Graphis of Excess Energy to the Grid

How Solar PV Can Become the Primary Electrical Energy Source

In order to have this discussion, it is necessary to look at electrical energy consumption patterns. Our energy sources have to match the timing of our consumption. The graphs below show the typical daily electrical energy consumption patterns for residential and commercial consumers.

Time of Day End of Hour

 

Overall peak energy consumption is from 2:00 PM to 6:00 PM. Residential peak consumption is from 4:00 PM to 10:00 PM. Peak solar PV production is typically from 9:00 AM to 3:00 PM. The majority of the solar PV energy is being produced during non-peak consumption hours. If the solar PV system is sized to provide base-loads only, this addresses part of the issue. However, it changes the load demand on the utility grid and makes it difficult to maintain stability of the grid voltage and frequency. The chart below shows the changes to the load demand when solar is added to the grid during the peak solar hours of the day.

2012 represents very little solar generation. Each year shows the actual added solar generation effect and projected solar generation effect on total load demand.

It becomes increasingly difficult and expensive for the utility to meet this type of demand load variation. One solution is to face the PV array toward the afternoon sun. This would help with overall consumption patterns but not for residential consumption patterns. It doesn’t address the issue of cloudy days with little or no solar PV generation. This brings in energy storage as the best solution. The energy storage capacity needs to be large enough to absorb the excess solar PV energy produced during peak solar hours.

Overgeneration risk

Energy storage is the only real solution for solar PV to become a primary electrical energy generation source (EEGS). There are several types of energy storage: Batteries are the fastest growing type of energy storage with Lithium-ion being the leader of that group; the conversion efficiency is pretty high (80% to 90%). Pumped water storage has been used by utilities for this purpose in some sectors of the electrical grid; the energy conversion efficiency is a little lower (70% to 80%). Other forms of energy storage such as fuel cells and capacitors may develop further in the near future but they are not competitors at this time.

Battery storage is the most versatile means of energy storage and it is crossing the barrier of cost effectiveness for shifting loads to a different time of day. To effectively compete with the other EEGS, solar PV with energy storage must have a levelized cost of energy (LCOE) that is lower than the other sources. To calculate the LCOE, divide the total cost of energy by the energy generated during the life-cycle of the EEGS. Twenty-five years is the typical life cycle used for PV systems. The cost of energy includes initial cost and all operating costs during the period of analysis. The kilowatt hour of generation during the period of analysis must be de-rated for non-operational hours and the warranted degradation of the PV output.

Examples:

Residential:

8kW PV system with energy storage:       Net Cost: $3.30/W = $26,400

8kW x 5 sun-hours x .85 x 365 days x 25 years x 90% = 279,225 kWh

$26,400 ÷ 279,225 = .094/kWh

Commercial:

500kW PV system with energy storage:  Net Cost: $2.60/W = $1,300,000

500kW x 5 sun-hours x .85 x 365 days x 25 years x 90% = 17,451,562 kWh

$1,300,000 ÷ 17,451,562 = .0745/kWh

Utility:

20MW PV system with energy storage:  Net Cost: $2.00/W = $40,000,000

20,000kW x 5 sun-hours x .85 x 365 days x 25 years x 90% = 698,062,500 kWh

$40,000,000 ÷ 698,062,500 = .0573/kWh

The above examples show LCOE rates that are competitive in some markets but not in all. The installed cost of solar PV is continuing to drop and the energy storage industry continues to improve and reduce costs. As these trends continue into the very near future, solar PV with energy storage will meet and beat the LOCE of most of its competitors in all markets.

Kelly Provence
Certified Master PV Trainer
CEO, Solairgen School of Solar Technology

Power Conditioner Image

Failure Causes in Solar PV Systems

During the first 10 years in service, the chance of failure within a PV system is approximately 10%. Inverters and other electronic devices account for 85% of all those PV system failures. Only about 1 in 2000 modules will fail during their warranted 25-year life. The system components most likely to fail are the ones with complex electronic circuitry.  The graph below identifies this type of equipment as Power Conditioning; it includes monitoring equipment, inverters, PV optimizers & other DC to DC conversion devices. The causes of failure are from manufacturing defects, improper installation, operating stress and accidents. The first of these is out of the control of the installation and maintenance contractors and the last of these, accidents, is usually outside of their control; the second two, improper installation and operating stress, are not.

 

Failing Power Conditioning equipment will perform at a lower efficiency than warranted; failed equipment will stop performing its function. Failures due to improper installation and operating stress are both avoidable. Causes of these failures are: Inadequate wire terminations, undersized conductors, environmental conditions that are outside of the equipment rating, inadequate protection from surge voltage and inadequate protection from physical damage. Once the equipment is operational, an infrared camera can detect damage that is occurring from heat at the terminals and inside the equipment. Terminal temperatures should vary no more than 3°C from one to another under the same current load. The internal parts of the equipment should not exceed the max rated temperature listed by the manufacturer. If equipment is failing but still operating, the conversion efficiency can be measured by reading the (Volts x Amps) at the input and output of the equipment. The difference should be no less than the rated efficiency of the equipment. Test six months after installation and then annually thereafter.

Module failures get most of the attention since they don’t usually fail completely but continue to function at a lower output; the causes of failure are numerous. A module is considered failed when one of the following occurs: Breakage, delamination, burned solder joints, browning of a PV cell due to overheating, bad bypass diode or degradation in performance beyond the warrantied percentage. These are covered by the manufacturer’s warranty; depending on the failure mode, proof of failure can be verified with a standard photograph, infrared photograph or by inspection test with a calibrated meter such as an I-V curve tracer. A module is considered failing if it performs lower than other modules of comparable design and type. An IR camera may detect hot spots on PV cells that decrease performance –  an IV curve tracer can determine whether the module is operating below its warranted performance. Test with an IR camera annually, and with an I-V curve tracer for large commercial projects.

The most common long-term failures are: Hot spots due to manufacturing defects in the cells, hot cells caused by high current flow in a de-energized state, potential induced degradation (PID) caused by leakage currents to earth ground, low cell conversion rate due to cracks within the cell, delamination caused by extreme heat and humidity and current loss due to shorts (shunting) between cells where the module substrate is damaged by wind and dust or other natural causes. An I-V curve tracer and an IR camera can identify most of these problems. For residential and some commercial projects module level monitoring will identify problems; it is easy to compare each module performance to the others around it.

The other failure category shown in the graph is balance of system components (BOS). This is generally all the wiring, conduit, switchgear, junction boxes and module support structure. Failure is usually due to improper wire sizing or termination, galvanic corrosion with incompatible metals, materials installed in environments beyond their rating and improperly installed components. Prevention of failure includes testing conductor resistance before startup, capturing IR images at terminals when equipment is operating, measuring resistance to ground on all grounded metal parts and making a visual and torque inspection of all physical and electrical connections. Test six months after installation and then annually thereafter.

The most valuable tool for inspecting PV system performance is a module level monitoring system; most new residential and small commercial projects now have this level of monitoring. The next best tool is an IR camera; since there are now IR devices that connect to smart phones this is a very affordable option. The next best tool is an AC/DC volt-amp meter. You can take readings on the input and output of any equipment and determine the loss factor for that piece of equipment. If you are working on commercial systems, you will want a conductor resistance tester to measure the conductor insulation resistance to leakage currents at the maximum operating voltage. The I-V curve tracer is unnecessary for residential and small commercial projects. They are usually required for large commercial and utility scale projects.

Kelly Provence
Solairgen School of Solar Technology
IREC Certified Master PV Trainer
NABCEP Certified Professional Installer

PV-House-4

Calculating Voltage Drop in PV Systems

Voltage drop (VD) is the loss of voltage in a circuit due to the resistance in the electrical circuit. To determine the amount of voltage lost in a circuit, we need to look at three parts: 1. Resistance of the conductor in Ohms (Ω), 2. The length of the circuit conductor, 3. The current flowing through the conductor. A forth component is to compare the VD to the operating voltage in the circuit to see the percent of voltage drop.

  1. The resistance of the conductor per 1000’ (Ω/kFT) can be found in Table 8 and 9 of Chapter 9 in the National Electrical Code (NEC). Table 8 is for DC and Table 9 is for AC. Divide by 1000’ to get the resistance of the conductor per foot (Ω/FT).
  2. The length of the conductor is the full circuit length; for DC and single-phase AC circuits, multiply the one-way distance by 2. For three-phase AC circuits, multiply the one-way distance by the square root of 3 (1.732).
  3. The amount of current flowing in the circuit directly affects the amount of voltage drop in the circuit; e.g. 2 amps of current will double the voltage drop of the circuit with 1 amp of current. Current is represented as intensity of current (I) in the formula.
  4. To determine the VD%, the operating voltage must be used. The operating voltage is dependent on the equipment and how it is connected. The PV source circuit voltage may be the product of modules connected in series or it may be controlled by DC-DC conversion devices and an inverter. The AC operating voltage is simply the nominal utility voltage at the premises.

DC and single-phase AC formula:  VD  =  I  x  Conductor length  x  2  x  Ω/FT

 VD%  =  VD  ÷  Operating voltage

Example: A PV source circuit operating at 9a and 400v using a #12 conductor in a circuit with 50’ of length one-way. Table 8 shows a #12 (7 strand) to have 1.98 Ω/kFT; 1.98   (.00198Ω/FT)

9a  x  50’  x  2  x  .00198  =  1.782 volts dropped or lost in the circuit (VD)

1.782v  ÷  400v  =  .004455  or  .44%VD

If you double the length of the conductor or double the operating current, the voltage drop would also double.

NOTE: This calculation is accurate using current and voltage data either from the PV module Standard Test Condition (STC) or the Normal Operating Condition (NOC). NOC test conditions represent the irradiance and cell temperature during the six critical sun-hours of the day. Both current and voltage are lower than STC. Since they are both lower, the VD% is close to the same as if you used STC current and voltage instead.

The AC side of the calculation is the same as The DC example above, however it may not be as accurate since the inverter rating can be sized from 80% of the PV rating to 135% of the PV rating. This affects the average operating current and the amount of voltage drop. We typically use the inverter’s listed max operating current if the PV array is sized 125% to 135% of the inverter rating. If the inverter is rated the same as the inverter, use 80% of the listed inverter max operating current.

Example: An inverter rated 6000 watts, 240v and 25a is connected to a 7200 watt PV array. The inverter AC output is located 30’ from the AC interconnection point. The conductor used is #10 copper rated 35a with resistance shown in Table 9 of 1.2 Ω/kFT   (.0012Ω/FT)

25a  x  30’  x  2  x  .0012Ω/FT  =  1.8 VD  ÷  240v  =  .0075 or .75%VD

The combined VD% of the DC and AC circuit is .44%  +  .75%  =  1.19%

If the inverter and PV array are the same size, multiply 25a  x  80%  =  20a. This reduced the VD by the same proportion.

We usually consider more than 3% VD in the entire circuit (DC and AC) to be excessive. Increasing conductor size reduces the Ω/FT and reduces the voltage drop in the circuit. The voltage drop percent is a loss factor with energy production. The example above reduces the PV system production by 1.2%.

Three-phase AC formula:  VD  =  I  x  Conductor length  x  1.732  x  Ω/FT

 

Kelly Provence
Certified Master PV Trainer
Solairgen School of Solar Technology

Managing PV Wire

Solving the Problem of PV Array Wire (or Cable) Management

Wires covered with wireThis is the one part of installing a PV array that never seems to get easier although racking manufacturers are doing their best to help. There are three objectives to managing these PV cables: 1. Secure them in a manner that is code compliant.  2. Protect the cables from damage. 3. Minimize visibility or secure them attractively. The objective is to select a method that does all three with minimum effort and cost.

Let’s start with #1. The NEC states that USE-2 (PV wire/cable) must be secured within 12” of a junction box and then every 48” of length. While it is easy to achieve the 48” support requirement, it is not as easy to meet the 12” of a junction box requirement, especially from the PV module junction box. This requirement is often overlooked by inspectors if the cables appear to be well secured. The picture below shows how this 12” requirement is achieved and how it is not.

12 inch cable

Secured within 12” with cable clips

18 inch zipties

Secured 18” with zip-ties to rails

Another code requirement is the minimum bending radius of USE-2 and listed PV wire. USE-2 has a minimum radius of 5x the diameter of the cable; that is about the curve of a large cup. PV wire usually requires a radius of 8x the diameter of the wire; that is about the curve radius of a good hamburger.The problem with zip ties is with their strength and usage rating. The typical black zip tie may not have a sufficient rating for the lifetime of the PV module.

There is also an NEC requirement for the work to be in a “neat and workmanlike manner”. This gives the inspector a lot of leeway. Chances are good that if an electrical installation is sloppy, it also has some installation errors.

For ground mounted PV arrays, protecting PV conductors from unauthorized personnel is also required. This can be done with a fence, adequate height (8’ minimum) of the cables above ground or a type of screen fastened to the PV array modules. (see images on next page)

Wires covered with wire   Larger panel wire covered with wire

By protecting the cables from unauthorized access, they are also easier to secure.

Code compliance usually addresses #2 and #3 objectives. The best way to meet these objectives is to use the racking manufacturer’s wire management system and supplement it with some generic products like wire clips that attach to the module frame and UV rated zip ties. Pictured below are two manufacturer designed products and features for wire management.

SnapNRack photo

SnapNrack uses their open rail system for wire management.
The plastic clips secure the cables into the rail trough.

ironRidge photo

IronRidge provides cable management clips that are secured into the top rail.

It is always a good idea to use the most common PV module frame mounted cable clips as a supplemental wire management system. One wire management system is never fully adequate for the various conditions that occur on site.

When using zip ties to supplement the wire management system, consider the life of the plastic tie. It needs to be UV and hard-use rated.

UV photo

The primary problem with wire management comes from lack of planning. By simply visualizing how wire management is to be handled prior to starting the job will go a long way toward making it a simpler process instead of a source of aggravation.

 

Kelly Provence
Solairgen
www.solairgen.com

 

The Best Methods for Energy Efficient Solar Homes

Solairgen-Installation475x317Your home’s overall energy efficiency is not as exciting to think about as a solar PV system, but it is much more important in most cases. Solar PV systems are getting more affordable, but that doesn’t help much if the overall energy consumption is higher than it needs to be. An energy efficient home will require about half the PV system size as a home that is not energy efficient. There are several low cost improvements that can improve energy efficiency; there are also many improvements that require an investment but provide good return on the investment.

The division of energy consumption in a home looks similar to the following pie chart taken from the Energy Industry Administration report.

Pie Chart of Typical Energy Usage for
Legend for EE Pie Chart

Appliances, electronics and lighting make up 40% of the home’s energy consumption. The lowest cost improvement is changing the energy user’s behavior, e.g., turn off lights and appliances when not in use. Replacing old appliances with higher efficiency ones as they require replacement, such as LED bulbs in long-hour-use fixtures.

Water heating costs can be reduced by several methods; the lowest cost methods are listed first. Insulate the hot water pipes from the water heater to the point of reduced access to the pipe. Buy and install an insulated jacket for the water heater. If your water heater fails and needs replacing, replace it with a high efficiency one. There are models that use a heat pump as the primary source of heat generation with heat coils as backup. Another, but more expensive option is to install a gas tankless water heater.

Heating and cooling together account for about 40% of the home’s annual energy usage. The best savings for the investment is to simply seal all cracks from the exterior to the interior of the home. This would be at the foundation, around doors and windows, and fixtures and access-ways to the attic. The next best investment is to improve the quality of insulation in the attic. The best insulation improvement is to have spray-foam insulation installed in the rafters and vertical walls of the attic. If there is a basement, the walls should be spray-foam insulated as well. Replacing blown-in insulation with spray-foam insulation can reduce heating and cooling costs by up to 50%. That would reduce the home’s total energy consumption by 20%.

It takes some effort and some investment to make the home energy efficient but it will not be nearly as expensive as trying to offset that portion of inefficient energy usage with a solar PV system. A 2000ft² consumes about 1800kWh/month. With an investment in spray-foam insulation, water heating insulation and replacing old appliances with high efficiency ones, it is easy to reduce the home’s energy consumption by 30% to 40% and spend less than $6000. That is about ½ the cost of a PV system to offset the same amount of energy.

Reduce energy consumption first through energy efficiency and then look at offsetting the remainder with a PV system. You may even have some money leftover to include energy storage with the PV system.

 

Kelly Provence
Solairgen
www.solairgen.com

Solar Shingle

The Future of Solar PV Shingles

Solar shingles seem like the most logical application for the future of solar PV systems, serving two purposes – a roof and a solar PV system – by simply integrating the shingles into photovoltaic roofing. There are problems with the solar shingle system, slowing its mainstream marketability, but may work if the following obstacles can be overcome:

(1) The cost of solar shingles is not competitive with conventional solar electric PV modules. Costs might balance with high penetration into the photovoltaic industry, but that takes time.

(2) The physical constraints of solar electric roofing shingles do not allow for custom fitting to varying roof dimensions. This is an obstacle that is difficult and expensive to overcome.

(3) The solar roofing contractor’s training is limited to the narrow market of solar shingle manufacturers. The manufacturers will not train contractors in areas where sales are not profitable, so the solar shingle market restricts customers’ choices and is controlled exclusively by the manufacturer.

(4) Roof warranties can only be fulfilled by the solar roofing manufacturer and its own factory-trained solar roofers. Repairs may be delayed if there is not a trained contractor in the customer’s area. Roof damage not covered by the solar roofing manufacturer would be difficult or impossible to have repaired by conventional roofers who are not trained to work with solar shingles.

I would like to see this product succeed in the market, but no manufacturer has made a successful long-term run with residential solar roofing to date, and some who are attempting it have yet to make a profit in the photovoltaic industry.

Mainstream success of solar shingle roofing may happen, but it doesn’t appear to be coming in the near future.

 

Kelly Provence
NABCEP Certified Professional PV Installer
IREC Certified Master PV Trainer
Solairgen, Inc.
706-867-0678
info@solairgen.com

Image of a Poor Solar PV Installation

How to Prevent a Substandard Solar PV Installation

No one wants a poor PV system installation, but it happens from time to time. The good news is it’s 100% preventable but you should first understand the causes of a bad installation, and then learn how to prevent it. We tell you how.

Problem #1: The installer is unskilled and unknowledgeable about the correct installation process, but how do you determine that?

Solution: Screen the installer. Ask for references and evidence of their experience such as pictures, invoices, permits and inspection reports.  Ask how much training they received, and where they received it. You can even ask to see their graduation certificates. Inquire about industry certifications (NABCEP) and whether they have a contractor’s license.

If they can’t or won’t provide any of the above information, don’t contract with them no matter what they promise you. A reputable installer will be eager to provide their credentials.

Problem #2: A skilled and experienced installer wants to install a brand-new product that is not fully understood or tested in the industry. It is not uncommon in this industry for changes in PV products to outpace the contractor’s full understanding of them. Don’t be the guinea pig.

Solution: Insist on tried-and-true system components unless it’s just an improvement over a product that has been around a while. It’s best to see how those brand new products hold up during beta testing. Find out by going to the internet and doing some independent research. Don’t be afraid to tell your installer what you learned and that you prefer another product.

Problem #3: The contract price is too low for the contractor to make a profit. Incorrect bidding is common when a contractor is inexperienced, but underbidding occurs occasionally even for experienced installers.

Solution: It is best to find out the going price for the installation prior to accepting a bid. If you don’t know the going price, get more than one bid and then compare. Most companies will give you a generic bid without a problem.

Some Advice: If the installer you select has underbid the installation, it may save you money in the long run to offer a fair, renegotiated price. Some contractors are very honorable and will do the same good job even if they lose money, but some will not and that may cost you more down the road. And remember, a deal too good to be true is usually exactly that, untrue.

In summary, the real responsibility is on you, the customer. Take a day or two to learn about the PV products, the installation process and who the good contractors are. There are many organizations out there to help you. Here are a few links to get you started: American Solar Energy Society, Solar Energy Industries Association, NABCEP, IREC, and The Solar Foundation.

Finding skilled, experienced solar PV installers isn’t difficult, and eliminates the frustrating and very expensive future problems of a bad, or failed, solar PV installation.

Kelly Provence
IREC Certified Master Trainer
Solairgen School of Solar Technology

Lineman in Ice Conditions

Better Utility Customers

Understanding the Effort to Provide Energy Makes for a Better Utility Customer

One thought always present in my mind during power outages is the electrical utility linemen who are working long days, often in extreme weather conditions, to get the power back on. They possess a level of dedication and commitment that goes beyond the ordinary. When the lines go down the electrical workers step up and work heroically until everyone has power again. I for one salute them all for that effort.

I enjoy the fact that I have my own PV system power when the utility power fails, but then there is the daily chore of checking and maintaining the energy storage system and backup generator. I’m always relieved when the utility power returns. I know how time-consuming it can be to generate and maintain electrical power even for one home and business.

Those like me, who own grid-connected PV systems with energy storage, have a slightly different perspective about energy. The PV system with energy storage is a luxury that is rarely used because power outages are rare in most parts of the U.S. When the grid goes down for several days, the true time and commitment cost of energy becomes obvious, especially if cloud cover blocks the sun.

People with PV systems who live off-grid know the time and commitment required every day. The daily chores include a fair amount of attention to maintaining the energy source(s) such as their PV system, energy storage and/or backup generator.

Then there are those who own a fuel generator as a backup source of power. If the power is off for a week, they face the same problem as the person with the PV system with energy storage. The exception is that they do not have the high upfront cost; most of their cost comes from the fuel necessary to keep that generator running and it does get expensive in the long term.

People who own a PV system without energy storage have their own perspective; they produce their own energy but only when the grid is up and within the limits of the utility interconnection agreement. They have no independence regarding energy, but they do appreciate the demands of generating it. When the grid goes down, they are totally dependent on the utility personnel to bring power back online.

Finally, those who have no self-generation sources are basically in the same boat as those with an interactive PV system but generally have less understanding about the true time and commitment costs of energy generation.

People with their own backup energy systems often have a better understanding and appreciation for the true “costs” of energy. I fall into the category of those who own PV systems with energy storage and I also possess a fuel generator to back up the solar. I prefer not to run the generator for several reasons but I’m glad to have it when the power is out and cloud cover blocks the sun for several days.

I am in the solar energy industry, and a staunch solar energy advocate, but I have the highest respect for electrical utility companies and especially for the linemen who push themselves to their limits for us during power outages caused by the vast and uncontrollable power of nature.

Kelly Provence
Certified Master PV Trainer
SOLAIRGEN
School of Solar Training
ww.solairgen.com

The Solar PV Eclipse of 2017

Nat Geo Solar Eclipse Photo

How will the U.S. solar eclipse of August 21, 2017 be different from the eclipse that will occur in April of 2024? (Hint, this is not an astrophysics, geography or geometry question, but just to briefly answer these science categories, the path of the August 21, 2017 eclipse will be a slight northerly arc from Oregon to South Carolina and cover a swath about 80 miles wide; the 2024 eclipse path will be from Texas to Maine with a slight westerly arc, and cover a swath of about 70 miles wide.)

The difference between the two eclipses I’m referring to has to do with their effect on solar power PV (photovoltaic) systems. The effect of this year’s eclipse will be negligible mainly because the level of solar penetration – the amount of solar power being put into the electrical grid – is not that great.

However, the level of solar power connected to the grid will be significantly greater in 2024. If we had the same level of solar PV penetration now as we will have in 2024, the eclipse could create instability in the grid because of voltage collapse along its path. Interestingly, we will have a different type of solar generation system when the 2024 eclipse occurs. Energy storage with smart power monitors and utility controllable inverters will be the standard in 2024.

Fortunately, there will be no noticeable difference in the effects to grid stability. Without energy storage and smart inverters that continually communicate with the utility, the effects of the eclipse would definitely be felt when the next eclipse occurs in the U.S., but we will sail through it as we would hope to, with our solar-safe glasses, a lawn chair and no worries about its effects on solar electric systems.

Enjoy the experience

Kelly Provence
Solairgen School of Solar Training Technology
IREC Certified Master PV Trainer
NABCEP Certified Professional PV Installer

Residential Solar: Which is Best – Ownership or Community Solar?

Solar Farm in Florida

Residential Solar: Ownership or Community Solar

Which is best for you? It really depends on you, your house and your utility. Consider the factors involved in placing a system on your home:

1. Is there room on the roof or ground for the PV array? The average 2000ft² home uses about 60kWh to 80kWh per day. To offset half of that energy a PV array would need to be 8kW to 10kW, and it would occupy an area of 600ft² to 800ft² on the ground, or it would require a roof area of 800ft² to 1000ft² due to required margins and offsets.

2. Will the PV array be a visual detriment to the home? It is possible to have the array visible and attractive with proper selection of materials, but a Homeowners’ Association could be a problem if the array is visible from the street.

3. Will it be financially beneficial? The matter of cost and return on investment (ROI). The federal tax credit provides a 30% reduction on total system cost. If you cannot take this credit, the value is diminished. If you live in a location where other incentives are in place, be sure that you qualify for those incentives.

4. The last factor is your personal reasons for owning a system. Seeing the array on your property, and knowing you’re saving energy and money on your energy bill is an important factor. Backup power is also an important motivator for owning a system, but if power is rarely lost in your area, a fuel generator may be a better option.

Consider these factors that would make community solar a good option:

The alternative to owning a system outright may be Community Solar programs. These programs are not available in all locations but their availability is growing quickly. Community solar farms are usually owned by the utility company. The customer can buy power from this farm through a program offered by the utility.

1. If locating an array on your home or property is a problem due to space or curb appeal restrictions, this may be a good alternative. These systems are huge and usually located within a few miles from your home. If it is a true community solar farm, there will be an area where you and your family can visit to learn about its function and performance.

2. The performance of the PV system will be maximized regarding the solar resource and the financial return on investment by the utility. This will provide the lowest cost for solar electric generation passed on to the utility customer.

The future of residential solar will be a mix of individually owned PV systems with energy storage, and community solar farms. Both will enhance the viability of the grid and reduce costs of electricity during the lifespan of the PV system. You should be able to pick the one that best fits your lifestyle and goals.

Kelly Provence CEO

Solairgen