DIY Solar for Those Wanting to Live off the Grid

Living off the grid is enticing. Decreased energy bills. Increased efficiency. Reduced carbon footprint. Simpler lifestyle. DIY solar power paves the way to this reality for you. While the initial cost of moving off the grid may be pricey, the component prices to make it happen are lower than ever before. Ongoing expenses are less with solar power and the boost to home resale with DIY solar rises. With modern technology and pricing, running your home on DIY solar is possible without noticing the difference between being on the grid or off-grid power.

Considerations

As a potential DIYer, there are several things to keep in mind. Doing this pre-work pays dividends in cost savings and headaches down the line.

  • Track your total power consumption and the power consumption of your appliances. This legwork assesses the reality of this move for you. Also, determining system requirements will require this data. Also, be aware of the time you run each appliance. Utility bills contain power consumption information. These facts determine system requirements and component specifications. Keep in mind that the less energy you consume, the less power you will need to generate. No math genius is required to see that this keeps system costs down.
  • Research the “peak sun hours” of your area. Peak sun hours is a measurement of the amount of sun an area receives. The National Renewable Energy Laboratory provides an excellent map for this purpose. Peak sun hours vary widely. For example, on the West coast, the number falls between six and seven hours while on the East coast, it is between four and five.
  • Check your homeowner’s association and county policies. These organizations may restrict placement and other considerations for reasons as simple as aesthetics. Knowing these restrictions before your DIY solar project saves costly changes and headaches.
  • Call your local government and ask about building permits required for the DIY solar project. While cities have waived the permit fee for installing renewable energy, it is important to check with authorities and obtain a license to avoid fines or to avoid tearing down an installation.
  • Contact an electrician. Even a DIYer needs sound advice. When you run into a snag, an electrician can assist. Plus, inspections for safety are required. The North Carolina State University’s DSIRE offers information on state and local regulations.
  • Research incentive programs. Beginning to explore financial assistance options from the start makes sound sense. This inquiry is especially valuable as some incentive programs maintain specific installation requirements. For example, incentive programs may not apply to do-it-yourself projects, only those completed by a professional. DSIRE provides this data as well.

The components

DIY solar consists of a photovoltaic (PV) system. The elements of this system include panels that convert sunlight into electricity, a charge controller, a set of batteries to store power and often, an inverter which turns the battery voltage into house current.

  • Panels

Solar panels or modules (PV panels) collect energy from the sun and convert it into direct current. Two kinds of solar modules exist: crystalline and thin-film.

Crystalline panels appear as big blue panels which we typically associate with solar power. This option is extremely efficient and durable and remains a popular choice. The drawback of crystalline panels comes with the installation. An elaborate racking system needs to support these modules. The lifespan of this option averages 40 years.

Thin-film comes as a roll of flexible material. This option is gaining popularity in the market due to ease of use. Convenience along with cost savings are the advantages of thin-film. However, this product proves less efficient in general but demonstrates greater efficiency in the dark. Thin-film can be expected to last around 25 years as it is less durable.

  • Mounting hardware

Solar module racking involves the hardware used to mount solar panels. Choices exist in this category as well when using crystalline panels. You can choose to install panels on the roof or ground. Consideration, in either case, must account for the size and weight of the panels. A 200-watt panel averages 60 inches by 40 inches by 1.5 inches and weighs about 40 pounds. Thin-film applies to a flat surface which does not require racking.

Roof mounts draw DIYers due to aesthetics, security and space conservation. The beauty and property of your yard are preserved. A vital consideration with this option involves actual strength and integrity of your roof. Heavy racking and panels require support. Another consideration is the shade that falls on the roof.  Avoiding shade increases solar efficiency. One module in the shade affects the efficiency of the entire system. Be sure to consider differing times of the day and the future as well. The greater the sun exposure throughout the day, the more power stored. Plus trees not blocking sunlight today, may be an issue within the next 40 years of panel life. Geographical location plays a factor as well. Panels pointing towards the equator (south, in the northern hemisphere) get the most direct sunlight and should be adjusted seasonally. And while these systems lower roof temperatures in hot climates, snow country brings inconvenience. Module placement angle should be adjusted seasonally for the best results.

Ground mounting necessitates having the land to sacrifice. Beyond space, soil and wind considerations exist. Racking placed on loose soil or located in windy sections of the yard runs the risk of falling over and worse, injuring those on the lawn. An advantage of ground mounting is that the panel can be secured on a pivoting pole. This option allows for greater sun exposure as the panel rotates to capture the moving sun. Expense causes concern, but the increased output of your system may allay such issues.

  • Charge controller

A charge controller ensures that the batteries receive electricity at a rate they can handle. This protection lengthens battery life. The traditional system matches a 12-volt solar panel, a 12-volt charge controller and a 12-volt battery. A newer and more efficient method strings a series of higher voltage panels, an MPPT controller and a 12-volt battery pack. Typically, these modules handle 100 volts or less, but at least 20 volts greater than the battery voltage. The MPPT controller reads and matches the most efficient performance of the panels to the batteries, allowing a 30 percent  power increase.

  • Batteries

Again, you have choices. A flooded lead acid battery and an AGM battery stand up to the challenge of providing DIY solar. With either option, deep cycle batteries, not starting batteries, provide the spark needed to power your system.

A flooded lead acid battery boasts vented caps, discharges hydrogen during charging, and requires venting. Rewatering fairly often maintains this type of battery. The cost of this marine or RV grade battery is less than an AGM unit.

The AGM battery brings a higher price but requires less maintenance. No venting is needed with this unit, and the battery is sealed which eliminates watering. The leaking of acid in the case of physical damage presents no concern.

Batteries come in 6-volts and 12-volts. Linking cells in a series adds voltage. Combining batteries in parallel adds amp hours.

  • Inverter

An inverter changes low voltage direct current (battery voltage) into 120-volts alternating current or house current. Be aware that inverters come in grid-tie (defined below) and off-grid versions. Also, checking the wattage rating to ensure capacity to handle your solar array proves prudent.

Another consideration involves a micro-inverter system. This system employs a small inverter for each panel instead of one inverter for all modules. The advantage of this scheme guards against the performance of one module affecting the entire system.

  • Disconnect

Fuses, breakers and disconnects connect solar energy to your house via the breaker box and allow the power to be shut off for work or in an emergency. PV Disconnect allows power to be cut off for working on the system. A valuable asset for avoiding electrocution. Fused disconnects are recommended between the solar panels and the charge controller, between the charge controller and the batteries, and between the batteries and the inverter. These safety features permit isolation of the components for maintenance or automatic disconnect in case of a short or equipment malfunction.

  • Battery monitor

The simplest though the least useful battery monitor is a volt meter. These units report the voltage of the battery pack. However, this reading tends to be highly affected by charging and discharging giving an inaccurate read.

An amp hour meter offers a more efficient method. This unit indicates amp hours deposited and amp hours withdrawn. Both standalone units like the Bogart Trimetric and integrated units like the Outback Flexnet DC exist.

  • Wire size

Wire size is a function of the amps being carried and the distance they need to move. Cables that are too small generate heat, possibly causing a fire. Also, dropping the voltage to less than useful levels presents itself with improper wire. If in doubt, confer with an electrician for advice. Though small in comparison to other components, wire size holds the cards of efficiency and safety.  Powerstream provides a calculator to assist in determining proper wire size.

Calculation helps

Calculations are critical to the pre-work and installation of DIY solar. For example, figuring the number of panels needed to achieve the solar power you desire requires math. Gathering your pre-installation data, the total monthly power consumption of your household divided by 30 gives you kilowatts used in a day. Divide this dividend by the daily peak sun hours in your area. This figure reveals the number of panels needed to match your usage. Sizing information and a chart showing sun hours for various areas can provide insight. Calculators for battery and solar sizing can be found on the Internet.

The math continues throughout the installation process. To brush up on your basic formulas, check out tutorials or consult professionals. Remember pride averts safety and efficiency. Seek help when needed.

Installation

From the above information, you may have a sense of how the installation will go. So just a quick overview. The racking with attached panels is mounted on the roof or in the yard. The panels connect in parallel unless an MPPT controller is used. Keeping array voltage below 100-volts is usually best. To link the modules, positive to positive and negative to negative are matched. The wires then run inside to the charge controller. Charge controller connects to the batteries. The batteries join to the inverter. Remember your fused disconnect between the panels and the charge controller, the charge controller and the batteries, and the batteries and the inverter.

Other options

  • A $4,000 do-it-yourself kit called the Solar Pod provides energy efficiency and convenience. This solution will not power your entire house, but will power some electronics and appliances. If you desire more power, additional kits can be added to your array.
  • Grid-tie presents an appealing option for those not ready to commit to off the grid. This solution boasts intriguing draws. Grid-tie means that your house remains connected to the utility company (“tied to the grid”) while utilizing solar power. The greatest advantage of staying on the grid is net metering. If your solar array enables you to collect excess power, this commodity can be sold back to the utility company. Utility companies pay substantial premiums to those who help produce green energy for the grid and reduce the strain on the utility company. Also, the network provides backup power as needed on cloudy days. A special meter which measures power going back to the grid is required. However, power companies often offer these meters free of charge.
  • Plugged Solar, based out of Houston, Texas, offers an innovative DIY solution. This company created a 1.7 kilowatt home solar panel kit which comes preconfigured and pre-wired. The necessary installation components, including racking, come in the package. The unit plugs directly into a standard 120-volt electrical wall socket and offers a grid-tie option.

The Plugged Solar kit comes with three racking options: roof mount, patio mount and ground mount. Just grab a ladder, measuring tape, drill and ratchet to build the racking and attach the solar panels. Connecting the solar panels ends, positive and negative, forms a circuit. The solar panel circuit is then linked to the inverter and the cord plugs into the grid-tie inverter. Finally, plug the unit into any standard, dedicated electrical outlet. The kilowatt generation displays on a wireless monitor.

  • Hire the work done. Although this may ache every bone in your DIY body, the goal needs to be kept in mind. Should you find the process overwhelming or parts of the installation beyond your current capabilities, be wise and look to the professionals. This option is a pricier and one humbling option. However, the goal is to install a safe, efficient solar power generator.

Cost

While solar energy claims greater affordability than ever before, the costs still add up. For an average 6 kilowatt system which fully powers an average household, crystalline panels would cost about $16,500 at approximately $660 each. Thin-film would set the homeowner back $20,768 at $472 each. Although the thin-film panels are more expensive, remember there is no need for racking. A micro-inverter for this system would cost about $3,999.00.

Battery chargers can run from $60 to $2500 with an integrated battery charger and transfer switch. Cheap inverters connect directly to an appliance while more expensive units connect directly to the breaker panel.

For partial power, $1000 to $3000 creates enough solar energy for a couple of lights, a radio and a small RV water pump up to some use of an LCD/LED TV or Laptop computer and a microwave. These costs compare to hiring a professional with a basic system starting around $35,000.

Kits such as Plugged Solar’s Plug-in Solar Kit generate energy savings of 30 percent on average home electricity costs with a payoff in less than six years. Calculating the 30 percent federal tax credit, the cost ranges from $800 to $3000.

The federal tax credit offers 30 percent savings on components of energy efficient systems. Many states, cities and utility companies provide additional grants, tax breaks, buyback programs and low-interest loans to offset costs of solar energy. DSIRE maintains an up-to-date list of these programs.

Supplementing off the grid power

Living off the grid requires more than installing your DIY solar array. For some, this one solution fails to power an entire household. Finances, logistics and lifestyle may limit your DIY power. Other solutions exist to supplement your newfound solar power and move you further off the grid. For example, propane is an alternate energy source. Though some would claim this move just puts you on another grid, the truth remains that this grid product can be stored and used as needed. Wood fired heat and cooking, wood and solar heated hot water, indoor or outdoor clothes drying lines, rainwater harvesting and a cistern, and composting toilets work to move you toward your dream of being off the grid. Check out Green-Trust for more ideas.

Sources:

Altenergymag

http://www.altenergymag.com/content.php?post_type=1650

DIY Home Solar: Planning a Solar Array (Beginner’s Guide)

http://www.instructables.com/id/DIY-Home-Solar-Planning-a-Solar-Array-Beginners/

Do it yourself solar for just $4,000

http://www.clarkhoward.com/do-it-yourself-solar-just-4000

Plug-In Solar Panel Kit That Is Truly DIY

http://cleantechnica.com/2014/03/14/plug-solar-panel-kit-truly-diy/