Moving off grid takes a mind switch

If only freeing ourselves from load shedding and surging electricity costs was as easy as investing in a couple of solar panels and pulling the plug on Eskom. Unfortunately, gaining electrical independence comes at a cost and can be a slow and often frustrating process. 

South African homes and businesses are feeling the harsh effects of six uninterrupted months of high-level load shedding. Beyond the sheer inconvenience of having to schedule our lives around power outages; the enforced, long-term reduction of income-generating hours, coupled with the financial pressures of price increases as consumers absorb the additional burdens on our food supply chain; everyone is desperate to get off the grid. Many have spent hard-earned savings to protect themselves from our country’s infrastructure failure, and all too often been disappointed by the outcome.

Chris Davidge from Eco-Consulting spells it out for us: “The harsh reality is that going completely off grid is most easily done on a new build. Retrofitting your existing home is far more difficult. We’re hearing more and more about failing battery backup systems. The truth is, these backup batteries just cannot cope with two to three power outages a day. They simply don’t have enough time to recharge between power cuts and many were not designed to be used as frequently as they’re currently required. Though they’re often sold as a comprehensive answer to load shedding, systems like these cannot completely replace grid supply.”

Chris advises home and business owners to manage their expectations and avoid disappointment by taking these limitations into account when evaluating independent power solutions. He says, “Going off grid is a process that requires a complete change of mindset.” According to Chris, your goal should shift from immediate self-sufficiency to reducing your carbon footprint. 

Here are 4 steps you can take towards reducing your reliance on Eskom:

Step 1: Take an honest look at your electricity usage

Work out how much power your household or business is using. How much of it is waste? How much is essential? Once you’re armed with the facts, you’ll find easy ways to save utility costs in the short-term while gaining a clear picture of the generation demands that will be placed on your off-grid system. 

Chris explains how to get a detailed view of usage:

“Each unit on a prepaid meter is equal to 1 kilowatt (kW) or 1 000 watts (W) of electricity per hour so taking a daily meter reading makes it easy to see how much you’re using in total each day. Figuring out how you’re using it is a little more complicated. Every electrical device consumes power, and each should have a power rating on its label. Take a look at the device’s power rating and multiply it by the number of hours it is in use to arrive at that device’s power consumption. Do this for each electrical item in your office or home to understand where your electricity is being used productively and where it is being wasted. 

“Here’s an example to illustrate the concept: A laptop with a power rating of 60 W, left on day and night, will consume 60 W each hour for 24 hours. That’s a total of 1 440 W or nearly 1.5 prepaid units per day. Simply shutting the laptop down overnight will halve its demand on your supply.”

Step 2: Consider the practicalities 

Once you have a realistic view of the kW you need to power your home efficiently, you can begin planning an off-grid system that will generate and store enough to meet your needs. 

As a rule of thumb, you’ll have 6 hours of usable sunlight each day to generate 24 hours worth of power, and it’s recommended that you ensure storage capabilities to meet your needs for 18 hours.

Chris cautions that going off the electricity grid entirely is extremely difficult. “Relying solely on solar power generation is precarious because we can’t predict or control the number or frequency of cloudy or rainy days the weather may bring.”

You’ll also have to look at seasonal demand and supply. Chris explains, “In Port Elizabeth we lose about 50% of our solar generation in summer. If you gear your system for winter weather, you’ll be wasting generation in summer. It’s best to use generation and need levels midway between those recorded at the height of summer and those of mid-winter to build an efficient and economic system.”

On top of this, there are a few practical issues to consider at the start:

• Do you have a north-facing roof?
• Is your roof big enough to house the solar panels?
• Are there trees or obstacles that shade the panels from full sun?

Step 3: Choose your system

Now you’re ready to customise your alternative power supply! Of course, costs will vary depending on your particular circumstances, but here’s Chris’s recommendation for a standard system that will work well, drastically reduce the electricity bill, and – essentially – take you off grid. You could generate 30 kW/h (the equivalent of using 30 prepaid units per day) with:

• 5 – 6 kW of Solar Panels
• 5 kW Pure Sine Wave Inverter
• 10 – 15 kW/h of Lithium Batteries

Taking into account that the cost of PV panels has been driven up by high demand and the more-expensive lithium batteries have been recommended as the best long-term value for money option, you can expect to pay upwards of  R150 000 for a system like this.

Step 4: Adapt your lifestyle

The mindset change required for living off grid translates into a different way of living, one that is continually mindful of electricity consumption. Chris leaves us with the following to consider:

“You have to reprogram the way you do things. A 5 kW inverter can run your dishwasher, microwave and toaster; but it can’t do it all together. You have to keep your home or office’s usage within the inverter’s capabilities. Your home has a base load – what normal appliances like fridge, hi-fi, wi-fi, etc. use. This should be around 500 W, amounting to 12 kW/h in 24 hours. If you reduce this base load by, for example, switching off your laptop; you’ll reduce it to 9.6 kW/h. When you only have 10 kW in storage and 30 kW to use each day, that 2.4 kW saving really counts.”

Putting Eskom in its place, as your back up rather than as your primary provider of power, frees you forever from the rollercoaster of load shedding and the upward battle of meeting escalating utility costs. Are you ready to make the switch?