Facts and Questions
LCP Solar FAQ’s
We could never answer all the questions one may have and the internet has a wealth of information available on the subject.
Considering that technology changes at a fast pace it would also quickly outdate any specific supplier information we might want to share.
Sometimes our clients are not too interested in all the detail and just want a system that “works”.
That would certainly be understandable. It would however also be important to us to meet or exceed our client’s expectations and the facts and questions that we have assembled are those that we think would be of value when discussing your solar solutions with us.
- What questions should I ask when requesting a quote for solar?
By approaching LCP Solar we already know that you have an interest in a solution. Let us guide you toward a cost-effective and sustainable installation.
We will need to determine at least the following:
- What is the motivation to install a solar solution?
- What would your requirements be that would also suit your budget?
- A qualified feeling of your load profile.
- Where the installation is situated and how we could optimise it photovoltaic (PV) production.
- Do you want a plug and play system where it gets turned on and you have little or no control or would you want a system that you could intelligently monitor, operate and even adjust to your needs?
- Would you like us to do remote support?
- What sort of warranty would you expect?
- Would you like us to propose a service plan?
- What process will LCP Solar apply when quoting me?
- We would like to understand your budget. This is not to get up to a price and probably more like getting down to an affordable solution. PV Storage is expensive. We would love to take you completely off-grid, in fact, it would be an honour. That is not necessarily the aim though, we just want to delight our customers.
- We will want to see four to six months of electricity bills. This is going to guide us as to what your monthly usage is. We could probably determine a daily average however it will not be completely reliable.
- We will want to understand your family and their requirements.
- At this point, we have probably been able to work out a budget.
- Should you be happy with a possible solution – we bring out the big guns. We will do a power analysis of your installation if necessary, this machine will over a few days give us your electrical heartbeat, what your baseload is, what and when are your electrical demand peaks. Is your electrical installation safe or are there other inherent problems.
- Good to go? We finalise the quote, you sign on the dotted line, we shake hands and commence on a wonderful and exciting journey of becoming independent.
- What process will LCP Solar apply when designing my system?
- Herewith some of the steps after determining the load profile and assessing your needs; we will start designing your solution.
- Determine the number of solar modules (panels) we will require. Practically we need to harvest 4.5 to 5 hours per day of solar irradiance to provide for reach 24 hours of required loads.
- Determine the fixing method, be it on the ground or on a roof structure, the placement and distribution of the solar panels.
- We will check the fixing spacing’s and the maximum spans the rails can be supported on your roof or slab but without compromising the support.
- Selecting the inverter and chargers will come next and their compatibility with each other assessed.
- Next, we will size the cabling and cable runs taking into account volt drop and positioning of the combiner boxes
- Energy storage (batteries) will need to be chosen and their compatibility with the charger and inverter will be determined. Considerations such as too few batteries or too many batteries will be taken into account. Again – we will have to determine cable sizes
Consider this – the wire to the light fitting above your head could be 1.5mm2. The cable to your battery could be 95mm2.
- Next on the menu are all the sundries such as AC and DC disconnects, fusing and fuse boxes, combiner boxes, trucking or cable trays and labelling.
- Finally, we will determine the earthing and surge arresting requirements and add them to the quotation.
- Should you accept our quote we will draw up a line diagram so that our installation team will have clear instructions and guidance.
- On close out we will issue a certificate of compliance for our portion of the work.
- Why is the term “Investment in solar” used?
- We tried to understand the term “Invest” in the context of solar and to try and best explain it we came across two definitions, one pretty modern and another, rather archaic but very apt.
- Modern definition: “The action or process of investing (money) for profit
- Archaic definition: “The surrounding of a place by a hostile force in order to besiege or blockade it”
We rather like the second one and explain why. Electricity is a grudge purchase. We need it and once we have (and paid for) it, it disappears and has no further value. Maybe we could see that power line snaking from our boundary as something to be placed under siege, even repelled whilst we provide for ourselves. Installing any level of solar would be investing in our future as not having to expend money with no long term return.
- How can I make a solar solution more affordable?
- One of the easiest and most cost-effective ways is to shift your peak demand to when solar is available and to harvest the suns energy as much as possible. An excellent example would be to change your pool timer to run during the day instead of at night.
- Choosing LCP Solar
- Why would I choose LCP Solar over another solar installation company?
- There are a number of valid reasons and we list some below:
- We are Solar installation specialists and we will be able to expertly place your panels in a manner so as not to compromise your roof structure. Just note that you would still need to ensure that the supporting structure of your home is able to carry the additional loads.
- We are Construction specialists – Our management and site supervisors have many years of experience in construction, buildings and installations. We are not merely electricians offering an installation service.
- We are IT specialists. Our in-house IT department will design the back end of the ESS (Energy Storage Solution) to fit your unique needs. Contrary to some opinions, a decently designed solar solution is not just a “plug and play” scenario. We always do our utmost to understand your needs and advise accordingly.
- We will do remote software maintenance. Should you require, we will be able to remotely maintain your system and make adjustments until your system is stable and functioning as intended.
- We will only purchase proper equipment from accredited suppliers who will be able to offer manufacturer back warranties.
- We use the correct tools to install your solution
- We will test your system and give you a test report. Just because your solar solution is functioning, does not mean it is necessarily installed correctly and is safe.
Our test equipment is the best there is available for PV installations. A plain multimeter just does not cut it here.
- We will provide a Certificate of Compliance for the portion we have connected to your existing electrical installation. Legally – you should demand one. See this section explaining the Certification of Compliance
- What products do you supply?
- We can supply any product of your choice to provide a complete solar solution, with the proviso that our accredited suppliers supply them and that they are backed by credible and sustainable manufacturer warranties.
- This could limit the field of choice somewhat. There are many excellent products on the market but we do tend to favour some products over others when it comes to specific usage requirements and our ability to support the products both from a software and hardware perspective.
- It’s the little things that count.
- What is meant by your statement about the little things that count?
- Well, a lot of things make up these little things.
- When you built your house, you were supplied with a plan by your architect. We need to supply you with an “as-built” installation schematic drawing. You will need this from a compliance, safety and maintenance perspective.
- We will adequately label your system. Imagine having your car sent in for repair and the technician does not know which wire or circuit where goes where or what to trace a fault to or from.
- We will ensure that the system is properly earthed. This does come at a cost but imagine the impact of surges where it could have been mitigated by proper earthing.
- We will sincerely recommend surge protection. It is currently not required in terms our legislation and SANS 10142-1
- Like any good installer, we like things tidy. We go to pains to ensure that our work is neat and tidy.
- We make good connections. It is easy to make a connection. It is just as easy to make GOOD connections. Not only does an average connection create losses in the system, we run the risk of DC arcing. No one wants DC arcing. DC arcing is dangerous and causes fires.
- Well, a lot of things make up these little things.
- What is the maximum size grid-tied inverter I can legally commission for a residential installation?
- There is no direct answer to that question and would depend on your AC installation and the supply to it. The short answer is that it is limited to the size of the circuit breaker from the supply of the utility. (A shared Low Voltage (400V/230V) feeder)
- A single-phase residential installation – not more than 4.6 kVA
- A three-phase residential installation – not more than 4.6 kVA per phase
- According to NRS097-2-3 of 2014, the combined PV system supply should;
- not exceed 25% of the shared transformer capacity. (This would, for explanation purposes, refer to the transformer on your street corner)
- any generator (Your PV modules are also known as PV generators) greater than 4,6 kVA should be balanced across phases.
- Is there a balance?
- Everything in life needs balance. Balance as an action could be seen as offset or compare the value of (one thing) with another.
How we see this balance is individually up to us.
My balance could be to only provide batteries for load shedding whereas your balance will be to save money by investing in solar purely to save money with no regard to power outages whilst the third person will want a complete solution wherein the savings will be used to offset the cost of storage.
- What is meant by base load?
- The base load is the minimum level of demand that your home will require over a 24 hour period (i.e.: the basic amount of electricity that is always required.)
- What is meant by peak demand?
- Peak demand (or peak load) is the daily fluctuation of your electricity use. Usually, lower in the early hours of the morning when most people are still asleep and higher in the early evening when most people are cooking and using their stoves and other appliances. Many families with children will be bathing in the evenings and using their geysers whereas some people only shower in the morning using less electricity.
- DC arcing
- To sustain an arc of significant temperature, the voltage across the arc gap must be in the range of 20 volts or more. Now imagine a little gap somewhere due to a poor or loose connection. Know also that on the DC side of your installation we will be dealing with voltages between 250v and 1500v DC.
- It should be noted that DC arcs can reach temperatures of over 3000 degrees C. Arcs of this temperature can melt metal, which can fall as slag and ignite nearby combustible materials. Preventative measures are therefore necessary to minimize the risk of starting the fire in the first place.
- A traditional string/central inverter PV system design is not beneficial in terms of addressing arc fault risk and firefighter safety.
- Strings are designed for the highest DC voltage to reduce current (I²R) losses, and multiple strings are placed in parallel to increase the DC current.
- This design also results in a large geographic distribution of DC wiring systems.
- All of these design factors increase the risk of arc faults and make it more difficult to suppress a fault once it occurs.
- Why is DC arcing even mentioned? We are discussing solar
- Well, to harness the suns energy we start with DC and then we convert to AC through the use of an inverter.
- A significant portion of the wiring on a solar solution are many parallel DC wires.
Where ever a joint is made:
- it has to be made in the correct manner;
- with the correct connector; and
- crimped with the correct crimping tool. An ordinary pair of plier or cheap crimping tool will not suffice.
- Should any of the 3 aforementioned conditions not be met – we run the risk of DC arcing.
A statistical review of the source of fire in 75 PV systems in a study in Australia, showed that the chance of the quick coupler causing the fire (29%) is nearly as high as for the rest of the module (34%) or other parts of the PV system (37%). There are no specific requirements in our local standards.
- Why Surge Protection?
- It is not installed on my current distribution board, my house is new and I have a valid COC.
- Although not required according to the SANS10142-1 standard, not installing surge protection leaves an installation exposed to potential damage by surges caused by the distribution network, or other types of fault conditions, lightning, induced voltages, etc.
- Insurance companies are unlikely to honour claims in the event of surges causing damages to solar equipment that have not been suitably protected.
- Inverter suppliers might also not honour claims in the event of damages caused by surges where no surge protection equipment was installed.
- Is testing important – It works.
- Sure it does but was it tested?
- How do we know that the system has been installed with the correct checks in place?
- What is an insulation test?
- Exactly as stated, it is a test to check the insulation of the system.
- We now understand the dangers DC arcing so the insulation must be tested and must be intact. This is however where the similarity with an “AC system” insulation test ends.
- In an AC system we must do an insulation test with the power disconnected but the circuit complete.
- With PV we cannot “disconnect” the system because as soon as the sun comes up the DC side is live.
- At LCP Solar we have the correct equipment to test a live DC system.
- Why should I be concerned about volt drop?
- Volt drop happens when the cable is incorrectly sized and very long.
- 500 or 1000volts sounds like a really high number. Why should I be concerned about a few volts?
- Volt drop is critical in DC systems. It is the difference between an inverter starting up or not, it is the difference if the battery charges correctly or not. Even half a volt on the battery side could be detrimental to efficiency.
- The higher the temperature of copper conductors, the higher the resistance in copper conductors. Volt drop according to the local installation regulations need to be lower than 5% from point to point.
- If the various international solar standards are scrutinized it can be said that 5% is way too high. In many installation manuals all calculations are done around a 1% volt drop.
- 3% is however internationally accepted as good practice for solar PV installations.
- The SAPVIA Solar PV Green Card
- The SAPVIA Solar PV Green Card is an industry led quality label that is inclusive in nature and becomes the key to ensure a high standard of quality for small-scale Solar PV installations. The PV Green Card is set to become a national, standardised hand-over or “as built” report for roof-top PV installations, aimed at improving the safety and quality of installations. It provides comprehensive documentation of the PV system including information on used components and personal data of the owner, and will be a voluntary service from the installer which will serve as a guideline to both the installer and the customer on how to secure a high standard of PV system operation.
- PQRS Photovoltaic / Solar certification
- PQRS Offers a range of Solar PV design and installation courses with the Excel and Exceed courses presented through the SAEEC (South African Energy Efficiency Confederation). As one of the leaders in the development of brand neutral Solar PV training course material in South Africa. PQRS provides a specialist training environment for and on behalf of most of the major solar equipment distributors locally.
- Key components in solar system design and references to standards and regulations support the course content.
- Accreditation – content is aligned with the solar PV service technician formal qualification and a range of unit standards.
Courses are also accredited with ECSA (the Engineering Council of South Africa) for 2,5CPD points per course.
- Assessment & Certification – Upon completion of the Excel course, students write the online P4 Level 1 test and upon completion of the Exceed Course, students write the Online P4 Level 2 Test for accreditation through AREP’s (Association for Renewable Energy Practitioners) Quality Assurance Programme. Candidates attending also receive an attendance certificate from SAEEC/PQRS.
Some more questions?
The internet is vastly populated with all the necessary questions and answers regarding solar PV systems.
We cannot answer them all here and why would we when we could point the reader to some links.
Here are some references which we think would be useful and some used on our website
In order to assist our reader, herewith some abbreviations and simplified definitions.
Definitions are also supplied to be read in context with a solar installation.
- AC: Alternating Current. This is the current consumed in your home and is the current on the LOAD or DEMAND side of the inverter.
- DC: Direct Current. This is the current supplied by your solar panel and goes to the SUPPLY side of the inverter. Thus the inverter “inverts” the DC supply to an AC supply.
- 230V AC: This is the Voltage supplied to your home and appliances in a residential scenario
- 250V – 1500V DC: This is the voltage supplied to the inverter depending on string sizes and other variables.
- String: This is a number of solar panels connected to each other in series – like a piece of string.
- PV: Photovoltaic. A solar panel is a photovoltaic panel.
- SANS 10142-1: This is the National Standard that governs electrical installations in South Africa. This standard was previously known as SABS 0142.
- SANS 10142-1-2 The National Standard that governs renewable energy installations in South Africa
- Derating: In this context specifically relates the mechanical driven alternators or gensets as we know them. Pretoria is roughly 1300m above sea level and a generating set must be de-rated at 1% per 100m above sea level.
- KVA: Kilo Volt Amp
- Power: This is what your appliances use and measured in Watts. 1000Watts = 1KW
- KW (Kilo Watts): This is KVA x 0.8
- Low Voltage: Voltage less than or equal to 1000VAC or 1500VDC