I'm also on master done and my space and any other social network beginning with them basically so Look just before I begin. I'm not a salesman. I have nothing you can buy I don't have any shares in solar panels I just want to share my love of all things solar and say look yes, even on this crowded miserable rainy Sodden Island that we live on solar power is effective. It really is. I'm gonna give you a brief overview of the kit that you need as well So, okay I'm just gonna go over a few basic definitions just to make sure that we are all on the same page here Okay, so The amount of energy needed to move one kilogram one meter is one jewel The power needed to move a kilogram a meter in a second is one watt To do that for an hour is one watt hour a kilowatt hour It is a thousand watt hours and that's what we use to measure domestic electricity use If you've got one of those old hundred watt light bulbs and you leave it running for ten hours Then that uses one kilowatt hour and the average home in the UK uses about ten kilowatt hours of electricity per day That I hope is fairly simple. If you prefer it in horse power. There is an equally simple formula So, um, how does solar panels work? So they are these big black glass things that you sort of stick up somewhere and they convert sunshine into delicious free range Electricity, but how do they actually work? All right, you probably wanted a slightly more detailed explanation than that as this is emf. So here it is What do you want from me? I am not a physicist that look are photons and they hit panels and there's quantons and electrons Here is a very practical explanation Photon comes down from the Sun it hits the panel and that generates direct current DC That goes down a wire into a box called an inverter Which convert it converts the direct current into alternating current, which is phase matched with your local grid But then gets fed down into your consuming unit It enters your wires as AC and then you have your gadgets convert it back to DC So they can do stuff if it goes into batteries and there's a further AC DC conversion So basically DC AC AC DC AC is everyone understood that? Yes. Good. Like let's just move on. So It is actually really really simple to get started with with solar panels So all you need is a clear view of the sky if you've got a roof That's great, but you can use any space which has a clear view of the sky if you have a Balcony if you're on a flat and I've got a balcony you can hang solar panels off the balcony as long as they're angle towards the sun They will generate electricity if you've got a shed or a field or a garden or anything with a clear view of the sky You can use solar panels A word on trees trees are the enemies of solar panels. You should chop down any tree that you That's not very environmentally friendly as that look the big problem with trees is they tend to cast Shadows and if there's it's solar panels in shade. It won't perform as well So if you do have trees near your solar panels either move your solar panels or just trim the trees a little Do not chop down trees trees are our friends So as well as the panels themselves you will need an inverter this converts as I said with a direct current Alternating current which you can use now you need that if you're doing this in a domestic setting But if you've just got you know if all you want to do is charge your gadgets and your gadgets already used DC You can just plug them straight into the solar panels So if you have a caravan or you know, you just want to charge small gadgets you can get Small solar panels no inverter needed plug your USB socket in there And you will just get electricity flowing from the Sun into your gadgets, which is amazing You will need space in your consumer unit, which some people call a fuse board You will also need a generation meter if you're doing this in the domestic setting because the government needs to know How much solar power you're generating and you'll probably want an export tariff so most Providers will Pay you to sell your electricity back to the grid this sort of bends people's minds a little bit So some hits the panels electricity is generated It gets used in your home But if you can't use all of the electricity it then flows down the wires out Into your neighborhood and your neighbors get to use your electricity and you can get paid for that because you are a power station Which is fantastic and sometimes You can get paid more to export electricity and you get charged to import it. She's pretty cool more on that later All right, you probably need a smart meter if you've got an old meter or spin backwards That's no good. You might need a new fuse for your home supply. It's free It's a 10 minute job from your local power company You might need some new wiring depends on how old and rubbish yours is and you might want a battery Batteries are great for storing excess electricity, but you don't have to store electricity as electricity You can use an immersion heater So there are solar powered immersion heaters what they do is they sense how much electricity is being generated if you are generating more than you use It will switch on the immersion heater and start heating up a tank of water for you Which means you do not need to buy gas to heat your bathwater or your tap water or Anything else. So solar panels don't just replace electricity. They can also replace or supplement gas Which is very exciting. All right So what do panels look like they are big huge things usually delivered by the palette each of these generates 315 ish kilowatts and although they are big They are light these weigh about 19 kilos each, you know, you can easily lift one by yourself They are light enough to be installed on top of your roof without your roof collapsing Or you can just remove all of your tiles, which is what we did. This is about half the tiles We removed and the reason to do this is if you put panels on top of your roof You might need netting around them to stop birds from nesting underneath them And also, I think this is what they looks like when they're installed I think they're quite nice when they're flush like that. You will also need scaffolding Lots and lots of scaffolding depends on how tall your building is But you will need people with metal poles to come and bash things together. Great So those are the panels panels installed next thing is the inverter, this is it This is a big magic box. You can see those sort of black wires going down the roof beams into there So they're carrying DC goes into the inverter. It's phase match with your local grid turns into AC And it, you know, it doesn't need to be wired in so has power It makes a bit of noise. It's got some fans. It's got some relays clunks a bit So that's why it's in the loft, but you know, you can put it anywhere that's sort of out of the way Now, there are lots of different models of inverters Why did we choose this one? Well, let me show you a close-up and you will immediately understand Because it has Wi-Fi And that means you can run firmware updates on your solar panels. Who wouldn't want to do that? This one also has serial ports and USB logging and an API. I just really like gadgets Okay, I don't think I need to explain myself to an EMF audience gadgets are brilliant Anything that has an Ethernet socket is automatically cooler than anything that doesn't This is the battery again. This is another big hefty box Makes a bit of noise with fans and everything Despite the size this only stores about two kilowatt hours So about 20% of our day domestic use and this has sensors which clip to your electricity feed And you know once it sees our electricity is flowing out of the house. It starts charging And it can be set to discharge in the evening or when electricity prices are high It's great. You can also see in the bottom right there a home plug because again This has an Ethernet socket which means it has an API which means I can get lots of data out of it Which means I can draw lots of graphs Now, would you like to see inside the battery? Please please raise your hands if you'd like to see inside the battery Well, listen, obviously do not open batteries themselves that lets out the magic smoke bad times my friends bad times But we can take the lid off this and look inside. It is some fiendishly complicated circuit You know, it's just a Raspberry Pi Everything in the world is Raspberry Pi now. My domestic batteries are Raspberry Pi's fantastic. Thanks, even again So let's take a look at orientation. How do you want to place the solar panels for the maximum efficiency? So Liz and I have moved house a lot and in the last 15 years we've lived in three different houses And we fitted solar to each of them. So the the best orientation Is the one on the left and that is southwest. So you might remember from, you know Life the the sun rises in the east and then sets in the west And so anything south facing is going to be illuminated by the sun But if things are faced west slightly then They will be illuminated more in the afternoon and evening which is great because that's generally when you tend to use a lot of electricity The the middle property is where we are at the moment and that has a perfect east west split So the east panels are being illuminated all the way through the morning And then at midday both of them are being illuminated and then the west side is being illuminated all the way through the evening And that works really well and I've got so many graphs to show you and on the right is the worst The worst orientation. This is the first place that we did which is northwest southeast and that's rubbish Because it just and yet It still generates all the electricity that that house needs across the year now, okay Satellite photos are one thing, but I think we can do a bit better for that as it's emf gonna fire up the drones Let's see if this video works No, that video has not worked. So Or has it worked, I can't tell anymore. No, can you raise your hands if you saw a video? No one saw it. Oh, there was a video. Okay. Well Hey, I took that video in the very brief period of time when it was legal to fly a drone on your own property It isn't anymore. So don't do it. It's naughty So there were some things that Solar panels can't do they are not completely magic and the first is they don't work in a power cut If you have them tied to the grid, there is a risk of two things first is that if there's a power cut and your Panels aren't generating enough electricity. You'll suffer brownouts in the home But also if you're generating too much and you're exporting it It will go to the grid and people who are working on there who think that the grid is is off Could be hurt Now with some newer systems, you can reroute all of your circuitry to go through The batteries and your house can be completely islanded. It's a lot more expensive They don't self clean Now we're really lucky in the UK because it rains. It rains a lot It's raining today And that will just wash off any bird poo or leaves or anything like that, which is really useful If you're in a hotter, duster climate. Yes, you might want to get up there with the squeegee and just clean them off occasionally Uh, nothing lasts forever. I'm sorry to say death comes to us all Uh, that's grim But solar panels have Guarantees usually for about 10 to 25 years They will degrade over time, but they will follow a very predictable degradation curve and Yeah, so if they Exceed that. Oh, sorry if they don't perform to expectations You should be insured for that but things like batteries and inverters can and will die So you might want to budget for that There is no way to reverse the polarity to generate extra sunshine Which I think is a big mistake and we need to get our top scientists working on that So okay nerds, it's graphing time So, uh, all these graphs are generated by guess what a raspberry pi bit of python bit of php It's all open source. It's on my github go nuts with it. So this is a typical spring day This is a a couple of days ago Not many clouds in the sky and you can see there on the left It starts generating from the moment the sun rises like 5 a.m We're generating electricity and then it stops generating electricity when the sun sets And that generated I think 24 kilowatt hours in a day That's twice the amount of electricity that our house used. So we used 10 m You can think of it as we used 10 and then we sold 14 back to our neighbors Now I said that the inverter gives me details from each side so we used them west So let's now split that graph in two and show you what each side Did so there we go the the orange is east side the blue is the west side Now what's really interesting here is you can see how weather conditions can affect one side But not the other. So there's this big dip in the east. I think about nine o'clock So they're obviously with some cloud cover there But because the west side isn't directly under the cloud cover. It's just receiving the diffuse light It doesn't suffer as much and we can see that on other days The weather conditions, you know on the west of the east will really only affect One side if you know, it's completely cloudy everywhere. It will affect both sides But splitting your panels so that one side faces one way one the other way is a really great way To to increase the efficiency of the overall efficiency of the system So all right, this is all about generating electricity But what does it do for us buying in electricity as we all know fuel prices are rising and rising and rising Uh, what does this mean for us? So we use octopus energy for our provider They take half hour the readings from our smart meter. This is from a couple of weeks ago So you can see sort of midnight to early morning our house uses about 200 watt hours And that's having the wi-fi on and you know gadgets in sleep mode and you know all the rest of it So we use a little bit of electricity Which is supplemented by by the batteries But as soon as the sun rises we stop paying for electricity Our smart meter knows exactly when we bought electricity and when we're not and it says oh you've stopped buying electricity now You're actually exporting it Now there's a little blip there in the morning that's sticking the toaster on or the kettle on and then once that's done We stop paying for electricity and you know, Liz and I both work from home We both have laptops and screens and everything like that and during the day We are not paying for electricity because we are the sun is giving it all to us There's a blip there in the middle that I think that's me sticking the microwave on for a delicious microwave lunch. Yeah Um, and then come the evening that there's a big spike there. That's probably you know Maybe that's turning on the tumble dryer or the play station or something like that Um, but yeah, that that's just showing that on a typical day On a fairly ordinary house with solar panels You don't need to pay for electricity. The sun will do it all for you. Um, and you know, we're also charging up the battery and discharging it now What what about selling electricity? This is great. Don't need to buy electricity. That has cut our energy bills Heftily, but this is how we make money from it. So again, I said most energy providers will pay you just a flat Five and a half p every kilowatt hour you export to your neighbors octopus Um Will they do spot pricing on the day before they say this is the half hourly price of electricity And this is what we will pay you. So the red line there is how much they will pay As you can see, there's more energy demand sort of at seven eight nine in the evening than there is earlier in the day But you can see there with those sort of thick purple bars. That's how much we're selling. Um And what we can do with the battery is say, oh, you know what energy prices are going to be really high this evening Don't discharge the battery until energy prices make it worthwhile. It's kind of up to you what you want to do Um, for us, you know, it's just easier to say, you know What supplement our domestic use when the when the toaster goes on start discharging the battery rather than buying in electricity Uh, but it's up to you, you know, if you want to turn this into a money making scheme Then yeah, you can absolutely say charge the battery when electricity prices are low and then discharge when they're high Different strengths of different folks. I wish we had a bigger battery, but batteries are super expensive. So Let's just go take a look at this is last week. Um, this is last week in power And it's been a fairly nice week But you can see the sort of difference in the days there, you know Some days are cloudy and rainier than others the yellow line is how much Solar power we generated the blue ish line is how much electricity we bought and when it's above zero, that's us Buying electricity. We're paying for it. It's below zero. That's the energy company paying us for electricity You don't need to be a mathematician and do lots of complex calculus to see that come spring and summer We tend to sell more electricity than we use And this is again the amazing thing about solar power in a domestic setting is that You end up generating so much more than you can use just off a fairly ordinary roof. And so I'm going to show you I think this is the last 14 months Of electricity and and the property we're in at the moment. Now you can see December there Rubbish hardly generated any electricity whatsoever. But remember what I said earlier The average uk home uses about 10 kilowatt hours of electricity per day Call it 30 months 30 days in a month. That's 300 Kilowatt hours per month and you can see there Seven out of 12 months. We exceed that we exceed that sort of 300 kilowatt hours per month In most months we generate more than we use and yeah, okay We can't store it all so we sell it to our neighbors But I'm just showing you here that it is for the majority of the time Solar panels will generate more than you can use Maybe I should buy less efficient electronics. That's another interesting thing. It's just a side note The average home is using less electricity now than it did 10 years ago Because our gadgets and our fridges and you know, all of our appliances are more efficient Which I think is interesting Now months do vary, you know some months are sunnier than others, you know, you might have a particularly rainy june Or a particularly sunny autumn, but you can see there that there's a bit of variation So I'm now going to show you Another graph. This is a property from a few years ago And again, this is four years of complete use and then two years So You can see there on the left. That's the you know, how much Electricity we've generated over the year more than 3.6 megawatt hours Of one roof and came 10 times 364. Yeah We are generating over 100 of our electricity needs. Um I just think that it blows my mind every time I see it that you know in a typical house It's entirely possible to generate, you know between three to five megawatt hours Per year. It's not enough to charge a DeLorean, but you know, it's it's pretty damn good. Um So I've done this sort of big overview I'm now going to sort of crash zoom in To to show you one day in detail and this is a really nerdy graph And I make absolutely no apologies for it. It's ridiculously complicated. So I'm going to talk you through it So the the yellow line is solar. There is no solar generated in the morning and then sunrise. Yay Nice solar and then down and I go great um red Is the electricity that we have used so you can see we're using a bit of electricity And then there's a spike in the morning a lunchtime spike and then this big spike In the middle is us charging an electric car and you can see that uses an awful lot of electricity Blue is the battery level. So during the evening, uh, well, you know midnight to sort of seven Our battery very slowly discharges. That's great. As soon as the sun rises it starts to charge again Oh, we cook in some toast the battery starts discharging. Oh, we stopped carries on charging up We start charging the car and the battery just goes Just pumps as much as it can into our Wiring which then goes into the car now the green is the electricity that we buy so you can see sort of Early in the morning, we're buying the amount that we use and the amount that we buy roughly the same as soon as the sun rises Yeah, we we stop buying electricity. We start selling it Take a look at the gap on that very big. I don't know why I'm pointing at the camera like this I have a laser pointer. If only I could fire lasers into emf That gap between the red and the green Is the difference between what we use and what we pay for and that difference is the amount of Sun which is generating electricity at the moment and the amount of stored electricity From the battery so you can see there is this really hefty gap. If you've got an electric car It is entirely possible to drive on sunshine You know, you can set it to slow charge just turn on when you know the solar power is at its maximum And you can start discharging your battery into your car Um, and that means you're paying, you know, nothing to drive around, you know If you thought petrol prices were were getting worse and worse Well, good news spend thousands and thousands on an EV and solar panels and you can drive for free Now, of course, not every day is this good. So, um, yeah, it turns out solar panels don't work in the snow This is why I said it would be really handy if we could reverse the polarity and heat the solar panels and melt the snow But you can see there, you know, once the snow does melt there's a, you know, tiny bit of electricity generated Um solar panels work in the rain. They work when it is cloudy They work when it is foggy. If you can see the solar panels by sunlight, then They will generate stuff not not necessarily, you know, gigawatts, but they will still generate even in the rather rubbish British climate Now I've been graphing these solar panels for for years, you know, rather than by sucking up all the data And I decided to publish it as open data. So if you want to see what, you know, real data from real solar panels is like I go to my website and download that and I am Blown away that people actually did that. Um, there are several proper scientific papers out by proper scientificians Who have used my solar panel data and published it. It's like, well, brilliant. Cool. Um, anyway As we get to the end, let's talk about the elephant in the room, which is cost Um, I really like this tweet that that someone did, which is, you know, you rarely ask, oh, yeah What's the payback on getting a new bathroom or stuff like that? For me, solar panels are environmentally kind of a moral issue, but, you know, I appreciate they cost money and they make money It does make me feel like mr burns sometimes, you know, I see a nice sunny day and I think I'm making loads of money from the sun So sending back makes a significant amount of money, especially if you've got a time of day tariff You can see that again a brief graph just showing that, you know, every day or every week How much money can make from from selling back? So I'm gonna I'm gonna go through and do some quick maths with you So, um The cost of equipment is going to vary it will depend on government subsidies It will depend on how complicated your house is Um, it's local councils quite often have group buying schemes. Uh, how many panels you need But if you, you know, if you just want to buy a few panels to charge up gadgets, you know You can buy them for for tens to hundreds of pounds on Online if you want domestic installed on your roof Expect to pay between 3,000 and 12,000 pounds now That is a big chunk of change and it's a big gap Um, and it really is going to depend on, you know, local installers and local conditions But it is worth, you know, getting lots of different quotes And seeing how much, you know Your roof can can bear There is that cost of installation Especially if you need scaffolding on on both sides or if you've got, you know, really tricky Wiring that needs doing there is a bit for maintenance So, you know, you might need to replace some things. Um, you probably don't need to wash down the panels But you might want to budget for that And then this is the other big cost the cost of changing your habits So Do you want to live in a world where you can only use the microwave when the sun is shining? That you can only turn the oven on when the battery is full You probably don't but you might find yourself changing your habits to go. Oh, you know what? I can see the weather forecast is going to be sunnier in the afternoon So that's when I'll schedule the dishwasher to go on changing habits is hard You know saying, uh, well, I only want to charge my carbon. It's the sun is shining might leave you with not enough mileage, but That that's worth thinking about but there are financial rewards as well So you can sell electricity back to the grid Which is great, but also you don't pay for electricity when the sun is shining Now we did the maths on this a few months ago before the latest price rises And for our house with the sort of I think five kilowatt Panels on our roof our panels Basically save us At least 800 pounds a year And that's a mixture of selling energy Selling electricity and not buying it Um if electricity prices go up that's going to go up as well. So you can start to work out. Well, what's the payback time? You know, if I'm spending 8,000 pounds on panels and I'm saving 800 pounds per year these 10 years a good payback period You can work that out for yourself There's also improvement to your energy performance certificate So if you want to sell the property, you need an EPC higher EPC is it's good So that helps making money But I think the most important thing is moral smugness Can you really put a price on how good it feels to be an eco hippie? I don't think you can Look what I wanted to say and what I hope I've encouraged you to understand with this talk Is that solar panels work not only do they work? They work really well in the uk And if you install them and if you get inverters with apis and batteries with ethernet ports, you can start doing really cool nerdy things with electricity And I think that's brilliant. I want to thank you so much for for coming to my talk I really do appreciate you taking the time and I look forward to seeing you at the next dmf