Is a 10 kWh Battery Enough? Solar Questions Homeowners Ask Every Day

We get asked the same solar questions every single day. How many panels do I actually need? Is battery storage worth it? What happens on cloudy days? Will it work with my ducted air con? We’ve heard every version of these questions. I’m Jason. I’m Cam. We’re the owners of Source Energy Group, where we’ve designed and installed countless solar and battery systems for Australian homeowners. In this episode, we’re going to rapid-fire through every solar question we get asked. So, by the end of it, you have everything you need to make the right decision for you.

Goodday, guys. Cheers for coming back and putting up with us. Guys, how you going, mate? Good, Cam. Yourself? Yeah, not too bad. Who we got here today with us? All right, mate. We’ve got Delph. Delph’s back. For anyone who hasn’t been watching, start watching. And this is Delphie. She She works not so much behind the scenes. She does all the PR and whatnot for us at Source Energy Group and all the connection applications and whatnot. Makes solar going on your roof actually possible. One question that I do get a lot is a 10 kW enough to run a house?

It’s not the right question they should be asking. They should be asking or looking how much they’re actually using the household. What am I using during the day? What am I using during the night? Then that’s going to, you know, provide them the answer on what size battery do I actually need, not what does a 10 kWh battery do? Because that’s what everyone’s Googling, searching online. A 10 kWh battery could be right, but it could be very, very wrong. A 10 kWh battery could run a house with very, very, very small usage, but the likelihood that is it enough to run a house? It’s generally going to lean towards no. How many solar panels are needed for a 10 kW battery?

How many solar panels are needed for a 10 kWh battery? So, the 10 kWh battery will will 10 kW battery will all be determined by how much leftover usage you’ve got during the day. Um Actual usage from the battery? Yeah. Um and yeah, obviously yeah, usage from your battery as well. Uh so the exact amount of solar panels can’t really tell. Like if I was to do it in the what we say or what we call the cookie-cutter spec, I’d probably say a 6.6, so 475 W panels, you’re looking at 15 panels. Uh I wouldn’t go any less than that. I wouldn’t go any more than that. Less is a waste.

So so yeah, 15 panels would be my answer. So essentially, you know, you’re saying 15 panels would be the minimum you’d put on there. That’s for that battery, but again, without actually looking at everything, we don’t really know if it’s the correct amount, is it? See what I mean? Someone with extremely high daytime usage might need more panels in a smaller battery. Someone that uses everything at night might have less panels and a bigger battery. That’s it. And that’s why every single detail matters, doesn’t it?

100%. 100%. Definitely. What else have people been asking or going through? Oh, look, I mean, I get a lot of price comparisons with a lot of other different companies that are advertising. Like I had a customer call me out the other day and she said, “Oh,but I I’ve just been sold this battery,but this battery is 3,400.” And I’m like,

what like what do you say to that, you know? That that’s one of the biggest ones that I get is a lot of price comparison, but I said to her, “You either go to Kmart or you go and buy a Louis Vuitton bag. Which one do you think’s going to last longer, you know what I mean?” Kmart. Better warranty at Kmart. Yeah, that’s it. Yeah, Kmart can break 10 times and still get replaced, though.Nah, I’m joking.

All right, guys, thanks so much for that. So, another really juicy question that I’ve got in here is how long does it take to charge a 10 kWh battery from the grid? Oh, interesting question. From the grid? Mhm. From the grid. Okay, so someone trying to take advantage of the 3 hours of power, I guess, where they import from the grid.Um

solar saver offer. Yeah. So, the 10 kWh battery During that 3 hours, you’re allowed to use I think it’s up to 21 or 24 kWh.It’s probably going to take about an hour and a half during that time to charge that 10 kWh battery from the grid. Okay? From the solar is a different story all together. Depending depending on what type of product it is as well. If it’s the depends on the inverter size.So, 5 kW inverter can charge at 5 kW max. 10 kW inverter can charge at 10 kW max. With 10 kW inverter, it’s 2 hours for

hours for a 10 kW inverter. 2 hours for a 5 kW inverter. All righty. Another lovely little question that we have in here is how long can a Powerwall run a house? Um the house should run away from the Powerwall. Um it again it’s it’s a hard one hard one to answer. Um Powerwalls come in different sizes. Um and it all depends on the home. Um But not knocking Tesla. We got two very nice Teslas sitting right here in the in the in the shop, so.

We sure do. Yeah, bloody beautiful.Yeah, great great vehicle. Mhm. battery.Just not a battery. It’s just not for everyone. Yeah, for the home. So, I again unless you know the size, we really don’t know how long it’s going to take to charge. Uh I guess one of the most common Tesla is it 13.5 kWh?

Kind of like that same previous question comes down to inverter size.Um again how much panels you got on the roof for production and where the limit taps out at. How long is a wet piece of spaghetti? Ooh, I love this question. Is it better to have more solar panels or more batteries? This is a good one. I think I just touched on that briefly before, you know. You touched me.

No, don’t touch me. Stop playing footsies, guys. Um Well, depends on your usage again like we keep saying, you know.A household where someone works from home and they’re home all day and they go to bed early is going to have a lot of daytime usage so they may have more panels than battery. The average working family, mom and dad and the kids are out all day and they’re using the power at night, they’re potentially going to have a bigger battery stack than than those people,aren’t they?Um but at the end of the day, it just comes down to the household usage like we keep saying and needs to be designed properly. That’s the only way that you’re going to know if you need more panels or more battery.

If a If a person’s working from home during the day, they probably need more panels to be able to charge those batteries. Um if they’re not home during the day, they need more battery to be able to utilize the nighttime usage.Pretty easy to sum it up. All depends on the correct design.Not a cookie-cutter design. Exactly. Household usage and design properly. designs. Love it. I really, really, really love this one and I’m excited about this one,too. Do you really need a battery with solar panels? Oh, I reckon we’ve touched on this in another one, Jay. I’ll let you

Tell us the last episode. Yeah, 100%. I’ll give that one to you. Do we need batteries with a solar panel?Same old thing, it comes down to your usage, but No, it’s a rip-off. [gasps]

100% this day and age with everything that’s happening with the power companies, feeding tariffs, supply charges, everything like that, if your goal is to save on your power bill, the battery is going to help you do that more effectively than solar panels alone. Will solar panels alone help you save?Yes, they will.But the solar panels and battery are going to give you the better result and overall return. So, that the only time it’s commercial might be the only time if it’s an operation all day. It’s actually It’s actually pretty much the opposite, I reckon. Um like do you really need a battery with solar panels?It’s more There There’s no case that not having a battery and only having solar panels is is better for you.Um I don’t think it’s the opposite.Having a You can’t have a battery without solar panels. Especially with these 3 hours of free power if you live in a an environment that you you can’t have any panels on your roof. Like, say,duplex living, retirement living,anything like that.You can force charge for your 3 hours of free power into that battery.

I already enforce charging while you’re sleeping at night and off-peak rates and then 100%. Using it the next day. swap your 44 cents for your 20-something cents. People actually do that. They currently do it now, too.

that? Which battery is best for a home solar system? So, you, Cam. Thanks, mate. Let’s go.

Uh so, I like this question because I’m uh very happy and very upset with uh this system we’re using. to the podcast would have seen you put your hand up there. Yeah. Oh, yeah. Oh, yeah. Cam had his hand up.

didn’t want him to know, either. goose.Um No, so yeah, I really like this question. Which battery is best for a home solar system? I’ll say uh GoodWe ESA.Uh I would say the one connected to your home. Yeah, that’s Yeah, it is. Yeah, that’s it. Yeah, the one connected to your house.Not the one in your remote. Um Uh I I reckon the GoodWe ESA purely because uh of its of its off-grid capabilities, its off-grid grid backup capabilities.Also, it’s charging and discharge, it’s it’s sleek design. And anyone that actually wants to get a full breakdown of that, we did do an episode of what we thought was the top four recommendations with obviously the GoodWe ESA our top recommendation.

All right. So, another little lovely question that we’ve had popped in here is what are the disadvantages of using solar batteries? There are none. Yeah, none. Zero. None.

None here. Uh unless you you know, unless you’re trying to burn your toast or something with it. But,yeah, that’s useless. Disadvantages of solar batteries. Yeah,actually I can’t think of any disadvantages.Um There’s no disadvantages. concerns that people have like guys are going to catch on fire and everything like that. That’s not a disadvantage. cost up.

Yeah, I’ll suppose yeah, disadvantages would be the only disadvantage would be the location and the space it does take up on your home. Um if you use the right type of battery hint hint the GoodWe ESA it’s very minimal. Yeah. So there is no disadvantage if the whole what the battery is designed to do is to design so you can be self-efficient with your energy and it does that regardless. Okay? I can’t think of any other disadvantage other than potentially location and size of where it’s got to go.

All right guys, another question that I’ve had pop in here is how much does a 13.5 kilowatt hour battery cost? From uh Arise Solar From uh solar TV. Oh, 13.5 that’s that’s the base

No, no, no, no. That’s the base Tesla, isn’t it?So a 13.5 Or is it 13.2? Uh 13.5. Yes, we we sell a No, actually we don’t. We What do we sell?16 8.3 16

13.5 kilowatt hour battery price. I wouldn’t have a clue to be honest. Yeah, so if it’s a Tesla it’s That’s what people are searching that size for is generally the Tesla. Um you know 20 25,000 is what most people installing the Teslas are charging. So I wouldn’t Cuz Arise don’t install Tesla. No.

No. What do they install? CSS As far as the 13.5 like without going down a specific brand it just comes down to many things we’ve talked about other episodes. Are you buying at the low end of the market,which is not mentioning any names, but alright. Are you in the mid end of the market,which we spoke about, which is generally a lot of the actual installers trying to break out and do their own thing, so they’re doing good work and potentially you’re hoping they’re picking the good products that are going to be around.Or then you get up into the mid to high end where everyone’s actually focusing on providing that long-term support. You know?You’re probably going to be paying, I’m just somewhere around there, plus or minus$10,000 for a 13.5, you know? And there’s other things to consider, it’s not just the battery, it’s like what system is it getting tied into? Have you had an old system up there for 10, 15 years, or you got a new system only a couple of years old? They’re other things that are going to affect the cost, aren’t they?

Definitely. Meter box up meter box upgrades,um is it next to the meter box, or is it 20 m on the other end of the house, cuz that’s the only place you can put the battery. Okay. All right, guys, so to piggyback off that question, we have how many solar panels for a 13.5 kWh battery? More than you would for a 10. That That was a one of the ask Oh, no,that was how many needed to charge.Um yeah. How many solar panels for a 13.5 kW battery?I’d I’d I’d stick with the same 6.6 on that one, I reckon. Um just as a guess, if if somebody’s uh somebody has written this question in the sense of they’ve already got a 13.5 kW battery,potentially, um and they they might be asking, is it Is like is the like is this 13.5 kW battery so not charging because

Because I haven’t got enough panels. So, to give that a bit of context, you know, um in Australia here, there’s the peak sunlight hours, the average is 4.2 across the country. You go further north, it’s more. Further south, it’s less. But, you know. So, 6.6, we multiply that by 4.2, that gives us 24.something um kilowatt hours of production per day on average. So, the 6.6 is not only is it going to fill that battery,but any daytime usage they have, that’s going to come directly from the solar,isn’t it? Then it’s going to charge that 13.5 kilowatt hour battery, so they can use that at night.Yeah.So, that’s I guess explaining how how it works. Yes, that is, you know, we need a 6.6. Yeah. Yeah. Yeah.

Hang on. Uh Same thing. How long is a piece of string, I guess. Uh You don’t need Don’t need any more or less panels, I guess. You You need a correctly sized system to your battery. Yeah. So, in other words coming and slapping a battery on the wall, they’re not doing you any favors. Yeah. So, in other words, if the 13.5 kilowatt hour battery was the actual back actual battery that you needed, um yeah, the 6 kilowatt system or 6.6 is going to be pretty close to what you’d have. Okay? But, it just comes back to that what we keep saying.Proper design for the household.

Cool Source Energy Group. What else is everyone asking the AI and the interwebs, my little dolphin? Ooh, they’re asking lots of little cool little questions in here. So, the next one that I have, this is a really interesting one and I love this question. How long will a 13.5 kilowatt hour battery last? Uh depends again on the inverter. And it depends on how much energy they’re actually drawing at the time.Well, you know, if they’re in bed and they’re not actually using anything other than the vampire appliances drawing,

that’s probably going to last all night,isn’t it? 100%. But, if they’re sleeping with their uh 16 kilowatt ducted aircon system, Yeah. I’ll bet that thing it’s probably going to drain in the first hour, isn’t it?So,

Uh the I actually had that phone call,which is a funny one. Probably tell me to shut up. you broke down what the household used at first and then sized the battery and solar off that,then you’d understand. going to do that. Yeah, I did actually have a customer call in and uh mention the system’s useless and it just goes flat immediately.Um I was like Was it turned on?

Yeah, yeah, yeah, yeah.I was like, man, I’ve got the same system on my house and mine doesn’t go dead. And he goes, “Yeah, but I’m running my air con every night.” I was like, “Yeah, so am I.” And um he’s running two air cons,like three fans, and they’re like down on 16 degrees. So, that’s bang on with what you’re saying about how long it’ll last.It depends on what you’re using and how you’re using it. I use my air con on 23 degreesand it’ll turn itself on and off um just to keep the house to the temperature you want it at.Running it on 16, that can then so it will never ever ever shut off. It’ll just run flat out, full full steam to the maximum power draw that that that appliance will use. It’s like just boiling your jug and then your jug’s boiled and you boil your jug again. I got a mate in South Australia, so we obviously don’t do it down there, so we can install it, but he had a 20 kW solar system with a 50 kW battery installed.And he’s like, “My bill’s still like$1,800 a quarter.”I’m like, “Okay, so he’s got him and his wife and then they’ve got five kids, so it’s quite a big family, big household.”I start asking him questions and we get through it. He’s got two 16 kW ducted air cons in the house and he’s got pool heating, he’s got a few other things.I’s like,”So,just tell me how you use the air cons.”He said, “Oh, they’re just on flat out 24/7,nonstop.”

Oh, yeah. All right, so do the kids do you close doors? Do you do anything?” I don’t know. It’s just on. So, Wow. So, then I done the calculations on that. One 16 kW system running flat out is using by itself just over 100 kW hours a day. Yeah. Yeah.

So, his system, the 20 kW system,that produces, you know, in summer he’s producing just over 100, but it uses like 80 just over 80 a day on average. So,he basically just using from the grid non-stop, even with the system that big.And this is why all these questions around, is this the right size and because everyone else is searching or Googling it or their neighbor’s got it,it’s just all irrelevant. It’s just you just need to design for your house. 100%.But, I might imagine what the bill would be if he uh

didn’t have solar. didn’t have solar and a battery to have to cover that. No, no, no. That was just an example before the price I they were paying 50 cents for the power. I don’t even know what they’re paying down there now. Oh, wow.Yeah, that’s huge. That’s right.

Yeah, sorry. Where were we going? All right. Got a little sidetracked there. We’re talking money here now, which is something that I get a lot when I answer the phones. much if if you ask me. No, worth every worth every penny.

Absolutely. So, how much is a 13 kW solar system with a battery in Australia? Oh, was it one from Audi? I hope not. Or was it Bunnings? Or was it special?

Yeah, the horse mate. On clearance. That’s just another one of those open-ended questions. It just depends on back to what you said earlier about came out bagging Louis Vuitton.That’s, you know, it could be What was it What size was it again? Uh 13 kW battery and uh 13 kW system.

kW solar system with a battery. Oh, look. Yeah, no size on the battery. I reckon you’re going to range anywhere from probably 10,000 at the low end up to 30,000 plus at the high end depending on who it is and what they’re selling you and you know, whether they’re taking the piss or they’re giving you a genuine price.

So,you know, like and that’s quite a big range, isn’t it? But, where should it be for, you know,somewhere probably around you’re going to be hitting around that 20 you know, 20 25 I reckon.That’s going to be the good ballpark where you know, you’re going to get a good quality system with a company that’s going to be around, answers the phone, um, and be there with support.Like the great support Delphy does. Thanks, guys. All righty eyes.

I better challenge you with another question then. So, how long will a 13.5 kW hour battery power house? That’s That’s the Very similar to a question about the 10 kW we had before, but this is where it comes down to does that battery have a 5 kW inverter?Does it have a 10 kW inverter? You know,is it on three phase and actually got a larger inverter? They’re probably not for that small battery. Okay.Um, if they got the 5 kW inverter is it charging the house or will it last? Power house, yeah.

Power house. Yeah, so if they’re using more than 5 kW at any one time well, 13.5 kW battery is going to last roughly just over two hours, isn’t it? Okay. If they’re only drawing a kilowatt or two kilowatts from their household usage at that one time, well, then they might get three or four hours or five hours. You know, it’s just that simple sum.How much are they drawing from the battery? How many hours will that last? Okay.Um, and if they got the good we here say that installed by Source Energy Group not only do they have the app where they can see that, they’ll get a phone call from Joe if that app drops out.

And Joe will let them know that it’s dropped out. Power of monitoring and Joe. Thanks,Joe. And then they can actually calculate themselves, can’t they? They can look We’re drawing currently drawing about 2 kWh from the grid or from the battery.Um and it’s going to last this long. All right, I haven’t heard this question before, but it is our lucky last one.So, which is better, lithium ion or LiFePO4? Both have different uses.Uh I think lithium ion is a good B ESA.LiFePO4 is more like your camp style batteries.

If you’re worried about the material at the end of the day,it’s I don’t know. Main difference is that standard lithium ion, usually cobalt or nickel-based,offers higher energy density for compact devices, while LiFePO4 excels in safety,lifespan, thermal stability,making it ideal for RV, solar storage,and off-grid power. Yeah. Yeah, so it’s one’s camping, one’s household. Yeah.Some rules on LiFePO4 batteries for caravans now. I’ll tell you what.I’ve put tried to put a King’s one in one and then bought the King’s battery and uh ended up I’m not allowed to put it in my caravan.

Oh, really? Yeah, rip off. Oh,there you go. Yeah, now they’ve got to be like some some sort of class or whatever to be in a sealed environment and be all locked away and otherwise you’re not insured.Anyway, off track. Off track.

Off track. All right, that concludes our questions,guys. off track. Yeah, that’s right. Yeah. Kept it off track.Nice little question there. Hope that uh rapid fired some some answers in the people.

It seems to be a pretty revolving answer, I reckon. It it just all comes back, no matter what question people are asking, it just comes back to get your system designed for your household. By all means, talk to people, talk to friends, neighbors, family, friends of their experiences, but at the end of the day, just because they have a a 13.5 kWh battery or a 10 kWh battery or a 13 kWh kW system,doesn’t mean it’s going to be right for you, does it? What was our push when we started this company? What did we want? We want essentially make the industry better. Yeah, 100%.

Industry get better. What are we starting to see? Industry get better. People starting to change their marketing. Oh, yeah. See it all the time. Saw one this morning. I was actually very, very proud of those fellows. Good on them.

Yeah.Yeah, it’s quite good. I liked it, too. Yeah, it’s good. It’s totally different to what everyone else has done for years and years. So Yeah, it’s bloody good. I think what we sort of double back to here is just call us. That’s what we’re here for.

Definitely. We can have a chat, and if I can’t answer the questions when they call me,we can put them on to our sales team. We can answer the questions really easily.It’s all obligation free. We’re here to help. That’s it. Ask the ask the questions to the experts. Get a company that will send an actual industry professional out to site. Don’t just get a cookie-cutter salesman. You won’t walk into a butcher and ask for a TV. Exactly. is one one part that we do, isn’t it?So, like we may still do the whole design and everything over the phone. We might do it in home. It comes down to personal preference of the customer, but at any time before we actually install,we’re still going to send one of our team, one of our SAA electricians, one of the directors, uh going to go to site and do the final site inspection and create an installation plan. Make sure there’s no surprises on the day.

Yep. All right, guys. If you guys have got any more questions, please pop them um in the comments below, and we’ll get back to you as soon as we can.