We often have clients tell us that they are interested in having a ground mount installed on their property. Most often it’s because of a fear of roof leaks, concerns about the structural integrity of their roof, too small of a roof to fit enough solar panels, or it could just be as simple as them “having that nice little space over in the corner of their property” that they’re not using for anything else. Whatever the reason, if its doable we’ll make it happen because 180 Solar Power is one of the premier solar ground mount installers in southern California! However, its not always doable, and/or its not always economically feasible because there are usually higher costs associated with installing a ground mount as opposed to a roof mounted system. So let’s talk about the pros and cons, and ins and outs of solar ground mounts to help you become better informed.
The best place to start when talking about ground mounts is feasibility, and feasibility is often limited by building codes. Every jurisdiction (city or county) in southern California has building codes that dictate how far a solar array must be setback from the property lines that surround the property. The codes vary by jurisdiction, and the setback requirements are usually different for the front, back and sides of the property. However, they usually range from 5 to 25 feet on each side. Additionally, there is usually a code that dictates how far from a home or business’ structural foundation the array must be setback. Because many of the properties in southern California are set on smaller land parcels, it disqualifies a good number of projects where there is not enough space to fit a ground mount after all of the setbacks are taken into consideration.
If a property is large enough to fit a solar array the next considerations are soil conditions, land contours (angle and pitch), shading obstructions, trenching distances, septic leach fields, etcetera; many of which can not only affect mechanical feasibility, but also potentially the economic feasibility of installing a ground mount. But before we get into any of that, a basic explanation should be given about how a ground mount structure is designed, erected, and secured in place, which is also regulated by building codes.
One of the first design elements that’s guided by these codes relates to wind shear, which is the amount of uplift that the wind causes on a solar array. Wind shear has a big impact on the design and construction of a ground mount structure, which is usually anchored on a two or three inch galvanized pipe frame. The higher the array is tilted off the ground the more of a sail-like affect the wind will have on the array. Therefore, the intent of the code is to make sure that the array is anchored well enough to withstand the strongest of winds, which is usually designated to be no less than 100 mph. To accomplish this, the code specifies what the depth of the post holes must be before the posts are set to depth and the holes are filled with concrete (piers). This varies based on conditions, but in general piers must be at least 12 inches in diameter, and 48 inches deep. It is also typical that piers cannot be spaced more than 7 to 9 feet apart, so it would not be unusual to have anywhere from 8 to 16 piers, or more, on a residential installation, and possibly scores or even hundreds of them on a commercial installation, depending on how large the array is. In addition to that, to get the electricity from the solar array to the property’s electric panel the conduit and wires that run from the array to the electric panel also have to be trenched and buried at a minimum depth of 18 inches. Depending on the site plan it can be a significant amount of excavation, which in turn could have a big impact on the cost of the project. Additionally, soil conditions can come into play. Excavation costs that may be reasonable for a standard clay-based soil, could soar beyond reason on a foundation that is set largely on granite or some other rocky substrate. That is not to say that it would be “mechanically” impossible to install it over a rocky substrate, but the cost could be so much higher that it could make it “economically” unfeasible to do so.
Another important code that could impact a ground mount’s feasibility is whether a property is on sewer or septic. If a property is on septic, neither the array nor the conduit can run over or through the septic system’s leach field, which sometimes disqualifies properties that would otherwise be good candidates for a ground mount.
As far as a property’s contours are concerned, we often encounter property owners who propose that an array be mounted on an excessively steep slope, or facing in a direction that would be detrimental to the power production of the solar system. If a site is excessively steep it may not be feasible because of codes relating to erosion prevention, and even if it is not subject to any such code, there could be higher costs incurred due to the added difficulty and time that may be associated with the project. Furthermore, if the only viable location on the property is on a hill that faces steeply to the north, for example, the reduced energy output of the array could render the project unfeasible because of the extraordinarily low power output and the potentially negative impact on the project’s return on investment (ROI).
Lastly, as with any solar system, shading obstructions need to be taken into consideration. If there is a tree shading the location, and it is on the property owner’s land, it’s shade can be mitigated by trimming or removing the tree. However, if the tree shade is coming from a tree located on a neighbor’s property one would need to get permission from the other property owner to trim or remove the tree. And if the shade is coming from an unalterable, unmovable object such as a neighboring building, or other structure, that too could simply render the project unfeasible.
There are other things to take into consideration that could also affect the cost of a ground mount, such as the distance from the array to the electric panel; because the longer that distance is, the more trenching that will be required, as well as possibly needing heavier gauge wire and larger conduit to counter act voltage drop. But regardless of whether or not that is the case, you can expect that the overall price of a ground mount will be higher than a roof mounted system because of the additional costs incurred for the excavation, concrete, structural materials, and labor associated with installing a ground mount.
For property owners who are interested in ground mounts because of their fear of roof leaks, it may not be an unfounded concern, depending on which solar company is hired to do the work. There is no denying that there have been horror stories about leaky roofs caused by shady fly-by-night contractors….who were also probably the lowest priced bid on the job. However, price and quality rarely go hand in hand, and most often the lowest priced product will end up having the highest cost of ownership, which could come in many forms including in the form of a leaky roof. On the other hand, if you hire an experienced licensed contractor with a strong reputation and documentable track record, like 180 Solar Power, roof leaks are not something a property owner should worry about. Having installed thousands and thousands of solar systems over the years, the 180 Solar Power team has developed well establish installation protocols to prevent roof leaks. That combined with the specialized sealants, flashings, and mounting brackets that we use allows us to offer comprehensive warranties that protect property owners against roof leaks. That is one of the reasons why the choice of which contractor to hire should be the most critical part of a property owners decision making process, and not the rock bottom lowest price.
If the concern is that a property’s roof has a more fragile lightweight or clay tile, there are installation methods and work-arounds for that, so it shouldn’t necessarily be a deterrent. For standard weight tile roofs, a property owner can expect that a handful of tiles will get cracked or broken in the installation process, but any reputable contractor will replace all cracked or broken tiles just like we do at 180 Solar Power. If the property’s roof tiles are older and are no longer being manufactured, they can still usually be sourced from businesses that specialize in selling older used tiles.
For property owners that have concern about their roof’s integrity, or its ability to support the weight of an entire solar system, it too may be a valid concern. In that case, the following things are important to know and could help make that determination. First of all, if your roof is nearing the end of its life, it should definitely be addressed. It makes no sense to install a solar system, which should have an operating life of 30 to 40 years, over a roof that will need to be replaced in the next few years. This is common sense for most property owners, but they still face the challenge of trying to figure out how to pay for the cost of a new roof. The good news is that there are many lenders that will finance a solar/roof project with zero money down, and the combined payment for the solar and roof together is often less than what the property owner is currently spending each month on their electricity bills alone. Furthermore, if in the course of installing a solar system you are going to spend thousands of extra dollars for either a new roof, or for a ground mount structure, many people find that it make more sense to get the duel benefit of investing it in a new roof rather than sinking it into a ground mount structure that still leaves you with an unaddressed roof condition. So, don’t let the fact that you need a roof replacement be a deterrent.
As far as overall weight concerns go, most solar systems will add less than 3 pounds per square foot to the roof, which is less than the maximum allowable under most circumstances. However, there are strict codes that dictate how much weight can be added to a roof by a solar system depending on the roof’s structure. Furthermore, every solar permit application must be submitted with detailed roof load calculations to show that the solar system’s weight will not exceed the capacity of the roof, and in some circumstances full engineering reports must even be submitted. Your solar contractor should be able to perform all of these calculations and manage the entire permitting process for you.
It is also worth mentioning that there are no reputable contractors that would not conduct a thorough, detailed, in-person site survey of your property as the first step of the process. Contractors that try to induce property owners to sign contracts without ever setting foot on their property are an invitation to disaster for the property owner and should be a warning to run the other way.
The goal of this article was to help bring some clarity and offer some education regarding the installation of ground mounted solar systems. As was stated in the opening paragraph, 180 Solar Power is one of the premier solar ground mount installers in southern California, we love doing them, and if a project if feasible we’ll make it happen. However, I also wanted to inform property owners that some of the reasons that they might fear installing a solar system on their roof may not be entirely valid. Also, keep in mind that this article can only offer general guidelines regarding the installation of ground mounted solar systems because every property and project is unique. Therefore, nothing in the article should be construed as a definitive assessment of your personal project. Before that can be done, a complete in-person assessment would need to be conducted by one of our technicians.
At the end of the day, whether it is installed on the ground or on the roof, solar and storage is a far better solution than continuing to pay ever increasing electricity rates to your utility company, year after year, without end. If you have more detailed questions, or would like to schedule some time with one of our licensed technicians to review a ground mount or any other type of solar and storage system for your property, call 760-264-4012 or email us at firstname.lastname@example.org. 180 Solar Power is Local, Trusted, Proven!
In this article we will discuss some of the key elements of battery storage systems for homes and businesses. It will provide you with a solid knowledge base to help you understand the basics of battery storage, to empower you to ask the right questions of the electrical contractors that you are interviewing, and to help you end up with a system that meets your specific needs, taking into consideration your budget.
After witnessing how rapidly and completely COVID-19 ravaged our society, and how ill prepared everyone was for it, it got me thinking about how generally unprepared we are for the inevitable disasters we have seen and been warned about year after year. And when one thinks about disaster preparedness for their home or business, the obvious starting point is to make sure you have a secure independent power supply.
Without electricity to power our refrigerators and freezers, our food and medical supplies will quickly perish. Communication and security devices will fail to operate. Fuel and potable drinking water will not be able to be produced and distributed on a mass basis, if at all. Businesses will lose billions of dollars’ worth of data, and their operations will be paralyzed. Everyone will literally be left in the dark. And the inevitability of catastrophic grid failures is a certainty.
Planned rolling blackouts caused by excessive load demand in the summer are already annual events, as utility companies struggle to meet peak demand. Utility companies also blackout entire regions during fire season when high winds threaten to blow down aging power lines which in turn could cause massive wildfires. But even beyond that we have repeatedly seen and been warned about bigger and longer lasting grid failures caused by earthquakes, volcanic eruptions, meteor impacts, EMPs (electromagnetic pulses), cyber-attacks, and the list goes on. Recent history proves this to be true in places like Puerto Rico where Hurricane Maria decimated the electric grid leaving most of the island without electric power for over a year, and even as recently as yesterday when tornados ripped through southern states leaving over 1,000,000 people without electric power, and with no idea when they will have their power restored. The only way to protect yourself from this same vulnerability is to have independent emergency battery backup power for your home and business; to be independent of the utility company’s electric grid. So let’s discuss battery storage, and answer some of the basic questions that many people have.
While some battery storage systems can be charged via the grid, this article is going to assume that your storage system is paired with a solar system for infinite charging capability in the event of a grid failure. Otherwise, when the grid goes down you will no longer be able to recharge your batteries, rendering the entire system useless.
With that said, the first thing to know about battery storage is that all batteries store electricity as low voltage DC electricity (the same as the low voltage DC electricity that your solar panels produce), but your home and business (“property”) runs on higher voltage AC electricity, so inverters are used to convert the electricity from DC to AC, and in some cases from AC back to DC, as explained in more detail below. Second, it is important to know that inverters fall into one of two general categories: string or micro. String inverters use a single inverter to convert all of your system’s electricity from DC to AC in one central location, whereas micro inverters convert electricity in multiple locations so you are not subject to the risk of being dependent on just one inverter, thereby providing a modicum of redundancy as added security. Additionally, micro inverter-based systems commonly offer more flexibility and have greater output capabilities, so in general they have a higher entry point in terms of price. As with everything, there are pros and cons for string and micro inverters. But regardless which you decide on, they are both proven technologies, and they both offer high levels of efficacy, so either one could be a good solution for you depending on your personal requirements. In Addition, some storage systems are bundled as “all-in-one” solutions, which means that all the critical component come packaged in one consolidated unit that includes inverters, transfer switches, charge controllers, etc. While others are constructed on a piecemeal basis with the various components of the system, manufactured by different companies, having to be put together by the installing electrical contractor on site. There is no right are wrong when it comes to these choices. Deciding which is right for you will depend on your budget and your performance requirements, and your electrical contractor should be able to provide you with unbiased information to help determine which solution is best for you.
The next item to be aware of is the difference between AC coupling and DC coupling. DC coupled storage systems tie into your property’s electrical system between your solar panels and your inverter, so the DC electricity from your solar panels can be stored directly in your batteries without having to be converter by an inverter. Thereafter, the DC electricity can be fed from the batteries into your inverter and converted into AC electricity that can be delivered for use in your property’s electrical system. AC coupled storage systems ties into your property’s electrical system between the AC side of the inverter and your property’s electric panel. Because of the location of the tie in, the stored electricity ultimately needs to be converted 3 times before it can be delivered for use in your property’s electric panel. Initially your solar system’s electricity is converted from DC to AC by your solar system’s inverter, it is then converted back to DC to be stored on the batteries, and lastly it needs to be converted back to AC one more time before it can be used in your property’s electrical system. Therefore, a DC coupled system could have a higher efficiency, however, it will also be more exposed to the risk of a catastrophic system wide failure that could come with the use of a single string inverter. If you are starting from scratch with a brand new solar and storage system, AC or DC coupling will be equally easy to install. However, if you are adding storage to an existing solar system it could be more efficient to install an AC coupled system, so you don’t have the added cost of replacing your existing solar inverter. Again, there are pros and cons and budgetary considerations for both, but regardless of whether you end up with an AC or DC coupled system, installing solar and storage will provide incredible financial savings and disaster preparedness for your property.
Power Versus Capacity
This is a largely misunderstood consideration for most property owners because it is usually inadequately explained to them by the person or company that is trying to sell a storage system to them. Capacity is the total maximum amount of electricity that can be stored on your batteries at any one time, and its measured in kWh (kilowatt hours). Power is a measurement of how much electricity can be delivered from your batteries to your property’s electrical system for use in real time, which is measured in KW, or kVA (kilowatts). To use an analogy, Capacity is like the gas tank on your car, which is measured by how many total gallons it will hold. Power is how much of your car’s fuel you can convert to horsepower in real time. So you can have a car that holds hundreds of gallons of fuel in its tank, but if you can only access enough of that fuel to generate 20 horsepower at any given time, it’s not going to do you much good. Most consumers only look at, or are only shown, a system’s Capacity. And as just stated above, all the Capacity in the world will do you little good if it can’t be delivered when you need it, and in the quantity that you need it delivered in. This is not to say that total storage Capacity is not important. However, Power should be equally, if not even more importantly considered, as that is the greatest limitation of most storage systems. Furthermore, storage systems are rated for Continuous Power Output, which is its maximum steady state output capability, as well as for Peak Power Output which is slightly higher, but will generally be limited to about 5 seconds to cover electrical surges that are caused by large appliances when they initially start up. You should know the Capacity and Power (continuous and peak) ratings of the storage systems you are considering, so when you need that emergency power you won’t have any unpleasant surprises.
Load Shifting, Emergency Backup or Off-Grid
Another important consideration for property owners is what they want their battery storage system to be able to do. In the old days before there were concerns about peak demand on the electric grid, rolling blackouts, Time Of Use billing, or catastrophic grid failures resulting from natural or man-made catastrophes, solar and storage was rarely considered other than in situations where a property was beyond the reach of the utility grid (thus, “off-grid”). However, all of that has changed. Now in addition to providing off-grid power to those who live beyond the reach of the utility grid, storage systems may have the ability to Load Shift, and to provide emergency backup power to grid tied properties. Load Shifting is when solar or grid electricity from a grid tied property is stored on the batteries during the day, and then discharged in the evening when utility rates are at their highest (Peak rates), thereby maximizing the return on your investment. Emergency Backup occurs when electricity that is stored on your batteries automatically discharges to your property in the event of a grid failure. Having solar and storage transforms your emergency backup system into a renewable energy source that can recharge itself every day, indefinitely, for as long as a grid failure exists. And whereas an off-grid system is generally designed to power an entire property, an emergency backup system can and often is designed just to cover a grid tied property’s critical loads (ie: refrigerators, freezers, communication and security devices, data system, and any other loads that you couldn’t live or exist without), thereby reducing the capital outlay required to install a storage system.
Today’s modern storage systems are all UL tested, and are extremely safe. However, various storage systems use different chemistries in their batteries, with some providing an even higher level of safety than others. In instances where electrical contractors or manufacturers make claims regarding the stability and safety of their chemistry, they should be able to provide independent laboratory testing to support those claims. Furthermore, a battery’s chemistry may also limit the storage system’s depth-of-discharge (how much of the battery’s stored electricity you can actually discharge without damaging the batteries), and the life span of the battery, which is measured in both years and “cycles” (how many times a battery can be discharged and recharged). This is something that needs to be closely examined because two different systems that both guarantee a 10 year life and 3,000 cycles can provide vastly different amounts of power over their life depending on their depth-of-discharge, Capacity, and continuous Power capabilities.
How Much Storage Do You Need?
No two properties are the same, and no two property owners’ needs and goals are the same. Just like when designing a solar system, every storage system should be custom designed to a property’s specific needs and characteristics. Therefore, make sure that you are working with an experienced licensed electrical contractor who can not only answer all of your questions, but more importantly, one that knows all the right questions to ask you, and one that can perform proper load calculations depending on your overall goals and which loads you want to back-up. There are few storage systems that are easily expandable, so in most instances you’ve only got one shot to get it right.
Financing and Government Incentives
Lastly, it is important to mention that there are financing options available for almost every property owner regardless of their credit history, many of which require little or no money down. Additionally, there are still huge state and federal incentive that could pay for up to half of the cost of your system, but like all good things they will be coming to an end in the near future. Our licensed technicians can provide you with detailed information on both.
I hope this information helps to make you a smarter consumer as you evaluate solar and storage for your home or business. If you would like more detailed information about your specific project, we would welcome the opportunity to personally answer all your questions and provide you with a free quote. We install solar and storage systems as a package, as well as retrofitting new storage systems to pre-existing solar systems. We can even design and install a standalone grid-tied storage system without solar if your only goal is load shifting. Like I said before, every system is custom designed to the specific property’s goals, characteristics, and budget.
180 Solar Power is a premier provider of battery storage and solar systems throughout Southern California. The 180 Solar Power team brings the experience of over 30 years, and thousands of installations to every job we undertake. 180 Solar Power installs and services residential, commercial, non-profit, and government solar and battery storage systems for projects up to one megawatt. Contact us for a quote on a custom designed system for your project today; no cost, no obligation, no pressure.
Peter Stern is the president of 180 Solar Power. He’s a pioneer in the solar industry in Southern California, having overseen the installation of thousands of renewable energy projects for more than a decade.