After living off-grid for almost 10 years and not paying the community or Eskom a cent for electricity for 240 months, not to mention the joy of not having to deal with load shedding, it is time to upgrade and replace my solar system Some components with more modern equipment.
The main reason is winter; The shorter days and days of cloudy weather and rain along the Garden Route make an upgrade inevitable, or I'll have the same blackouts that the rest of the country experiences. A second reason is that there are much better things now.
Subscribe to unrestricted access to all of our tools for share and unit trust data as well as our award-winning articles and support quality journalism in the process.
The only problem after 10 years is that my batteries are dead. I had to separate two to power the other two and the remaining two are not getting along.
A decade on a battery bank with only four batteries isn't bad considering that the batteries were initially used golf cart batteries.
Ten years ago it was thought that golf cart batteries were probably the best batteries available because rich golfers don't want to get stuck on the 16th fairway.
Golfers also change their batteries regularly because they don't want to get stuck without their wheels.
Despite their much easier job of running a small solar system, even those good batteries eventually wore out. Still, 10 years ago they were a good investment at the price of R2,000. (Nor did I have to pay the municipality R80,000 to install a transformer and run 200 meters of cable to my house)
The other parts of my system are still working fine, but some will work too as there are much better devices out there now.
Solar panels last for years, the exact lifespan depends on who you ask and the specific installation. In essence, they work as long as they work. A quick test with an electrician's multimeter will quickly spot any problem.
It is more important to have enough solar panels, which is not a problem considering that solar panel prices have almost halved in the past decade.
However, Ryan Oliver, general manager of operations and procurement at Specialized Solar Systems, warns that solar panel prices have risen recently. “The raw material prices for the production of panels have risen steadily, while the freight costs have risen sharply.
“It looks like prices have reached a turning point,” says Oliver.
He notes that the demand for solar systems is constant and that the standby systems always increase somewhat when the load shedding deteriorates.
A small system with eight 100-watt panels can easily produce 4.8 kilowatt hours (kWh) of electricity per day even in winter, based on the general assumption that there are six hours of sunlight each day and that the panels are correctly angled.
Experience has shown that longer summer days deliver much more electricity, even without adjusting the angle of the solar panels.
Charge controllers, measuring devices and inverters
Newer devices combine charge controllers and measuring systems with the inverter in smaller residential systems. Previously, a charge controller was required to regulate the electrical current flowing to the battery bank, and another (optional) small box to measure what was coming in, the condition of the batteries and power consumption.
An inverter that converts 12V, 24V or 48V direct current (DC) to 220 alternating current (AC) to power household appliances is now at the heart of the system, which includes a charge controller and energy management system. Several models are connected to a computer program or a mobile phone app for external management.
Nowadays, medium range inverters (which cost between R5,000 and R15,000 depending on power) include the better MPPT (Maximum Power Point Tracking) charge controllers and a management system.
As a result, my basic charge regulator, voltmeter, and older 1200W inverter are all replaced with a single 3kW inverter that combines all of its functions into one unit. With a surge power of 6 kW, it is more than large enough to accommodate the surge in power when an electrical device is switched on.
A point of contention in the solar industry – and among existing and potential solar users – remains the reluctance of municipalities or Eskom to allow homeowners to use the national power grid as a “battery”.
This would be achieved by feeding electricity into the national grid while the sun is shining, and withdrawing it at night if necessary.
If this were allowed in combination with reasonable tariffs, roof-top solar systems would be more affordable by eliminating half the cost of an installation – buying expensive batteries.
Batteries are expensive. Huge technological advances have resulted in a better product and the choice between maintenance-free lead-acid batteries, gel batteries and the newer (and more expensive) lithium batteries.
Unfortunately, the cost of batteries is still almost 50% of the total cost of a solar system.
In my case, four new 150 amp hour batteries are enough to power everything. The total cost of improvements is R18,000, the majority of which will be spent on the new batteries, R12,000 (R3,000 each).
A very desirable 48 volt lithium battery with a lifespan of 20 years costs (unfortunately) about 30,000 R.
Little installation is required as the panels are already open and all wiring is in place. Even in winter, the system will produce at least 4 kWh of electricity per day and at the same time be able to supply electrical devices with a value of 3 kW.
This shows that a (small) off-grid solar system isn't for everyone, considering that a decent coffee maker uses 4kW even if it's only used for five or ten minutes at a time.
A hair dryer also puts a strain on a small inverter – and even a larger one if multiple refrigerators, a tumble dryer, vacuum cleaner, and air conditioner are also on.
Oliver says larger household solar systems are not always an option because the cost is higher and the capital outlay is upfront. “Houses in urban suburbs still pay reasonable prices for electricity, which makes it too expensive to consider off-grid systems overall,” he says.
While hybrid systems (systems tied to the national grid or systems connected to the grid) are good alternatives, regulatory changes and new guidelines are required at the local level.
Rural homes and commercial farms are finding it increasingly profitable to switch to solar as electricity costs rise, especially due to efforts by local authorities to increase fixed fees.
Ray Nolan, Project Manager at Specialized Solar Systems, cites the example of an installation on a small farm where the owners paid more than R2,000 a month in fixed availability fees and only a few hundred a month for electricity themselves.
“In this case, it makes perfect sense. In fact, Eskom is effectively paying for the installation, ”says Nolan.
He says the first step in phasing out the grid is to reduce electricity consumption. “You can save 70% of your electricity consumption by switching to a gas geyser and stove, reducing the size of the solar system required,” he says.
Businesses, including commercial firms with massive roofs and commercial farms, are at the forefront of the transition to solar energy. Not a week goes by without a company or large farm announcing a new solar system. Investors are demanding it, and it enables an improvement in ROI.
The problem is, municipalities and Eskom are losing their highest paid customers – those who can afford R100,000 to take their homes off the grid and companies who can afford more than R500,000 to do so.
A comment from a Moneyweb reader on an article about the problems at Eskom a few weeks ago summed it up. AP wrote, “The biggest risk to Eskom would be a breakthrough in solar / renewable energy technology that makes it affordable to the masses. I [believe] This day is not too far away. ”