Introduction

This book is meant for the average house owner who wishes to install a solar electrical system himself or have one installed by somebody else.

This book will give the data and understanding of how a solar electrical system works and the relationship the varied parts have to one another. You'll have a smart idea of what your installer is doing and if he is doing a competent job, and you'll have the data to at least ask the right queries. One of your first tasks on deciding to install a solar electric system should be to find out what the building and electric codes are in your neighborhood. With the augmenting recognition of alternative home energy systems have come mass production and the standardization of parts. The designs of most systems are similar, with lots differences having to do with the dimensions of the system.

Parts and systems on the market today can sometimes pass local electric inspections so long as the elements are UL or CSA licensed. An experience of the system, it's elements, and how they function re one another will save you plenty of time, money and frustration. In the appendix there are diverse worksheets to help with the sizing of your system, and a glossary and other helpful info.

Solar Energy Living

Living alongside solar electrical power involves making a personal choice. You'll have to become more conscious of the energy you use and the way to preserve it.

Few solar electrical systems supply the bliss of unlimited power. We must employ our electricity in considerate and suitable ways. This isn't to assert that we should live in the dark or go without power tools and regular household gadgets.

Regardless of what sort of alternative energy system you install, it is always less expensive not to use energy at all. There are tons of paths to preserve energy and economize with small effort. One thing to begin with is to switch off appliances when they aren't being used. This applies to radios, TVs, PCs, and so on. Turn the lights out when they are not being used. Use what you want, but use as little excess power as possible. Today's world is chock-full of technological decisions. The challenge to you, as the owner of a solar electrical system is to select the acceptable technology.

Lighting is a major user of power in the home. DC fluorescent lights, rather than incandescent lights can save you up to two / a few of the price of lighting your place. If you like to use AC lighting, there are energy saving incandescent bulbs available. Dearer, they seem to be a lot better and will preserve power. AC fluorescent lighting is also a power saver. Your chiller will be one of the biggest users of energy in your home, on a continuing basis. Many of these appliances are available in propane or natural gas versions. A solar thermal hot water heating system can be awfully efficient and cost effective.

You may wish to run some loads like washing machines and massive power tools off your back-up generator, whilst charging your batteries at the same time. You need to doubtless do your energy budget a number of times to see what appliances you can eliminate or convert to different types of energy. In order for you, the potential owner of a solar electrical system, to get the maximum potency and benefits from your system, you have to 1st know how an independent electrical system works. When using alternative energy, batteries are generally wanted to store that energy so that it is available when you would like it, night or day - rain or shine. An exception to this is some micro hydro systems, where with the right situation, batteries won't be.

Another good thing about a battery bank is that it can be enlarged as your wishes change and grow. The power from the batteries can be delivered as 12- volt DC ( Direct Current ) or though the use of an inverter as 110-volt AC ( swapping Current ).

There's also the added benefit of no more power bills. You will feel empowered, instead of limited, knowing that you are responsible for your own power system and. You may be sure that you're going to not run out of power so long as you are mindful of your consumption. It's not not easy to be aware of your power wishes and use. If you plan in advance and size your system correctly, it becomes an easy matter of daily agenda to look at the meters on the wall to grasp the standing of your system at any given point. You have to learn how to be conscious of your electrical consumption and to get rid of waste, in order not to surpass the boundaries of your system. Green energy isn't a new concept, but it is an idea that is becoming more valuable and more likely for more folks all the time.

With the apparently consistent energy crises across the continent and around the planet, and the negative result on the environment that conventional sources of energy are having, there's certainly a thing to be declared for being at least partly energy self-sufficient.

Using Photovoltaic (PV) Cells To Generate Electricity

If you want reliable power in an area where you are not hooked up to the electric grid, a solar electric system can supply power for lights. Solar electrical kit are used around the globe in remote locations to power houses and full hamlets, reinforce cell telephone signals from remote mountain tops, pump millions of gallons of water a day, monitor air quality and plenty of other things.

Solar electrical systems also supply a wonderful alternative for people who are tied to the application grid, but are on the lookout for a back-up power system.

If you live more than quarter of a mile from the use grid, a solar electric system may be a particularly cost satisfactory way for you to have a constant supply of power, particularly when you account for the pricetag of power line extensions and monthly electrical bills.

Other alternatives are wind generators, a micro-hydro system, or a gas or diesel generator. In reality, if you are off the grid, you can most likely have a generator as a back up regardless of what kind of system you install.

If your place is off the grid - meaning that you are not hooked up to utility power - you have these choices:

     1.    Connect to the local electric company if possible.

     2.    Live without electricity.

     3.    Provide your own electricity.

With a little research and some considerate planning you shouldn't have any difficulty becoming energy self-sufficient in most circumstances. Remember that you do not need to commence with a huge system. You can start little, plan in advance and add on as required. A major advantage of photovoltaic ( PV ) systems is their relative ease of installation and maintenance.

After first consultations with the makers and / or your local provider, most smaller systems can be installed and maintained by non-experts. Most providers of PV systems are extremely well informed and useful, but having a basic awareness of your own will make you much more happy with the method in the long game. Most providers can also help you with the design segment of the system.

With any electric system, safety is a supreme consideration.

Installation and Maintenance

A major advantage of photovoltaic systems is their relative ease of installation and upkeep. After first consultations with the manufacturers and / or your local provider, most smaller systems can be installed and maintained by non-experts.

Most providers of PV systems have a tendency to be intensely informed and beneficial, but having a basic awareness of your own will make you much more happy with the method in the long game. Most providers can also help you with the design segment of the system.

With any electric system, safety is a supreme consideration. Ensure that you get any required building and electric allows needed and that your system is installed according to the topical countrywide and local electric codes.

Getting Started

If you are beginning to consider installing your own solar electrical system or are into the 1st planning stage, there are a few things to do and consider before you purchase elements and begin to install your system.

Remember the more planning you do and the more information you get in the beginning, the much more likely your experience will be a delightful one.

It's going to be less annoying and ultimately less costly. Here are many initial steps to take.

• Figure out how much power you will need. List all of the appliances you plan on using, both AC and DC, and how much power they consume on a daily and a weekly basis. Once you know your average daily/weekly power usage, use these figures to calculate your PV array size, battery bank size, and the size of your controller and inverter. There are charts and worksheets in the appendix to help you with this.
• Get information on local building/electrical codes regarding solar electric systems.
• Do a site analysis to determine where and how your array will be mounted. Figure where your battery bank and other components of your system will be located.
• Calculate the size, type and amount of wiring you will need.  If you plan to start with a small system and then add to it as your needs change or your budget allows, you may want to consider buying a larger controller and inverter so you can add more PV panels and batteries later. You may wish to make your battery bank enclosure large enough to accommodate more batteries in the future.

Planning ahead can save you cash, time and work in the future. If you go into your project with as much information as feasible, your disappointment level is sure to be minimized. You may find different costs and levels of service from one provider to the next.

Electricity Basics

One analogy that is sometimes used is the flow of water thru a pipe. The electrons would be comparable to drops of water in a pipe.

When you have enough electrons, with force behind them, this may be used to do helpful work.

Electric energy is measured in amperes, volts and watts. Voltage is the pressure of the electrons flowing thru the wire and is measured in volts.

Customarily , the bigger the voltage, the more pressure or force behind it. This is equivalent to water pressure or psi ( pounds per square in. ).

Amperage is the amount or rate of flow or current in the wire in a given period of time. This is measured in amperes or amps for short. This would compare to the gallons per second running out of the pipe.

This is their relationship to one another:

   Watts = Volts x Amps

   Volts = Watts / Amps

   Amps = Watts / Volts

Obviously, if you have values for two of these you can figure out the third.

-A kilowatt (kW) is 1000 watts.

-A megawatt is 1,000,000 watts.
 

A kilowatt-hour is 1000 watt hours. This is the unit used on your electrical bill. Example : 10 100watt light bulbs left on for 60 minutes will use one-kilowatt hour of electricity.

In power systems the total amount of energy consumed over a period is measured in either amp hours or watt-hours. An one-amp draw used for 4 hours would be four amp hours.

AC vs. DC

Alternating current (AC) is the sort of power the application company supplies to your house.

Solar panels produce direct current that may be stored in batteries or used to run direct current (DC) loads at once. In all power systems, electricity must be moved from one place to another. Transferring electricity is rarely a hundred percent efficient, due to resistance in the wire. In wire, the loss of electric power is an element of the resistance of the wire and the quantity of current.

High voltage AC power can be conducted over long distances with comparatively low transmission losses. When using DC power, the distance from your charging source ( solar panels ) to your battery bank becomes an element, as will the distance from your batteries to the diverse loads, due to high line loss.

Sizing Your System

The design stage is vital if you are to get the maximum for your cash and have a power system that meets your requirements. The target of the design stage is to develop the most cheap system that meets your power needs. The design stage will consider many factors including how much power you want and when you want it. The kind of power you intend to use is also critical.

You need to have as much info about your current position before you approach a PV provider. Insolation or daylight power is measured in equivalent full sun hours. A full sun hour is equivalent to the quantity of daylight striking the earth when the sun is explicitly overhead in a clear sky. Though the sun might be above the horizon for, say fourteen hours a day, you could be receiving only five or six equivalent full sun hours.

This is because of the fact the lower the sun is in the sky, the more atmospheres the light must pass thru. In the atmosphere reflect and absorb some of the light passing thru it, reducing the insulation.

When the sun is explicitly overhead it is passing thru the smallest amount of atmosphere. Almost all of the sun's energy is delivered between 9:00 am and three hundred pm, when the sun is highest in the sky. Shorter days, cloud cover, and the sun's position in the sky scale back the available energy in the winter months.

This diagram illustrates the trail of the sun over varying seasons. Your PV system provider or the weather bureau should have complete charts for the insulation of your area. When sizing your solar array, take the equivalent full sun hours figures and average them over a given time period. If your site is only to be used for part of the year,eg a holiday cabin, average only for the months you'll need power. This is when your energy wishes will be rising and your insulation values will be declining. Some accommodations, for example a bigger battery bank and a generator, must be made per winter months. Big amounts of electricity can be put into the battery bank comparatively quickly with a gas or diesel generator. When figuring the loads you're going to be running, AC loads and DC loads must be figured separately.

Wattage's can often be found on a tag on the rear of the appliance or in the owner's manual.

Components

While system components can vary considerably from one installation to another due to size, location, needs, etc., most systems will contain many of these same basic components.

• Solar PV panels or modules - generate 12V DC electricity from sunlight.
• Batteries - store your electricity for future use.
• Controller - regulates the power to and from your batteries.
• Inverter - transforms low voltage DC power to high voltage AC power.
• Monitors, Gauges, Meters, etc. - keep you aware of the status of your system and the individual components.
• Wiring - Connects the various components of the system to each other and to the loads.
• Fuses, Breakers, Switches, and Disconnects - designed for overload and short circuit protection.  They allows you to isolate parts of your system for safety and maintenance.
• Battery Charger - This allows you to charge you batteries from auxiliary sources.
• Backup Generator - provides power to your system and charges your batteries when necessary if your solar panels are unable to generate enough electricity.

Electricity-Generating Solar Panels

Sunlight can be turned into electricity by Photovoltaic, or PV cells.  Photovoltaic principles are not the same as solar thermal principles. Solar thermal elements convert the sun's energy to supply hot liquids or air. When daylight falls on a PV cell, electrons are proud and move thru the silicon. They find the attached electric circuit the best way to move from one side of the cell to the other. This is called the photovoltaic effect, and ends up in direct current ( DC ) electricity being produced.

PV cells are wired together to form panels and these panels are in turn wired together to form arrays. The dimensions of the solar array, together with your location determines the quantity of electricity produced. Solar panels have a life expectancy of 20-30 years, depending on their strategy of construction.

They don't have any moving parts and are virtually upkeep free. All they need is to be cleaned off once in awhile. PV modules produce electricity in proportion to the quantity of daylight falling on them. This makes it imperative to mount your panels where there's minimum or, better yet, no shading. PV panels, when hooked together in an array can be wired in series, in parallel or both. When wired in series, the negative terminal of one panel is wired to the positive terminal of another panel.

This increases the voltage, but has no effect on the amperage.

2 12-volt / 3.5amp panels, wired in series, would produce twenty-four volts at 3.5 amps. In a similar way , 4 12-volt / 3.5 amp panels wired this way would produce 48 volts at 3.5 amps.

When wired in parallel, the terminals are wired together positive to positive and negative to negative. Wiring this way would have no effect on the voltage but would increase the amperage.

Panels may also be wired together to extend the voltage and the amperage. The output of your solar array is conditional on light power and the quantity of exposure to the sun, not on how hot it is. On a cold, bright winter day your panels perform just and in summer.

Batteries

Batteries are the heart of your solar electrical system.

They are where your power is stored - your reservoir.

A battery storage bank is what permits your power system to supply a consistent level of power to your electric loads. Without batteries you would have no power when the sun went down and perhaps not even enough during sunlight hours, depending on cloud cover, for example. Even with many days in a row of rough weather, your battery bank can continue to store power thru the method of a back-up generator. Almost all of your solar electrical system wishes very little upkeep.

Upkeep isn't troublesome or extraordinarily time consuming, but if the batteries are neglected, degradation can happen at a particularly quick pace.

Deep Cycle vs. Shallow Cycle

How much a battery is discharged is named the depth of discharge.

A shallow cycle is when the top 20% or less of the battery is discharged and recharged. Batteries in your automobile or van are designed for this kind of cycling. These kinds of batteries shouldn't be employed in your solar electrical system. Due to the sort of use they are getting they wouldn't last particularly long. They aren't made for consistent deep discharging and recharging.

A deep cycle is when up to eighty percent of the battery capacity is discharged and recharged. Deep cycle batteries are what you need for your house solar electrical system. The depth of cycling has a bunch to do with how long your batteries last. As the depth of cycle increases, the battery life is employed up quicker. For max battery life it's best to shallow cycle your deep cycle batteries.

Sizing Your Battery Bank

In order to determine the number of batteries to have in your battery pack, you will need to consider the following issues:

• Your electricity usage.
• Period that batteries may go without charging due to bad weather or other factors.
• The minimum level of charge you can accept before recharging.
• The temperatures at which batteries will be stored.
• The capacity of your charging system.
• Your budget.
   

In general, the more batteries in your bank the better, as you will have more reserve power available and the level of discharge will be lower. Just as in your auto, the less your batteries have to work, the longer they'll last. For the best overall performance in time, select the biggest, best quality battery bank that you are able to afford.

Battery Installation and Wiring

Batteries can be wired in series to extend voltage or in parallel to extend capacity,. 2 6-volt batteries are wired together in series to make a 12-volt battery.

These 12-volt battery strings can then be wired together in parallel to form more reserve capacity. This has the results of turning 2 6-volt batteries into one 12-volt battery. If you were to wire 4 6-volt batteries together this way, you would have a 24-volt battery. In parallel wiring, the positive terminal on one battery is hooked up to the positive terminal on another battery and the negative terminal is connected to the negative terminal.

If you took 2 12-volt battery strings with a capacity of 220 amp / hours each and wired them together in parallel, you would have one 12-volt battery with a capacity of 440 amp / hours.

Battery Connections

Connections from battery to battery and from the batteries to the systems elements and the loads are urgent. Always follow the maker's suggestions per wire or wire size. If unsure, go to the following bigger sized wire. The battery terminals should be clean and greased, and the fasteners should be tight.

Higher resistance on one string of batteries ends up in less charge to that string and thus shorter battery life. When wiring strings of batteries together, it's best to put the main positive lead and the main negative lead on opposite corners of the battery bank. ( The "main positive lead" and the "main negative lead" refer to the leads that go to your appliances or loads. ) This is to keep the variation of resistance from one cell to another little.

Affects of Temperature

Batteries should be kept where they are warm (10 - 25 degrees C.) and dry. Temperature will determine the speed of the chemical reaction in a lead-acid battery. The colder the temperature, the slower the reaction and the longer it will take the battery to charge. Conversely, the warmer the temperature, the faster the reaction and the more quickly the battery will charge.

Think of how your car battery doesn't want to crank over as fast on a cold winter morning. A warmer battery turns over much better. It is the same with your deep cycle batteries.

Extreme cold or extreme heat can seriously damage batteries. If batteries are to be stored where it is colder than recommended battery capacity must be increased to make up for the subsequent de-rating.

Gassing

When flooded batteries are charged they give off hydrogen and oxygen gasses. These gasses can be explosive and corrosive to objects they come in contact with. When charging batteries confirm they are well vented to the outside, and that there's no open flames or sparks present.

The chemical reaction that happens when gassing consumes water. Check water levels intermittently and replace as required with distilled water only.

Enclosures

Batteries should be installed in a warm, dry place ( 10- twenty-five degrees C. ). If the temperature is noticeably lower or higher battery performance and longevity will suffer. Batteries produce a possibly explosive mix of hydrogen and oxygen gasses. Because of this, it's important to vent the battery area to the outside.

Because hydrogen is lighter than air it tends to rise.

Thus , if venting is placed in the pinnacle of the battery enclosure and air is brought in from the bottom, the gas will move up and out.

Enclosures for most home battery banks are custom built, though some pre-built enclosures are available. One idea is to build your enclosure outside, tight against an exterior wall of your building.

Warm air may also be vented from the building, into the battery enclosure, to help keep the batteries at the correct temperature. However, with a hint of thought and planning it should not be too hard to come up with a solution that fits your circumstance.

Aging

As batteries age, their serviceable capacity steadily decreases till finally they do not want to carry a charge at all.

The call of when to replace the batteries after they have started their decline will rely on how long they are holding their charge and the significance of their performance.

Some of the signs that batteries may need replacing are:

• Rapid voltage rise when charging - the charger shuts down early.
• Rapid voltage drop under light loads.
• Specific gravity between cells varies by 50 points or more.
• Cell to cell voltage variations of 0.05 - 0.1 volts.
• Increased water consumption.

Maintenance

If your battery bank desires replacing it is recommended that all the batteries get replaced, not just a few of them.

If you wire together new - full capacity batteries with ones that are reduced, your bank will be out of alignment and the weak batteries will draw down the powerful ones.

Some important things to remember:

• Keep batteries above a 50% state of charge to extend battery life.
• Maintain proper electrolyte level. 
• Fill batteries with distilled water only.
• Protect batteries from excessive overcharge and from complete discharge.
• Periodically clean and re-tighen battery terminals and all connections

Capacity

Battery capacity is a first concern in home solar electronic hardware. The storage bank must have enough storage capacity to deliver your power wishes between charging cycles.

A minimum storage capacity in your battery bank should be about double of what you would use, in the way of power, in a standard or average day. Deep cycle batteries are normally measured in "amp / hour" capacity. An amp / hour is one amp of current drawn for one hour of time.

Deep-Cycle Batteries

Deep cycle batteries are built to have a giant amount of the stored power discharged between charging cycles. RV / Sea batteries are customarily 12-volt and are available up to capacities of one hundred amp / hours. They are tiny, simple to handle and comparatively cheap. They are typically employed in little home power applications or cartable power applications, for example RV's, boats, for example.

Golfing cart batteries are sometimes in the 220-amp / hour range and up. They'll customarily be 6-volt batteries, so 2 of them would be connected in series to make one 12-volt battery. They are sometimes less expensive, per amp / hour than RV type batteries. These are fantastic batteries both price smart and performance smart for little to medium sized home power systems.

They are available in a wide selection of capacities, up to three thousand amp / hours. These batteries have the longest life span of all deep cycle batteries. This makes them hard to move and they must be put on a well-supported area.

Business batteries are wonderful for bigger home power installations.

Charge Controllers

When your batteries are totally charged, the controller stops the flow of current or slows it to a slow drip. Connecting your solar array to your batteries without a controller seriously risks hurting your batteries and probably causing safety issues.

Charge controllers are rated and sized according to the systems they protect and to the quantity of current flowing from your solar array. Amperage ratings range between one amp to over one hundred amps.

For safety reasons it's best to oversize your controller by at least 25%. For instance, if your 12-volt system has 4 solar panels rated at 4.0 amps each, total output would be sixteen amps. Adding 25%, you would need at least a 20- amp controller.

Apart from shielding your batteries from over charging, there are some other features that may be included in your controller:

Other than protecting your batteries from over charging, there are several other features that can be included in your controller:

• Reverse Current Leakage Protection to prevent current from flowing backward from your batteries.
• Low Voltage Disconnect - reduces damage to your batteries by avoiding deep discharges.
• System Monitoring - can include meters, indicating lights and/or warning alarms.
• Temperature Compensation - adjusts the charging voltage according to the temperature.

Always Use Proper Sized Wiring and Connectors.

Invertors

An inverter is a central component of any alternative power system that requires AC power. Inverters transform low voltage 12-volt DC power to standard 120 / 240 volt AC power (also referred to as 110 / 220 volt) used to power most modern appliances and tools.

In an inverter, DC (direct current) is switched back and forth to produce AC (alternating current). This is then transformed, filtered, stepped, etc. to get it to an acceptable waveform. The more processing, the cleaner and quieter the output, but the efficiency of the conversion is reduced. The goal is to produce a waveform that is acceptable to most loads but does not lose too much power in the conversion process.

Types

An altered sine wave is close but not matching to the waveform that comes from your public use. Also, some appliances like radios and florescent bulbs may give off a conspicuous humming or humming noise.

Changed sine wave inverters are relatively cheap and have a particularly efficient DC to AC conversion ratio.

One is the successive output rating and the other is the surge capacity rating. The successive output rating is how much power, in watts, the inverter can supply steadily, hour after hour. Use 2 or 3 times more power when they start up than is necessary when they're up and running. Inverters can deliver noticeably more power for two or three seconds, when these loads start up. Inverters come in various sizes, from tiny ones that plug into your auto's fag lighter and have a single outlet, all the way up to 11,000-watt inverters which will power your complete house. The dimensions of inverter you want is reliant on the loads you need to power.

Permit for no less than a 15% inefficiency factor. ( Multiply your total AC wattage by 1.15 ) this may be the minimum successive wattage you'll need. To be on the safe side, it is always better to have an inverter that could be a bit bigger than your forecasted wishes. Remember the limitations of the inverter are basically charging system limitations. All the power your inverter delivers comes from your batteries through the charging system. A big enough inverter will convert any amount of DC power to AC power. You may often run any size AC load with an inverter. Just remember the DC power that is being used must get replaced thru your charging system. There are some loads that are just not terribly efficient to run on AC power in a solar electrical system. Most inverters are 120 volts AC, but 240-volt AC inverters are available should you want to run loads that.

In some cases you may also "stack" 2 similar 120-volt inverters together to provide 240 volts. Lots of today's bigger inverters come with built-in battery chargers. This is simply and economically accomplished due to the design of most inverters. Inverters change DC power to AC power and step up the voltage.

Battery chargers do the opposite of this ; that is, they change AC power to DC power and step down the voltage. A little added circuitry is all that is wanted to add a complete 2nd function to your inverter. There also are other features available when you buy an inverter. It is urgent to use the correct sized wires and wiring when installing an inverter. Using smaller conductors than needed is hazardous and will not permit the inverter to perform to its full rating.