Solar Advisory Services brings you some of the basic but very important good to know information before you may look for Sun's rays to produce electricity.
Each consumer has a unique need for Electricity to run their appliances. Hence there is no fixed package which can serve a customer that will fit for the need for another customer.
The need for customized use of power brings in the room of opportunity to build the solar setup that meets the specific requirement. This can be as simple as a 5 watt system to 500 MW utility. Below are the few of most commonly asked queries anyone must learn before investing.
WHAT KIND OF SOLAR PANEL CAPACITY I REQUIRE TO MEET MY POWER DEMAND?
It’s very simple to evaluate the Panel size by its wattage to meet your energy demand. It’s a math to work backwards.
There are TWO lights of 30 watt capacity and a Fan of 40 watt capacity which is run for 5 hours a day.
So the total energy requirement is
(2 Lights x 30 watt) + (1 Fan x 40 watt) = 100 watt / hour is the requirement. (The system should generate sufficient electricity to constantly supply power to meet 100 watt load requirement for one hour.
Now for 5 hours we require (5 hours x 100 watt / hour) = 500 watt for a period of 5 hours.
The minimum capacity solar panel that must be used should be 100 watt as it meets power need for 1 hour.
In practice considering the electrical systems losses we assume 80% to rated power wattage per panel. So 1 Solar panel of 100 watt capacity shall produce 80 watts per hour. However the requirement is 100 watt hence we add additional 100 watt (typically use the same capacity wattage panels and brand). Hence we need 200 watt solar panel (0.8 power factor = 160 watts on solar panel) to meet 100 watt per hour energy need. The excess power can be stored in a battery to use for later time when there is no Sun light.
Should you have a requirement, feel free to consult us, we shall be happy serve you both onsite as well as remotely!
HOW TO DEAL WITH NO SUNSHINE OR A CLOUDY SEASON FOR MANY DAYS?
There are 2 ways to deal with such situations
- Hybrid solar setups can toggle between Grid supplied power when Solar power is unavailable
- A higher capacity solar setup can be designed to produce more power and store the excess energy in batteries to be used during shady days or complete night when there is no sun light. Usually batteries are included to store power for 3 to 5 days during solar setup design. However this would also increase the cost of ownership, decreases dependability on utility grid.
WHAT IS THE LIFE OF A SOLAR PANEL?
The active component in the panel is the Solar Cells. The silicon or any amalgamated wafers. These would last a life time of a human life for 50 to 60 years. However their efficiency is reduced slowly depending on the nature’s abuse as well as short circuit possibility. A guaranteed life span of 25 to 30 years are aimed, thus the panels in satellites power the system while they focus on the sun light. However on Earth surface periodic maintenance (at least once in a year) is required to let them last long.
HOW DO I MAINTAIN SOLAR POWER SYSTEM AND COMPONENTS?
A well maintained solar power system produces optimal desired power output.
Few of the tips are as follows
- A periodic check on the panel surface for any dust and dirt accumulation
- Regular check on the diodes and circuit breakers connected for protection
- Be cautious during lightning and thunder storms for flash power
- Regular check on battery fluids and voltage across terminals
- Have a dashboard panel to review voltage and current parameters of both AC and DC power
HOW SOLAR PANELS DESIGN ARE DIFFERENT?
The Cell structure and the material defines the light absorption potential of the Solar Panel. In the market there are panels available based on different materials used in the cell design. Some of the most commonly used panels are as follows.
Monocrystalline solar panels – highly efficient to produce more Ampere current even during less sun light availability, but relatively expensive.
Polycrystalline solar panels – made of more than one material that requires ample sunlight to get the electrons flow to create the Ampere. The cost is minimal and the size of the panels are usually larger in surface area.
In research there are few amorphous silicon wafers which have the ability to absorb wider wavelength of sun light spectrums and thus highly efficient to produce more power despite less sun light and longer duration of time even post sunset. These cells are relatively expensive, however highly efficient and reliable.
HOW CAN I FIND OUT HOW MANY WATTS MY APPLIANCES USE, SUCH AS COMPUTERS AND STEREO ETC.?
It is important to know how much power each of the devices are using to do the design plan on Solar Electricity setup.
- The easy way to locate the power consumption of an appliance is to read the product description marked on them.
- Alternatively you may add a watt hour meter to measure the consumption of electricity by each equipment.
- A reactive way of identifying the power consumption is by checking the details on utility bill.
WHEN DO I ACHIEVE THE BREAKEVEN WHILE I INVEST IN MY SOLAR POWER SETUP?
The ROI typically would be during 5 years to 6 years, depending on multiple factors.
- Proper maintenance of your solar components [solar panels, battery, charge controller, inverter, wiring, circuit breakers]
- Considering the periodic hike in utility gird tariff
- Depending on the model of operation the solar setup is executed
- Upfront purchase
- Solar power as service
- BOOT model [PPA]
WHAT ARE THE ADVANTAGES OF SOLAR POWER OVER WIND OR HYDRO ELECTIC?
Wind / Hydroelectric
WHATS THE BEST INVERTER TO USE FOR SOLAR POWER GENERATION.
Inverter is an electrical device which converts DC power to AC. The way these inverters are used for a specific purpose categorizes them as following.
- Modified sine-wave inverter or pure sine-wave inverter most commonly used in domestic solar power environment.
- A utility power grid integrated inverter
- Central sine-wave inverter
- Micro inverter
- Offers up to 25% additional energy to normal inverters
- A power optimizer is a DC to DC converter technology developed to maximize the energy harvest from solar photovoltaic or wind turbine systems. Has a higher 98.3 peak, 97.5% CEC inverter efficiency
HOW DOES A MICRO INVERTER OR CENTRAL INVERTER WORK OR STRING INVERTER?
Minimal panel voltage as this DC to AC is included per panel
Ability to integrate 3 phase voltage system
High DC voltage at source usually operates at 48 V and more
Minimal DC current as inverter is coupled with single panel
Standard DC current as defined
High DC current at source
Minimal DC wiring
Standard rated DC wiring as per current carrying ability
Commercial safety norms has to be adhered to.
Cost of Ownership
Expensive as individual micro inverters have to be coupled to generate DC to AC per panel
Optimal when compared to micro and central inverters
Very expensive mostly large scale public or government funded projects carry String inverter
Recovery during a failure
Quick and minimal impact
Few hours to troubleshoot and fix
Depending on the scale of issue, can take days to fix an issue
When to deploy
Small domestic scale < 1Kva demand
Mid sized 1kva to 10kva demand
Usually in Mega watt demand
WHICH IS BETTER TO CONNECT ARRAY OF SOLAR PANEL, IN SERIES OR PARALLEL?
Both Voltage and Current is very important in Electrical system.
Voltage: - the ability of the circuit to create potential difference. Similar to water flowing from a high elevated place to a low ground level. Voltage is the system which enables this cyclic difference to happen in AC, in DC its constant.
Current: - the flow of electrons which brings life to a circuit or charged ions. Current follows the path thus created by voltage, the flow of direction. The more the current the higher the charging capacity in batteries. [High currents are not recommended for batteries]. It must be noted DC current has ablity to cause fire, an appropriate diameter wire must be used to carry the current.
Likewise Voltage and Current have their use depending on the purpose they are used.
Voltage and Current are related to Power. Power in watts = Voltage in volts x Current in amps
SOLAR PANELS IN PARALLEL
SOLAR PANELS IN SERIES
Parallel connected solar panels voltage remains constant across the panels output
Series connected solar panels voltage adds and magnifies with rated per solar panel voltage
Current is magnified or added with each additional solar panel.
Current remains same across output
Due to high DC current higher rated thickness wire should be used
Standard rated wiring is sufficient enough to carry the current.
When to use
Cost of Ownership
Wiring cost is high
Wiring Cost is less
Destruction due to fire is high
Destruction due to fire exist however the trigger is minimal
WHAT ARE THE ADVANTAGES OF A MICRO-INVERTER?
Areas where sunlight has a shade disturbance on the solar panels, micro inverters help in handling power generated by each panel separately. This helps in allowing to shift the orientation of the panel in a way where maximum sunlight is available to each panel.
Few of the best known advantages are as follows.
- Optimize per panel power generation
- Maximum Power Point Tracking (MPPT)
- Longer Warranty
- Highly Scalable
- Performance Reports
- No Single Point of Failure
- Improved Safety
- Silent Operations
- Suitable for Home + Corporate Energy Storage Systems
FREQUENTLY ASKED QUESTIONS ABOUT BATTERY SYSTEMS
WHICH DC INVERTER VOLTAGE IS BEST TO SELECT 12v OR 24v OR 48v?
The Solar system DC source power is used to charge a 12 or 24 or 48 volt battery system. The load requirement is less than 800watt a 12V system should suffice.
For larger loads > 1kva it is recommended to use a 24 or 48V battery system. The DC from solar panel should carry the same power.
The current in DC requires attention. A proper wire thickness should be used for larger current produced from DC.
Usually DC volts of 24 or 48 or higher is achieved through solar panels connected in series, in a series connected circuit the current remains constant.
Hence a standard wire thickness is good enough to carry the DC current unlike the parallel connected solar panels which increase the DC current.
HOW TO UNDERSTAND THE CHARGING VOLTAGE IN A SOLAR POWER SETUP?
Multi-meters are easy to use devices using them one can measure the charging voltage. Alternatively a volt meter fixed to the DC battery will tell the charging voltage.
Voltmeters display the voltage on live instant charge or discharge in a battery. The effective way to measure the charging status is by use of amp-hour meters.
HOW TO HANDLE BATTERIES?
DC power is stored in batteries of different sizes depending on the power need. Batteries are various types.
- Lead acid batteries
- Sealed lead acid batteries
- Lithium ion batteries
- Gel batteries
These batteries have acids formed due to H+ ions over a period of time due to chemical reactions between the plates and the charging current. This will lead to release of hydrogen gas in most cases.
It is advisable to keep batteries in a dry, room temperature and ventilated area. A heated battery is an indication of unable to store the charge, alternatively possibility of deep discharge over a longer period of time.
It’s very important to maintain the battery temperature. Batteries dry out of acid due to continuous usage, hence regular check on their acid levels should be monitored typically once in 30 days on heavy usage.
For a 20 to 10% rate of discharge to battery capacity a 3 months check is good enough.
The charging current, the rate at which it is charged must not exceed the standard rating meant to charge the specific battery. Any variation would lead to decrease in battery life, ability to hold the charge.
HOW TO EXTEND BATTERY AND SOLAR PANEL LIFE?
Solar panel has a design life of 25 years to 30 years at 80% rated efficiency. However solar panels have to potential to produce power for a maximum of 50 to 60 years depending on the dirt and abuse on the surface.
Batteries last for 5 years to 7 years with a 25% to 35% average discharge, batteries can last long for 8 to 10 years with a 10% discharge and if maintained well.
HOW TO EXTEND POWER FOR DAYS WHEN THERE IS NO SUNSHINE?
Usual solar power setup design is done considering 1 day power requirement multiplied by 4 to 6 days of storage. In other words the batteries store the required power and on days when sun does not shine well these batteries provide the power through discharge.
Another option if the sunshine is minimal for a longer period of time in specific geographic location additional panels will pump the required current and help meet the power demand.