Getting Off the Eskom Grid
Jacques du Rand 2022-10-21
What Is Required To Go Off-Grid
It is not as simple as calling up a solar power company and getting them to switch out your existing power systems. First you need to know “how much off-grid you want to be” as it influences quite a few things - price above all else.
WHAT IS YOUR BUDGET - This is probably the number
one requirement when looking to make a major change in your housing
structure, such as being power self-sufficient and moving off
Eskom’s power grid. Of course you’ll save money
long-term, but that is quite possibly after 5-7 years, depending on
your set-up. So don’t let cost saving be the reason you look
at getting solar power.
WHAT IS YOUR ENERGY REQUIREMENT - It is quite
expensive to do a like-for-like system and you may need to forego
some conveniences in lieu of saving costs.
Think about if you only want your lights on during load shedding. Do you want lights, TV, router, alarm, electric gates and to be able to boil a kettle? Do you want to use everything and not feel as though anything has changed.
HOW ENERGY EFFICIENT IS YOUR HOUSE - Besides
looking at the way your home is built - the important areas to look
at are any existing big energy users. These are things like indoor
heating, air conditioning, geyser and the oven for example. Are
there ways to make your existing appliances more energy efficient?
For example buying your geyser a geyser blanket to reduce heat loss
and thereby using less power to heat water. Having a hybrid oven
system that cooks with part or full gas. Or relooking your
insulation to see why heat is escaping or being trapped - which
could cause you to use additional heating sources or
air-conditioning if not insulated well.
Can your existing appliances deal with the new power levels? Older, less energy efficient appliances may draw large amounts of power. It may be prudent to replace with newer, more energy efficient appliances, which can make the total cost of the project quite a bit more than “just getting solar installed”.
DO YOU HAVE A PLACE AND SPACE FOR SOLAR PANELS -
Depending on your energy requirements, you may need more or less
panels fitted. Solar panels by their nature need to be positioned in
a place that receives at least 6 hours or more of full sun daily in
order to draw and generate enough power for the average home to use.
Roofs are usually a great option to fit solar panels, but you need
to make sure that your roof is safe and faces in the right direction
to receive good light and that it is big enough to support the
number of panels for your system. Having panels built onto a frame
at ground level is another option, but then you need quite a bit of
space for that and may lose your garden area.
BATTERY STORAGE - Power generated from solar panels
(or wind energy) are usually stored in batteries. Batteries are a
critical part of the entire system, as they need to store energy so
you have sufficient storage to last through rainy days. Of course
one can back-up power by using generators to charge the batteries,
but if you plan well in advance, you might only need this
There are two main types of batteries used in these types of setups, one can choose from: Lead-acid based or lithium.
Proper maintenance of batteries can extend their life quite a bit. Lithium batteries are the better option, but are expensive. Although lead-acid batteries are cheaper they require quite a bit more maintenance than lithium. They are generally considered slower to charge, heavier and you require more of them for the same charge as lithium. If you can afford lithium batteries from the start, they are the better option.
As mentioned, lead-acid batteries have a lower capacity to store “Eskom-Juice'', and you are really only able to extract about 50% of the available capacity. Example: If your lead-acid battery has a 100AH (Amp Hours) rating you really can only use about 50AH.
For these reasons many people turn to hybrid systems.
Hybrid systems allow for your energy to be partly off-grid and partly using the grid on for example days where you don’t have enough energy stored up due to lack of sun.
With the hybrid system your house can run off your solar power and only draw from the grid as a backup. These systems are a lot cheaper than being fully off-grid as you require far less solar panels and batteries. A hybrid system can be an interim step to getting fully off-grid as budget allows.
How to calculate solar system size?
Find your average monthly usage in kW, divide that by 30 (days in the month) then divide that number by 5.5 (average peak sun hours per day in South Africa). This will give you the size of the array that you’ll need. Then you take your array size and divide that by the watt rating of a panel like a 455W panel to find out how many solar panels you’ll need.
- 900kWh average monthly usage / 30 days = 30kWh daily usage
- 30kWh / 5.5 average maximum production hours = 5454.54kWh array size needed
- 5454.54kWh / 455W solar panel rating = 11.988 solar panels needed so round it up to 12.
Costs Involved For Being Self-Sufficient
It is really difficult to provide a ballpark cost as every home is different, and every set-up is too.
Basic Hybrid System for a 3 bedroom house and small family can start at R70,000.
Basic Off-grid System for a 3 bedroom house and small family can start at R170,000.
Solar panels: PV Panel 250w to 350w - R1,200 to R2,000 per unit
Inverter 5kVA - 10k to 30k per unit.
Lead-acid batteries - Start from R17,000 per unit setup.
Lithium-ion batteries - Typically 4 x CFE 5.1kWh for a small house. From R20,000 per unit setup.
Registration with Municipality - required by Eskom and government. From R5,000
Certification of set-up - Certificate by recognised installer. From R3,000
Although the costs do seem really high, it seems an inevitable task to make sure that houses and businesses have power in the long run as archaic systems keep declining year over year.
With costs of getting off the Eskom grid starting to soar due to demand, there are companies that do allow you to pay off the installation in monthly instalments. There are also new companies emerging allowing you to rent systems and in so doing save on the huge initial outlay of getting off the grid.
Why Doesn’t Eskom Welcome This?
All around the globe renewable energy resources feed into and are part of the larger grid system. Many places that have off-grid power systems in place also have the choice to feed into the grid and provide the local power network with any surplus energy generated for the day.
As cities grow and the demand for energy grows, most international countries have welcomed citizens to go off-grid to lower demand on primary energy providers.
In Europe it is rumoured to be mandatory to supplement your own energy by 2023 by installing solar panels.
So why is South Africa one of the few countries pushing back on letting their citizens be self-sufficient? A country with great opportunity for using renewable energy such as the wind, or even solar.
By reprimanding users who wish to be more self-sufficient, Eskom is shooting itself and the larger country in the foot instead of thinking that they could benefit from those users who wish to feed surplus energy into the grid. It is crippling the country for its own selfish reasons.
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