+ WHAT TYPES OF SOLAR &/OR RENEWABLE ENERGY POWER SYSTEMS ARE THERE AND HOW DO THEY WORK?
WHAT TYPES OF SOLAR &/OR RENEWABLE ENERGY POWER SYSTEMS ARE THERE AND HOW DO THEY WORK?
Solar Power systems are typically used as "off the grid" (not utalising a power utility like Escom) systems. They reduce your utility bill while still giving you the electricity you need to run your house, business, farm or factory. They are ideal for locations where grid power is not available, where it is expensive to get/operate or where a client wants to get off the grid for environmental and/or cost saving reasons. Where grid power is available, the client can stay on the grid and use it as a backup if needed, but using solar energy as their main source of power. This is beneficial during prolonged period of rain or periods when more power is utilised than the solar system can produce. In this case you will still get a Escom/power company bill, but it will be greatly reduced.
A solar power system typically consists of solar panels that convert solar rays into electric current (DC - Direct Current), this current is send to a charge/MPPT controller that manages the charging rate and output voltage of the current flowing to the battery bank. From the battery bank the power flows to an inverter that converts the 12/24/48 Volt DC (Direct Current) power to 220/230 Volt AC (Alternating Current) that you can use in your home, farm, business or office.
As can be seen this is a complex system and requires indepth solar, electrical and technical engineering along with extensive product knowledge to design.
(Click here to get a quotation on a Solar Power Sytem)
Grid tied solar systems (also known as a grid interactive system) are used where the electricity/Escom grid is available, but where the client wants to send access or generated power back into the grid or use the grid for power storage. This system will turn the electricity meter backwards (old wheel type meters only). Thus when the system produces more power than is utalised, the access power gets pushed into the grid, acting like a giant battery, when power is needed (e.g. at night) it is drawn from the grid making the meter run forward again. Thus this will be at a 1 unit to 1 unit off set. Grid tied systems have the benefits of reducing your electricity bill, reducing your carbon foot print, negating the need for having batteries for power storage purposes. The negative part is that when there is a power outage (the grid goes down), you will not have power (accept if a Hybrid Tied Solar Power Solution is used - See below), the client needs an "old wheel type"/non-digital electricity meter and needs to ensure that the local authority allows for this kind of system.
A grid tied solar power system typically consists of solar panels that convert solar rays into electric current (DC - Direct Current). From the panels the power flows to a special grid-tied inverter that converts the 12/24/48 Volt DC (Direct Current) power to 220/230 Volt AC (Alternating Current) that you can use in your home, farm, business or office. The power that is not utalised is than send to the grid and when the power requirement is higher than what the system produces, this power is drawn from the Escom/electricity grid.
When batteries are added a grid tied system is refered to as a hybrid grid tied system. The benefit of adding batteries is that when there is a power outage (the grid goes off), there is still some backup power available to work from. Please specify whether you require this as an optional extra when making an enquiry or requesting a quotation.
Backup power solutions are used mainly to counter the crippling effects of power outages to homes, businesses and offices. When a client is reliant on power in their daily lifes or operations this can have negative effects on your ability to work, service customers or conduct daily business and in turn may effect turnovers and cause considerable inconvenience. A Backup Power Solution solves this problem by giving the client an additional source of power when the grid/Escom goes down. The battery bank is kept fully charged by grid power using a special inverter charger. The backup power stored in the battery bank and the power consumed determines the period that the backup power will last. Inverter chargers have automatic change overs that switches over to the battery backup when the power goes off and also cuts off the power when the battery bank power reaches a certain level. When the power comes back on, the batteries are charged to float level again. Typically a backup system is designed to last for 4 hours, 8 hour, 12 hours or 24 hours dependant on the clients requirements.
A Backup Power solution consists of a special inverter charger and a battery bank. The inverter chargers have an automatic change over. Some backup systems also allow for a generator to be connected to it in order to charge the battery back if the power stays off fro prolonged periods of time.
+ WHY SHOULD I CONSIDER A SOLAR POWER, RENEWABLE ENERGY OR BACKUP POWER SOLUTION?
WHY SHOULD I CONSIDER A SOLAR POWER, RENEWABLE ENERGY OR BACKUP POWER SOLUTION?
-
Increasing cost of grid based electricity: This factor and the inevetable increase in power costs to come in the future. Thus you will be saving yourself money. The sooner you start using renewables, the more you will be saving in the long run.
-
New connections or isolated areas: In most cases it will be more cost effective to use solar power or renewable energy than to make a grid connection. This is usually the best options specifically for farmers and individuals in rural areas. Pole costs being charged by Escom can run into thousands of rands a year, this can be better invested in a solar or renewable energy system.
-
Avoid power cuts and outages: When you have your own "Independent power station", you don't have to worry about poor maintenence, escalating infrastructure cost, under budgeting, etc from power producers like Escom. You are in control of your own consumption and production. By 2030 the demand for electricity would have doubled but it is doubtfull if the supply side would be able to meet this huge demand.
-
Food safety and limiting of losses: Power outages cause fridges to run down, ruining food. They are also a safety issue deu to lights, gates and alarms not working.
-
Carbon footprint: Decrease your carbon foot print and energy consumption for the sake of the planet and generations to come.
-
Limiting of pollution & negative environmental effects: Renewable energy causes no pollution, exhausting of resources, has no emissions, has no/low noise factors, is low to no maintenence.
-
Fuel and maintenance savings: Solar and Renewables do not use costly feuls like petrol and/or diesel, oil, etc and will not require engine repairs due to wear and tear like in the case of generators. There also isn't a noise problem like with generators.
-
Affordable prices & good quality: Renewable energy systems and componenets have come down in price and gone up in quality since becoming a mainstream industry.
-
Can start with a basic system and enlarge it over time: Even if you only convert a portion of your energy use to renewables you will start to reep the benefits. Please in the same vein be on the lookout for companies not stocking original brand names.
+ WHERE DO I START IF I'M CONSIDERING SOLAR AND/OR RENEWABLE ENERGY
WHERE DO I START IF I'M CONSIDERING SOLAR AND/OR RENEWABLE ENERGY
Here are some facts about solar and renewable energy:
-
Become as energy efficient as possible. This means minimising your watt hour usage as far as possible and might include:
-
Switching to energy saving or LED lights. A normal incandecent light uses on average 60-100 watts per hour while a good quality equivelant energy saving/LED light uses 3-5 watts per hour and produces the same amount of light.
-
Switch your electric stove to a gas stove or use an induction hob that is 50% more energy efficient. Low wattage slow cookers or microwaves might also be a good option. Compare the daily watt hours (wattage hour x hours of use) between these options. 220 Volt stoves and other appliances with elements are not build to run off solar.
-
Replace your geyser with a solar geyser or retrofiited solar collector panel. A typical geyser consumes 30-40% of your monthly electricity bill. Replacing this is a good investment. 220 Volt geysers and appliances with elements are not build to run off solar.
-
Change your in-efficient appliances for efficient ones. These include tube televisions, fridges, freezers, washing machines, etc. Shop for A+ or A++ appliances, but always check the wattages as some might have a good rating but still be in-efficient. It is a good idea to give your appliances a second live by selling them on sites like www.olx.co.za and www.junkmail.co.za. This helps to conserve the planet by reducing the need for mining of raw materials to make new ones.
-
-
Decide if you will be needing a power solution or a backup solution. See above FAQ.
-
Decide if this needs to be grid tied or off grid. See above FAQ.
-
Decide if you want to go totally off grid or if you want to do the change over in stages.
-
Investigate the natural resources you have available. These include sun, wind, water and biomass.
-
Send SREG a quote request for on of our solar or renewable energy solutions:
​
Some other good facts to know (taken from our Energy Pre-planning and solar calculators):
-
Add all appliances and lights to the list: Go through your whole house, office or business and fill in all the appliances, lights, etc that will be ran off the solar or renewable energy system.
-
Lights & Appliances: Renewable energy sources are only made to run low energy/wattage appliances for instance lights which are not more than 15 Watts per hour. Preferably do not run lights for more than 6 hours. Use Energy saving/LED lights.
-
Appliances like Fridges & Freezers: All renewables are only made for appliances that are designed to run off low energy (wattage), for instance the fridge freezers Solar Energy Group (Pty) Ltd sells. This principle applies to any and all appliances. Tip: You can give your appliances a second life by selling them online on sites like: olx.co.za, bidorbuy.co.za, junkmail.co.za, etc
-
Chest/Box Freezers: Normally chest/box freezers running on 12/24/36/48/60/etc Volt DC are not made for alternative power generation. If running these types of appliances on higher DC Voltages, it will normally influence the long term sustainability of the solar panels.
-
Self contained security lighting: Solar Energy Group (Pty) Ltd does not sell this type of lighting. These need separate panels and batteries to work off DC power.
-
Maximum watt hours: If the watts calculated below exceed 34000 watt hours, please adjust within the ranges of 8000/16000/24000/34000 watts hours to allow for the use of multiple systems. This is The Solar Groups on The Science of Alternative Power. Exact wattage per hour cannot be guaranteed.
-
Heavy Duty appliances: Washing machines, tumble driers, dish washers, etc can only be used when the sun shines to maximise the life and power capacity of the batteries. A usage schedule will need to be drawn up and kept to for optimal effect.
-
Stoves: When it comes to 220 Volt stoves the best advice is to rather go for gas or low wattage induction hobs.
-
Borehole pumps: 220 Volt borehole pumps must be replaced with special borehole pumps sold at Solar Energy Group (Pty) Ltd. Converting existing borehole pumps cost on average 4 times more than a comparable solar water pumping system.
-
Geysers: 220 Volt geysers should be replaced with special solar geyser(S) or solar heat collector panel(S) sold at Solar Energy Group (Pty) Ltd.
-
Heat pumps: It is suggested that you rather go with solar geyser(S) or solar heat collector panel(S) sold at Solar Energy Group (Pty) Ltd. Heat pumps use less energy than conventional geysers, but still use a considerable amount of energy. The return on investment on a solar geyser is also much more and the payoff period shorter.
-
Solar & Renewable Energy Book: All of the information above, and much more, have been taken from the Book “Solar All about”. We highly recommend that you buy this book because it will give you a good understanding of what solar & renewable energy is about.
-
Unknown wattages: If you are unsure about the wattage of any appliances, please write down the current (in amp) and the voltage (usually 220/230 Volt) for us to calculate the wattage (Watt = Amp x Volt). Normally ratings are written in amp on the appliances.
-
Usage schedule: Bear in mind that you will have to draw up a usage schedule for the appliances and lights mentioned above and will have to ensure that your family, employees and staff keep to this schedule in order for your power system to operate optimally. Solar Energy Group (Pty) Ltd will provide a template to work from.
-
T’s & C’s and copyright: Read the Solar Group terms & conditions as well as copy right restrictions before purchasing or entering into agreement with SEG
+ MISCONCEPTIONS & URBAN LEGENDS IN THE SOLAR & RENEWABLE ENERGY BUSINESS
MISCONCEPTIONS & URBAN LEGENDS IN THE SOLAR & RENEWABLE ENERGY BUSINESS
Due to solar and renewable energy sectors growth rate over the last number of years unscrupulous companies have entered the market that do not have the knowledge, background or experience to be able to advise clients correctly This has led to a number of misconceptions, inaccuracies, fallacies, rumours and urban legends abounding in the market. Here we attempt to address these, create some clarity and state the truth as it is so you can make good decisions;
-
You don't need to make any changes to switch over to solar and/or renewable energy: Using solar and/or renewable energy requires a lifestyle change & adaptation. Because you will basically be planning, installing & managing your own power station you need to become as energy efficient & concious as possible before purchases, doesnt matter which brands you buy anywhere from anyone, be on the lookout for over/under quoters promising you can run anything, you will waste your money! You have to replace inefficient/high wattage appliances and/or lights to efficient/low wattage ones. Your consumption needs to be planned, monitored and managed to get optimal performance from your system, & to understand the ins/outs. See the question above. Alternative power is not automatically sustainable without proper planning, & its not only a switchover, its a conversion with all the strings attached & more however made easier from SEG!!
-
You can run stoves, geysers and other element based appliances off solar or renewable energy: These appliances are simply not made to run off solar. See point 1 in the previous question.
-
One can plug in anything on solar or renewables (without e.g. Monitoring etc): There is a plug in limit when it comes to systems called a peak. If you exceed this peak you will strain your system and run the risk of damaging components like inverters, charge controllers, batteries, etc.
-
A house can be run off 1 solar panel: You usually need a whole solar panel array (multiple solar panels connected together with wiring) to generate power required to run a household, business or office. The exception is a grid tied system where the grid still supplies some of the power required, but then you will still be dependent on Escom power. The number of panels, wattages of these panels (these differ from 10 Watt to 320 Watt), type (polycrystalline or monocrystalline) is determined by your spcific energy use requirement. Dont get confused by /through e.g. geysering panels & powering panels as well!
-
You can buy a "standard package", "solar power kit", "pre-designed system" or ballfigure KW system and it will work: This is one of the biggest fallacies, your energy usage profile determines (determined by filling in one of our solar calculators & energy use profiles, this is comparable to an energy audit but much more customised) your eventual system design and components depend on how much power you use, how you use it, what time of day you use, what the maximum plug in and peak is, etc, otherwise you will waste your money on e.g. Eskom/ AC chargings e.g using esok as backup etc. The appliances, number of appliances, usage time, peak use, power storage requirements, day time and night time use, etc all differ from household to household, business to business or office to office. All of these factors are ignored with "standard packages. With this approach clients are either over charged or under charged resulting in wastefullness or additional costs at a later stage. S-E-G VERY strongly advises against this practice, going with an option like this will be a gamble and a risk. Everybody's energy consumption profile differs, but the methodology we employ always stays the same thus we treat everybody equally and fairly.
-
Please AGAIN be on the lookout for standard packages, kits/ so called meduim househould/ office systems /kit/s, as companies selling these do not know YOUR energy ratings on YOUR appliances, even if appliances are e.g. the same brand/ related wattage are not necessaraly the same.
-
To learn more see the following sections:
+ WHAT ARE THE KEY CONCEPTS TO UNDERSTANDING HOW SOLAR GEYSERS AND HOT WATER HEATING WORKS?
+ HOW DOES SOLAR WATER PUMPING WORK?
HOW DOES SOLAR WATER PUMPING WORK?
Solar water pumps have been in production since the 1980's. The concept is rather straight forward, even though a lot of cutting edge design, engineering and manufacturing has gone into the process of manufacturing these pumps; A solar panel array (1) converts sunlight into High voltage DC electrical current (power), the array is connected to a controller box (2) (linear current booster / MPPT / Maximum Point Power Tracker) that converts the high voltage DC to low voltage and then drives a special low voltage submersible Solar Water Pump (3)(Helical or Centrifugal type depending on delivery and depth requirements). The motor and wet end then pumps the water out of the borehole, river, dam or pit into a tank, reservoir or dam. The pump continues to deliver water for most of the daylight hours. Batteries can also be used to drive the pump, but in most cases this is not necassary. There are also dry run protection prods (for the pump) as well as over-flow/tank prods available that prevents the motor from running dry and/or the tank/reservoir from running over.
These solar water pumps (e.g. Oil/water based etc) are suitable to provide waters for: domestic use (pottable water), drinking water supply, irrigation, lifestock watering (suiping), pressurising, pond management, etc. (GPS monitoring/related @ e.g. switchup etc can be installed on SEG pumps, same applies to other power products!)
+ WHAT ARE THE MAIN REASONS FOR CONSIDERING A SOLAR WATER PUMPING SYSTEM?
WHAT ARE THE MAIN REASONS FOR CONSIDERING A SOLAR WATER PUMPING SYSTEM?
Cost effectiveness and long life: Once the pump has been bought and installed there are no running costs. With generators there are fuel and maintenance costs and the effort of keeping the tank full. With 220/360 Volt electrical pumps (dompel pompe) there is the cost of power and monthly Escom pole fees. With wind mills there is maintenance costs and well as the fact that the least amount of wind is available when water is needed the most. Sun is also more reliable than wind. We can build a pumping system for a deep well at a modest cost.
Low to no maintenance: The pumps are brushless, permanent magnet, oil filled units that are build to last many years in the field and since they are located a number of meters below ground they usually cannot be physically damaged. The solar panels typically have a 25 year warranty on their efficiency, if the rain does not wash the dust off the panels, then dust needs to be cleaned off every so often. The control boxes as also very reliable and water proof. So all in all it is a straight forward sytem with little room for error. The pumps can also be installed by hand and pulled up easily if need be.
Ideal for remote and rural areas: These pumps can work in areas where it would be very expensive to have grid power (Escom power) installed and can operate independently. Once installed and setup the pumps work on their own and do not need to be switched on or off. The pumps start pumping when the irridation from the sun reaches a certain level (in the morning) and stops when it falls below a certain level (late afternoon). Due to dry run protection prods and overflow protection prods that are installed with the pumps, they do not have to be manually monitored and swithched off.
Water when you need it: Solar pumps pump the most water during dry and sunny weather/days when it is needed most. Also works well on low yield boreholes (syfer boor gate) which only allows for drawing off small amouts of water over a longer period. Other pumps tend to pump these holes dry.
Pumping from multiple sources to multiple storage units: Solar water pumps can pump water from boreholes, dams, rivers, deep wells, shallow wells, ponds, streams, aquifers, etc. One can pump water to tanks, dams, aquaducts, cripps, animal watering ponds & holes, etc.
Suitable for various uses: Domestic (home use) water, off-grid homes, farms & cabins, aquaculture, livestock watering (suiping), etc.
Access to good quality, abundant water resources: Water may well be abundantly present on the Earth, but the salt water of seas and oceans accounts for 96.4% of the total water volume. Fresh water only accounts for 3.4% of the total volume of water on our planet. This supply of fresh water is broken down as can be seen below:
2.15% is contained in glaciers or permanent snow (this makes up about 70% of the total fresh water)
0.019% constitutes the surface waters : lakes, rivers of all sizes (about 0.6% only of the total fresh water)
(Please note only pumps made to work on this method (to be discussed) is cost effective, to put ANY 220 volt pumps especially to work from alternatives are not cost effective EVEN IF QUOTATION WAS/IS BASED ON PREPLANNING/NOT, there are e.g. Battery sustainability issues ETC; concerning all/any companies; Please be vigilent concerning " too good too be true quotations"; applied to this phenomenon especially, within industry). This prinsiple applies in general to all appliances (bought anywhere) not made to run of renewables (called non ecofriendly appliances etc), even if used for shorter periods of time. ALL Dc appliances must not work straight from batteries (any type), controllers are recomended, please see solar book section/consultation sessions for more! Savings are clean & easy with SEG!
+ What are the different types of batteries you get?
absorbed glass mat (AGM) battery
A relatively new type of sealed battery construction that uses saturated absorbent glass (boron silicate) mats between the plates instead of a gelled or liquid electrolyte. AGMs batteries are more expensive than the flooded (liquid) variety but offer a number of advantages.
Since all the electrolyte (acid) in AGM batteries is contained in the glass mats, it can't spill, even if the battery is broken. Being thus non-hazardous, AGM batteries are cheaper to ship. Additionally, since there's no liquid to freeze and expand, they're practically immune from freezing damage.
Nearly all AGM batteries are recombinant, which means that the oxygen and hydrogen recombine inside the battery. Recombinant batteries use gas phase transfer of oxygen to the negative plates to enable recombination back into water while charging, thereby preventing the loss of water through electrolysis. The recombining is typically more than 99% efficient.
The charging voltages are the same as for any standard battery, so there is no need for any special adjustments and no problems with incompatible chargers or charge controls. Since the internal resistance is extremely low, there is almost no heating of the battery even under heavy charge and discharge currents.
AGMs have a very low self-discharge – from 1% to 3% per month is usual. As a result, they can sit in storage for much longer periods without charging than standard batteries.
Even under severe overcharge conditions, hydrogen emission of AGM batteries is far below the 4% maximum specified for aircraft and enclosed spaces. The plates in AGM's are tightly packed and rigidly mounted, and will withstand shock and vibration better than any standard battery.
Even with all the advantages listed above, there's still a place for the standard flooded deep cycle battery. AGMs cost 2 to 3 times as much as flooded batteries of the same capacity. In many installations, where the batteries are set in an area where you don't have to worry about fumes or leakage, a standard or industrial deep cycle is a better economic choice.
lead-acid battery
An electrochemical battery that uses lead and lead oxide for electrodes and sulfuric acid for the electrolyte. Lead-acid batteries are the most commonly used in photovoltaic (PV) and other alternative energy systems because their initial cost is lower and because they are readily available nearly everywhere in the world. There are many different sizes and designs of lead-acid batteries, but the most important designation is whether they are deep cycle batteries or shallow cycle batteries.
Deep cycle batteries are designed to be repeatedly discharged by as much as 80 percent of their capacity so they are a good choice for power systems. Even though they are designed to withstand deep cycling, these batteries will have a longer life if the cycles are shallower. All lead-acid batteries will fail prematurely if they are not recharged completely after each cycle. Letting a lead-acid battery stay in a discharged condition for many days at a time will cause sulfation of the positive plate and a permanent loss of capacity.
Sealed deep-cycle lead-acid batteries are maintenance free. They never need watering or an equalization charge. They cannot freeze or spill, so they can be mounted in any position. Sealed batteries require very accurate regulation to prevent overcharge and over discharge. Either of these conditions will drastically shorten their lives. Sealed batteries are well-suited for remote, unattended power systems.
Shallow cycle batteries, like the type used as starting batteries in automobiles, are designed to supply a large amount of current for a short time and stand mild overcharge without losing electrolyte. Unfortunately, they cannot tolerate being deeply discharged. If they are repeatedly discharged more than 20 percent, their life will be very short. These batteries are not a good choice for a PV system.
lead-acid battery maintenance
The quickest way to ruin lead-acid batteries is to discharge them deeply and leave them stand "dead" for an extended period of time. When they discharge, there is a chemical change in the positive plates of the battery. They change from lead oxide when charged to lead sulfate when discharged. If they remain in the lead sulfate state for a few days, some part of the plate does not return to lead oxide when the battery is recharged. If the battery remains discharged longer, a greater amount of the positive plate will remain lead sulfate. The parts of the plates that become "sulfated" no longer store energy. Batteries that are deeply discharged, and then charged partially on a regular basis can fail in less than one year.
Check your batteries on a regular basis to be sure they are getting charged. Use a hydrometer to check the specific gravity of your lead acid batteries. If batteries are cycled very deeply and then recharged quickly, the specific gravity reading will be lower than it should because the electrolyte at the top of the battery may not have mixed with the "charged" electrolyte. Check the electrolyte level in wet-cell batteries at least four times a year and top each cell off with distilled water. Do not add water to discharged batteries. Electrolyte is absorbed when batteries are very discharged. If you add water at this time, and then recharge the battery, electrolyte will overflow and make a mess.
Keep the tops of your batteries clean and check that cables are tight. Do not tighten or remove cables while charging or discharging. Any spark around batteries can cause a hydrogen explosion inside, and ruin one of the cells, and you.
It is a good idea to do an equalizing charge when some cells show a variation of 0.05 specific gravity from each other. This is a long steady overcharge, bringing the battery to a gassing or bubbling state. Do not equalize sealed or gel type batteries.
With proper care, lead-acid batteries will have a long service life and work very well in almost any power system. Unfortunately, with poor treatment lead-acid battery life will be very short.
Safety precautions
Always use extreme caution when handling lead-acid batteries and electrolyte. Wear gloves, goggles and old clothes. The sulphuric acid in lead-acid batteries will burn skin and eyes and destroy cotton and wool clothing. Adopt these specific measures for maximum safety:
1. Someone should be within range of your voice to come to your aid when you work near batteries
2. Have plenty of fresh water and soap nearby in case battery acid contact skin, clothing, or eyes
3. Wear complete eye protection and clothing protection. Avoid touching eyes while working near batteries. Wash your hands when done
4. If acid contacts skin or clothing, wash immediately with soap and water. If acid enters eyes, immediately flood eyes with running cool water for at least 15 minutes and get medical attention immediately
5. Baking soda neutralizes lead acid battery electrolyte. Vinegar neutralizes spilled NiCad and NiFe battery electrolyte. Keep a supply on hand in the area of the batteries
6. NEVER smoke or allow a spark or flame in vicinity of a battery or generator
7. Be extra cautious when working with metal tools on, and around batteries. Potential exists to short-circuit the batteries or other electrical parts which may result in a spark which could cause an explosion
8. Remove personal metal items such as rings, bracelets, necklaces, and watches when working with a battery. A battery can produce a short-circuit current high enough to weld a ring, or the like, to metal causing severe burns
9. If a remote or automatic generator start system is used, disable the automatic starting circuit and/or disconnect the generator from its starting battery while servicing to prevent accidental starting during servicing
|