In my first article, I wrote about our decision to power our new backyard sleepout with solar and batteries rather than paying to connect it to the grid. At the time, it was all still hypothetical, and I promised to come back with a reality check once we had the wisdom of hindsight. Well, we’ve built it, plugged everything in and lived with it for a while. So, did it actually work?
Long story short: it works! Yay! And actually, slightly better than expected.
I took a measure on a sunny day on 26 July, when we generated almost exactly 2.4kWh from our two 475W solar panels. A few weeks later, on Sunday August 16, we generated 3.77kWh in one partly cloudy day — the longer days are increasing our capacity quickly.
Given that we are not perfectly positioned for the sun, that is great. Our section slopes slightly to the south, and there is a big tree exactly in our noon sun. We mostly get to harvest the afternoon sun.
As previously mentioned, we wanted a system that we could control and scale with a predictable budget. We started with a 3kWh Pecron power station, which can be expanded if needed. At this time of year (August), we can fully charge it on a sunny day, or over two average Dunedin days. Given that we don’t use the sleepout every day, that is enough for the time being.
With this amount of power, we can warm the room up and do something there for half a day, which is how we will use it most of the time.
However, right now, as I am writing this, we have had several sunny days in a row, which has quickly maxed out our battery. I am now having to run the heating so as not to waste the incoming sunshine.
The Pecron power bank app showing the solar power going in and the power going out to the sleepout.
Looking back, we set down this track when we learned that it would cost about $4,000 just to connect the sleepout to mains power, after which we would still have to pay for power.
Our Pecron power station cost us $2,300 on sale with free delivery. Nice! We spent about $800 on solar panels, cables, brackets, delivery and a few other peripherals.
There are always peripherals, and they do add up.
For the time being, we have a power supply — free but limited — for less than the original shock to the plans.
That doesn’t mean the process of getting here was straightforward.
It’s been a learning experience. It isn’t called a learning curve for no reason, and it is hardly a journey without some bumps along the way. However, a curve still suggests some smooth arc of progress. I would say this has been more of an off-road experience.
Looking back, it doesn’t sound so bad, but the mental load at the time was real.
Mostly, it was the research involved in figuring out the options while worrying about making mistakes that might end up costing us more than we set out to spend. What if I got it all wrong and we spent the money, time, and effort only to end up with something that didn’t work?
As part of making solar the cheaper option, we deliberately chose components that were DIY-friendly. For example, the Pecron power station is a battery pack with a built-in inverter and all the types of outputs you could need.
That meant we could put all the parts together ourselves without needing an electrician; our solar system is an appliance rather than infrastructure. But DIY-friendly doesn’t necessarily mean everything goes smoothly.
When ordering the solar panels and cables, I decided to outsource the mental load of learning how to attach the correct plugs to the cables.
I knew I could figure it out, but my brain was full, so I paid the supplier to do that part.
When the cables arrived, even my tired, stretched brain could tell it wasn’t right. Like, imagine unwrapping an AA battery and noticing bumpy bits on both ends: the plugs were the same on each end.
I did a quick sanity check in a Facebook group (thank you for the prompt advice, everyone) to confirm that, yes, they were wired wrong.
To the supplier’s credit, he fast-couriered me some replacement plugs, which I then learned to replace myself.
It was actually very easy. It took me ten minutes.
But I had lost some hair by then, which at my age probably won’t grow back. Because it’s not just the 10 minutes to fix the one thing, it was the stress of questioning the whole system when you realise that the experts get it wrong too. After that, I unearthed my multimeter, watched YouTube videos, and checked the polarity of the panels, all the connecting cables, as well as the voltage coming through. I needed my own source of truth at that point, and I measured everything I could before I plugged things in. With DIY, you do have to know enough to know what is safe.
We also encountered a small charging glitch during setup, but the Pecron team were very helpful in diagnosing the problem and sent a firmware update over the Wi-Fi. After-sales service really means a lot!
It is always a little scary buying big-ticket items online, as you never quite know if there will be a human to talk to afterwards. But these folks were great. They were also the most cost-effective power station available at the time.
Very happy.
The solar cable plugs the wrong way around.
The builder finished the sleepout about a week before the coldest month of the year, and I had a bit of time to reflect and despair over the impossibility of heating the place.
When it is -7 °C overnight, it takes a serious amount of energy to get a standalone building up to anything close to room temperature. As a colleague pointed out, when every wall is an outside wall, you are really up against the weather.
But now that the temperature is consistently above zero and sometimes even over 10°C, warming the place up is now quite doable, especially if you start with a sunny afternoon of free power.
Before next winter, if our budget allows, we might also get a small heat pump for the space because it is about four times as efficient at heating compared with an oil heater. And if we are feeling flush, we may also invest in an expansion battery to more than double our storage capacity, so we can literally save it for a rainy day rather than use excess power on sunny days when we need it least.
I now know enough to feel confident that our solar setup is working for our needs. I also know exactly what it would cost to expand, but it is not urgent — we can make do with what we already have. It feels good to be in control of the process, and we have saved some money along the way.
Understandably, given the limitations, no professional would ever recommend this setup because it is too small, and we sometimes need to top up the battery from mains power when there hasn’t been enough sun.
But, you know, relative to our needs, we can do all that we want to do, and we can see a scalable path if we ever need more. I’m okay with that.
That really was part of our thinking from the beginning. We weren’t trying to build a solar system capable of meeting every possible peak-use scenario. We wanted something that would meet our actual needs without over-investing, and which we could expand later if those needs changed.
That seems to be exactly what we have.
We originally called it “the Shed” because it replaced a shed, but that definitely didn’t do it justice.
So it became “the Sleepout”.
Now it is “the Studio”, because it is more of a creative space than a place to snooze, although snoozing can be a legit part of the creative process. It’s a little place for us to step out of the routine, whether that means actually making something or just watching the clouds drift past from a quiet space.
It might yet get another name; I recently cut down a tree that was shading the Studio, and the trunk would make a great prop for a bunk bed for when the kids want sleepovers. I can already see a reading lamp made of fairly light wire in the shape of a bird’s nest sitting in the branches above the bed in our Treehouse!
It will be glorious. Sometime next year.
Until then, I will continue to get great satisfaction from watching our solar app when more power comes in than our little oil heater is using.
While I am not a builder by trade, my house is still never finished, as they say.
The builder is done, now we just need to finish painting and build a deck — a job for summer.
Olav is the Head of Growth at PocketSmith. He loves surfing, gardening and hiking in the mountains. He is a numbers guy, an artist, and he would totally grow all his own food if time and climate allowed it. He lives with his partner, two teenagers and a couple of young avocado trees in a suburban orchard.
