Can It Be True? Solar PV Panel Systems Provide Free Electricity

Categories: Solar PV Panels.

Solar PV Panel Systems 101 - Converting Sunlight into Electricity

solar pv panel

A lot of occupiers’ homes are attached to the utility’s electricity grid and many people think about ways of keeping their electric utility bill low. The answer is simple economics. You remain free to use as much electricity as you want whenever it's required as you use the power you pay for it. Use less and pay less.

Grid power is very convenient. You can switch on the appliance and use the electricity supplied. It's there in your home from the electricity company when needed. When the appliance has completed its task you switch it off and it's no longer consuming power. You do not have to think about electrical circuit loads in your household. That is unless you overload a power outlet or its circuit.

 There are those rare occasions of a ‘brown-out’ or ‘black-out’. In most countries the utility power is always or usually there. A total loss of power is usually a scenario resulting from unforeseen circumstances. You can become accustomed to drawing whatever amount of electric power you need any time.
Solar PV when power is out

Anyone could operate their lights and run appliances in their home at any time if they chose without a second thought. You can do that as long as the limit of the particular circuit breakers are not exceeded and for as long as the utility company is providing power. Your power utilisation account provides for that privilege of consuming whatever amount of electricity you need.

If you want to avoid paying for very expensive electricity you could either live with using less, putting in timers to limit use or live without it. Life without electric power creates an unpleasant and unsocial environment. Or, you can find an alternative source of power that is cheaper to produce. That is the subject for this blog. Solar power from a roof-mounted array provides free electricity within limits. This blog sets out what those are.

Large Solar PV

A Big Solar Generating Station (Source: Canadian Solar)

Solar PV panels are described as providing ‘alternative’ and ‘clean’ sources of energy. The cost of electricity generated from solar PV systems was once more expensive. It was higher per kWh than the cost of utility power. Governments supported this alternative energy by putting subsidies in place to encourage more solar PV panels on houses. With the subsidies in place, more homes installed solar panels. Thus reducing the prices of solar PV panel systems over the past twenty years.

Because of better solar PV panel technology and improved efficiency at less cost, people now see the option as viable. Pricing has encouraged conversion to renewable solar power generation with the cost of a solar system justified. Solar PV panel system owners may also gain with subsidised feed-in tariffs.

Some of what we cover here is background and basic material so skim read what you already know.

Solar PV roof array

Solar PV panels are those black glass collectors with contrasting grid patterns you see installed on many a house roof. They contain multiple photovoltaic (‘PV” Photo = light & Voltaic = electric) cells material that converts sunlight into electricity. The solar PV panel’s cells transform the sun’s light energy into electrical direct current (DC) power electricity. However the sun’s heat energy isn’t converted into electricity.

Solar PV panel cells consist of layers of crystalline semiconductor material. This is usually a silicon layer separated by an insulating layer. Manufacturers place these layers under a support material or membrane such as glass. Thin, flat continuous layers of silicon crystal are positioned in layers to form very thin PV cells.

Manufacturers often use sheet glass for the support material. That is because sheet glass is transparent, stable, inert and stiff. Glass is easy to maintain and you can produce it in thin sheets at low cost. But, it is subject to damage during storms, transport and maintenance activities. Thin film photovoltaic panels use plastic sheets as support layers for flexibility. But, plastic will deteriorate in sunlight.

How Solar PV Works

Source Google images

When sunlight shines on the solar PV panel the light photons pass through these silicon cells. In the photovoltaic process photons of sunlight excite the irradiated silicon atoms. Some light photons will collide with electrons orbiting silicon atoms in the cell. A photon will hit into an electron and knock it away from the silicon atom's bond.

Free electrons have a negative charge. The electrons are preferentially attracted to one side of the silicon semiconductor cell. This creates an electrical differential across the cell. One side of the semiconductor layer gets a positive charge. The other side of the cell's charge becomes negative.

The solar PV panel cells get wired together into groups. Manufacturers wire these groups of cells together into panels to generate more direct current (DC) electricity. (The term 'panel' and 'module' are often used interchangeably for the same group of solar PV panel cells.) This arrangement channels and collects the generated PV voltage.

Manufacturers produce the solar PV panel cells in modules for connection. Often they configure modules with 36 to 72 cells. Installers wire the individual solar PV panel cells in a module together in series. In series format a solar PV panel array accumulates the contribution of each cell in the line.

Large solar panel installations cable together many solar PV panels into arrays. Each solar array connection would end in an array combiner. A fuse is set to protect each array. That is, one electrical box for the array with a set of safety protection fuses.

solar PV is scalable

PV modules are specified in international standards by their ‘watt-peak’ rating for Standard Test Conditions (STC). The STC provides what nominal power the solar PV cell at the standard solar radiation level generates.

The STC level is 1000 Watts per square metre set at a latitude of 35°N in summer.  Within the STC the cells and the air temperature are set at 25°C. A single solar PV cell typically produces nominal output DC voltage rated between 150 watt-peak and 300 watt-peak. However the actual solar PV cell output may be around 25 volts.

The power output is measured while varying the resistive load at the module between maximum and minimum resistance. The highest power result measured in Watts under those test conditions becomes the 'nominal' power of the module. That nominal power is compared with the light power falling on the photovoltaic device area (area m2 × 1000 W/m2). The ratio of the device's electrical output as a percentage of the incident energy indicates its efficiency.

The nominal power (kW/m2) and efficiency of the solar PV cells are relevant for comparing modules. The solar PV panel’s price divided by its nominal power output is another comparison metric. The total nominal power is used for sizing the design of an installation. This is used to correctly dimension the solar PV system components, cables and its inverter size.

Source of solar PV

You can optimise the solar PV output for an installation's physical location. You get the most sun during the day by directing the solar PV panels towards the sun angled at the azimuth angle of its location’s latitude.

You can maximise solar radiation onto the panel by using solar tracking devices. An alternative and cheaper option is to install support brackets that are correctly angled for orientation. Face the panels towards the equator for maximum sun. That means the panels face south in the northern hemisphere and north in the southern hemisphere.

You can also adjust the orientation of the solar panels to be slightly towards the east to provide more solar energy in the morning. If you adjust to be slightly more west facing, this will provide more of the sun’s energy in the afternoon.  You might prefer that set up where you have a particular period of the day when you use more power.

The more direct sunlight on the solar PV panel location means the more power will be generated. When the sun is brighter the module current will be higher. Also in poor or obscured light the module current is lower. The sunlight intensity and cell temperature will vary throughout the day. There is also variation during seasons of the year. Generally as the solar cell’s ambient temperature increases the voltage output from the cell will decrease.

The usable hours of sunlight will reduce and cause your voltage output to decrease when:

  • Partial shading from planting reduces the solar PV panel array’s access to light
  • Weather at that particular time of day becomes inclement (snow, rain, cloud cover)
  • Wind speed and sky conditions that prevail cause the solar collector to cool and/or heat up
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    The solar PV panel glass is not clean (not free from dust, leaf litter and bird droppings)

These effects can collectively reduce the sunlight transmission to the solar PV panel cells and reduce electrical output.

You can make some or all of those factors more favourable. Each improvement that you make raises the annual generating capacity. When you recognise the negative impacts you can mitigate them. That means you can improve your annual power production (kWh).

To be practical and use the power generated from a solar panel in your home it needs to be connected to the household electrical supply. Most people with a solar power generation system use their roof to access the sunlight. The roof area of most homes is usually a large area that is often oriented at some direction that will catch sunlight during the day.

Not every roof will have the perfect orientation. Not every panel will have an open aspect or be at the appropriate slope or inclination angle. The correct angle of panel inclination will enable your solar PV panel systems to work best.

solar PV suburban roof tops

The solar panels are set in place and secured to the roof structure using a mounting system. Mounting brackets can orientate the face of the solar PV panel to the best slope when the roof slope doesn't. The mounting system not only orientates the solar panels, it distributes the load from the panel and wind forces into the roof. The mounting is unseen but important to the safe operation of the solar generating system.

Better orientation is going to enable the solar PV panel system to be more effective. Erecting a solar PV panel array in an open ground or on top of a structure without obstructions to cast shadows with mounting brackets works best. That way you can optimise the orientation of those fixed location solar PV panel set-ups to improve solar access.

solar PV -panel on pole

Orientations as well as tilt-angle may be adjusted to improve or optimize energy production. You can customize orientation to suit local peak usage energy needs for particular times of a time of day (with E/W orientation change) or a particular season of the year (by changing the tilt angle to the sun).

The Solar PV panel that you design with tracking uses pivoting, tilting or rotating panel arrays. You can use mechanical or electrical operating mechanisms for those solar arrays to follow the sun’s path during the day across the sky. PV systems with tracking are more efficient. That is because they maintain their best orientation. It will maximise solar PV panel output longer. However, the tracking mount systems are more complex, have moving parts and are more expensive than a static solar PV system.

It is important to have a basic understanding of the angles of the sun to get the best efficiency from your solar panels.  Maybe you have wondered about the seasons, why they affect the orientation of the sun at your home during the year?

The earth's orbit of the sun isn't circular. Also the earth has a tilt angle relative to its path around the sun. Check out the images and explanation below.

solar pv panel

Image source:

The declination angle (δ) varies each season due to the tilt of the Earth on its axis of rotation. The angle of declination is the apparent angle of the sun relative to the imagined line between the Earth and the sun.

The Earth moves around the sun and the Earth's axis tilts at 23.45° to the plane of rotation. The declination angle varies between plus 23.45° and minus 23.45°. It is the angle between a line drawn from the centre of the Earth to the centre of the sun and the plane of the equator.

solar pv panel

image source:

The elevation angle is the angular height of the sun in the sky measured above the local horizon. At sunrise the elevation is 0°. The elevation is 90° when the sun is directly overhead. Your elevation angle varies during the day. Elevation angles depend on the latitude of the location and the day of the year.

solar pv panel

Image source:

The azimuth angle is a compass angle. It measures between north and the direction from which the sunlight is coming. Earth's sun appears directly south in the northern hemisphere.

It's north in the southern hemisphere at solar noon. Your azimuth angle varies throughout the day. The sketch above shows the relationship between the sun and north.

Let's look at the basics of a solar-powered system:

  • Solar PV panel (to turn sunlight into DC electricity)
  • Charge controller/solar regulator (This is controlling and regulating the DC charge into the battery)
  • Batteries (for storing DC power)
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    Inverter (This is for converting solar DC power generated by panels into AC for feeding into the grid/ home). There is a MOSFET that is inverting DC voltage into sine wave AC required for the grid. (The MOSFET is a real-time microcontroller switch within the inverter)
  • check
    Converter for changing AC power into DC. That's required for appliances using DC power

The Solar PV system is more that the roof top array, albeit this is the most visible component in any solar PV electrical system. The output of the system is governed by the number and size of solar panels that you have connected, which in turn is usually set or depends on how much power you will need to use. In this section we will explore the complete solar set up.

Here are the four main components that make up a solar power system. Copper wire joins them all together and safety fuses make sure the wiring is not overloaded.

The Solar PV panel array is the most visible component in any solar PV electrical system. The number of solar panels determines how much power you will have available. You can calculate your power needs for whatever you power up. Know the appliance wattage and durations of those appliances used each day. Multiply them together and add them all up for a day and you can determine the watts per day.

The number of solar PV panel units may be larger if you wish to charge on-site battery storage. A solar storage system will provide you capacity for electricity when the sun is not shining.

If you are a grid independent proponent, choose a modest solar PV panel system. Use mounting devices to optimise the orientation of your panels to the sun. With fixed or portable panels you need a charge controller, battery bank and plug in points. For AC appliances add an inverter and for a set up that has space involved add wiring consoles. The plug in points will power any backup equipment you might need.

You need more power for a larger spread out property. That is because there are more cooling and heating needs for larger properties. Similar situations exist with a property having many outbuildings. You will need to protect the electrical runs between buildings. When you bury electrical cables remember to mark their locations and protect them. Be aware that there are more electrical losses associated with the extended DC wiring.

solar charge controller regulator

A Solar PV panel in very bright sunlight creates a lot of electricity. Reflected sunlight from a nearby building’s glass or off a hill of snow for a part of the day can cause a surge of electricity. That electrical surge can affect and damage the solar system’s electrical components. The charge controller acts as a backstop filter to regulate the solar PV panel power surges.

The purpose of regulators and charge controllers is to regulate the current. It controls current from the solar PV panel to the batteries. The charge controllers prevent overcharging that results in damage to the batteries.

A solar regulator senses that the battery's charge level is at full. It reduces or stops current flowing to the battery. Solar regulators also will cut the solar PV panel electrical DC supply to the battery. The regulator does that when the voltage falls below the assigned cut-off level. This feature prevents the battery from permanent damage.

At night the regulator closes the link from the battery to the solar panel when no longer any current being generated. That mechanism prevents the battery losing its charge into the solar array. You rate solar regulators by the amount of current they can receive from the solar PV panel.

Electrical converters, inverters and transformers perform similar functions. Transformers are discussed separately.


Converters convert AC electrical voltage into DC. Converters have a major disadvantage; they have a poor capacity or tolerance of current overloads.


Inverters input DC electricity and output AC electricity. DC electricity comes from power sources like solar PV panels and batteries cells. Your household appliances need AC to operate.

You use a device called a MOSFET for inverting. MOSFET is the acronym of Metal Oxide Semiconductor Field Effect Transistor. Inverting happens by switching and amplifying electronic signals within the inverter. An inverter uses this MOSFET's solid-state switch mechanism. The switch alters DC power from the solar PV panel array into AC power.

Grid-tied solar PV panel users also use an inverter between the solar PV panel DC power and the grid’s AC power. The inverter converts DC into a form matching the network’s AC sine wave frequency and amplitude. This allows the homeowner to feed power back into the grid and potentially get paid or a rebate for the electricity.

Solar PV inverter for AC power

More Inverter Explanation

Manufacturers make inverters for a range of wattages. The greater the wattage rating of an inverter the more load it can handle.

Modern inverters are very efficient (it's typically around 97%). Electronic control systems keep the solar PV panel array producing at its perfect voltage. Micro-inverters can be mounted at the solar panel to convert DC power from solar panels to AC for the network grid. Utility regulators need the inverter to operate as a dead grid safety precaution. When main grid power isn’t available the inverter prevents solar AC power supply to the network.

 Try to locate the inverter as close as practical to the solar PV panel and in an accessible location. The inverter is often positioned near to the electrical main or sub panels. Inverters can make some humming noise, so consider that when selecting the inverter location in a residential application.
Solar PV back up generator

A generator is not a part of the solar power system but it can be a back-up to give you a boost of electricity if required. When you need to start an electric motor with high start up loads a generator helps. Inclement weather and overcast skies can last several days.

In those periods the solar panels may not have created as much electricity as you need. A generator will boost and charge the batteries, storing electricity for you to use later.

An appliance that draws a lot of power to start won’t start with insufficient power. You may decide to run the generator for a short period of time while that appliance is being used.

For example, to start an electric motor that requires a large amount of power to turn it over, you should start the motor with a generator running. You would run the generator only to start the electric motor. Once the motor has started the power needed to keep it running is less.

I have explained the components of solar in this overview. You might want to buy the components and set up a working solar power system. It is not difficult to complete a self-build with the correct instruction. If you start the solar power system with a shed, cabin, workshop, it can be a stand-alone system on which you can rely when the sun shines.

You can add batteries and then it can become an autonomous solar powered centre that works day and night. The same principles apply to large panels and to portable panels used on RVs and boats. Here is a short video that explains how to install a small solar system for your boat, or maybe RV, including the necessary components and tools.

A transformer is not strictly part of a solar power system. We cover it as it has a part to play in the national AC electrical power grid’s infrastructure. The transformer is usually part of this grid infrastructure to increase or decrease AC electricity voltage.

The role of transformers is to ‘step up’ AC to a higher voltage for distribution. The transmission of AC power between power plants and cities is done at very high voltages. At the high voltages the electrical losses are smaller. Transformers then ‘step down’ the AC voltage to a level around 110v to 220v for use in homes and businesses.

How Do Transformers Work?

There are two sides of the transformer. Power steps up or down from the primary (input) side of the transformer to the secondary (output) side. Each side of the transformer has a coil of wire sized in relation to the other. The proportional relationship increases the AC voltage or reduces it. An input coil of wire sits next to a second output coil. A fluctuating electric current that energises the first coil, in turn induces an electric current in the second coil of wire. The primary current occurs in the first coil and a secondary current in the second coil wire.

AC current in the first coil induces an AC current in the second coil. The primary and secondary coils both wrap around a soft conductive metallic core. That enables the electrical energy to pass from one coil to the other with better efficiency.

Transformer Technical Detail

Fluctuating electric current flowing through a wire generates a changing magnetic flux around it. When a magnetic field fluctuates around a piece of wire, it generates an electric current in the wire. The transformer uses this repeated reversing current for developing this phenomenon. Transformers do not work with DC wherein the current flows in one direction.

The magnetic flux density result is directly related to the size of the electric current. The bigger the current in a coil of wire the stronger will be its magnetic field. Wrapping the coil around a column having an iron core makes the effect more efficient. Where two sides of the transformer combine around the iron core the voltage in the coils go together. The increase or decrease in the secondary loop is according to the ratio of the number of coils.

The power (Watts) in an electric current is constant (watts = volts x amps). A transformer with 100 coils in the primary loop and 10 coils in the secondary loop will reduce the voltage. That transformer will step the voltage down by a factor of 10. But in the conversion it will multiply the current by a factor of 10.

In theory the power in the primary coil and secondary coils remain the same. In practice a transformer loses some magnetic flux from the core as heat energy. A step up transformer has a ratio of coils in the reverse order of say 10 primary to 100 secondary.

If you are working on building a home power system that will be tied into the grid you might need to find a reliable licensed electrical installer to help you along the way. Work with tradesmen having the appropriate electrical certification if the complete house system is linked to any external power supply.

You might develop a standalone system for a workshop or cabin in your garden to learn the techniques and refine them. Remember and think about electrical safety as you do the work. You know that even briefly contacting with live electricity on a solar PV panel system can be fatal.

Here are the steps for your own DIY solar panel system:

solar PV explanation
  • Determine how much power will be needed
  • Account for maximum electrical loads and add on the electrical losses
  • Size the solar PV panels, the charge controller, inverter, wiring, and safety fusing
  • check
    Size the battery and converter
  • check
    Plan out the physical area to ensure the components fit the space
  • Roof, standalone, portable/ mobile
  • Decide where your solar PV panel will go
  • Set up mounting brackets or poles and supports designed for your panels

Here are the issue you need to consider when installing your solar batteries:

  • The ventilated so gasses can be vented (important for lead acid type)
  • Accessible for maintenance
  • Not accessible by children or animals
  • check
    Secure from interference (locked dry cage or shed)
  • check
    Out of the weather– covered space
  • Install your charge controller near to your solar panels
  • Connect the charge controller to the solar panels
  • Standalone and off-grid solar PV panel applications with batteries use a charge controller. That is a DC to DC inverter with built-in charger. The charge controller converts power from the solar PV panel array into DC at a rate the batteries can store
  • Connect a voltmeter to the batteries
  • You should see the reading on the voltmeter rise as the solar panels begin to charge the batteries

You should be able to plug in and use AC appliances with the Inverter when the solar panels are operating and later when the batteries are charged

A solar array erected on a platform on elevated open ground, away from possibility of shadows, will receive maximum sunlight and produce the most power possible each day. Some solar PV roof array installers recommend connecting your solar panels to an oversized inverter. They say this will allow you to power up most appliances and allows for expansion. It is best to calculate the correct sized array for the loads that you will draw and match the inverter to that.

Your grid-connected house must have an installed automatic disconnect device. This device ensures solar generated power will not flow into a dead grid. That means you isolate the solar array from the utility's electrical grid if the grid loses power and is inactive.  

Keep the batteries and electrical equipment where they will remain dry and ventilated. They will last longer that way. Also keep electrical wiring to equipment isolated and away from animals that might chew on wires. Maintain sufficient barriers in place so that curious children cannot touch electrical components. Use residual current device safety breakers between the solar panels and charge controller. Also use an RCD at the power board for your home appliances.

There are a number of solar PV panel system calculators that can help you to determine what you will need. Here is a video that will assist you in reviewing the solar calculations.

When you put up a solar power generator on your roof you need to be assured that it works. There are instruments in the solar system components that help you to monitor the system output. It’s good to know everything is working and to get assurance from the numbers. You buy a solar PV panel to generate electricity and you want to achieve the most kWh at least cost.

A small solar PV panel system installed costing $10,000 in the US producing at 5kWp is converting to cost $2,000 per kWp (or $2 per Wp). Peak power is not the same as power output under actual radiation conditions. You can lose up to 20% of solar energy to thermal heating in the solar PV panel cells. The solar PV panel modules account for about a third of the system cost. The mounting frames, inverter, wiring and labour account for 70% of the system cost.

Watt-peak is a convenient measure, and a base on which the solar energy industry compares prices. It is also used for industry sales growth numbers. Watt-peak isn’t the most important measure for your solar PV’s performance.

You'll usually be interested in the actual power that a solar PV cell generates. What you're looking for is Watts/hour output under real-life conditions.

Compare the actual output (kWh) in relation to the total price you paid. You want to check the cost per watt from your solar PV panel system. Maybe compare that cost with what that amount of power would have cost purchasing from the grid. Current costs of around $0.65 to $0.70 US per watt from your solar PV panel is typical but remember the system is more than the solar PV panel.

From this calculation below you will know whether installing a solar PV system was worthwhile. Will it pay for itself and if yes, what will the timeframe be?

solar PV panel on hut

The environment is important but before people buy an alternative power system they want to know, will pay for itself and how long will it take. These are questions most of us ask when investing thousands of dollars into a system.

The good news is that you can determine the likely payback period for the solar panel system.

You can get data for that calculation. Solve to find P (the payback result in years) using the formula below:

A - The total price of the solar PV panel system. (Including installation and maintenance for electricity production).

B - The projected annual power output (kWh) of the solar PV panel system matching demand from the home.

B2 - The projected annual power output (kWh) of the solar PV panel system more than the demand from the home.

C1 & C2 - The current annual power consumption during the daytime and during night-time.

D1 & D2 - The comparative cost of grid power per kWh at day rates and night rates.

E – The grid feed-in tariff per kWh rates.

From that calculation you can determine the solar PV panel’s power output and savings. P is how long will take to repay the investment.

The calculation looks like this. Saved expense plus income from excess power fed into the utility grid. Take off night power used at the night-time rate. That gives a net cost or saving.

Saved expense = (C1 x D1)

Income from excess power fed into the utility grid = (B2 x E)

Night power used at night-time rate = (C2 x D2)

Payback (P) = $A : $F/year where F = [(B2 x E) + {(C1 x D1) –(C2 x D2)}] $/Yr.

The above gives the math calculation for payback period but investment in the solar PV panel system can be considered to be like a prepaid electricity account. The time taken to amortise the full cost of the installation depends on a large number of variables but there is definitely a long run benefit for the cost.

Some people object to solar PV panel arrays on rooves because of how the panels look. Some installations appear to affect streetscape aesthetics because they are stuck onto the roof without any thought to good design. This has influenced some local government authorities to require a permit to be issued for solar PV roof installations. You'll possibly need to have a certificate from an engineer or builder to show that the roof has been inspected and is sound.

The bracketing that fixes the roof to the panels to hold the solar array in place during wind and torrential rain usually adds to the structural integrity of the roof. The panels provide shade and protection to part of the roof, keeping it cooler.

Your roof mounted solar PV panel array design may need approval from building planning departments of local authorities to sign off the location of the panels. Town planners may ask the adjacent neighbours for a comment and planners want to ensure solar panels are not seen from the streetscape. Usually a good installer can help with achieving that. Good install design and the use of high efficiency PV panels will assist with solving the ability to reduce the panel footprint.

The electrical utility will require the installation to be approved by them before connection to be maintained and for the installation to be signed as compliant (usually a licensed electrical installer can do that).

Aesthetics And Solutions

Solar panel on a red roof

Your neighbours might prefer the locality to keep the uniform look of clean roof lines. That is possible with modern solar panels. There are areas where there are many a house roof featuring different roofing styles. Roofs can be a mix of tiled, painted corrugated steel sheeting and shingles. Even with the huge variation in roof designs and colours, solar panels brackets (usually of older times) that were poorly mounted will standout.

Modern sleek panel bracketing and slim panel supports now look better than they did a few years ago. But, even thought they are less perceptible in the roofline than earlier times, the installers will place the panels on the roof areas so they are not visible from the street. With improving technology the roof itself will have modified roofing materials that are actually the solar collection system. When considering the orientation of your solar PV panels, the use of designed brackets will be helpful in optimising their access to light so they don’t become ugly attachments to the roof.

Large solar PV panel systems mounted on brackets that are protruding above an urban roof line don’t look good and are at risk of having panel damage in high winds. You want your installer to orientate roof panels to absorb as much light energy as they can get, but to choose options with good design for no impact. The solar PV panels can be incorporated into the slope of a rear roof, onto a patio roof, built into a structure used as a pool shelter, added to a garage, or made up as solar wall in the backyard. These suggestions will make the solar panel almost invisible to neighbours.

A large household with children uses a lot of energy. Add heating requirements, air conditioning, a pool or an electric car and the power bill gets big. The number of solar PV panels you need will be more than a modest home with a smaller electrical footprint. A part of designing the solar PV system involves auditing the power used by a large electricity user. If the bill is large you will need to prioritize the electricity load. Which parts of the energy consumed can be conserved, rationalised, saved by change use patterns, made less by using more efficient appliances or eliminated as wasteful activities (turn lights off when not used during the day).

You might have more a modest home but have need for cooling. A solar array with a charge controller will operate a home and charge a battery storage system. Electricity from the batteries and an inverter will run electrical appliances and lights. In humid hot climates you might need a small room air-conditioner in your home. In hot and humid conditions a small room air-conditioner appliance might save a baby from overheating and dehydrating.

Solar PV Panel With Batteries

Solar PV with back up

A solar PV power array has better utility when it's backed up with battery storage. This will allow you to have your electricity on tap even when the sun isn’t shinning. Battery backup comes at extra cost but the investment is worthwhile.

Your inverter disconnects the house solar from the grid. Automatic solar disconnection from the utility network means the backup electricity supply goes. The solar backup options are only available with an integrated solar battery installation.

If you want to know more about the various and different solar battery options I briefly talk about them in another blog article which you can see here.

Some people don’t want their solar panels installed on the roof where they live. It might be they are renting or will be renovating and the roof will be part of the work area affected.  It might be that you don’t want to dish out for the cost for a large system but want the convenience of a solar back up.

Maybe consider using a portable solar PV panel system to harness solar energy? Put it onto a separate part of the site, maybe like the garage, workshop or shed roof.

You could consider a standalone isolated power source on a trailer or maybe skid mounted so that it can leave when you do. That scenario is like camping in your back yard, using the back-up power up until the grid power resumes. You could pull the essential appliances out from your home and power them from the backup unit.

If you have a back patio or a shed the appliances could be put in there until the emergency passes. If the power goes out often then having some spare appliances in the shed for quick go to access is a great standby for any power out scenario. In the mean time the back up keeps the beer fridge cold.

You could use a portable solar PV panel with battery pack at your home. You could store excess DC output in batteries during the day and use it later. It would be an isolated back-up to the power system not connected to your home.

Of course, using a generator unit might seem like a viable option for when power goes out but again you can't connect it into your home supply unless you have the approved cut out switching. You will breach safety regulations if you make any connection of the generator to the house or grid without grid isolation.

Let’s recap on what we have covered. Remember, you want a well-designed solar PV panel array on your roof. You need good wiring and correctly sized fuses and RCD or overloads and safety protection. Consider buying battery storage to ensure power continuity. A well thought system design can support your energy independence.

An efficient functional solar PV panel array will reduce your reliance on grid provided electrical energy. The upfront capital costs for a roof mounted solar PV panel array is high. However, if you have good solar access and the system has been installed well the investment will pay for itself. In the long run a solar PV panel system will save you money and help the environment.

If you are going buy a solar PV panel system get transparent facts. Click here for the free checklist. The checklist will help get you started. If you need a comprehensive outline about solar and renewables I have written an e-book that explains it in simple terms. There are many articles on this website that cover pretty much every topic about solar power and panels. If you find a topic not covered let me know and I will write to explain that too.

The most important thing is to do your own homework before you decide to DIY or call for a quote. Make sure you are knowledgeable on your requirements. Only then can you get answers of design, sizing and costs.  Initial costs are only one part of the equation. You must consider the ongoing costs. If you have solar panels and no battery backup the ongoing costs will be lower than if you have a bank of batteries. Depending on the type of battery you have installed, replacement can be every 5 to 20 years.

I hope the blog article has boosted your understanding of Solar PV panel systems and if you have questions or comments, leave them below in the comments box.

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