Solar Panels annd Difference Between Monocrystalline and Polycrystalline

Photovoltaic solar panels absorb sunlight as a source of energy to generate direct current electricity. A photovoltaic (PV) module is a packaged, connected assembly of photovoltaic solar cells available in different voltages and wattages.

Photovoltaic modules constitute the photovoltaic array of a photovoltaic system that generates and supplies solar electricity in commercial and residential applications. Difference Between Monocrystalline and Polycrystalline Solar Panels are given below with advantages and advantages of both types. 

Mono-crystalline solar panels:

The mono-crystalline solar panels cells are also known as single crystalline cells. They are incredibly easy to identify because they are a dark black in colour.

Mono-crystalline cells are made from an incredibly pure form of silicon, which makes them the most efficient material for the conversion of sunlight into energy.

Additionally, mono-crystalline cells are also the most space-efficient form of silicon solar cell. They also have the advantage of being the ones that last the longest out of all the silicon-based solar cells.

In fact, many manufacturers will offer warranties of up to 25 years on this type of system – a warranty that lasts half of their expected life. However, while these systems are superior, they do come at quite a hefty price.

Mono-crystalline cells are the most expensive option out of all of the silicon solar cell types, mostly because the four-sided cutting system results in a large amount of waste. Poly-crystalline acts as a cheaper alternative.


➢ Advantages of Mono-crystalline solar Cell:

Monocrystalline solar panels have the highest efficiency rates since they are made out of the highest-grade silicon.The efficiency rates of mono-crystalline solar panels are typically 15-20%. Sun Power produces the highest efficiency solar panels on the U.S. market today. Their E20 series provide panel conversion efficiencies of up to 20.1%. Update (April, 2013): Sun Power has now released the X-series at a record-breaking efficiency of 21.5%.Monocrystalline silicon solar panels are space-efficient. Since these solar panels yield the highest power outputs, they also require the least amount of space compared to any other types.Mono-crystalline solar panel produce up to four times the amount of electricity as thin-film solar panels.Mono-crystalline solar panel live the longest. Most solar panel manufacturers put a 25-year warranty on their mono-crystalline solar panel.Tend to perform better than similarly rated poly-crystalline solar panel at low-light conditions.

➢ Disadvantages of Mono-crystalline solar Cell:

Mono-crystalline solar panels are the most expensive.From a financial standpoint, a solar panel that is made of poly-crystalline silicon (and in some cases thin-film) can be a better choice for some homeowners.If the solar panel is partially covered with shade, dirt or snow, the entire circuit can break down. Consider getting micro-inverters instead of central string inverters if you think coverage will be a problem. Micro-inverters will make sure that not the entire solar array is affected by shading issues with only one of the solar panels. The Czochralski process is used to produce mono-crystalline silicon. It results in large cylindrical ingots. Four sides are cut out of the ingots to make silicon wafers. A significant amount of the original silicon ends up as waste.Monocrystalline solar panels tend to be more efficient in warm weather.Performance suffers as temperature goes up, but less so than polycrystalline solar panel. For most home owners temperature is not a concern.

Poly-crystalline silicon Solar Panels:

The polycrystalline solar cells are also known as polysilicon and multi-silicon cells. They were the first solar cells to be developed when the industry started in the 1980s.

Most interestingly, polycrystalline cells do not undergo the same cutting process as the monocrystalline cells. Instead, the silicon is melted and then poured into a square mould. This is what creates the specific shape of the polycrystalline.

One of the benefits of this process is that the solar cells become much more affordable. This is because hardly any silicon is wasted during the manufacturing process.

However, they are less efficient than monocrystalline solar cells, and also require a lot more space. This is due to the fact that they have lower levels of purity than the single crystalline cell models.

Poly-crystalline also has a lower tolerance for heat than mono-crystalline. This means that they are unable to function as efficiently in high temperatures. This can be a massive disadvantage in areas with hot climates.

Solar Panels

➢ Advantages of Poly-crystalline silicon Solar Panels:

The process used to make poly-crystalline silicon is simpler and cost less. The amount of waste silicon is less compared to mono-crystalline.Poly-crystalline solar panel tend to have slightly lower heat tolerance than mono-crystalline solar panel. This technically means that they perform slightly worse than mono-crystalline solar panels in high temperatures.Heat can affect the performance of solar panel and shorten their lifespans. However, this effect is minor, and most homeowners do not need to take it into account.

➢ Disadvantages of Poly-crystalline silicon Solar Panels:

The efficiency of poly-crystalline-based solar panel is typically 13-16%. Because of lower silicon purity, poly-crystalline solar panels are not quite as efficient as mono-crystalline solar panel.Lower space-efficiency. You generally need to cover a larger surface to output the same electrical power as you would with a solar panel made of mono-crystalline silicon. However, this does not mean every mono-crystalline solar panel perform better than those based on poly-crystalline silicon.Mono-crystalline and thin-film solar panels tend to be more aesthetically pleasing since they have a more uniform look compared to the speckled blue color of poly-crystalline silicon.


Electromechanical induction type Energy meter and Its working Principle

Electromechanical induction type Energy meter

An electricity meterelectric meterelectrical meter, or energy meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device.

It is the popularly known and most common type of age old watt hour meter. It consists of rotating aluminum disc mounted on a spindle between two electro-magnets. Speed of rotation of disc is proportional to the power and this power is integrated by the use of counter mechanism and gear trains in. It comprises of two silicon steel laminated electromagnets i.e., series and shunt magnets.

Series magnet carries a coil which is of few turns of thick wire connected in series with line whereas shunt magnet carries coil with many turns of thin wire connected across the supply.

Breaking magnet is a permanent magnet which applies the force opposite to normal disc rotation to move that disc at balanced position and to stop the disc while power is off.

Working Principle:

The working of single phase induction type energy meters are based on two main fundamentals:

i.  Rotation of aluminum disk.

ii.  Arrangement of counting and displaying the amount of energy consumed.

Rotation of an Aluminum Disk:

The rotation of metallic disk is operated by two coils. Both the coils are arranged in such way that one coil produces a magnetic field in proportion to voltage and the other coil creates a magnetic field proportion to current. The field produced by voltage coil is delayed by 90° so that eddy current is induced in the disk. The force exerted on the disk by the two fields is proportional to the product of the immediate current and voltage in the coils.

As a result of it, a lite weight aluminum disk rotates in an air gap. But there is a need to stop a disk when there is no power supply. A permanent magnet works as a brake which opposes the rotation of the disk and balances the speed of rotation with respect to power consumption.

Energy Meter

Arrangement of Counting and Displaying the Energy Consumed:

In this system, the rotation of the floating disk has been counted and then displayed on the meter window. The aluminum disk is connected to a spindle which has a gear. This gear drives the register and the revolution of the disk has been counted and displayed on the register which has series of dials and each dial represent a single digit. There is a small display window in the front of the meter which displays the reading of energy consumed with the help of dials. There is a copper shading ring at the central limb of the shunt magnet. To make the phase angle between flux produced by shunt magnet and supply voltage about 900, small adjustments in the place of the ring is required.

Read for more about Energy Meters


Types of Energy Meter and their working Principles

Energy Meter

Energy meter is an instrument which measures amount of electrical energy used by the consumers. Utilities install these instruments at every place like homes, industries, organizations to charge the electricity consumption by loads such as lights, fans and other appliances. When energy savings during certain periods are desired, some meters may measure demand, the maximum use of power in some interval. “Time of day” metering allows electric rates to be changed during a day, to record usage during peak high-cost periods and off-peak, lower-cost, periods. Also, in some areas meters have relays for demand response load shedding during peak load periods.Most interesting type are used as prepaid electricity meters. Types of energy meter are given below with explanation

Basic unit of power is watts. One thousand watts is one kilowatt. If we use one kilowatt in one hour, it is considered as one unit of energy consumed. These meters measure the instantaneous voltage and currents, calculate its product and gives instantaneous power. This power is integrated over a period which gives the energy utilized over that time period.


Types of Energy Meter

Energy meter are classified in three basic types accordance with various factors such as:
1. Type of display

2. Technical like single phase, LT, three phases, HT and many more.

3. Type of Usage like domestic, commercial and industrial

4. Type of metering point

Types w.r.t Construction

According to construction energy meter classified into three types which are given below.

1. Electromechanical induction type

2. Electronic Energy Meter

3. Smart Energy Meter

Types w.r.t Phase

According to phase energy meter classified into three types which are given below.

1. Single Phase Energy Meter

2. Three Phase Energy Meter

Electronic Energy Meter

Electronic meters display the energy used on an LCD or LED display, and some can also transmit readings to remote places. In addition to measuring energy used, electronic meters can also record other parameters of the load and supply such as instantaneous and maximum rate of usage demands, voltages, power factor and reactive power used etc. They can also support time-of-day billing, for example, recording the amount of energy used during on-peak and off-peak hours.

These are of accurate, high procession and reliable types of measuring instruments as compared to conventional mechanical meters. It consumes less power and starts measuring instantaneously when connected to load. These meters might be analog or digital. In analog meters, power is converted to proportional frequency or pulse rate and it is integrated by counters placed inside it.

In digital electric meter power is directly measured by high end processor. The power is integrated by logic circuits to get the energy and also for testing and calibration purpose. It is then converted to frequency or pulse rate.

➢ Digital Electronic Energy Meter:

Digital signal processor or high performance microprocessors are used in digital electric meters. Similar to the analog meters, voltage and current transducers are connected to a high resolution ADC. Once it converts analog signals to digital samples, voltage and current samples are multiplied and integrated by digital circuits to measure the energy consumed.

Types of Energy Meter

Microprocessor also calculates phase angle between voltage and current, so that it also measures and indicates reactive power. It is programmed in such a way that it calculates energy according to the tariff and other parameters like power factor, maximum demand, etc and stores all these values in a non volatile memory EEPROM.

It contains real time clock (RTC) for calculating time for power integration, maximum demand calculations and also date and time stamps for particular parameters. Furthermore it interacts with liquid crystal display (LCD), communication devices and other meter outputs. Battery is provided for RTC and other significant peripherals for backup power.

Smart Energy Meter

A smart meter is an electronic device that records consumption of electric energy and communicates the information to the electricity supplier for monitoring and billing. Smart meters typically record energy hourly or more frequently, and report at least daily.

 Smart meters enable two-way communication between the meter and the central system. Such an advanced metering infrastructure (AMI) differs from automatic meter reading (AMR) in that it enables two-way communication between the meter and the supplier. Communications from the meter to the network may be wireless, or via fixed wired connections such as power line carrier (PLC). Wireless communication options in common use include cellular communications (which can be expensive), Wi-Fi (readily available), wireless ad hoc networks over Wi-Fi, wireless mesh networks, low power long range wireless (LoRa), ZigBee (low power, low data rate wireless), and Wi-SUN (Smart Utility Networks).

It is an advanced metering technology involving placing intelligent meters to read, process and feedback the data to customers. It measures energy consumption, remotely switches the supply to customers and remotely controls the maximum electricity consumption. Smart metering system uses the advanced metering infrastructure system technology for better performance.

Types of Energy Meter

These are capable of communicating in both directions. They can transmit the data to the utilities like energy consumption, parameter values, alarms, etc and also can receive information from utilities such as automatic meter reading system, reconnect/disconnect instructions, upgrading of meter software’s and other important messages.

These meters reduce the need to visit while taking or reading monthly bill. Modems are used in these smart meters to facilitate communication systems such as telephone, wireless, fiber cable, power line communications. Another advantage of smart metering is complete avoidance of tampering of energy meter where there is scope of using power in an illegal way.

Read for more about Energy Meters

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Synchronous Motors Main Features and their Applications

Electrical motor in general is an electro-mechanical device that converts energy from electrical domain to mechanical domain.A synchronous electric motor is an AC motor in which, at steady state,[1] the rotation of the shaft is synchronized with the frequency of the supply current; the rotation period is exactly equal to an integral number of AC cycles. Synchronous motors contain multiphase AC electromagnets on the stator of the motor that create a magnetic field which rotates in time with the oscillations of the line current. The rotor with permanent magnets or electromagnets turns in step with the stator field at the same rate and as a result, provides the second synchronized rotating magnet field of any AC motor. A synchronous motor is termed doubly fed if it is supplied with independently excited multiphase AC electromagnets on both the rotor and stator Based on the type of input we have classified it into single phase and 3 phase motors. Synchronous motors are more widely used in industrial

Main Features:

Some of the main features of synchronous motor are as follows:-

  1. Synchronous motors are inherently not self starting.

  2. They require some external means to bring their speed close to synchronous speed to before they are synchronized.

  3. The speed of operation of is in synchronism with the supply frequency.

  4. At supply frequency is constant they behave as constant speed motor irrespective of load condition.

  5. This motor has the unique characteristics of operating under any electrical power factor. This makes it used in electrical for power factor improvement.

 Application Of Synchronous Motors:

  1.As synchronous motor is capable of operating under either leading and lagging power factor, it can be used for power factor improvement.  A synchronous motor under no-load have leading power factor. It is used in power system in place of static capacitors.

 2. Synchronous motor is used where high power at low speed required. Such as rolling mills, chippers, mixers, pumps, pumps, compressor etc.


Difference between Synchronous and Induction Motor

Both synchronous and induction machines work on AC supply, ie; they are AC machines. For AC machines, the basic requirement is to create a rotational magnetic field so that the rotor can rotate, and energy can be obtained. (mechanical for motor, electrical for alternator) Now, the difference between a synchronous machine and an induction machine is based on how the rotational magnetic field is utilized.

The three phase supply, when given to the stator windings, creates a rotating magnetic field. Now, the rotor of an induction machine is a group of short circuited windings where the rotating magnetic field is to act. The underlying principle is electromagnetic induction, similar to transformers – the rotor gets an induced current, that means – a current carrying loop inside the magnetic field. This makes the rotor rotate. But, if both rotating magnetic field and rotor rotate in the same synchronous speed, there will be no induced EMF inside the rotor, because the field will be then constant w.r.t the rotor, and for rotation, change in flux should be there.

Thus, the rotation happens with a “slip” between the rotor and the stator. The slip refers to the inability of the rotor to catch up with the (speed of) rotating stator magnetic field. Thus rotor will rotate, and output is obtained, if there is slip between the rotor and stator magnetic field. This is the principle of working of an induction machine.

Now, consider am utilizing the rotating magnetic field by making an electromagnet rotate as a rotor, which is fed with a DC supply. In such a case, the machine will run in synchronous speed, and this machine is called a synchronous machine. However, it is to be noted that due to inertia of the rotor, the rotor electromagnet cannot immediately respond to the rotating magnetic field. This means that the synchronous machine does not start by itself. To provide the starting torque, additional winding called “damper winding” is provided in rotor, which make the synchronous machine similar to an induction machine during starting. As the machine starts, the rotor naturally locks up with the rotating magnetic field and rotates in synchronous speed. This means that during normal running conditions, the damper winding will carry no current. (Similar to the rotor winding in an induction machine at synchronous speed)


Here are the few Differences between Synchronous and Induction Motor



Synchronous Motor and Methods of Starting a Synchronous Motors

Electrical motor in general is an electro-mechanical device that converts energy from electrical domain to  mechanical domain. Based on the type of input we have classified it into single phase and 3 phase motors. Among 3 phase motors, induction motors and synchronous motors are more widely used. When a 3 phase electric conductors are placed in a certain geometrical positions (In certain angle from one another) then an electrical field is generated. Now the rotating magnetic field rotates at a certain speed, that speed is called synchronous speed. Now if an electromagnet is present in this rotating magnetic field, the electromagnet is magnetically locked with this rotating magnetic field and rotates with same speed of rotating field. Synchronous motors is called so because the speed of the rotor of this motor is same as the rotating magnetic field. It is basically a fixed speed motor because it has only one speed, which is synchronous speed and therefore no intermediate speed is there or in other words it’s in synchronism with the supply frequency.

Why is a synchronous motor not self starting?

At starting position of synchronous machine, the rotor could have any alternative position as shown here.

When rotor is initially at position (a):

The like pole of rotor will get repelled and the tendency of rotor will be to rotate in anticlockwise direction. But after some time the N-pole of rotor and S-pole of rotor comes face to face and will try to get attract with each other. Now, the tendency of rotor is to rotate in clockwise direction but the rotor have some mass and cannot attain such a high speed (synchronous speed) to that of stator’s rotating magnetic field. Hence, rotor remains at rest.

When rotor is initially at position (b):

Here, the unlike pole of rotor gets attracted but as explained earlier the rotor cannot attain synchronous speed immediately and remains at rest.

As a result, the average torque exerted on the rotor is zero. Due to the large inertia of the rotor, the rotor fails to rotate along with the stator poles. Hence again the difference of position of magnetic axis gets created and rotor gets subjected to quickly reversing torque. This is because the speed with which rotating magnetic field is rotating is so high that it is unable to rotate the rotor from its initial position, due to the inertia of the rotor. So under any case, whatever may be the starting position of the rotor, synchronous motor is not self starting.

Methods of Starting a Synchronous Motor

The synchronous machine, however, is not self-starting. The synchronous machine has to be rotated to near the synchronous speed of the stator before it can “catch” the stator field and begin rotating on its own. Basically there are three methods that are used to start a synchronous motor:

To reduce the speed of the rotating magnetic field of the stator to a low enough value that the rotor can easily accelerate and lock in with it during one half-cycle of the rotating magnetic field’s rotation. This is done by reducing the frequency of the applied electric power. This method is usually followed in the case of inverter-fed synchronous motor operating under variable speed drive applications.To use an external prime mover to accelerate the rotor of synchronous motor near to its synchronous speed and then supply the rotor as well as stator. Of course care should be taken to ensure that the direction of rotation of the rotor as well as that of the rotating magnetic field of the stator are the same. This method is usually followed in the laboratory- the synchronous machine is started as a generator and is then connected to the supply mains by following the synchronization or paralleling procedure. Then the power supply to the prime mover is disconnected so that the synchronous machine will continue to operate as a motor.To use damper windings or amortisseur windings if these are provided in the machine. The damper windings or amortisseur windings are provided in most of the large synchronous motors in order to nullify the oscillations of the rotor whenever the synchronous machine is subjected to a periodically varying load.

Each of these methods of starting a synchronous motor is described below in detail.

1. Motor Starting by Reducing the supply Frequency:

If the rotating magnetic field of the stator in a synchronous motor rotates at a low enough speed, there will be no problem for the rotor to accelerate and to lock in with the stator’s magnetic field.The speed of the stator magnetic field can then be increased to its rated operating speed by gradually increasing the supply frequency f up to its normal 50- or 60-Hz value. This approach to starting of synchronous motors makes a lot of sense, but there is a big problem: Where from can we get the variable frequency supply? The usual power supply systems generally regulate the frequency to be 50 or 60 Hz as the case may be. However, variable-frequency voltage source can be obtained from a dedicated generator only in the olden days and such a situation was obviously impractical except for very unusual or special drive applications.

Synchronous Motor


But the present day solid state power converters offer an easy solution to this. We now have the rectifier- inverter and cyclo-converters, which can be used to convert a constant frequency AC supply to a variable frequency AC supply. With the development of such modern solid-state variable-frequency drive packages, it is thus possible to continuously control the frequency of the supply connected to the synchronous motor all the way from a fraction of a hertz up to and even above the normal rated frequency. If such a variable frequency drive unit is included in a motor-control circuit to achieve speed control, then starting the synchronous motor is very easy-simply adjust the frequency to a very low value for starting, and then raise it up to the desired operating frequency for normal running.

When a synchronous motor is operated at a speed lower than the rated speed, its internal generated voltage (usually called the counter EMF) EA = K_! will be smaller than normal. As such the terminal voltage applied to the motor must be reduced proportionally with the frequency in order to keep the stator current within the rated value. Generally, the voltage in any variable-frequency power supply varies roughly linearly with the output frequency.

2. Motor Starting with an External Motor:

The second method of starting a synchronous motor is to attach an external starting motor (pony motor) to it and bring the synchronous machine to near about its rated speed (but not exactly equal to it, as the synchronization process may fail to indicate the point of closure of the main switch connecting the synchronous machine to the supply system) with the pony motor. Then the output of the synchronous machine can be synchronized or paralleled with its power supply system as a generator, and the pony motor can be detached from the shaft of the machine or the supply to the pony motor can be disconnected. Once the pony motor is turned OFF, the shaft of the machine slows down, the speed of the rotor magnetic fieldBR falls behind Bnet, momentarily and the synchronous machine continues to operate as a motor. As soon as it begins to operate as a motor the synchronous motor can be loaded in the usual manner just like any motor.

Synchronous Motor


This whole procedure is not as cumbersome as it sounds, since many synchronous motors are parts of motor-generator sets, and the synchronous machine in the motor-generator set may be started with the other machine serving as the starting motor. Moreover, the starting motor is required to overcome only the mechanical inertia of the synchronous machine without any mechanical load (load is attached only after the synchronous machine is paralleled to the power supply system). Since only the motor’s inertia must be overcome, the starting motor can have a much smaller rating than the synchronous motor it is going to start. Generally most of the large synchronous motors have brushless excitation systems mounted on their shafts. It is then possible to use these exciters as the starting motors. For many medium-size to large synchronous motors, an external starting motor or starting by using the exciter may be the only possible solution, because the power systems they are tied to may not be able to handle the starting currents needed to use the damper (amortisseur) winding approach described next.

3. Motor Starting by Using damper (Amortisseur) Winding:

As already mentioned earlier most of the large synchronous motors are provided with damper windings, in order to nullify the oscillations of the rotor whenever the synchronous machine is subjected to a periodically varying load. Damper windings are special bars laid into slots cut in the pole face of a synchronous machine and then shorted out on each end by a large shorting ring, similar to the squirrel cage rotor bars. A pole face with a set of damper windings is shown in Figure.

Synchronous Motor


When the stator of such a synchronous machine is connected to the 3-Phase AC supply, the machine starts as a 3-Phase induction machine due to the presence of the damper bars, just like a squirrel cage induction motor. Just as in the case of a 3-Phase squirrel cage induction motor, the applied voltage must be suitably reduced so as to limit the starting current to the safe rated value. Once the motor picks up to a speed near about its synchronous speed, the DC supply to its field winding is connected and the synchronous motor pulls into step i.e. it continues to operate as a Synchronous motor running at its synchronous speed.


What is Synchronous Machine and Its Basic Working Principle

Synchronous Machine

Electrical motor in general is an electro-mechanical device that converts energy from electrical domain to mechanical domain. Based on the type of input we have classified it into single phase and 3 phase motors. Among 3 phase motors, induction motors and synchronous machine are more widely used. When a 3 phase electric conductors are placed in a certain geometrical positions (In certain angle from one another) then an electrical field is generated. Now the rotating magnetic field rotates at a certain speed, that speed is called synchronous speed. Now if an electromagnet is present in this rotating magnetic field, the electromagnet is magnetically locked with this rotating magnetic field and rotates with same speed of rotating field. Synchronous motors is called so because the speed of the rotor of this motor is same as the rotating magnetic field. It is basically a fixed speed motor because it has only one speed, which is synchronous speed and therefore no intermediate speed is there or in other words it’s in synchronism with the supply frequency.

Synchronous motors are available in self-excited sub-fractional horsepower sizes to high power industrial sizes.In the fractional horsepower range, most synchronous motors are used where precise constant speed is required. These machines are commonly used in analog electric clocks, timers and other devices where correct time is required. In higher power industrial sizes, the synchronous motor provides two important functions. First, it is a highly efficient means of converting AC energy to work. Second, it can operate at leading or unity power factor and thereby provide power-factor correction.

Synchronous speed:


The synchronous speed of a synchronous motor is given:

in rpm, by:


and in rad·s−1, by:



 is the frequency of the AC supply current in Hz,

 is the number of poles per phase.

 is the pair number of poles per phase. 



 is the number of pole pairs per phase (rarely, planes of commutation) instead, simply divide both formulas by 2.

where f = supply frequency & p = no. of poles

Synchronous Machine


Synchronous motor is a doubly excited machine i.e two electrical inputs are provided to it. It’s stator winding which consists of a 3 phase winding is provided with 3 phase supply and rotor is provided with DC supply. The 3 phase stator winding carrying 3 phase currents produces 3 phase rotating magnetic flux. The rotor carrying DC supply also produces a constant flux.


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Chargepoint Home Flex EV Charger Installation Services

Electricians Review of the Chargepoint Home Flex

In the past few months, Root Electric has had quite a few requests to install wall connectors for newly purchased electric vehicles.  As more and more manufacturers are beginning to release electric vehicles, the demand for home charging solutions that will work with a variety of different vehicles is on the rise.  One new product of note is the ChargePoint Home Flex wall connector.  There are many technological features, such as the ChargePoint app that are easily understood from the standpoint of the average consumer.  However, since I am a professional electrician, I would like to review this product based on my knowledge and experience as an electrician.

The ChargePoint Home Flex is designed specifically so that the user can select the amount of electrical current drawn to charge the vehicle.  The range of current draw options for the ChargePoint Home Flex range from 16 Amps, all the way up to 50 Amps.  You may be reading this review thinking, “Well why would I want to set up the wall connector to charge my car at 16 Amps, when I can just set it to 50 Amps?” Well, that’s the correct question to ask, because it has the largest effect on the potential installation costs and future upgradeability of the installation.  I am going to delve into some of the more technical aspects of home EV charging for the benefit of the serious EV enthusiast.  Likewise, if you are an engineer reading this article, you may find that some of the more technical aspects are, let’s say, “general” for the sake of the less technically inclined. So if your mind begins to wander, or if the numbers aren’t tight to the NEC tables, please bear with me.  

One of the largest hindrances to installation of a home charging option for electric vehicles is the size of the electrical service on most homes in the United States.  Most homes in American suburbia are in the range of 50 years old or greater.  Most of these older homes have electrical services that range in size from 60 Amps to 150 Amps, while newer homes in most areas have a minimum service size of 200 Amps or greater.  The reason for this gradual increase in the size of home electrical services is the rise in reliance on electricity for cooking, refrigeration, heating, and cooling. In the mid 20th Century, most homes used fuel oil or natural gas for heat and cooking, but since the 1970’s, electricity has come to play a larger role especially because of the increased popularity of central heating and air conditioning.  Industry research has shown that the HVAC system in your home accounts for at least 30% of its energy consumption.  That said, many older homes that originally did not have air conditioning have since been upgraded to feature central air conditioning.  The rub is that while the HVAC system was upgraded, more often than not, the electrical service was left at its original size, which was not designed for the additional load of the air conditioning.  This leaves many older homes with an already maxed-out or overloaded electrical service that technically cannot handle additional load.  To make matters worse, many new homes are built with an electrical service that is pushed to its max.  So while the service may be rated at 200 amps, there may be precious little room for electrical upgrades. 

Customer Testimonial

Exemplary electrical work and customer service. This is the second time I have used Root Electric and they will continue to be my “go to” electrical contractor. The on-line estimate quote process works very well – there were no surprises. Bill Sr. gave me a 10:00 – 12:00 service window; he called at 10:00 to say he would arrive in 30 – 45 minutes. Bill wore a protective mask at all times, was very respectful and aware of social distancing. The two jobs were completed quickly. All in all, a real pleasure to work with.

Bruce G.

So what does this have to do with the installation with an electric vehicle?  Well it comes down to the amount of electrical current that a wall connector such as the ChargePoint Home Flex can pull.  At it’s full 50 Amp setting, the wall connector pulls as much electricity as your average kitchen electric range.  However, unlike your range, which is generally only being partially used (for example, you may only use one of the burners at once, or the oven itself without the cooktop), the EV charger is pulling its maximum current for hours at a time.  Because of this, electricians have to calculate the load placed on the electrical system to allow for the extended time high-current draw of the electric vehicle wall connector.  As an example, for standard residential electrical load calculations, your 50 amp range may only be calculated in at somewhere around 50% of its full load.  For easy math, that means if you have a 50 amp range, only 25 amps will be calculated into the total load placed on your electrical service.  This is because you are not using your range all of the time, and when you are, you are likely only using a fraction of its potential electricity draw.  A power connector for an electric vehicle, on the other hand, has to be calculated at 125% of its total draw.  This means that if you have a power connector rated at 40 Amps, you have to enter 50 amps to calculate the draw on the service.  If you have a newer home with gas heat and a 200 amp service, this won’t be a problem, but if your house was built in the 1950’s and has the original 60 amp service, and a central air conditioner installed in the late 1970’s, along with a remodeled kitchen, the service may not be able to support the load of the power connector without having to be upgraded.  This means additional expense on top of what you just spent on the car and on having the circuit and power connector installed.  (Although, if you have an older house, upgrading the service is a very good idea both for the long term safety and value of the home.)  

So where does all of this electrical mumbo-jumbo come in to play when it comes to the ChargePoint Home Flex?  Well, let’s say you just signed the lease on a shiny new Audi e-Tron and had Amazon deliver a new power connector to your doorstep.  Then you call an electrician to give you an estimate for installing a new 50 amp circuit, plus mount the new wall connector.  When he tells you that your service is not heavy enough to support the 50 amp load, you still have options to set the wall connector to 32 amps, 24 amps, or even 16 amps, and still have the option to increase the load to the full 50 amps in the future if you upgrade the service.  (Assuming the conductors feeding the power connector are large enough to support a 50 amp wall connector). 

Another advantage to having the option to pick the wall connector’s current draw is that you can choose how you want the wall connector to connect to your electrical system.  If you want maximum current draw at 48 or 50 amps for the fastest charge time, you can opt to have the ChargePoint Home Flex hardwired.  However, if you are willing to sacrifice a little bit of charging speed (limiting you to 40 amps or below) for the sake of being able to install more advanced power connectors in the future, you can have your electrician install a NEMA 14-50R or 6-50R outlet, which will work with just about every EV mobile connector or wall connector.  If you plan to sell your house in the near future, installing a 14-50R outlet or 6-50R outlet is a smart choice, since it will let the next homeowner install a power connector of their choice to power their own electric vehicle, which adds value to your home at the time of sale.  

If your head isn’t spinning by now, hopefully you now have a better grasp of the technical reasons of why the ChargePoint Home Flex is an excellent choice for a home EV charging power connector.  If you have an older home with a small electrical service, or even a newer home with a heavily loaded service, the ChargePoint Home Flex will give you options to safely charge your electric vehicle.  Additionally, it grants you the flexibility to set it up for fastest charging time or maximum future flexibility and upgradability.  There are many power connectors on the market, and while I am not in any way endorsing or promoting the ChargePoint Home Flex, I am saying that it would be worth a look for your electric vehicle charging needs.  


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Your Electrician in Prince William County: Root Electric

Electrical Services in Prince William County

Root Electric’s commercial and residential electricians are proud to be considered some of the best in Prince William County. From electrical repairs and home improvements to office electrical repairs and commercial tenant improvement projects, Root Electric has been serving the residents and businesses of Prince William County for more than three decades. Over that time, we have become the electricians Prince William County residents and business owners have come to rely on, time and time again for the safest, highest quality electrical work in the county. Your safety and satisfaction are our top priorities!

With the average home age in the county standing at about 25 years old, with many homes much older than that, Root Electric has the expertise necessary to upgrade electrical systems in older homes to make them safer, more efficient, and better able to handle the increased electrical demands of modern life and all of its gadgets. With businesses throughout Prince William County updating older spaces for retail, office space and workshop space, our electricians are also highly skilled at updating and improving electrical safety for commercial spaces. 

So, whether you need a residential electrician or a commercial electrician, Root Electric is the one to call for the safest, up-to-code, high-quality electrical work anywhere in Prince William County. Whatever your electrical needs are, contact our Prince William County electricians at Root Electric today for any of the following projects: (703) 494-3989.

How We Became the Electricians Prince William County Trusts

Of course, we can say we’re the top electrician in Prince William County—it’s easy enough to say, but harder to prove. And, naturally, there are certain things you’ll want to look for in your choice of residential electrician or commercial electrician. For Root Electric, the proof is definitely in how we have served our customers over the last 30+ years. For us, it’s more about family than anything else. Root Electric is a family-owned and operated team of electricians who’ve grown up in Northern Virginia. We know the homes and businesses here, and we have a sense of history and a deep knowledge of what our customers need because we’re from here too. But how can you tell for sure that Root Electric is the Prince William County electricians for you? Here are 5 things you should always look into when you are searching for the best electrician in your area:

For starters, you can take a look through our customer testimonials for the real experiences that your neighbors have had with us. We wouldn’t have lasted three decades without a commitment to quality and safety that our customers deserve. You can also look through the awards we’ve earned from EBSCO, local reader’s choice awards and Angie’s List. Root Electric maintains an open dialogue with our electricians and customers to ensure customers are satisfied with our methods and quality of installation.We are also licensed, bonded and insured, which is an essential protection for all of our clients and our expert electricians. We also continue to invest in new equipment and technological upgrades so that we can provide the best quality and most advanced solutions for any electrical repairs, electrical upgrades, remodeling projects, office electrical repairs and tenant improvement projects.The bottom line is that our entire team at Root Electric is committed 100% to your safety and your total satisfaction with your electrical repairs or upgrades. We provide the most extensive and clear estimates (now offering virtual estimates as well) of any electrician in Prince William County because we believe you deserve to know exactly what needs to be done and how the prices break down before anything else happens. For Root Electric, clear communication with our customers is one of the hallmarks of our top notch customer service! We care about you because you’re our neighbors! And that’s how we approach every project.

Customer Testimonial

Great work that has paid off! Had them install a subpanel about two years ago so we could power our most essential circuits off the generator. With all the rain lately, a tree just took down the only power line into our neighborhood. But we are doing just peachy, even if it takes Dominion all night!

Adrian W.

Call the Best Electrician in Prince William County: (703) 494-3989

Our Prince William home electrical services and commercial electrical services also span the entire spectrum of any electrical upgrades, improvement projects, installations and electrical repairs your home or business may require. Take a look through the following list to see what types of electrical projects we can do. Then please feel free to contact us to ask questions, discuss your project and get an estimate: 

Prince William County Residential Electrical Services

Electrical upgrades for older homesElectrical panel and circuit breaker installationCircuit breaker and electric panel replacement Electrical sub panel installationLight fixtures and recessed lighting installation and upgradesCeiling fan installationExhaust fan installationOutlet installationHome office electrical upgradesPlug and switch repairs, upgrades and installations “Heavy ups” – complete home electrical upgradesNew home wiringReplace aluminum wiring in older homesElectrical wiring and installations for home remodels and renovations Outdoor lightingSecurity lightingDeck lightingGFCI Outlet InstallationOutdoor outletsEmergency generator installation and serviceWhole home surge protectionPool wiring and hot tub wiringLandscape lightingAdditional wiring for appliancesADA-Compliant home electrical updatesHome electrical safety inspectionsEnergy-saving electrical upgrades and evaluations 

Prince William County Commercial Electrical Services

Commercial tenant improvement projects and build outs Office electrical repairsOffice wiring upgradesCommercial electrical panel installation or replacement Industrial lighting installation and replacement Retail lighting installation and repairCommercial office lighting upgradesWall pack service and replacementEmergency lighting installation and repairExit sign lighting Ballast replacementMetal halide repair and replacementHigh-pressure sodium repair and replacementFluorescent bulb replacementOffice LED lighting upgrades and replacementsOffice light fixturesCommercial property electrical safety inspectionsCommercial energy saving evaluations Underground fault locatingTroubleshooting Electric meter conversionsCommercial emergency generator installation and serviceCherry pickersBucket trucksInfrared thermography inspections

Choose the Best Electrician in Prince William County for Your Project

As local Prince William County electricians, Root Electric is dedicated to ensuring that homeowners and businesses in the area receive the best electrical repairs and service available, with the safest team in the area. Contact your electrician in Prince William County today for residential electrical services or commercial electrical services. You can expect courteous and prompt service, the best electrical upgrades, installations and repairs and the safest electrical work in Prince William County. 


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Deck Lighting and Outlet Installation Services

Deck Lighting and Electrical Outlet Installation Services

Installing deck lighting and outdoor outlets in your yard can extend your outdoor living opportunities well into the evening while also improving your home’s resale value. As the nights get warmer and with more families looking for ways to make close-to-home spaces seem more exotic, this is an excellent option that adds a lot of curb appeal too. There are many beautiful options for deck lighting that can improve safety and security as well. And extra outdoor outlet installation can give you more options for adding string lights, outdoor appliances and even a place to plug in your laptop for some outdoor home office scenery.

4 Deck Lighting Installation Ideas 

Depending on your deck design, outdoor living habits and goals, and how you’d like to improve those things, there are a number of different deck lighting options you can consider. And within these 4 deck lighting ideas, there are also many variations that you can consider: 

1. Step Lighting or Deck Stair Lights

One way to better illuminate your deck stairs is to install lighting right on them – on the vertical surface of each step, or under the lip of each step so that the light from the upper step shines clearly down on the lower step. This keeps the light focused downward to enhance safety going up and down the steps in the dark, and can also enhance your security lighting options as well. It also prevents light escaping upwards at night if you’re hoping for a good view of the stars.

2. Deck Post Lighting

There are many different styles and materials of deck post lighting. You can choose styles, colors and materials (from copper, aluminum or stainless steel and even plastic) that will look great and provide a decorative touch even during the daytime. Deck post lights should face down, again to illuminate the footpath or stairway at night. Deck post lighting is a very affordable option and can usually be installed quite easily. But if you’re a stickler for viewing the night sky, remember that these can produce more light pollution because they’re situated higher up than step lighting. 

3. Recessed Lighting on the Deck

Recessed lighting can be a great solution if you have a large overhang that needs illuminating on your deck. It provides great illumination to everything below and can be focused on certain areas that you particularly want to highlight or provide extra visibility for on your deck or backyard. Under-deck recessed lighting can only be installed if there is a covered porch above. 

4. Deck Rail Lighting

Deck rail lighting is also a great option that can be built flush into your deck rails in such a way as to make them invisible when you’re sitting. Again, they focus the light downwards toward the walkway or the stairs and also show people where the rail is.

Customer Testimonial

Very professional from the first contact by Bill Root through the free estimate and completion of the job. They kept the work area (my kitchen) very clean and made very few holes in the ceiling. My workmen included an apprentice. I think it is great that a company is assisting a young person to become a Master Electrician. I highly recommend Root Electric.

Chris R.

4 Reasons to Install Outdoor Outlets

In addition to installing extra deck lighting, if you really want to get more use out of your deck area, installing outdoor outlets that are protected from the elements is another smart move: 

1. More Deck Lighting Options

In addition to the deck lighting ideas listed previously, having a few extra outdoor outlets installed gives you more options for adding string lights or other electric-powered holiday decorations for the holidays. Just make sure you also have enough extra circuits to provide the power necessary to keep those lights brightly shining. 

2. Outdoor Cooking Appliances

As outdoor living and cooking become more popular, home chefs will need safe outlets and spaces that are protected from the weather to cook and use kitchen appliances outdoors. Whether that means you want to have an outdoor fridge or powered cooler, an electric grill or any other appliance, you’ll need to install outdoor outlets. 

3. Extending Your Home Office to the Outdoors

After several weeks of working from home in the kitchen or the living room, or maybe a dedicated indoor home office, you may be feeling the pull of the outdoors. If you’re tempted to tote your laptop outside to the deck, make sure you have a place to plug it in safely while you’re out there so you don’t lose power right in the middle of your next Zoom meeting. 

4. Safety Upgrades for Outdoor Outlets 

All outdoor outlets should be GFCI outlets that automatically shut power if they become wet. But newer models exist that provide extra protection from the weather and elements. Safety is always the most important consideration, so if you are not sure about your current outlets or want to install new outdoor outlets, contact us today for a virtual estimate and we can provide guidance. 

Install Deck Lighting and Outdoor Outlets

Remember that installing new deck lighting or outdoor outlets is a job best left to a licensed electrician for safety reasons, but also quality and insurance reasons. Get the job done right, and beautifully, the first time by contacting us today at Root Electric: (703) 494-3989.


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