What to expect when going off-grid

We recently sat down with Steven Cooper, one of our senior software engineers, to learn about his experience taking his home electricity usage completely off grid. We dive into some of the nitty gritty details and motivations for this kind of transition in South Africa.

 

What motivated you to go off-grid?

Firstly, I wanted to be free from load shedding because it was difficult navigating changing schedules while raising three kids and working from home. Secondly, by going completely off grid I’d be increasing my savings, which would allow me to pay off the solar system much faster. Some people get solar just so that they won’t be inconvenienced by load shedding, but if they do this they’re missing out on potential savings. By moving all my electricity usage off grid, my electricity bill went from around R2500 to R150 per month.

In the long term, I’d like to be able to sell power back to the grid to help improve the overall system.

 

What energy sources do you rely on for electricity and heating?

Before going off-grid, Eskom was my primary source of electricity and I used a generator during load shedding – now, we are primarily running off solar. 

 

How did you design and set up your off-grid systems?

The first step is understanding that there is a big difference between going off-grid and having a backup system during load shedding. The size of storage and solar needs to be much larger on an off-grid system. 

The next step is to determine your average usage per day, as well as your peak power demand. The average can be calculated by your electricity purchases over time, and can be easily grabbed from your monthly electricity bill. When you’re looking at your average monthly use, it’s important to account for seasonal differences – most households use a lot more power in winter than in summer.  Peak demand is simply the maximum amount of electricity you are going to use at any one time. For example, running a pool pump, geyser, and oven at once. When you’re considering solar, the installation company will often install a device that tracks your peak demand for you. 

Next, you need to determine how long you want to be self-sustainable for while there is no backup power available. This could be the case if there is prolonged cloudy weather.

All of this information will determine the size of your inverter and battery, as well as how many solar panels you need. A good tip is to install a few extra solar panels, this helps your system keep the lights on during cloudy days.

 

What challenges have you encountered during your transition to off-grid living?

One of the biggest behavioural shifts my family and I needed to make was to mindfully use power when it is available. In other words, you want to consume most of your electricity when the sun is shining and your panels are generating electricity. Here are some examples:

• Dishwashers use a lot of energy! Only switch them on in the mid morning. 
• Pool pumps should only run in the daytime between 9am and 3pm.
• If you are going to cook food in the early evening, preheat the oven at 4/5pm when there is still solar energy available.
• Use an electric kettle between 9am and 4pm, and a gas kettle in the evening and early morning.

 

What have you learned about energy conservation and efficiency?

Anything that heats uses a huge volume of energy and some of these aren’t what you’d expect! Here are some examples:

 

 

How do you maintain and repair your off-grid systems and equipment?

The panels should be cleaned once every 3 months with just water and a mop. This is even more important if the panels are flat and not at a 30 degree angle. Batteries should be cycled and run within the depth of discharge levels. The normal for this is 80% depth of discharge, so running them down to 20% but not lower. Batteries like to be cycled so don’t let them hover between 80-100% and never lower than 20% as this is also bad for them.

 

What advice do you have for someone considering going off-grid?

Make sure you do your homework upfront. Understand your energy needs and then design a system that’s 10-15% higher than this.

 

Have you experienced any major successes or breakthroughs in your off-grid journey?

One of my biggest takeaways was that using the geyser to store energy is very cheap. The geyser uses about 50% of the household energy and so having more capacity allows the solar system to run longer. I took my system from using 5-6kWh from the grid each day to off grid by simply adding a series geyser which is heated when there is available power. People often make the mistake of powering their geyser from the grid, because they don’t want it to ever be powered by the battery – however, if it’s powered by solar your geyser acts as an additional battery.

Going off grid is a big, expensive decision, and if you’re not optimising for your usage, you can get stuck without sufficient power, or not experience a good return on your solar investment. Luckily, there are some great installers out there who can help guide you through the transition, and talking to friends and family can help you colour in what you don’t know you don’t know.

If, like Steven, you are wanting to see your ROI on investing in solar, look no further. Learn more about how HotBot works smarter and not harder to get more bang for your solar buck!