The Benefits of a Free Solar Site Evaluation

If you’re curious about getting a solar power system installed on your home or business, one of the first steps that you’ll want to take is to have a free solar site evaluation done. This will give you a good idea about the potential for a solar photovoltaic (PV) array at your location, as well as answer any of the questions you might have about the cost of solar and the generating capacity you can expect from your installation. Having a solar site evaluation done will help you to understand both the benefits of owning a solar array, as well as the costs involved with installation.

During a solar site evaluation, a qualified solar contractor will come to your home and assess a number of factors that will determine the optimal size of a solar array at your location, along with the potential capacity of that solar power system, so you can make an informed decision about getting started with residential solar power for your home or business.

One of the first things that the person doing the solar site evaluation will look at is the size and orientation of the building’s roof, because those two elements will set the design constraints for a roof-mounted solar array. While it may seem like common sense to use the south-facing portion of the roof for a solar panel system (in the northern hemisphere), that may not necessarily hold true for every location, as facing the solar panels to the west may actually yield more electricity during peak demand.

Another factor that can determine the size of a potential roof-mounted solar array is the available area on the section of the roof with the correct orientation. A south- or west-facing roof that has multiple penetrations in it, whether it’s for the heating or ventilation system, a plumbing vent stack, or electrical conduit, may limit the size of the potential array due to having to design a racking system that avoids these obstructions.

The pitch of the roof is another determining factor in a solar installation, as solar panels must be oriented the best angle to the sun in order to get the most power from the system. The tilt of the panels is generally set so that the maximum amount of solar energy is generated over the course of an entire year (which takes into account the changing angle of the sun during the year). Roofs with a relatively flat pitch may require additional racking components to install solar panels that are at a higher pitch to catch the most sun, and roofs with a steeper pitch may require racking that positions the panels at a lower pitch than the roof itself.

For both roof-mounted and pole-mounted solar arrays, another element that affects the site location is the amount of solar access to the site throughout the year. This may be limited by factors such as a nearby house that casts shade on potential solar array locations during certain parts of the year, or certain times of the day, or by large trees that will shade the panels and limit their generating capacity. Some of these solar access issues can be addressed, such as through trimming or removal of the trees that will cast shade on the system for long periods, and others, such as a nearby building, may simply need to be worked around, usually by siting the array in a location that won’t be affected by the shade.

During a solar site evaluation, a solar contractor will also inspect the condition of your roof to determine its structural and surface integrity to ensure that they aren’t installing a solar array over the top of a roof that may need repairs in the near future (which would require the removal of the solar panels and racking). They will also want to measure the location, size, and spacing of the rafters and beams of the roof, in order to calculate the optimal location for installing the solar panel racks and to work around any roof penetrations.

In addition to space for the solar panels themselves, the installation will also need to be designed with the wiring and inverter in mind, in order to locate the inverter as close as possible to the panels and to route the wiring in a way that is not only efficient, but that is as out of sight as possible, yet still accessible. For pole-mounted arrays, this may require trenching to bury the cabling, which has to take into consideration any existing subsurface infrastructure, such as the location of water lines, sewer lines or septic tank, natural gas and electric lines. Solar arrays that are tied to a battery bank (for off-grid locations) will need to be designed with the energy storage location in mind, to accommodate both the size of the battery bank and all of the necessary wiring to connect from the array to the battery room to the house itself.

Another factor in determining the location for installing a solar power system, is access to the property, as well as to the location where the solar array will be installed, in order for the solar contractor to be able to determine how to best deliver the panels and racking and other components.

The solar site evaluation should also involve a discussion with the homeowners about their average electrical use, including times of peak demand, and whether the potential solar power system could offset their entire electricity costs throughout the year (and perhaps generate an excess to be sold back to the grid) with their current appliances and lifestyle, or if it will just be used to lower their electric bill. For offgrid solar installations, energy storage will be a big part of the conversation, as without a grid connection, solar homes will need to include enough storage capacity to bridge the gap between peak production and peak demand, including factoring in cloudy, overcast, or snowy periods that can limit power production during certain times of the year.

After the solar site evaluation, you should have a much clearer idea about the potential for solar power at your home or business, and find out what your options are in terms of both generating capacity and the cost of the solar system, and can move forward with determining how to best finance your solar array.

[Originally published at Cost of Solar]

About the Author

lives in southwestern New Mexico and digs bicycles, simple living, organic gardening, sustainable lifestyle design, slacklining, bouldering, and permaculture. He loves good food, with fresh roasted chiles at the top of his list of favorites. Catch up with Derek on Twitter, RebelMouse, Google+, or at his natural parenting site, Natural Papa!
  • Excellent article but when it comes to financing your solar project, if you’re interested in the best return on your solar investment, steer clear of solar leases and PPAs.

    On the surface, getting a solar system on your roof from a solar leasing company for no money out of pocket might seem like a great deal, but here are the facts behind this type of rental financing. When you sign that solar lease contract you’ll be forfeiting the 30% federal tax credit which can typically be worth about $3,500 to $10,000. You’ll also be forfeiting any applicable cash rebate or other financial incentives.

    After collecting both the 30% federal tax credit and any cash rebate, the leasing company will also apply accelerated depreciation. Despite applying all of the financial incentives, on a $0 down 20 year solar lease, the leasing company will then charge you 20 years worth of leasing payments that many times will include up to a 2.9% annual payment escalator that will raise your monthly payment, every year for twenty years.

    The leasing companies will try to convince you that a solar system requires a lot of maintenance and expensive insurance and costly monitoring when nothing could be further from the truth. Modern grid tie solar system require little to no maintenance and the bulk of any repairs are covered by the manufacturer’s and installer’s warranties. Solar panels and many inverters come standard with a 25 year warranty. Insurance can be added through your homeowner’s insurance policy with little to no increase in your premium and many solar systems come standard with built in, web based monitoring.

    The bottom line with insurance, repairs and monitoring is that a leased solar system will typically cost you up to three times more than a purchased solar system, so it is actually you who will be paying for these services, not the leasing company. The leasing companies will try to convince you that these services are free but with a system cost that’s triple that of a purchase, these services are absolutely not free.

    The leasing companies will try to convince you that a purchased system requires a lot of upfront costs and that their rental financing is the only $0 down option in town, which again is not true. There are plenty of $0 down loans available that even offer tax deductible interest and require no upfront costs. Solar leases and PPAs do not offer tax deductible interest.

    What’s worse is that after paying 20 years worth of leasing payments that amount to triple the amount that you could have paid if you purchased your system instead, you won’t even own the solar system. It will still be the leasing company’s property. If you want to own it after paying your lease off, you will still need to buy it from the leasing company at fair market value. All this for only a 10 to 15% reduction in your electric bill. This is just the tip of the solar lease and PPA iceberg. For more information simply search the term solar lease disadvantages in any major search engine. There’s a lot you should consider before signing that airtight 20 year lease contract.

  • But, if you’d like a free estimate without the hassle of scheduling a site visit with a salesperson in your home, get an instant estimate at No email address or phone number required!