RESOURCES AND TIPS
Need a bit more info? Find here helpful summarised information that may help.
(Also please refer to the FAQ page for the answers to common questions.)
Expert advice really is key.
This page is not exhaustive, but rather provides basic quick summarised tips in bullet form.
WHAT ARE THE DIFFERENCES BETWEEN DIFFERENT TYPES OF BACKUP POWER SYSTEMS?
Firstly, there are two main reasons for considering solar or backup power solutions:
- You want to not be impacted by power outages or load shedding. (Any backup power or solar solution will help with this.)
- You want to generate your own power and save on your electricity costs. (Only full solar or wind power generation systems will help with this.)
Assuming you want to as a minimum have backup power, then you can consider the following solutions:
Buying a generator. (This is the cheapest option.)
It is noisy and produces toxic fumes and heat when running.
It costs money when running (because it uses fuel).
It needs regular servicing (like a car).
Many houses, apartments and estates are not allowed to use generators due to noise and other regulations.
Install backup batteries. (This can be a good start, especially if you can add solar panels later.)
Seamless backup power without any noise or fumes.
You charge your batteries when you have mains power, and only use them when needed.
Any house or apartment can use backup batteries, even mobile homes.
Costs more than a generator (especially if you use good long lasting batteries).
A solar (or wind) generation system, including batteries.
You have backup battery power, but additionally have power being generated whenever the sun is shining. You use power from your batteries whenever there is not enough sun , like during cloudy weather or at night. When you have excess sun power, you use that to charge your batteries.
You generate your own electricity, and don't need to buy all the power you use on a daily basis.
By saving on electricity costs, you can actually let the system pay for it self. (Typical solar payback periods are from 6 to 8 years, thereafter you are making money.)
The most expensive, but the most capable system, and the only solution that saves you money over time.
IMPORTANT THINGS THAT MOST SOLAR INSTALLER DON'T TELL YOU.
People usually get advice and quotes from various different installers before deciding what to go for. The cheapest option always look very attractive due to its affordability, and we often need to explain what are the shortcomings in alternatives systems.
As in general, you usually get what you pay for... If you want to buy something that transports you from point A to point B, then both a bicycle and a car can do that, but a bicycle has many more limitations. Installers providing you with a cheap quote and hoping you go with them typically hide the below limitations of their cheaper alternative.
That cheap inverter is not going to work that great:
Many cheaper inverter brands have a very high failure rate. Expect it to stop working unexpectedly and not too far in the near future.
Cheap inverters usually don't allow feeding power back to the input side of your house circuits, limiting your savings.
Cheap inverters don't allow "syncing" with the grid to pass power through your inverter when exceeding your inverter limit.
It will overload more easy.
You will not be able to power your entire house, and the system may have significant limitations in terms of what it will be able to power. This may also result in your system being overloaded and failing.
They are not including enough solar panels. Cloudy and rainy conditions often occur, and one needs to plan for that. Do not use "peak sun" as the norm when sizing your installation.
The battery they are recommending is too small:
Good batteries are important but expensive, so that is a easy place to cut cost.
A too small battery will shorten its lifespan, as it will be worked too hard.
Your savings will be less, because you will run out of backup power quicker, especially at night.
There are important things that you should install, but are being excluded:
Lightening protection
Surge protection
Good quality fussed and circuit breakers
Cheaper roof mounting is being used, that could void your solar panel warrantee and also result in a leaking roof with water damage.
Their install is not 100% compliant, and/or they are not planning to issue you with an updated Certificate of Compliance, since it will cost you extra.
WHAT SIZE SOLAR SYSTEM DO I NEED?
Without a more detailed consultation, this is difficult to answer short and accurately. But let's cover some basics!
As mentioned, realise that there are different types of installs depending on client needs. The main categories are: Pure backup power (no solar panels), off-grid systems (no Eskom power and no mains DB board), and grid-tied hybrid solar systems (also generating your own solar power).
A good, well sized full solar system must allow you to:
Save at least 50% of your monthly Eskom bill,
Run on backup battery power (i.e. during the night) for at least 10 hours.
Allow you to as a minimum still use your key electric appliances (such as plugs, lights, microwave and maybe boil water), even during load shedding.
Be convenient with: integration into your existing house electric system, auto switch-over during outages, and low maintenance.
Assuming you are a residential client that wants a system that meets the above criteria, then a rough guide for residential solar sizes are:
A small install: Your monthly electricity bill is less than R2,000 and your household consists out of 3 or less people. (Below R140,000.) You will need:
3 to 5 Kw good hybrid inverter.
7 to 14 Kw of battery storage.
12 or less solar panels
A medium install: Your monthly electricity bill is R2,000 to R4,000 per month and your household consists out of 4 or less people. (R140,000 to R180,000.) You will need:
A 5 Kw good hybrid inverter.
14 Kw of battery storage.
At least 12 solar panels
A large install: Your monthly electricity bill is R4,000 to R8,000 per month and your household consists out of more than 4 people. (R180,000 to R300,000.) You will need:
A 8 Kw to 15 Kw good hybrid inverter.
14 Kw to 28 Kw of battery storage.
At least 18 solar panels
(Obviously you can still go bigger, even for a residential install.)
Keep in mind the following additional tips when considering size and cost:
A good quality medium-size full solar system typically does not cost less than R140,000. (Refer to pricing page to see what spec system we consider as medium.) This system will work well for most small to medium households.
If you get a quote for considerably less for similar type specs, then usually there is cost-cutting on the equipment that will result in poor performance. On the other extreme end of price, if a medium system costs much more than we indicate, then the installer is probably pocketing some fat profits.
Good quality Lithium Iron Phosphate (LifePo4) batteries are expensive. For this reason, clients often opt to buy a battery that is too small. A properly sized good battery is critical in getting value out of your system and also drastically impacts your potential electricity savings.
A good base system costs a fair bit of money, but often spending just 10%-20% more gives you a much more capable system. For example, a 3Kw and a 5Kw inverter basically costs the same. While moving up to 8Kw or even 10kW could just add another R10,000 to R20,000 to your install cost. Sometimes the relatively little extra cost makes a significant difference. (Most installs push the equipment constantly to their limits due to bad advice and/or trying to save some cents, leading to system failures, replacements, early upgrades and repairs.)
As a rough guide, 80% of all installs we do fall in the medium household category that put them in the R140,000 to R180,000 range in terms of cost.
I WANT TO GO COMPLETELY OFF-GRID. IS IT POSSIBLE AND FEASIBLE?
Yes, it is possible and the prospect of fully producing your own power seems promising, but not a good idea for most households or businesses. This is mainly because:
Max load requirements: If you are not connected to Eskom, your system needs to cater for the highest possible load you may require at any given point in time. (It can not use Eskom for a portion of the load.) For example, if you have a high demand of 8,000 watts for even just a minute a day, then you need a 8,000+ watt inverter (and batteries and panels). So your very big and expensive system is working at its full capacity very seldom.
Return on investment: Related to the first point, if you need to over-invest to cater for short spikes of maximum load, then it will take much longer to pay off your solar system. Effectively an off-grid system costs considerably more, but your savings are sometimes just marginally better in comparison to a well design hybrid grid-tied system.
System maintenance: Components do sometimes fail. If you can not switch over to Eskom, then you will be without power while equipment is being serviced or repaired.
Sunshine / Wind: If you rely only on your own power generation, you run the risk of running out when there is insufficient sun for extended periods of time. (It could be rainy and cloudy for many days.) To reduce this risk, you again need to oversize your solar panels and batteries, increasing cost.
WHAT COMPONENTS ARE IN A TYPICAL SOLAR SYSTEM?
A full solar system has a couple of distinct (but connected or integrated) components. The total system is only as good as the weakest link, and understanding how the components interact and that they are sized accordingly is key.
A base medium solar system has the following minimum components (indicative normal component pricing shown):
A good inverter to convert your battery power into usable higher voltage power that your household 230 volt appliances can run on. (usually R20,000 to R40,000 per 5 Kilowatt inverter.)
A solar charge controller to charge your batteries through your solar panels. Converts solar panel voltage to the correct battery charge voltage, and implements charging algorithms. (Sometimes built into the inverter, but add R5,000 to R15,000 if not included)
Batteries - Ideally a decently sized battery bank of good quality. Lithium Iron Phosphate batteries that should well beyond 10 years+ and have many other benefits. (R60,000+)
Solar panels. Typically at least 12x 350+ watt for a medium install. (R25,000)
Then additionally, you will also need:
A solar installer that sets up inverters, connects your batteries and (most importantly) installs solar panels on your roof. The installer also wires all of these components together, and adds the required solar panel DC boards. (R10,000 to R20,000.)
An electrician (who is sometimes also the above solar installer), to wire your inverter into your house main electric distribution board, add a sub-DB for your solar system, add some manual cut-over switches, and make sure the whole system is electrically compliant. This is needed if you want to seamlessly switch to backup power. (R10,000)
Battery cables, fittings, connectors, solar panel wires, etc. (R5,000)
Then, there are some "nice to have" extras to consider, such as:
A battery monitor. It measures electricity flow precisely and greatly improves your ability to measure how much power you are using and what you have left in your batteries. (R3,000)
Remote monitoring devices that store and/or publishes data to some form of web portal. Allows you to view all your data and statuses, but also sometimes to configure your equipment remotely. (R3,000)
WHY ARE SOME INVERTERS MUCH CHEAPER THAN OTHERS FOR THE SAME SPECS?
There are about 5 main brands of good quality inverters that are readily available in South Africa and that we prefer to work with. (There are probably many other good brands, but we prefer to have expert knowledge on fewer products rather than being a Jack of all trades.) Some of the tier 1 good inverters are more competitively priced (for example Deye / Sunsynk), while others are more premium (such as Victron). All of these are built using high quality hardware and very capable, and the more expensive ones are usually just more advanced in terms of their software, remote access and configurability.
Do realise however that there are dozens of 2nd or even 3rd tier inverter brands on the market and consumers are spoilt for choice. If you are on a tight budget and you know what you buy, this sometimes makes sense. Just keep in mind the following disadvantages when picking a lower tier inverter:
They often do not perform according to spec. For example, it may be sold as a 5 Kilowatt inverter, but only be able to output 4 Kilowatt of power reliably.
They have shorter (or no) warrantees, and do fail quicker.
They have less robust protective circuitry, such as overload and short-circuit protection. It is easier to damage them unwillingly.
Their software is buggy, difficult to use, and lacks functionality. More expensive inverters on the other hand has many useful settings, limits and programmable logic that greatly enhances their capability and utility.
Their is no (or very limited) data publishing capabilities online, with no remote monitoring / management or history views.
Power input and output connections are limited, resulting in no real ability to split essential and non-essential loads going through the inverter. It is not that smart and often has only one power output line. On the other hand, higher tier inverters usually additionally cater for generator inputs, second "non-essential" programmable outputs, and smart feedback to your source DB board.
They do not have the ability to operate in line-interactive mode, which means they can not intelligently share/split a high load with mains (Eskom).
They have a hard output inverter limit and there is no higher pass-through headroom. (If the inverter is rated at 5Kw, you are not able to pass any direct Eskom power more than this through it.)
They possibly lack other hardware, such as a good quality built in AC or Solar charge controller, data connecting ports that work, Wi-Fi connectivity or touch control screens.
WHAT MAKES A SOLAR INSTALLER GOOD VS. NOT SO GOOD? DOES IT MATTER?
Many solar installers are unfortunately novice electricians, who moved into solar when demand picked up. Unfortunately a lack of knowledge, poor quality workmanship, bad advice and the inability to correctly configure hardware often results in a solar installation not performing as it should and leading to a bad experience. Check the following before committing to an installer:
Qualifications: Check for level of electrician qualifications / certifications and also specific solar certifications.
Certificate of compliance: Is an installer able to provide you with a certificate of compliance after the installation? Only a qualified electrician is able to issue a certificate.
Inverter and configuration knowledge: Does the installer truly understand the inverter (and other equipment) he/she is installing? Often installers sell and install any product, but only has basic knowledge resulting in non-ideal performance and/or premature equipment failures.
Pre-install consultation: A good installer would not mind to spend a bit of time with you before providing you with a quotation. Clients have vastly different needs, and without understand your unique circumstances, the system could be incorrectly specified, wired and/or installed.
After-install follow-ups: Unfortunately installers do not plan to spend any time with a client after an install. Clients are often left in the dark (literally) with no knowledge on how to use the system and very limited support if something does not work as planned. This is also one of the reasons we choose EneFrame batteries, as they remotely monitor your batteries and system health for free, and service the batteries whenever required. (Read more at www.EneFrame.co.za)
Expert knowledge and skill
90% of the time we outprice our competitors with a significantly better price, using higher quality hardware!