Going Off-Grid


I love living in South Africa. It’s very likely so because I haven’t lived anywhere else, but I will add that I’ve now lived in various population densities. That aside, living here doesn’t come without its challenges. A consistent problem in South Africa has been the concept of load shedding: Eskom, the power utility, implementing rolling blackouts to preserve the integrity of the network. At the core, the concept makes sense, but years of mismanagement at the state-owned enterprise have led to this situation. It’s been something Saffas had to deal with for more than a decade. Throw in a good mix of COVID-19 pushing people to work from home, and you’re bound to be left with headaches on those days that Eskom can’t keep up.

Initial Solution

In August 2020, I bought myself a little 2.4 kVA inverter + batteries. We were living in a tiny 44 square meter apartment on the 1st floor and didn’t have the opportunity to consider a solar installation as a backup. It chased a good R10k out of my pocket, but it brought with it peace of mind that I would be able to continue providing power to my laptop and router while we have our 4-hour blocks of load shedding1. The inverter + battery specs were as follows:

  • 2.4 kVA Mecer Modified Sine Wave Inverter (1400W)
  • 2 x 100 Ah AGM Deep Cycle batteries (600+ cycles)

A quick tally of a laptop + screen + router puts my required use at less than 500W. I made it through a 4-hour block of load shedding with the batteries only just dipping down to 50% before the power would come back on and start charging things up. Back then, we weren’t experiencing load shedding multiple times per day, so my batteries charged back up to 100% before the next block struck.

A few months later and we’ve moved into our house. Shortly after the move, our municipal power utility, CityPower2, announced that we’d be moving to 2-hour blocks of load shedding. The change felt like a godsend, but the crumbling infrastructure ended up straining under pressure and often left us without power for 4 hours instead of the scheduled 2. I understand why there was no respite due to this, but when Eskom bumps load shedding to a high stage, we end up living with three or more blocks of 2 hours each. The scheduled 8 hours can quickly get closer to 14 hours for the day due to CityPower failing to restore power in our area on time.

My little inverter struggled to cope with this, and where I had previously left it on to keep the router going, I now had to turn it off. Turning the inverter off helped prevent it from discharging unnecessarily; we could live without internet for a while, especially if load shedding occurs in the little hours. The downside was that I suspect the deep cycles had already taken their toll. I’d also used the inverter to keep my sim racing rig going, gaming PC, screens and steering wheel on race nights where I’d experience load shedding. I recently upgraded to a Direct Drive wheel that meant I risked damaging my wheelbase if I ran it from a modified sine wave inverter. I made peace with that fact, but a recent bout of load shedding had me noticing that my inverter couldn’t even keep just my laptop, router and screen going for more than 1 hour. I faced a dilemma: either I could replace the batteries for around R3k or look more closely at another option.

Going Green

The other option is to move to a hybrid system that allows me to keep the house running during blocks of load shedding, but this comes at some cost. I had my system installed last week and posted some pictures on our company’s Slack, and someone responded:

Guys, this is an expensive journey 🤣

~ Francois Mentz

I quickly responded that I disagreed because while it takes a significant upfront investment, it does pay in the long term. There’s a whole lot of implied prerequisites in that statement I’ll admit, but another colleague quickly countered with the following:

Also, it only makes sense if you own a home that you plan on living in for the next 10 years or so. For Sas, this makes sense.

If you renting or live in a smaller place with plans to buy a house in the next 5 years, rather go with a smaller setup that you can do yourself and easily “pack up” when you eventually move.

I think the people that have it worst are those in flats with only a balcony. Their options are limited to basically an expensive inverter. If you can run a generator, its probably still your best bet. A big 2.5+kVA generator will cost you between R4k-R5.5k and will basically be more than enough for emergencies.

The more quiet alternative is still just a battery and inverter, especially if you live in a flat or complex. Just pay a little extra for a large enough battery.

~ Tinus van den Heever

I wanted to type out some thoughts at this time but found myself quickly writing a bunch that I could instead put in a blog post. Well, here goes nothing.

My Needs

I’m not going to sugarcoat things. We bought a much larger house than we need right now. That said, the intent is that this is the house my wife and I will raise our kids in and live in until about the day we retire. That’s a good stretch of at least 20 years we’re planning on staying here. So given that, I took inventory and looked at what the core components are that we’d like to keep going:

  • 3 fridges
  • pool pump
  • Laptop
  • Screen
  • Router
  • OTN

In some cases, my sim rig will replace the laptop and screen. The sim rig consists of 4 screens, a 200W servo motor (my sim racing wheelbase) and my gaming PC (a 500W power supply installed). The pool pump doesn’t run at night, so that’s not a worry, although in some rare cases, I might have a race where I’ll have to be mindful of the pool pump also running. These components put my general usage to around 0.6kW, with peaks going to between 1.2kW and 2kW.

Show Me What You Got!

I spoke to an electrician in the business of installing solar systems, and he recommended the following:

  • 8kVA Pure Sine Wave Hybrid Inverter
  • 2 x 5.1kWh Lithium-Ion batteries
  • 12 x ~400W solar panels (I’m not 100% sure what the wattage is)

This system is what I went with, and in total, it cost me about R130k, all components supplied and installed.

The Prerequisites

Now back to Tinus' response. He’s recently bought himself a small system with the intent of just running a few items in his study on it. It’s not a permanent installation, and with the system not wired into his house, there’s a bit of inconvenience that comes with a system like that. Granted, that is the limitations he’s working within because he’s not looking to install something in a place that will have to stay put if he moves out.

He mentioned something about not planning on staying at the place for the next ten years or so. While it’s a very rough estimate on his end, I’d argue the current situation can pull that number down by quite a bit. Some very rough calculations on my end show I’ll have the potential to save around R1000 on my electricity bill every month. Without inflation, I’d pay off the entire system in 10 years, but historically our electricity unit-cost has gone up by quite a significant percentage3.

It’s essential to consider this because you’ll likely find you’ve saved enough to cover 75% in five years due to the increase in electricity costs. I’m not even using that reasoning to justify my installation; I want to save enough to cover replacing the batteries in 10 to 15 years. The rest of the system I’m viewing as a value increase in the cost of our property. If we were to sell the property, I’m confident we’ll be able to recoup the costs of the system. As more and more households start coming with solar systems installed by default having a solar installation might not have as significant an impact, but at present, I’m sure it has made a difference.

What I’m trying to get at is that it’s important to crunch the numbers for yourself. After running the system for a few days, I think I’ve found we’re likely a little optimistic about our savings. Still, we haven’t been up and running for a representative timespan yet. We’ll only get a feel for just how much our system contributes to our daily needs in a few months. I’ll be monitoring that in the long term, and perhaps I’ll write a follow-up in a year or so (I don’t scoff at free stuff to write about).

Tinus does mention some important considerations if you don’t own the property. I can concede that fact, but I’d also consider having a frank discussion with a landlord on the possibility of having a system installed. My cousin has told me people move their entire kitchen with them when they move out of a rental property in Germany. From installed stoves, dishwashers to light fixtures! I think there’s an argument to be made for doing the same at a rental space if the landlord is willing. If you’re able to move your solar system with you, it will make the purchase hurt much less, at the cost of having to get someone to install it multiple times. I’ll leave crunching the numbers as an exercise for the reader.

Generators and Fuel

Something I feel important to single out is the idea of running a petrol/diesel generator. I’ve noticed generators running in my neighbourhood during load shedding, and on the surface, it looks like a low-cost alternative. I’ve bought a small generator for myself when we had a sub-station blow up that left us without power for two days. I considered using it to run my study while I work, but I decided against it because the noise was too much for me to concentrate and I took a few days off work while CityPower fixed the substation. It was a highly stressful time, and I only ran the generator to bring the temperatures down to operating temperature and help prevent spoiling a bunch of foodstuffs.

My main gripe with a generator is the running cost. Electricity isn’t the only thing getting prohibitively expensive. In 2021 alone we’ve seen our petrol price increase by an astonishing amount as well. In November 2020, a litre of 93 octane petrol would cost R14.39, and in November 2021, a litre of 93 octane petrol costs R19.32. That’s a 34.26% increase in ONE YEAR! You might be able to buy yourself peace of mind that you can keep your lights on, but I’d argue using the money you’d spend on a generator as a deposit on a loan for a solar power system. You don’t have to go full 8kVA as I have. People have told me that they’ve installed 5kVA systems for less than half what I’d paid, and with a tiny bit of management, they’re pleased with what they have. If you can get a loan with an interest rate less than the historic price increase for electricity, this honestly becomes a no-brainer decision for me.

Conclusion

I’m fully aware that I’m in a VERY privileged position to afford this hybrid system. The daunting side of this is just starting to figure out what your needs are. Installations can vary by a lot depending on the willingness of someone to adjust their lifestyle. I’m taking a bit of a heavy-handed approach. Still, I grew up seeing how my grandparents had to bend over backwards to manage their electricity usage on the primitive solar power installations they were running. I’m not against some level of adjustment, but finding a way to track it other than a monthly utility bill is helping me a lot. The inverter is generating nice graphs for me, and it’s showing me what impact my solar power generation is having. Allowing me to be in touch with what is happening with my daily usage motivates me to live a “greener” life. Deep inside my heart, I still believe that things will turn around in South Africa, but for the time being, I need to take some steps to safeguard myself a little. I hope this bit of insight has been helpful to you as the reader, and I’d love to have more discussion on the topic if you feel so inclined. I’ll be monitoring for comments down below!


  1. My grasp of the English language is relatively decent, but it wasn’t until I sat down to write this article that my editorial software was constantly screaming at me for writing “loadshedding”. I don’t think it has made it into the vernacular, but I’ve gone as far as using “loadshredding” to describe the situation. Bad spelling habits sometimes die hard. ↩︎

  2. In a large metro like City of Johannesburg, which consists of Johannesburg, Randburg, Sandton, Fourways, Midrand, Soweto, Alexandra, Diepkloof, and many more Eskom hands over the distribution of electricity to the municipality. Some small towns in South Africa follow the same model, but I think CityPower is the largest distributor of its kind in South Africa. ↩︎

  3. According to this article, the price of electricity has risen by 753% from 2007 to 2021 whilst inflation over this period was 134%↩︎