Dave looks at his 3kW home solar power system after being in operation for 18 months and analyses the results.
Original video: https://www.youtube.com/watch?v=VGENVguQQmo
Timelapse install video: https://www.youtube.com/watch?v=fQAd7nposJQ
How much energy was produced?
How does net and gross metering work?
What is the payback period?
What is solar insolation?
The 3kW system uses 12 x 250W LG MonoX panels
http://www.solarclarity.nl/wp-content/uploads/2011/09/Data-Sheet-LG-Mono-and-Multi-X-ENG.pdf
and an SMA Sunnyboy 3000TL inverter.
http://files.sma.de/dl/15330/SB5000TL-21-DAU131211W.pdf
Uploading data to PVoutput.org using PVbeancounter and bluetooth from the Sunnyboy inverter.
PVoutput data: http://pvoutput.org/list.jsp?sid=20402
Forum: http://www.eevblog.com/forum/blog/eevblog-724-home-solar-power-system-analysis-update/msg630168/'>http://www.eevblog.com/forum/blog/eevblog-724-home-solar-power-system-analysis-update/msg630168/ #msg630168
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Hi back in 2013. June to be precise I Had this solar array installed three kilowatt a solar power system on my home roof here. and if you haven't seen that video, I'll link it in down below as the installation of it and going through all the various technical aspects of it. I've got how many Two, four, six, eight, ten, twelve, LG mono exit panels for a total system of three kilowatts here, a total nominal power output of three kilowatts anyway.

so it's been running for not quite two years now, but you know, good 18 months. So a lot of people have been asking can I get the data from this and see how its are performed over that time and comment on that? So yeah, let's do it. Let's take a look at some of the figures I've gotten out of this thing because I have been logging all the data that comes out of it and see if this thing has been worthwhile or not. Let's go.

and for those wondering I know I haven't cleaned this system at all. In well, in a sense it's been installed. So of course, see, when you get dirt on these things and little little bird droppings and all sorts of crap like that, it cannot reduce the output efficiency. But look, this has never, ever been cleaned.

Yeah, it's got some dirt on it, but yeah, it's hard to get an actual benchmarked figure of whether or not the dirt has made a difference, but not really, they've been I think they've been fairly are self-cleaning in that respect. Anyways, and things like the DC isolator box here which I haven't touched since installed I think I'd have to check my previous footage but I think it was a pretty white box when they installed it so maybe it's um, it's turned yellow. Maybe some bromide in the plastic? the roof penetrator here for example. um, that's still in really good Nick Looks like no deterioration of the rubber or anything like that, so the system seems to have held up quite nicely in terms of maintenance.

I mean it has as I said, been absolutely zero maintenance over all this time and you can probably it might be able to see some on there I can't see it on the screen, but yeah, it's I've had no issues. so the installation was all fine and these LG mono exit panels no issue. They are top of the line up panels of course. I paid a lot extra for these LG mono X ones.

not just you know, some cheap-ass no-name ones. and of course I paid a lot extra for this Sonny-boy inverter as well. Once again, top of the line. it's the SB 3000 RTO It's got the Bluetooth interface and that's what I've been logging the data from on this thing and and you can actually see the Isolators here.

Yeah, I think that's the SE original color of that isolator box. so I do have auto white balance on this thing but yet trust me, that other one is very yellow so it's had some light on it. This one is on the shady side of the house and it's basically covered by a big tree. Here it basically this system.

the inverter does not get any sunlight. That's one of the things you don't want to install one of these things. I'm in direct Sun which is why they actually went to the effort to mount it right on this side of the house. This is on the other side of the house.
so they actually there's some loss in the very long cable runs which have to come from the solar panels which are on the other side of the house here. But anyway, let's have a look at our total power output. They're basically very overcast. At the moment, we're only generating a hundred and sixty watts.

It's bugger-all It's 4:30 in the afternoon here and it's it's sun's starting to go down, but usually it's still generating a lot more than that. You can see that today, we've generated at ten point six kilowatt hours for a system total. This thing has not been reset at all since it was installed. So the total power with it output from our solar panels over however long we've been doing 18 months is seven point, Three nine, six megawatt hours.

Beauty. So you can see the curve for today how it ramped up like that and it's just really dropped off. It was sunny before, but now it's overcast and if I tap on this like oh, there we go, there's the backlight. I should turn that on before, but I can give it a double tap.

It's got a little tap sensor in there. This is now armed the output per day. So this is 20 kilowatt hours like that and you can see every day. It's sort of.

You know, it depends on how sunny it is really and cloud and solar insulation as well and the whole thing. but that's just some data output over lustre a week or two. And here's my meter box. here.

you can see my old dark meter which they disconnected when they installed this thing and they installed two new meters here. And yeah, and there we go. We've got one here and one there. This top one here is basically that is how much I have consumed and it's almost 6.7 megawatt hours.

Over all this time period, I'll get the exact number of our days soon when we do some mark calculations. But Tada, you can see that just from a warm fuzzy point of view. This this three kilowatt solar power system has generated more energy. You remember, it was a almost 7 point 4 megawatt hours and we've used six point seven megawatt hours.

So we've basically generated about point seven megawatt hours or 700 kilowatt hours more than the power we've consumed the last 18 months or whatever. It is brilliant. So right there it's a win. A three kilowatt system is good enough for a family of my size and a house like this running all your regular stuff including air conditioning and things like that and this meter down here.

This one shows how much energy we've exported to the grid because we've got what's called a net metering system here. and what that means is that I only get paid for the energy on this meter here I this is the one that I've exported out to the grid. so I haven't used I've got no battery storage system here, so I can only use the power while it's being generated. So the difference in that is the amount of energy that we've used and it's about it's about a third or there abouts I've used.
so I've used about a third of that 7.4 megawatt hours I've actually used in the house. Two-thirds of it has been exported and unfortunately, this net metering system is nowhere near as good a payback as the old system where you used to get paid for all of the energy that you actually produce. so I only get pay for the stuff I export and I get an extremely low rate only eight cents per kilowatt-hour It is piss-poor so right there, get your calculator out, you can figure out how much I've earned. Ah, it's not much.

Now having only used 1/3 of the power that we've generated is not really surprising. It's basically what we expected because we're not always here during the day, of course. but with a young family. Yes, we're you know.

I I Hear a lot of hours during the day. More than your average family, You know we're both parents, work, both kids go to school, and and there's basically no one here. Yeah, we do some stuff and we changed our habits as well. our washing machine and our dishwasher, for example.

We'd put those on during the day instead of like overnight we used to do before. So now that so those sort of appliances would only use energy during the day here so often, you know I'd come out here and watch it and we're not experts. Sometimes we were exporting very little and it was full Sun and everything. You can see the number of impressions here.

This little flash will give 800 impressions per kilowatt hour, so you can see it slowly flash or it turn over here. So we did sort of arrange our our habits a bit in that respect so we'd use more of the solar panel power because basically we're buying electricity. I'll show you the rates later. We're buying it at a much higher rate than what we're exporting it.

so it's basically use it or lose it. pretty much because we don't get paid much for all this energy that we've exported. So if we had some other power stuff that was going during the day and we could use all that energy, then it would be much more beneficial. But hey, we're actually using more power than your typical family would from their arm solar system.

So yeah, we're doing pretty good in that respect. So it's no real surprise that most people use most of the energy in their house at night because well, of course you get home from work, the kids get home from school. Yeah, lights go on your TVs go on your computers. Go on.

you start cooking dinner. Yes, we do have an electric cook top. We do have gas here, but we've only got guests for the water and the barbecue out the back. We don't have guests our cooking so the electric cooktop goes on.

all that sort of jazz. So yeah, you know things that we could do during the day. We did like the dishwasher and the washing machine. for example, we rarely use a dryer we're here in Australia we got a, you know, and Hills Hoist in the backyard got a clothesline.
So yeah, everything dries naturally so, but still, you know. Lights, TV computers, all that sort of jazz cooking all goes on at night and you just chilling two-thirds of your power. And in my case, that's exactly what it turned out to be. Pretty close to it, but unfortunately, we've got the net metering system here.

which means we get paid like one third of what we get charged for So measured on this meter, we're getting like, you know, 24 cents per kilowatt hour or something down here. we're getting like one third of that bastards. If we had a storage system here battery storage to where I capture that energy during the day, then hey, we could be actually completely grid independent here if we wanted to. Although you'd still connect to the grid, you know, just for the emergency, you wouldn't rely completely on your battery system.

Let your less you out in a rural property, it just wouldn't make sense. So if we had a battery storage system here, we're technically we wouldn't pay a cent for our electricity from the maintenance cost of the battery system of course, and the amortization of the installation of the solar powered system as well. But hey, as I said, we've had no maintenance issues or whatsoever. having two had never had to go up on the roof, do anything anything at all, so it's been super reliable.

it's been a couple of years, not a bad test so far. and yes, we do have our fairly energy-efficient lighting here. We used to have all our compact fluorescent stuff here in the house, but I've switched over to all LED lighting in the house so that may have lowered our lighting budget and things like that. but and didn't seem to make a huge amount of difference because we're already running that fairly efficient compare flurries, no incandescence or anything like that here.

and we do actually have to split system air conditioners here, but we don't often use that. The house has that thermal insulation in the walls. this is not our double brick by the way. it's only see, but there is insulation between the brick and the gyproc inside and we've got insulation in the roof.

Fairly well insulated house so we don't often have to turn on the aircon or if we do there. It's not a big central air-conditioning system so just cool down a little bit we want and then we switch it off. We're not well as families, it just run them 24/7 seven with some bloody climate controlled temperature thing. A lot of people around this area do that, believe me.

So I'll just quickly explain the difference between the net metering and the gross metering. That concept for those who still don't get it yet because it is a bit confusing. As I said, I've got the net metering system, which is what is displayed here. So I've got two different meters.
The top one there calculates the energy that I've used and the bottom one there calculates the excess energy which I haven't used during the day while the sun is shining so it gets exported to the grid. Now if I was home all day, I wouldn't be exporting much. In fact, you know if I was using if I was generating three kilowatts for example and I was using two kilowatts in the house, then I wouldn't be exporting anything. So I wouldn't be earning any money for that energy exported.

But I wouldn't be paying for any of the electricity coming from the grid ie. that top meter that twenty four cents per kilowatt hour that I'm being charged to buy energy from the grid. Now in my case, here in Sydney Australia I'm Ben I'm only earning eight cents per kilowatt hour for the energy I export or one third of what I have to buy it for from the grid. It is an absolutely ridiculous system, but hey, that's how it works here in our state.

So with the net metering system, if you were getting charged at the same rate as you were using the power, then, well, that's okay. You wouldn't have to really be home during the day to make use of that energy. But because my state here has got a ridiculous law where I only earn 8 cents per kilowatt hour for this system to be really effective for me I have to be home during the day or using energy during the day while the sun is shining and my system is generating otherwise. I Basically lose it because I'm only only allows the eight cents per kilowatt-hour if I export it and don't use it.

Now, a gross metering system is different in that you export all of the power that you generate to the grid. You Don't have the ability to use it. Well, at least in metering wise, you don't have the ability to use it locally and consume it while you're home during the day. So you will be by always buying energy from the grid at that twenty four cents per kilowatt hour.

So in my case, if I was on a gross metering system, it wouldn't make sense because I'd only be getting charged eight cents per kilowatt hour. so everything is warded to the grid. so I wouldn't have the advantage of being able to use that energy during the day. So for a gross metering system to be effective here I would have to be getting chat I would have to be earning at least the same as what I was taking it from the grid to get a good payback on the thing.

So it really depends upon how much you're getting for feeding back. I II the solar tariff for feeding your energy back into the grid and your usage scenario. Are you home during the day? So it's not a clear-cut case of you know one's better than the other, It depends on your circumstances now. Unfortunately I missed the boat on my system because quite a few years ago, the New South Wales government were giving massive feed-in tariff rebates to promote the solar energy take-up in the solar industry and that sort of stuff.
And they were giving you 60 cents per kilowatt hour Gross. and that was Ah. that was unbelievably generous. In fact, it was too generous that so many people took it up here in New South Wales that they had to stop the scheme because so many people rushed in because your payback period would be like like a year or two or something.

It was crazy. So unfortunately now it's dropped down to eight cents per kilowatt hour and net metering. Ah, Oh well. as I mentioned, I've been logging the output of this thing since I installed it and I use a website called PV Output Org and I'll link it in down below.

All this data is like so basically every day I upload I capture the data with my Sonny Boy inverter. it stores it inside and then I use a program called PV bean-counter to automatically extract that via the Bluetooth Sonny Boy interface and then upload it to the PV Output Dot Org website and this is all my basically daily output here. but I can go to monthly for example and you can see it changing over the seasons. This is when I installed it from July 2013 of course, which is winter here in Australia everything's upside-down here and it Peaks in about December there which is the middle of our summer and then it goes down and didn't quite reach the same heights.

but unfortunately the data for December 2014 and January this year are incomplete. I've captured the data I've got them in the CSV files, but unfortunately I'm having a bit. I've been having a bit of an issue with my program for the last month or two, so I'll eventually be able to upload that data. You can see that's only partial month 15 days and like two days in February and 15 days only in December.

But anyway, you can see the changing trends through the season. Now if we go back to the daily data here, I've not only got the maximum output you can see how much I've generated in this column here per day, and also the efficiency. and I can actually compare these with other similar ones in my area. For example, here's my one and it's a three kilowatt system.

By the way, I am tilting it roughly 15 degrees roughly Northwest ish or there abouts and my efficiency. for example, 3.75 watt hours per kilowatt. That's got nothing to do with the size of my array. It's basically how efficient my particular installation is relative to my nominal 3 kilowatt output figure.

So you know this number can either be fudged by saying oh yeah, my systems for kilowatts when it's actually 3 or if you got manufacturers who don't rate their panels properly and things like that, that can all cause discrepancy. But of course it's going to change with the solar insulation as well, which is the amount of solar energy hitting the earth per square meter, basically. And that does change. It's not going to be, you know, December 30th One year is not going to be the same output as December 30th the next year.
Even though it's completely cloudless, the solar insolation actually varies a lot day to day, and we'll be able to probably see that in a second. So I'm doing relatively well on my relative efficiency there. So if we go to my outputs here, the daily ones, for example, look, Oh, this looks like one of my best days here. I Generated 19.3 kilowatt hours.

Let's have a squiz at that and this is my output time. You can see it starts ramping up at about 5:40 p.m. the sun's just poking up. There's a little bit of a dip there, so I don't know what happened.

Maybe a cloud passed by or something like that. Few little ripples up here, but it basically goes very nicely. I Do sometimes get a fairly sharp drop off at the end because I've got like a house next door, which right at the stream end of the day depending on the season, will start to shadow my solar panel. So maybe we can see that a bit better on another one.

But let's choose another day that was very similar. Look, this one was nineteen point two kilowatt hours. But look at this. look at all these huge dips in here.

Obviously we had some huge cloud cover coming over, so instead of like two and a half a kilowatts Here I am getting, you know it drops down to under a thousand watts so. but that day generated as much power as the other day. So obviously even with these huge dips in there. so obviously this is to do with the solar insolation figure, the amount of radiation the Sun happens to be output in that particular day, and if you came to know about solar insulation, then well go check it out.

There's tons of info out there for reading. It's not a very often knowing art field, but it's also known as that solar irradiation as well. and it varies daily with the output of the Sun and all sorts of factors. And it's by an instrument called a pyrometer.

And here's a couple of pictures of these things. and some people actually have them installed on their solar systems like this so that they can log this solar insolation data as well like during the days. Unfortunately, our Tyranno meters are very expensive instruments generally like you know, in the like thousand plus dollar range or something like that, so they're not very cheap to install. But anyway, you can actually get the data from various government agencies in various countries.

Here in Australia it's the bomb the Bureau of Meteorology and they've got it. Looks like you used to be able to get this data back when I worked on my solar air heater my solar sponge which I'll link in down below. It's a very old art project which I don't have anymore, but I experimented with that solar air heaters and I used to get the live daily A data from that but I think you have to like subscribe. Now it's free to get the data.
But anyway, the several sources, you can see this map here of Australia just showing the changing solar insolation figure, but that will change daily as I said. I'm not just daily hourly, minute by minute. even if you've got a perfectly clear sky and the sun's in exactly the same spot. The output can change depending on what the Sun is doing and other factors.

so it's quite a complicated field. So solar insolation is expressed in watts per square meter and you solar panels Here here's my LG Mano X up panel. It's not the exact one. I've got a 250 watt one.

Anyway, it's still exactly the same. The standard test conditions are for a solar insolation or a solar irradiance of a thousand watts per square meter. So when you buy like a 250 watt panel, it's assuming that it's a thousand watts per square meter and it's correct. Or you know the correct tilt and everything else to give you your nominal 250 watts output at a certain load, etc.

etc. Then you have to get into the loker's and all sorts of things. and I specifying the output of solar systems can get really complex really quickly if you take everything into account. So as I speak.

Here's that's just after 10 a.m. here in Sydney And here's my live output data that's been updated from home I left my machine on there so it does update live. otherwise it just waits until the end of the day when I next turn on my computer and downloads all the data because the Sonny-boy inverter can keep our full daily data for up to what two weeks. So as long as I upload it within two weeks, it should all still be there.

and I can do all sorts of weird and wonderful things with PVR Poor guy can analyze my data and I can download it and if I had the hardware, I could also log the temperature each of five minutes and I could also log my voltage mate mains voltage as well or the output of my solar panels and energy use and power use for example. But I don't have any energy meters hooked up that I can actually export data on and tied in to the whole watt system. that's more complex I Never bothered with that, but at least I've got my Art Solar data and allows me to do lots of fantastic stuff. Here's my weekly chart and just allows me to follow things really quite nicely and how it's tracking and all the data is there.

And if you want to see one of my worst days, well, it was a couple of days ago. It was pretty horrible. here. was dark, stormy, overcast like end-of-the-world type stuff all day and it sort of peaked at about 800 watts.

and there may be the Sun Shine for two seconds I Don't know, but it was a really horrible day and it got you know right down. At one point it got down to well outputting 72 watts from my three kilowatt system a couple of times. Look at that pretty horrible stuff. But even that day there generated 3.5 kilowatt hours.

So you know that's on a horrible day, that's still pretty good. That's probably still the energy I use sort of like one third of the energy I use for the whole day. So that's pretty much all of my daily energy even on a really horrible day. And my three kilowatt system generates enough power for me to use.
So here's what everyone wants to know how much power and money have I saved by installing this a kilowatt solar power system on my roof? Well, here is three shots of my before and after bills basically. so the top one there. from July to September 2013 when I have the new solar power system to my bill in the previous year July to September 2012, you can see it's dropped from nineteen point one kilowatt hours on average for daily usage down to twelve point Eight seven. So that's a decrease of almost thirty three percent in my grid usage.

Awesome! And you can see the other time periods there from October to December and April to June as well. Once again, both when I have the solar system and when I don't. And of course there's different daily usage figures there because we're changing the seasons. Of course you use more or less power summer or winter, but look, the total average there is a rate just over 33% I've reduced in my grid power usage.

So there you go. I've automatically reduced my bill by 33% right there. So that's pretty much exactly what I expected to get because we're not using most of our power during the day when the sun is shining, when we can make use of the energy from the solar panels, we're using it at night when we have to draw it back from the grid. So using about two-thirds at night and one-third during the day.

But because the stuff the one during the power we use during the day is being supplied by the solar panels. bingo, we've got around about a 1/3 reduction. Of course, this might be significantly different for different people who have different usage scenarios. If you use a lot of power during the day when the sun shining, then you can get a much greater return than this.

So that grid power saving of course, translates directly into a kilowatt hour energy saving per day. and I've got the exact same mark, three quarters worth of bill data there, and I've just subtracted the difference in the kilowatt hours per day and the average figure comes out to five point Two six kilowatt hours. And we can use that in a minute to calculate our total saving and total payback for this system. And if you're curious to actually see my bill, well, here it is and what I'm actually charge.

You can see here the charge rate in that cents per kilowatt hour is twenty 2.71 cents. Now this is just recently dropped like in the last year because we used to have a carbon tax here which the current government bloody will scrap. So our rate did drop, but then artificially went up before. that.

arts ridiculous. Anyway, that's my current rate, but I Also pay extra two point eight cents per kilowatt-hour here to get a hundred percent err, audited an accredited green power my one actually comes from wind farms just up the coast somewhere I Forget exactly where. But anyway, there we go. My total usage for the last quarter.
Seven hundred and twenty five kilowatt hours, Four eighty five days, and you can see down here that I'm that cost me a total. Of course there's a servicer charge as well, whereas that supply charge. There we go. So I'm getting charged sixty dollars a quarter for the supply charge.

I'm not sure what the controlled load is. An extra four bikes are guard, They whack on everything they can everywhere. But anyway, it's two hundred and seventy four dollars a quarter. and that's not much at all.

I Know somebody else in my street who pays well over a thousand dollars a quarter for their electricity? Oops, Um, yeah, they're doing something horribly long wrong. like leaving their totally ducted air con system on 24/7 Most likely. Anyway, here is where I get my payback Here We go: the solar contribution here. We go for the eighty five days I generated 858 kilowatt hours.

And of course I get paid a lousy six cents per kilowatt hour. So roughly one-quarter of what I have to buy it for from the grid. That's what I'm being paid to feed back into the grid. It's a bloody rip-off It really is anyway.

So there you go I get fifty one. I Got 51 bucks for the last quarter. It doesn't sound like much, but when you count in the one-third drop that we looked at before, plus his payback, well, let's look at the total figure I Don't know what it is yet, haven't added it up. Let's do that.

Oh, and just to be clear, that 858 kilowatt hours that they've read here, you're but this is a net metering system, so this is what was read on those two meters. You can see the difference in the figure there, which they read from one to the other. That is the just the energy I've exported to the grid. That's not the energy I generated with the solar panels because you remember I used a third of it so it would have and just add an extra third on top of that and that's what I would have generated roughly.

And of course, if I was home during the day and was able to use all that energy from the solar panels, well I wouldn't have anything on here. there would be I'd be exporting nothing to the grid at all in theory if I used it all. but of course I want to use it all because I'm only getting paid that lousy six cents to feed it back into the grid and I've got to buy it at like you know, 25 and a half cents total. so it's better to use it than to feed it back in my particular case.

But if you live in an area where you're getting like a one to one feedback tariff ratio so you can sell it back to the grid at that 25 cents or whatever it is, then you know, Hey, it's better to have a bigger system like that, but for my purposes, it's actually kind of detrimental to have a larger solar system. If I put a 10 kilowatt system in there I'd probably never get the payback because I'd never be able to use all the energy. So I'd only be getting a lousy six cents per kilowatt hour for feeding it back. And as you see, it's only 50 bucks a quarter? It's bugger-all.
So summing up what everyone wants to know: was it worth doing this financially well? Let's take a quick look at the numbers: I averaged a savings start from the top here up in the green I averaged a saving of 489 dollars a year based on just that energy saving because I was using 1/3 of my energy during the date from the solar panels that will vary from person to person. But there you go. it's almost 500 dollars a year there. Then in the blue, there, we've got the average solar contribution payback ie.

the energy I didn't use during the day I exported back to the grid. That's a hundred and eighty five bucks a year because I'm getting a very low feed-in tariff rate of six cents per kilowatt hour. Could be as much as 8 cents per kilowatt hour if I went to another supply. But let's not go there.

There's arguments both ways. I That's one hundred eighty-five dollars a year. So there you go. My total saving per year is six hundred and seventy four dollars and there's been no maintenance so far after almost two years install.

but I've got a twenty five year warranty on the top of the line. LG panels plus I've got a ten year warranty on the inverter and the installation as well. So during the payback period, it's basically all covered. There should be no extra fees at all.

So to install my three kilowatt system cost me around about five thousand dollars. Now that I deliberately chose a very expensive system with top-of-the-line LG Mono Ex panels plus the Sonny-boy inverter. you can actually get a three kilowatt systems for as little as three thousand dollars here. but I deliberately paid more I wanted better quality components that would last a long, long time.

So I deliberately paid extra. But anyway, the payback period is that five thousand dollars divided by the six hundred and seventy four dollars a year that I'm saving. And these are measured figures. These are calculated.

They're basically pretty much our average measured figures that I've got. So the payback period is seven point four years. Not terrific. But considering that I'm in a state which pays a lousy six to eight cents per kilowatt hour I think I'm doing pretty darn good to get a payback in 7.4 years now if you are bought the cheaper three kilowatt system and get it for as little as three thousand dollars or if you bought a smaller system I don't need a three kilowatt system so as you can see, most of my savings were actually made up in the green.

there were made in actually saving energy during the day. not for the payback period. So anyway, it could have got away with a smaller system because I get that low feed-in tariff. But assuming you pay three thousand dollars for a system that's only four and a half years payback, and that's pretty darn good considering that I live in once again, a crap state that pays you nothing if you lived in one of those good states where, or a good country where they pay you at least the same rate you buy it from and your payback period can be as little as a couple of years.
And as I said in New South Wales used to have a 60 cent fee in tariffs, so it was absolutely crazy. It was more than three times what you would actually buy the energy at, and the payback period was like less than 12 months. It was crazy. So there's actually no telling what that tariff is going to do in the future.

I Don't think it's ever going to go down I Think it's only ever going to go up. You know a new government gets in. They could, actually, you know, change their mind and bump it back up again. That's my hope anyway.

and in a couple of years time, I might have myself an electric car a fully electric car and I've got the lifestyle I live close to home so I'll be able to I even charge it during the day and make use of that excess solar that I'm not actually using, so that'll be fantastic. And for those who aren't aware, Australia actually has quite a large percentage of homes adopting solar power at once again because of that scheme that the government put in a quite a few years back. I think last time I checked we had about 12% of the homes in the entire country with solar panels on their roof. It's very common around my area.

My street for example, has like I think it's about 90 percent of the homes have that solar panels. So extremely popular. But anyway, there you go. Um, it's yes, it has been very well worthwhile.

So I hope you enjoyed. That's been a bit of a lengthy video longer than I expected, but I covered quite a few things. So there you go. If you want to discuss it, jump on over to the Eevblog for and I'll leave YouTube comments down below or comments on the blog website.

If you like the video, please give it a big thumbs up on YouTube Thanks! Catch you next time you you.

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By YTB

27 thoughts on “Eevblog #724 – home solar power system analysis update”
  1. Avataaar/Circle Created with python_avatars Boncholio VL says:

    I got to get those safety-slippers 😅

  2. Avataaar/Circle Created with python_avatars Daniel Horne says:

    is this true in uk that solar feed in tariff / payback has been cancelled in 2019 ? . well i wouldn't care if i dont get paid for it ill just use all of the energy it produces by taking the thing off grid lol so the main grid cant have the energy back or hook it up to batteries then use them later on (i currently dont have any solar panels on my roof at the moment but if i did that's what i would of done )

  3. Avataaar/Circle Created with python_avatars Jeffrey Morrissey says:

    Are you a net energy producer or consumer?

  4. Avataaar/Circle Created with python_avatars Jeffrey Morrissey says:

    You can get a large electric hot water heater and save on gas.

  5. Avataaar/Circle Created with python_avatars theuncalledfor says:

    "Bird droppings and all sorts of crap like that."
    I… I would hope there wouldn't be any more sorts of feces besides bird feces on the rooftop solar array.

  6. Avataaar/Circle Created with python_avatars Marco Franceschini says:

    Super great greetings from Italy…Dave…

  7. Avataaar/Circle Created with python_avatars Derek McDaniel says:

    Are there good home storage methods besides batteries? like a gravity water pump or something?

  8. Avataaar/Circle Created with python_avatars Hola! Sense says:

    yes but how about powering the solar by MOONLIGHT!

  9. Avataaar/Circle Created with python_avatars Billblom says:

    What sort of aggravation would you run into putting in a life battery bank? You could end up cutting that peak usage rate…. Utilities here are screaming duck curve, and no longer paying much of anything for power pumped back into the grid.. a major pain. Think 1 to 3 cents per kwh. When people were told they could get 20 cents per KWH, they were looking at that to pay for the systems here.. No longer. I'm looking at it for full power backup… I figure 9 kwh worth of batteries would be needed, so I've started linking up the pennies in the pigging bank….

  10. Avataaar/Circle Created with python_avatars Sundancer says:

    Switch to a gas stove, for sure!

  11. Avataaar/Circle Created with python_avatars suavek says:

    Because you're missing expensive battery storage that means you are buying energy from the grid during night time or anytime solar panels are not producing energy. That means that 6.7 kilowatts of energy you consumed include grid energy you purchased while 7 kilowatts of energy produced include energy you used and also sold to the grid. Where the negative price difference between kilowatt sold to grid and imported from grid, the math becomes not that great when you speak about how much you used and how much you produced. Overall interesting video.

  12. Avataaar/Circle Created with python_avatars Mr Mobodies says:

    I had panels installed many years ago and the company tried to trick me into polycrystalline by forging the wrong paper work. I managed to get them swap it over for free as their website recommended monocrystallines. It pays for the bills and it is a feed in tariff and I got that Sunny data logger so i can check for any problems.

  13. Avataaar/Circle Created with python_avatars David James says:

    That is only about $800 of electricity total. Well below the cost of the equipment and assuming most of that was used to charge batteries which are far less than 100% efficient (power out vs. power in), maybe $500 of useful electricity generated in 1.5 years. Not very impressive.

  14. Avataaar/Circle Created with python_avatars SolarizeYourLife says:

    I been thinking, maybe a temperature sensor on the panels to measure the overheated panels will help configure the temperature coefficient of the panel at the time. We all are losing a lot of power in the heat of the Sun, and we just don't know it…
    Have you ever configured the power loss with the temperature coefficient of your panels?
    Our panels are never at 25° C except maybe in 'winter'…

  15. Avataaar/Circle Created with python_avatars Easter Stedman says:

    You can find perfect idea for that on Avasva Solutions website.

  16. Avataaar/Circle Created with python_avatars Mark Cotner says:

    Wow, $0.25 . . . no wonder you all are going for solar. I pay $0.07 here. Solar is harder to justify.

  17. Avataaar/Circle Created with python_avatars joseph john says:

    Nice video. Do more Solar energy videos

  18. Avataaar/Circle Created with python_avatars Solar and Gardening stuff and DJ Stuff says:

    Do you have a battery or 2 and more panels now?

  19. Avataaar/Circle Created with python_avatars tom duke says:

    cheesus, what kind of demon posessed you to skip the batteriebank? you could have payed it back in like 2-3 years, including the batteriebank….

  20. Avataaar/Circle Created with python_avatars Greegor47 says:

    I've seen that Google has some monster huge server farm facilities and solar panels.
    In that scenario why even bother to try to sell power to the grid at a low rate?
    Every watt hour their solar array produces just replaces what would have cost them the full rate from the grid.
    Would placing these on a gazebo or picnic shelter 20 feet from the house solve the firefighter problem?

  21. Avataaar/Circle Created with python_avatars mat robbins says:

    Piss poor install, dektites shocking. Rooftop iso screwed into panel. No. Conduit entry in the tops of all isolators

  22. Avataaar/Circle Created with python_avatars Murray Runge says:

    Here in Sask Canada, we are charged 14 cents a Kwh but also basic charge and taxes so 500 kwh is 100 bucks or really 20 cents. You could easily pay off an electric water heater with the extra power your not using and put it as a pre-tank to your gas one. But without a battery bank to store and reuse your power when you need it your giving your savings away. over 7 years to pay off 5000 is pretty crappy. one day selling excess for 6 cents next day buying it back for 24 plus taxes sounds pretty ridiculous. I wouldn't want a system like that.

  23. Avataaar/Circle Created with python_avatars milodudeful says:

    So wow my energy company for net metering only gives you 2.47 cents USD for every kWh when they charge 8.40 cents per kWh during winter or 32 cents per kWh (during peak hours) wow. I guess that this is what you get when companies have a monopoly

  24. Avataaar/Circle Created with python_avatars S Puneeth Kumar says:

    have you done a tear down of the grid tie inverter that you are using?

  25. Avataaar/Circle Created with python_avatars Medicine Man says:

    how many do I need to run the 80 horsepower blower in my shop?

  26. Avataaar/Circle Created with python_avatars Laggger Engineering says:

    Just 8c per kWh? F*ck that, store it in some batteries and use energy from those.

  27. Avataaar/Circle Created with python_avatars mattimus ?? says:

    .06 dollara doos!! can't you force higher pay rates like the power companies do? theres gotta be a way to get more money for the power u generate.

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