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How To Build Your Own Solar Power System

Author: Jesse Adams

How To Build Your Own Solar Power System

Book Series: Build your own


Many people wonder if it is possible or even worth it to install their own solar power system. The prospect can certainly be daunting, especially when dealing with electricity and the installation of large photovoltaic (PV) arrays. The learning curve can be steep, but it is possible to do it and to realize significant savings as a result.

There are certain steps to take to make the process efficient and successful. These include:

• Doing a needs analysis, where the individual reviews their annual energy and electricity usage and determines their annual kilowatt requirements.

• Determining the type of system to install and whether to tie into the utility grid or go stand-alone.

• Conducting a site analysis where the individual analyzes proposed locations for the array. They determine the site’s solar window and look for a location with minimum shading throughout the year.

• Designing a system that includes all of the necessary safety, as well as the renewable energy system, features.

• Identifying what skills will be necessary to build and install the system and whether the individual possesses these skills.

• Determining what equipment and tools will be needed and whether the individual possesses them or has access to them. If not, purchasing them will be an added expense that must be factored in.

• Identifying all necessary permits required to install a solar power system. Will a building permit or an electrical permit or both be required? Does it make a difference if the system is roof, ground, or pole-mounted?

• Determine the projected savings from the individual installing the system versus hiring a professional installer.

• Researching available financial incentives and rebates to determine which type of system will bring the best return on investment.

• Determine how the system will be purchased. Will it be paid for in cash or financed?

Following these steps will help make the process as easy as possible when an individual decides to install a solar power system themselves. The installation process can be complicated, but taking it a step at a time will help ensure it gets done safely and correctly.


One of the most important considerations will be the size of the solar power system. There is a great difference in cost between a small 12-volt system designed to power a few lights and an appliance or two, and a multi-kilowatt, grid-connected, ground-mounted system providing up to 600 VDC.

The smaller system is a fairly simple do-it-yourself (DIY) project, while the second, although certainly a conceivable DIY project would require significant skill and experience, with a clear knowledge and understanding of the National Electrical Code (NEC).

Another critical factor is what type of system to install. Some solar power systems are battery-based, while others do not require batteries, but are instead tied into the electrical grid. Each of these systems requires different levels of preparation and types of equipment.

There are currently three types of solar power systems. These are the stand-alone off-grid system, the battery-based grid-tied system, and the batteryless grid-tied system.

Grid-tied systems may be battery-based or batteryless. The most common of these systems are batteryless. These are also the most cost-effective, environmentally friendly, and simplest grid-tied systems. These systems are often available as packages and are fairly easy to install and operate.

The systems typically include micro-inverters or central string inverters pairing each module to its own small inverter. Arrays using micro-inverters operate at 240 VAC instead of the high-voltage DC. This makes it safer to work with the electrical wiring.

Batteryless grid-tied systems are tied to the utility grid and possess no batteries, just the equipment to generate electricity. These systems have no back up should the grid go down, which is a negative to installing this type of system.

When installing either type of system, those using micro-inverters or those using central inverters, it is critical to have the necessary skills, savvy, and tools. However, batteryless grid-tied systems are generally pretty easy to understand and install. They consist primarily of modules, racks, inverters, wiring, and disconnects.

A grid-tied battery-based system is a bit more complicated. Adding batteries to the equation requires planning, set-up, and operation. To begin, an individual must know the amount of battery storage they will require. This means understanding and analyzing energy use, calculating the profile for the backup load, and determining the average length of a potential energy outage.

Battery-based grid-tied systems operate in a manner similar to the stand-alone systems. These systems also use batteries as a back-up system, but they are also attached to the utility grid. This allows the system to send any surplus electricity generated out to the grid and to use the grid’s energy when necessary.

It is possible to buy pre-wired parts for battery-based grid-tied systems, however the battery bank will still need to be configured, wired, and tied into the PV array and the grid. Even the most skilled do-it-yourselfer may require assistance with this system. Additionally, operating a battery-based system is more complicated than a batteryless system, requiring battery maintenance and replacement.

Off-grid stand-alone systems require a certain amount of commitment. Anyone living off-grid must be dedicated to conserving energy since their off-grid system is all they have. Designing this system is one of the most important steps. The individual must have a clear understanding of their load profile, their equipment needs, their own skills, and additional resources.

Stand-alone, off-grid systems operate completely independent of the local utility grid or system. Stand-alone solar power systems must have a back-up power system to provide energy when input is low or use is high. These back-up systems are typically composed of batteries.

Advantages of Being Off-Grid

The primary benefit of an off-grid system is the independence from a grid and therefore, local utility terms and policies. Off-grid systems also are not impacted by blackouts, brownouts, or rate increases.

Putting in an off-grid system may be less expensive than extending a utility line onto a property. Rural properties are especially good for installing off-grid systems; however there will be ongoing and up-front costs.

Off-grid systems may be expanded a bit more easily than grid-tied systems. This is a benefit if an individual wants to grow the off-grid system as they can afford new components. Many individuals who switch to off-grid systems do so gradually, weaning off fossil-fueled systems as they add more renewable energy capacity.

Most off-grid systems force the individuals to use electricity more efficiently. These systems are very different from being plugged into the utility grid, so the individual must find ways to save on energy use. This makes the systems much more environmentally friendly, since they make the owners think about how to use their energy wisely.

Disadvantages of Being Off-Grid

The biggest disadvantage is the cost. It will likely cost more upfront to install an off-grid system than it would to remain on the electricity grid. These costs can be mitigated in certain situations by financial incentives or tax breaks. There may also be savings if the local utility rates are extremely high.

Going off-grid with new construction can be well worth the investment. Anyone considering a new solar power system should compare the cost of an off-grid system with the cost of extending a utility line to the new residence.

Other considerations are system troubleshooting and maintenance. As with any home system, these are ongoing with an off-grid system. Being tied to the grid means calling the utility company and having someone come out and fix the problem. Being off-grid means fixing the problem yourself.

Off-grid systems also use batteries as their back-up system. These batteries store surplus electricity to be used when solar input is low or when use is high. These batteries will need to be replaced, usually between five and fifteen years. The minimum requirement for a battery bank will cost an average of $1,000 and industrial batteries, which last longer, but are much more expensive, will cost three to four times that amount.

Batteries also waste energy. Batteries are typically about ninety percent efficient. This means that for every ten-kilowatt hours of input, they will provide about nine kilowatts of energy. Temperature changes can also impact battery effectiveness. All of this means that the older, colder, larger, or hotter the batteries, the more energy wasted.

Stand-alone off-grid systems also waste the surplus energy they generate. When a system is tied to the grid, any renewable energy produced is fed back into the utility. This provides the individual an energy credit, as well as allowing the system to continually run at full capacity.

These grid-tied systems help maintain the efficiency of the local grid and the individual gets credit for the energy their system produces.

Energy produced by off-grid systems must either be used or it is wasted. Most off-grid systems turn off their array when the batteries are full, thus shutting down energy generation. Individuals who are savvy off-grid operators schedule their energy use around the peak input hours. For example, they will do laundry during the middle of the day.

Off-grid systems generally also require a back-up generator. Using a generator is expensive, especially when factoring in the purchase cost of the generator and the ongoing cost of fuel. There is also the disadvantage of noise and pollution from a generator. Generators will also need to be replaced after a number of years use.

Living off-grid requires flexibility in energy use and a realistic attitude about what it will take to make it all work. It may be necessary to turn on the generator if nature will not cooperate or reschedule certain activities around changes in the weather.

Advantages of Being On-Grid

When a home renewable energy system is tied to the grid, the individual can sell any surplus energy back to the utility and draw energy from the grid when necessary. This can be the best of both worlds. If an individual cannot afford a full renewable energy system right away, they can install what they can afford and tie to the grid to supplement their energy needs.

When a system is entirely off-grid, the individual has to make do with the energy their system produces or turn on a generator. This uses a great deal of fossil fuel and can be very expensive.

When a system is tied to the grid, there is really no need to alter lifestyle or conserve energy. The system can support the same energy draw that the grid would, offsetting usage with the energy it produces and drawing from the grid when it must. A grid-tied system with a battery back up provides the independence of a stand-alone system, energy when the grid goes down, and access to the grid to sell back surplus energy.

Disadvantages of Being On-Grid

One of the primary disadvantages to being tied to the grid is less incentive to conserve energy. When an individual knows that their energy is limited, they tend to adjust their habits and end up saving energy and helping to protect the environment.

A batteryless system tied to the grid will have no back up should the grid go down. This is a real disadvantage to those located in very rural areas where there are frequent power outages.

Additionally, even grid-tied systems with a battery backup tend to have a limited amount of back-up capability. It would take a very large battery array to provide enough energy to meet all of a home’s requirements.

There may also be government and utility hurdles to overcome when trying to connect a renewable energy system to the grid. This can be true especially if grid-tied systems are new to an area and local officials are not familiar with how they operate.

Comparing Costs

A battery-based off-grid system will generally cost anywhere from 30% to 40% more than a batteryless grid-tied system. The individual must also consider the cost of extending utility lines to a property. This can be very costly, sometime running as high as hundreds of thousands of dollars if a property is a long way off the utility line.

Intangible costs are more subjective. While it may cost $50,000 to install a solar system off-grid, the individual will be rewarded with no utility bills, independence, and the satisfaction of knowing that they are helping the environment.


With a solar energy system, sunlight is key. The PV modules should be situated to receive sunshine for the majority of the day. Shade can render a solar array useless, so a sunny location is a must.

A PV module puts out energy in direct proportion to the amount of sunlight it takes in. Energy is produced when photons from sunlight knock electrons into motion. When there is less sunshine, for example because of poor placement or a cloudy day, there are fewer photons hitting electrons creating less electricity. Shade, however may completely shut down energy production.

While most PV modules have built-in systems to help mitigate the effects of partial shade, an entire row of shaded cells may completely disable a module. This is the reason why it is so important to do a thorough site analysis as part of planning a solar system.

While completely unobstructed, dawn-to-dusk sun exposure is the ideal; most sites will have some type of shade. As a result, most solar system designers will try for a 9 A.M to 3 P.M. unobstructed solar window. This is when the majority of solar radiation occurs, although it may vary a bit from region to region.

Analyzing the Site

It can be difficult to predict when shading will occur using sight alone. It would require a series of observations taken over a year’s time. Instead, there are several tools available which can, in only one site visit, help assess how the shading on a site will occur throughout the year. These tools vary in price and technique, but all are capable of doing the job.

Solar Pathfinder is a tool that has been in use since the 1970s. This tool consists of a clear plastic dome and sun-path diagram. The tool predicts times of day and the month when objects will shade a site. Solar Pathfinder provides sun-path charts for various latitudes, each depicting the amount of sunlight available per hour for each month.

Wiley Electronics Acme Solar Site Evaluation Tool (ASSET) uses a digital camera mounted on a base that can be adjusted according to compass direction. The software takes the downloaded photos and creates a panoramic view from the site. The software then superimposes a sun-path diagram over this photo, which shows any obstructions that may shade the array.

Solmetric SunEye is handheld and integrates a digital camera, fish-eye lens, and a touch-screen interface. The user selects their location and then snaps a picture. The touchscreen reports the annual percentage of sunshine for the seasons, as well as the monthly averages.

All three of these tools contain compasses and bubble levels since they must be aligned and leveled before a measurement is taken. All measurements must be taken exactly where the array will be located. For instance, if the array will be roof-mounted, the measurements should be taken from the roof. If it will be mounted on a pole, then the measurements must be taken from a scaffold or ladder set up at the proposed height of the array.

A reading should be taken at every corner of a proposed array location, as well as the top and bottom of the site. This ensures a proper measurement of the entire area’s solar window. A site reading may show that an array would be shaded during the day because of objects on the horizon or because of foliage.

Solutions for Shading

When shading obstacles are discovered, an individual may be forced to relocate the array or to remove the obstacle. If the obstruction causes shading on the lower part of the array, perhaps the array could be moved up or be elevated. It may even require a pole mount.

An array can always be redirected, as well. For example, if the eastern side of an array is shaded, the array could be rotated to face more westward. If trees or foliage causes the shading, it may require trimming or even relocating them.

Of course, trimming may cause other problems. Trees may be providing much-needed shade on the west side of a home. Removing them may increase the energy load on the solar system, especially on the fans or air conditioner. This may offset any energy savings gained from cutting down those trees.

It is also important to remember that bushes and trees grow. When designing a solar system, future growth and how it may shade the array must be considered in array placement. The three site analysis tools are all able to predict the impact of removing an obstacle. They can also predict how much sunshine would be lost if an obstruction is added.

When the Shade Cannot Be Escaped

Different solar systems are impacted differently by shade and the resulting reduced power production. A stand-alone off-grid system can be severely impacted by even the most minimal shading. Shading reduces the amount of energy a system produces, which may necessitate changes in load management, or the use of a generator.

A grid-tied system is not as severely impacted by partial shading. Shading simply reduces the amount of energy produced and thus, the amount of grid energy the system offsets.

Realistic energy estimates are necessary in order to design an efficient system. Losses from shading must be factored into annual energy predictions for a solar system. It may be possible to increase the size of the system in order to offset losses due to shading.

With the proper tools and data, a solar system may be designed to plan for energy reductions caused by shading. Solar systems represent a significant financial investment and the system can only produce electricity when it has enough sunlight. Site analysis ensures an array is properly located to maximize energy production.


There are many steps involved when designing a solar power system. Before beginning, it is important to include all the variables such as size, type, and location.

The first step is to evaluate the situation and then determine the goals of the system. The individual should closely observe the site and ensure that there is a good solar window available at the proposed location of the array. This window would ideally occur between 8 A.M and 4 P.M.

There may be times when this solar window does not occur on the roof, but happens in the yard. This is when a ground-mounted system may be the solution. Perhaps the individual would like a four-kilowatt system, but has a shade-free space big enough for only two kilowatts. In this situation, a pole-mounted system with more modules or another inverter may work.

The system must pass electrical inspection, so it is important that anyone installing a system themselves be aware of all the NEC requirements pertaining to their installation. They should also be familiar with any local requirements. For example, many inverters provide integrated AC and DC disconnects, however local requirements may state the need for additional disconnects.

Fire codes may also impact an installation. For instance, there is a requirement in some regions for a three-foot setback on roof-mounted arrays. This is to allow pathways for firefighters and for smoke ventilation.

It is also important to consider performance factors as well. Anyone installing a solar power system should know how to optimize the design of the system to take advantage of available sunlight. Any amount of shading during prime solar hours, no matter how minimal, can significantly impact a system’s output.

Also, temperature changes may impact the performance of a PV module. This means whoever designs the system must factor in temperature fluctuations and ensure good airflow around the PV modules.


The complexity of the system will determine how skilled an individual will need to be to do their own installation. At a minimum, the individual will be performing design, mathematical, electrical, and mechanical work. The system design may actually be the most difficult.

The individual must clearly understand their projected energy requirements, the amount of solar resource available, their equipment, and how everything fits together. If the design is not correct, it will not matter how skilled they are at electrical or mechanical work.

The individual should spend plenty of time researching, planning, and designing so that they get it right the first time. Those who are experienced with other types of home improvement projects will typically be better prepared to install their own solar power system.

They will need to know how to perform mechanical work such as how to construct pole or roof-mount attachments, secure heavy electrical components to a roof or a wall, or how to install roof flashing. A different set of mechanical skills are required to construct a battery bank or enclosure, including hazard protection, security, and working with heavy weights.

The electrical work is more detail-oriented and hazardous and is often more critical than the mechanical work. After all, electricians study for years before becoming certified. These skills include how to correctly and safely pull wire, bend conduit, and secure connections. They must also ensure everything adheres to the strict requirements of the NEC.

It may help to have a mentor or someone to turn to for advice, especially for the electrical work. Electricians typically have significant training and experience and know techniques and tricks to make the job easier. Taking a basic wiring or electrical class at a community college or technical school may also be helpful.


One of the cardinal rules to buying the equipment for a solar power system is not to buy cheap. It is really important to purchase quality equipment to ensure consistent energy production and delivery. This is something that is taken for granted when on the utility grid, but poor or low quality equipment can make or break a solar power system.

Good research includes determining which products suppliers are selling in quantity and what the professional installers are using. A product sold by only one source should be very carefully considered. It may be better to wait until the professionals within the industry are using that product.

Buying from a dealer will not necessarily garner the best price. Many times, those installing a solar system themselves try to get a good deal from a dealer, but end up with no follow-on support at all. This is especially important if it is the first time a do-it-yourselfer is installing a solar power system. Having someone who can provide advice and assistance can really save you money.

It also helps to try and buy locally. When buying from someone in the local area, it is possible to build a relationship with the supplier and dealer. This makes it easy to ask questions, get clarification on design issues, and resolve problems with an order or product.

It may also be possible to collaborate with a local, professional solar power system installer when buying through a local company. There may also be individuals available to provide technical expertise such as design review or a pre-inspection. This can prove to be a great help if there are issues during the installation process.

Local suppliers are concerned with maintaining their reputation and relationships within their community. This means that they may be more willing to help with advice for an individual who is installing their system themselves. Big manufacturing companies who sell through retail outlets generally do not have dedicated resources available to help with those types of technical details.

The necessary equipment will depend upon the type of system. Not every system requires each piece of equipment.

  1. PV Modules or solar-electric modules.

These are the solar power system’s primary component. This is where sunlight is turned into direct current (DC) electricity. Most PV modules have a shiny surface behind which semiconductor materials use photons from sunlight to move electrons in a circuit. This is known as the photovoltaic effect.

PV modules are rated based on the maximum power that they can produce, given ideal sun and temperature conditions. The energy output is rated in watts and an individual can use this rated output in determining the number of modules necessary to meet their energy needs.

When several modules are combined together they create an array. PV modules are usually framed and connected together, however PV technology is also available in roofing tiles and shingles and even in peel-and-stick laminate tiles for metal roofs. PV modules are typically very durable, lasting a long time. They withstand extreme weather and most carry a 25-year warranty.

2. Array Mounting System.

This includes the various racks and mounts required to hold the PV modules. The mounting system holds the modules securely in place, and oriented in the right direction. The modules are typically mounted on the roof, on a pole, or on the ground. Specific pieces required will depend upon the system selected.

Arrays installed in suburban or urban areas are usually mounted on a roof facing South (if in the Northern hemisphere, or North if in the Southern hemisphere) and parallel to the slope of the roof. This is done because that has the highest incidence of direct sunlight all year.

It is possible to also use roofs facing east or west. Most consider this to be the most aesthetically pleasing way to install a roof-mounted system and it is often a local requirement. If the roof will not work, then a pole or ground-mounted array may be the answer.

An array mounted on a pole can also be set up to automatically adjust or track the sun as it moves across the sky. This type of set-up can greatly increase a system’s daily output, sometimes by as much as 25% to 40%. They are, however more complicated and more expensive and require more maintenance than a fixed array.

3. Battery Bank.

The solar power system’s PV modules only produce energy when the sun is shining on them. If a system is not connected to the grid, then it will need a battery bank. This is a group of batteries that are wired together to store energy. This provides energy to the system for nights or cloudy days.

A battery bank for an off-grid system is typically sized to provide enough energy to run a household for three days. Systems tied to the grid may also have battery banks. These banks provide energy in case of a power outage, so they are usually smaller than those of an off-grid system.

While similar in appearance to car batteries, the batteries used in solar power systems are deep cycle batteries. These batteries are built to withstand the constant charging and discharging of a solar power system. The most common type of battery used is a flooded lead-acid battery.

These are the least expensive choice, but must be replenished occasionally with distilled water to replace water lost during charging. Sealed, gel-cell, and absorbed glass mat batteries do not require adding water, but are more expensive. These types of batteries are sometimes used for grid-tied systems since the battery banks are smaller.

4. Battery Bank to Charge Controller Disconnect.

It is required by the NEC to place a disconnect between the battery bank and the charge controller. This is typically a circuit breaker and is used to isolate the charge controller from the battery bank during servicing.

5. Combiner Box.

Also known as a series string combiner, these are used to wire and combine parallel strings of modules. These are found most often in off-grid systems, although some larger on-grid systems may also use combiner boxes.

A combiner box has negative and positive wires each with its own terminal, for individual module strings. These wires are located on the input side of the combiner box. The positive wire and terminal is connected internally to a series circuit breaker for that string. The output of each of these is connected together with a common bus bar and a positive output wire.

The series negative wires are connected to a common bus bar and have a negative output wire. There are some batteryless grid-tied systems that have an integrated combiner box on the input side of the inverter. This eliminates the need for a separate combiner box. Some grid-tied systems have only a few PV module strings, typically three or less and thus, do not need any combiner box.

6. DC-to-DC Converters.

These are also the power boxes, distributed power harvesters, and module maximizers of the solar power systems. These units help maximize the power output of a PV module and reduce energy losses because of variances between the output of an array’s modules.

These converters are wired directly into each module and then bolted to either the PV rack or the module frame. Power boxes are connected, either in parallel or series and their combined output is then wired to the PV disconnect.

7. DC Disconnect.

This component is used to safely interrupt the electricity flow from the PV module array. This component is essential when a system needs troubleshooting or maintenance.

Its presence may also be mandated by local requirement. The disconnect enclosure, which may sometimes be part of the inverter package, also houses the electrical switch rated for DC circuits.

8. Charge Controller.

This component’s primary job is to protect the system’s battery bank from over-charging. The controller moderates the output of the PV modules as the battery charges. Once a battery is completely charged, the controller will shutdown the flow of electricity to the batteries.

9. System Meter.

The system meter measures and displays different parts of a solar power system. It shows the performance and status. For example it can track how much electricity the array is producing or how full the battery bank is. It can also provide the individual details on energy usage.

Some meters include web-based monitoring which is very handy for overseeing the entire system and troubleshooting any problems that may arise. A meter is one of the most important features on a solar power system, providing the individual vital information on the system’s ability to do the job.

10. Inverter.

Also known as a DC-to-AC converter, an inverter transforms DC electricity produced by the solar power system’s PV modules or batteries into the AC current typically used by pumps, lights, and other household appliances.

On a grid-tied system, the inverter synchronizes the system’s electricity with the grid’s AC electricity, which allows the system to feed surplus solar electricity back to the grid. Grid-tied inverters typically work without batteries. They either use a series grouping of modules or a micro-inverter for each module.

The micro-inverters are similar to DC-to-DC converters, offering monitoring at the module level, which maximizes the array’s output by enabling every module to operate independently of the others.

Off-grid systems or grid-tied systems with battery banks will often use a battery charger with the capacity to charge the battery bank either from a generator or the grid. This is typically used during cloudy weather or during a power outage. Battery-based inverters are not weatherproof, so should be mounted indoors near the battery bank.

11. Battery to Inverter Disconnect.

The disconnect in battery-based systems is usually a large, DC-rated circuit breaker. This is mounted in an enclosure made of sheet metal. Turning on this breaking quickly disconnects the inverter from the batteries for servicing. This protects the inverter-to-battery wiring against current surges.

12. Inverter AC Disconnect.

Local utilities typically require an AC disconnect between the grid and the inverter. Grid-tied systems may have the AC disconnect already integrated into their system, but this may not meet local requirements. When this happens, a separate AC disconnect box must be installed, typically near the utility kWh meter.

Battery-based systems also require an AC disconnect, this time between the AC breaker panel, the inverter, and any other AC power source. This AC disconnect is typically integrated into an inverter bypass breaker assembly. This allows the AC loads to be fed by the inverter or by another AC power source, if the inverter is not available.

13. AC Breaker Panel.

The breaker panel or main panel is where the electrical wiring for the entire building connects to the electricity source, whether that source is the utility grid or a solar power system. This is typically a wall-mounted box or panel and is generally located in the basement, laundry room, garage, or on the exterior of the building.

The panel contains a series of labeled circuit breakers that route electricity to the household circuits. Each breaker is connected to a specific circuit and allows electricity to be disconnected from that circuit for servicing. These breakers also protect the wiring in the building from too much current, which can cause electrical fires.

Inverters need to be wired through an AC circuit breaker, just like all the other electrical circuits. The inverter circuit breaker is typically located within the building’s main panel, allowing the inverter to be shut off when servicing is required. This also protects the circuit’s electrical wiring.

14. PV Production Monitoring.

This is typically an additional meter used to monitor how much energy the PV modules produce. This meter measures solar production and can be useful for production-based or per kWh incentives. This type of meter can be a web-based package to monitor data or a dedicated kWh meter directly measuring the kWh output.

15. Kilowatt Hour Meter.

Solar power systems that are tied to the grid will have AC electricity going back and forth to the grid. The utility company will generally provide a bidirectional kWh meter capable of tracking and measuring the electricity flow in both directions. These meters are typically provided at no cost.

16. Generator.

Used as a back-up power source for off-grid systems and batteryless grid-tied, generators provide power during cloudy days or power outages. Even though a solar power system may be sized to provide electricity even on cloudy days, the resulting system would be very large and very expensive.

The smarter choice is to size the solar power system more moderately and purchase a generator to provide power during the sunless stretches or a power outage. The generator can also help with charging batteries or supplementing power during high use periods.

Generators are typically fueled with petroleum diesel, bio-diesel, propane, or gasoline. They produce AC current, which a battery charger then converts to DC and stores in batteries. Generators do tend to be loud and dirty and require maintenance. However, a well-designed solar power system should only require generator assistance between 50 and 200 hours annually.


The structure of a power solar system is not all that complicated. Each part has a purpose and once the task each part performs is understood, the entire system begins to make sense. It could also be helpful to tour a solar power system in person to see how it operates.

The Right Tools

Anyone installing their own system will need to a wide variety of electrical and construction tools. The tool list for the simplest installation, a batteryless, grid-tied, roof-mounted system includes both cordless and AC drills with attachments, including hex bits, Phillips bits, drill bits, and hole saws; socket wrenches; a level; a hammer; a reciprocating saw; and open-end wrenches and screwdrivers.

Necessary electrician tools include cutters, wire strippers, and crimpers; a hole-punch kit; lineman and needle nose pliers; a fish tape; and a conduit bender. This list expands when the system to be installed is a battery-based one. This is because a battery box will need to be built, along with cutting and connecting large battery cables and lugs.

When the system is pole or ground-mounted, equipment for digging post holes or trenches will also be required. This includes a post-hole digger, shovels, or a power trencher and auger. Other tools that may be helpful include a digital multi-meter, which verifies polarity and voltage during installation and a torque wrench to tighten wire terminations.

Another handy tool is a DC clamp-on amp-meter, which is used for checking the output of individual array circuits or strings. Safety equipment may also be required, depending upon local laws.

As mention earlier, solar site analysis tools can be very helpful, both for analyzing site placement and design and for installation. Most available sites will have some type of shading, so shade analysis will probably be necessary.

Site placement and shading specifics can impact the types of components in a system, as well as the design and layout of the array. They may even impact available financial incentives. Too much shading can significantly reduce the system’s energy output, thus reducing the return on investment for purchasing the system.

Solar site analysis tools can determine a site’s shade factor. This can then be used to compare the solar window available on various array locations. For individual doing a one-time installation, the price of these tools may not make them worth the investment. There are applications for iPhone and Android smart phones, while not as accurate as the more complex systems, still offer individuals a tool to conduct a simple shade analysis.

If an individual does not already own a good set of tools for home improvement projects, the cost of acquiring the tools necessary to do a solar power system installation may offset the savings expected from installing it themselves.

Necessary Permits

It will be necessary to obtain certain permits before installing a solar power system and then, once the system is installed, it will have to pass inspection. Getting the system to this point can be a painful process, especially if this is an individual’s first time doing a solar power system installation.

Depending upon local requirements, an individual may need a zoning and a building permit before they can even get started. Then, once the system is completed, inspectors will go over it with a fine-tooth comb. They will charge a fee to perform their inspection, and if the system does not pass, they will charge another fee every time they come back out.

The inspectors will be looking for any violations of the NEC standards. This may include improperly sized conductors, improperly grounded or labeled equipment, lack of conductor protection, or even just sloppy work. Inspectors will usually give a closer look to a system installed by an individual as opposed to a system installed by a professional installer.

Potential Savings

Professional labor costs to install a solar power system are typically about 10% to 20% of the system’s overall cost. For a simple 3 kW batteryless, grid-tied, roof-mounted solar power system, the labor costs would average between $2,000 and $3,500. How much an individual could save by doing it themselves would depend upon the size, type, and mounting method of the system.

A battery-based solar power system is much more complicated and time-consuming to install than a batteryless grid-tied system. There are many extra components such as batteries, the battery box, battery cabling, battery metering, charge controllers, overcurrent protection, and extra disconnects.

Another factor impacting labor costs is array size. The size of the array dictates the number of modules required and how many mounts and inverters needed. This will impact the amount of time necessary to install the entire system.

How the array will be mounted will also determine labor costs. A ground-mounted system requires a great deal of work as compared to a roof-mounted system, including digging conduit trenches and footers, setting posts, and pouring concrete.

Another consideration is how a DIY solar power system will impact tax or rebate incentives. The system will still be eligible for the 30% federal tax credit (USA), but it may not qualify for some utility or state and local credits or rebates. It is possible for a self-installer to lose thousands of dollars in utility and/or state incentives.

Thoroughly research all tax and rebate incentives to see what the solar power system will qualify for. The Database of State Incentives for Renewables and Efficiency can be found at www.dsireusa.org. In order to earn all possible savings, it is important to capture all available incentives.

Safety First

When installing a solar power system, it is critically important to follow all safety precautions. Working with electricity can be a very dangerous occupation. Work should proceed methodically, slowly, and with caution, ensuring that all design and installation safety rules are followed.

To start, during the design of the system, safety must be a priority. The array’s hardware and fastening systems must be designed to securely attach the frame to the roof or the entire array could come crashing down during a severe windstorm.

All wiring and overcurrent protection devices must be the right specifications to prevent electrical fires. All conduits should be the right size for the system and have the correct number of conductors within. The method of installation must meet NEC standards. If the solar power system is building-mounted, there must be ground-fault protection. This is also a requirement for some ground and pole-mounted systems as well.

When there are batteries involved, there are additional safety issues to consider. Batteries represent large amounts of stored energy. They also require dealing with ventilating flammable hydrogen gas to avoid buildup, handling sulphuric acid and avoiding short-circuiting the batteries during maintenance or installation.

Once installation of the solar power system begins, OSHA safety considerations should be followed. These may be found at www.osha.gov/dep/greenjobs/solar.html. Since most solar power systems operate at very high DC voltages, electric shock hazards are present during their installation. It is important to take precautions to avoid injury.

One way to prevent electric shock injury is to have a wire management plan before starting installation. Closely inspect all array wiring for pinching between the mounting structure and the modules. This can damage wire insulation and lead to ground-faults. Ground-faults can cause arcing when the system is connected.

It is also important to wear personal protective equipment. This includes ear protection, eye protection, and respiratory protection. It is also very important to always wear high-voltage electrician’s gloves and glove protectors when working on live high-voltage DC circuits.

There are potential fall risks associated with working on roof-mounted systems, sometimes lethal risks. Even if an individual is comfortable working on a roof unassisted, they should wear fall protection equipment. This includes safety lines, harnesses, and proper anchoring systems. When working with ground-mounted systems, individuals will face safety hazards from trenchers and power augers.


Note: - All incentives discussed here relate to the USA. If you live in another country, you should ascertain what incentives your government offers, as they will be different.

Federal Incentives

The primary federal tax incentive is the investment tax credit or ITC. This tax credit was signed into law under the Energy Policy Act of 2005. The ITC covers solar power systems, fuel cells, and solar hot water systems. The tax credit is 30% of the qualified expenditure for the system up to $2,000. The credit was extended in 2008 to cover small wind systems.

The tax credit is extended to 2016 and may be applied against the alternative minimum tax for federal tax returns. The $2,000 cap was removed under the American Reinvestment and Recovery Act of 2009 for all solar power systems, small wind systems, and solar water systems placed into service after 2008. The tax credit covers system costs, including labor, components, and wiring.

A tax credit is applied directly against taxes owed. This is compared to a deduction, which is subtracted from income to determine how much tax is to be paid. Credits provide much higher tax savings than deductions. For a new solar power system, the tax credit date is when the individual takes occupancy. If the tax credit is more than the tax liability, excess may be carried over to the next year.

There are additional requirement for a solar water heating system to qualify for tax credits. At least 50% of the home’s water heating must be provided by the solar water heating system and the Solar Rating Certification Corporation, or a state-qualified comparable entity, certify all system equipment. The credit only applies to domestic water heating systems – solar heating systems for spas and pools do not qualify.

One important note is that no matter what the technology, to qualify for the credit, the home served by the solar power system does not have to be the individual’s primary residence. Additionally, any tax incentives, buy-downs, subsidies or other rebates provided by public utilities are not taxable. This includes modifications and installations such as solar power systems, solar water systems, and wind-electric systems. Houses, condominiums, apartments, boats, and mobile homes are all eligible.

It is always best to consult with a tax professional or CPA on tax credits and deductions. The calculation of the ITC can be complicated, so it is helpful to have the advice of a professional. After consideration it may be better to take advantage of Section 136 and not include the cash subsidy in income. This means reducing the basis of the Qualified Expenditure.

If, however a cash subsidy or rebate is included in income, then the Qualified Expenditure does not have to be reduced to determine the ITC. Instead, it is simply calculated as 30% of the Qualified Expenditure.

State, Local, and Utility Incentives

In addition to federal incentives, there are also state, county, city, and utility incentives available depending upon where the solar power system is located.

Lease or Lease-Purchase.

Some local utilities and municipalities offer low cost leasing programs for solar equipment. There are even local governments that will supply, install, and maintain a system for its residents. The government or municipality owns these systems and the individual typically pays an installation fee, as well as a monthly service fee.

Green Building.

Some counties and cities offer fee reductions or waivers on permits for solar power systems. They may also offer expedited permit processing.

Local Loan Programs.

Many local governments have partnered with lending institutions to provide low-cost loans to their residents for solar energy systems. Residents will typically agree to have an energy assessment conducted on their home in order to qualify for the loan.

Production Incentives:

The leader in implementing renewable energy is definitely Europe with its attractive incentives and forward-thinking policies. Many European countries are using feed-in-tariffs which are legislated tariffs requiring utilities to pay higher rate over a period of time, typically 15 to 25 years, for all electricity produced by renewable systems and fed into the grid.

Feed-in-tariffs are usually three to four times more than the normal retail electricity tariff, which means an individual who installs a solar energy system realizes a dramatic reduction in their system’s payback period. These types of tariff programs exist in Florida and are under consideration in Oregon and Vermont.

An individual can determine whether or not a feed-in-tariff will work for them by considering their energy consumption and the size of their solar energy system. If they are a low user of electricity, rarely using enough energy to reach peak tiers, they may be better off selling their power back to the grid.

However, if they are a heavy user and are tight on space, they may need to install a peak-shaving solar power system and then opt for a net-metering system so they can claim the rebate. They might want to confer with their financial advisor who could calculate the net-present-value ratio and determine which option is better.

Washington State has a feed-in-tariff program where the rate depends upon the number of customers who pay into the program and the overall energy produced by the participants. This approach serves two purposes. The first is that the green-pricing rate helps subsidize the feed-in-tariffs for those who want to invest in solar or green energy systems. The second is that the program allows taxpayers to choose to pay a slightly higher rate for renewable electricity.

Washington also has production incentives for businesses, individuals and local governments who generate electricity from solar power, anaerobic digesters, and wind power. The base rate of the incentive paid to producers begins at 15 cents per kWh and is then adjusted by a multiplier that is based on system type. Larger multipliers are used for systems built with equipment manufactured in Washington State.

Production incentives range from 12 cents to 54 cents per kWh depending upon the multiplier used. They are capped at $5,000 annually and the renewable-energy credits’ ownership remains with the customer who generates the energy. They are not transferred to the utility or the state.

Local Rebates.

Municipalities and local governments may also provide cash rebates to those individuals who install solar power systems. These local rebates are usually in addition to those available from the state or utility. There may also be additional rebates available for low-income residents.

Property Tax Exemption.

States offer exemptions or abatements on property tax to individuals who install solar power systems. Oregon, for example waives taxes on added value provided a property resulting from the installation of a qualified renewable energy system. These include solar power, solar water heating, or wind systems.

The added value of these systems may not be included in the property’s tax assessment and is exempt from additional property tax. Other states have also exempted renewable energy systems from additional property taxes, including California, Indiana, Kansas, Massachusetts, Michigan, Nevada, Rhode Island, Tennessee, and Texas.

State Loan Programs.

Several states offer programs providing low-interest loans to finance renewable energy systems for residences. In Oregon, for example, the Oregon Small-Scale Energy Loan Program pays for small, distributed generation projects such as roof-mounted solar power systems and residential solar water heating systems.

Oregon’s program will lend up to twenty million for a project, although the average loan is for less than $100,000. The loans are repaid over 5 to 15 years with varying interest rates. The Alternate Energy Revolving Loan Program in Iowa loans up to 50% of the cost of a renewable energy project with 0% interest up to 20 years.

State Rebate Programs.

Some states also offer cash rebates to individuals who install renewable energy systems. The leader in this effort is California, which offers several different rebate programs. The California Public Utilities Commission oversees the California Solar Initiative program providing more than $3 billion in solar-energy incentives.

In California, the original incentive program paid incentives only to people who received power from the state’s investor-owned utilities. That changed in 2006, when the program was expanded to cover municipality utilities and offered another $800 million in incentives. The program pays a one-time incentive for smaller projects, based on expected performance.

Larger projects are paid based on performance-based incentives which are calculated by the actual number of kWh the system generates. This incentive is paid monthly over a five-year period. Installations larger than 50 kWh must take this incentive and the rebate declines per a published schedule as a targeted production schedule is reached.

While most of these funded programs are solar power systems, the rebate also funds solar water heating systems, as well, except for pools and spas. California’s Center for Sustainable Energy manages this pilot program and it is limited to customers in San Diego. The maximum residential rebate amount is $1,500 and can be adjusted downward based on performance.

Sales Tax Exemption.

States also provide an exemption from sales tax for qualified renewable energy systems. For example, Colorado exempts all components in a renewable energy system used to produce electricity from its sales-and-use tax. Additionally, solar thermal systems components are also exempt. These exemptions only apply to state taxes, not to county or municipal taxes.

States can grant local authorities the ability to grant exemptions for renewable energy systems. States that have implemented state-tax relief for renewable energy systems include Arizona, Florida, Maryland, Massachusetts, Minnesota, New Jersey, Ohio, Vermont, Washington, and Wyoming.

Utility Rebates.

There are many utilities that offer rebates for renewable energy systems including solar power systems, solar heating systems and small wind systems. There are 27 utilities in California alone that offer rebates to help buy down a renewable energy system’s purchase price.

The rebate for solar power systems and small wind systems is typically determined by the system size and is measured in watts. For solar water heating systems, the rebate is calculated based on the square footage or the number of collectors.

The Earth Advantage Rebate Program in California provides rebates for solar power systems and solar water heating systems. Rebates are offered to those installing renewable energy systems in residences or businesses in Redding, CA. The rebates range from $2.60 to $3.55 per watt, depending upon azimuth, tilt, and if there is a tracker involved in the system. The rebate for solar water heating systems is 50% of the project cost, up to $2,000 for three collectors.

Utility Loan Programs.

There are local utilities that offer loans to individuals to finance the installation of renewable energy systems. These loans are typically funded through a partner finance institution or through the utility. In New Jersey, PSE&G, a utility company, offers customers loans at 6.5% interest for 40% to 60% of the system cost to install solar power systems.

PSE&G’s customers may then repay the loan through a combination of solar renewable energy credits and cash. One solar renewable energy credit equals one megawatt-hour of green electricity. The State of New Jersey trades these solar renewable energy credits, so their value varies. When the value increases, customers enjoy a higher return.


If they have a tax liability, then every individual is eligible for the federal renewable tax incentives. There are additional incentives that vary from state to state, or from municipality to municipality, and from utility to utility within a state. An individual must do their research in order to capture all available incentives.

More and more incentives are appearing almost daily. These provide individuals with good returns on their renewable energy investment. It is possible to get good prices on supplies and components, and this, coupled with these financial incentives, makes it a good time for individuals to install their own solar power systems.

Paying for the System

With all the financial incentives available, investment in a solar power system can be a very attractive option. This can be especially true considering cash rebates, property tax exemptions, tax credits, and increased property values. When all of these are factored in, many individuals decide it creates a very compelling picture and decide to make the investment.

Once the decision to install a solar power system is made, then an individual must decide how to pay for the system. A solar power system is a big-ticket item, generally costing about the same as a swimming pool or a new luxury car. Additionally, individuals normally pay for their electricity on a monthly basis, so paying upfront for their energy system can be something of a shock.

Most individuals do not have large sums of cash available to purchase the entire system in cash. When this is the case, there are options for paying for the system.

Charge Cards.

Charging the purchase cost of the solar power system will work providing an individual has a high enough limit on their credit card. The downside, of course is that the individual will be paying interest on that purchase unless they pay off the entire amount. Depending upon the interest rate, this can add up.

Cash Out.

Another idea is to cash out a certificate of deposit (DC), borrow against a 401k, or withdraw money from a money market account. This option works for those individuals who have a comfortable cash reserve and live where the investment in a solar power system provides a return on investment that exceeds what they were earning in their conventional accounts.

First Mortgage or Refinance.

The best way to pay for a solar power system is to add it into a home mortgage or refinance. The interest on these is tax deductible and the payments are stretched out over a longer period of time. A first mortgage is based on the entire value of the home, including the solar power system.

The loan is approved at a loan-to-value ratio and the loan repayment period is typically 15 to 40 years, with the average being 30 years. Interest rates on 30-year loans are currently at some of the lowest interest rates in years, making them a very good way to finance a solar power system.

Home Equity Line of Credit and Home Equity Loans.

These types of financing options are the way solar power systems are generally purchased. These loans are taken against a home’s equity or the amount a home is worth over the amount an individual owes on their mortgage.

Interest on a home equity line of credit or HELOC is charged only on the money actually borrowed. This means that even if a HELOC is approved for a higher amount, the individual only pays interest on the amount of money they actually use. There is no fixed time repayment period for the loan and the interest rate may vary.

Interest rates on HELOCs are higher than those on mortgages or refinance loans, but the interest may be tax deductible. There is also usually a fee to take out a HELOC and there may also be an annual maintenance fee as well.

A home equity loan and a home equity line of credit are similar, except a home equity loan is usually for a specific amount and must be paid back over a specific period of time. The interest rate is also usually set and does not vary. A home equity loan may include points and fees, both of which may be tax deductible, along with any interest.

Bank Secured or Unsecured Loans.

Some banks offer loans to finance the purchase of solar power systems. These loans may be either secured or unsecured. A secured loan is typically a home-equity based loan and interest paid may be tax-deductible. If the loan is unsecured, interest paid on this loan will not be tax-deductible.

Power Purchase Agreements (PPA).

This is an arrangement where an energy provider pays for, installs, operates, and owns a renewable energy system on an individual’s property with no capital investment required from the individual.

The installed system will generate clean and renewable energy during the term of the PPA and the individual will only be billed for the electrical output, usually per kWh and at a discounted price. The individual is buying the electricity from the PPA provider instead of the utility and paying for it monthly. The individual may have the option to purchase the system at some point during the PPA.

The PPA provider is assuming all of the operating risks and maintenance responsibilities for the system. Also, if the system is not generating electricity, the individual is not paying for electricity. PPA contracts typically run for 12 to 20 years, so these systems are generally very reliable and provide optimal energy production.

Vendor Financing.

There are some solar power system manufacturers who offer financing. This financing is typically provided through partner retail outlets and specialty banks. Repayment terms are usually spread out anywhere from 15 to 30 years. These repayment terms may offer lower monthly payments, making this an attractive financing option.

These loans can be adjustable, fixed, or a combination of both. It is also possible to get no payments for a year or six months, same as cash options. The interest rate offered will depend upon the individual’s credit score. Individuals interested in this option should ask their supplier about financing options.

Utility and State Loan Programs.

There are several utilities and states that offer loans to help individuals purchase and install solar power systems. Terms typically vary depending upon the nature and the size of the project.

Local Government Financing.

Some municipalities have instituted programs where individuals can borrow money from the local government to install a renewable energy system and then pay back the loan through an increase in their property taxes. If the individual moves out of the property before the payback period, the property tax assessment remains with the property.

Association Financing.

The Electric and Gas Industries Association (EGIA) provides financing to individuals for renewable energy systems. This is in partnership with its GEOSmart Sustainable Financing Solutions program and GE Money.

Energy-Efficient Mortgages.

Energy-efficient mortgages may be used to finance many different types of renewable energy systems, including solar power systems in a new or existing home. The Federal Housing Authority and the Veterans Affairs programs subsidize these loans. Rates and repayment terms are similar to conventional first mortgages.

Finding the Right Financing

With a variety of financing options available, an individual should do their research to ensure they select the one that best fits their situation. They should read the fine print so they clearly understand all the terms and how they will impact the individual’s financial situation.


By following these steps, an individual can successfully design, install, and operate their own solar power system. It is very important to follow all of the safety steps and a good idea to ask advice when there are any questions, especially when the subject is electricity.

A person can have a lot of fun, and achieve a great sense of accomplishment, by installing their own solar power system. These are two very good reasons for doing it, above and beyond the financial incentives and the energy savings.