FAQs

FREQUENTLY ASKED QUESTIONS ABOUT SOLAR ENERGY

Commercial and Nonprofit Solar

How will my building roof be impacted by solar photovoltaic (PV)?

A rooftop PV should not harm the roof if installed correctly. The business owners’ main concerns about commercial rooftop PV systems usually include the possible impact PV may have on roof integrity, building permitting, roof warranties, and business operations, however, all of these risks can be eliminated or mitigated, as outlined below. All rooftop PV systems should be designed and installed by reputable solar companies. Although national certifications are not required for PV designers and installers, many installers are certified by the North American Board of Certified Energy Practitioners (NABCEP).
How are PV systems attached to the roof?

For commercial building roofs, there are two leading mounting techniques for PV systems: 1- Ballasted Racking which uses heavy weights, usually concrete blocks, to secure PV systems on a flat roof. These ballasted systems require detailed engineering reports and evaluations to ensure that the wind loading and dead loading issues of the system have been properly addressed. 2- Attached Racking that uses roof penetrating hardware to mount PV systems on any type of roof. There are many types of attached racking systems for different applications. The number of required roof penetrations will depend on the roof structure, PV system design, and local building codes.
How do commercial rooftop PV systems impact roof drainage, or maintenance of other rooftop systems?

The PV system will not impact other rooftop systems and drainage. A quality PV company will assess existing rooftop equipment and roof drainage routes and will design the system to make sure it does not influence drainage, and access is available to all systems on the roof for proper maintenance.
Will a rooftop PV system increase the possibility of damage to the roof from wind/snow loads?

No. Solar companies should design PV systems to meet local building codes for wind and/or snow loads. For this purpose, PV installers carry out a roof assessment to evaluate the roof’s structural integrity before installation. The requirements for determining structural loads on buildings and other structures are given in the standard ASCE 7 – Minimum Design Loads for Buildings and Other Structures, which has been adopted into the building codes. Moreover, the designs must be signed and approved by a licensed engineer before installation and must also receive approval from the local building inspection authority.
How will rooftop PV impede firefighters’ ability to extinguish a fire or increase the risk of fire?

Reputable PV companies must design PV systems following new requirements in the 2015 International Fire Code (IFC 605.11) that require clear space at the edges and peaks of roofs for firefighter access. Most PV installers will also share the PV system designs with the local fire department to approve the design.
Who is responsible for the warranty, and code compliance of my roof?

The solar company will be in charge of designing and installing the PV system according to relevant building codes. Normally, a reputable solar installer will contact the original roof manufacturer to ensure that the PV system installation does not void the roof manufacturer’s maintenance and warranty requirements. Also, after the PV system is installed, the roof manufacturer will inspect the system to confirm that the system meets the approved design and that the roof warranty remains intact. If any damage is done to the roof during installation, it will be covered by the solar installer’s warranty. Dependable solar installers provide a suitable workmanship warranty before installing a rooftop solar system.
What happens if I need to replace my roof?

The solar installer will perform a roof assessment and find out if the roof will need to be replaced during the life of the PV system. Typically, if the roof will need to be replaced, building owners are encouraged to replace it before installing the PV system to benefit from the Federal Solar Tax Credit for Roof Replacement. However, PV companies include the temporary removal of the PV system for roof replacement after PV installation in their agreement.

Dual-Use Solar

Will solar modules contaminate the soil underneath or around them?

Silicon-based PV cells are the most widespread solar photovoltaic technology used. Most solar panels have a glass front that protects the PV cell and an aluminum or steel frame. Research shows that “leaching of trace metals from modules is unlikely to present a significant risk due to the sealed nature of the installed cells.”

Some solar modules use cadmium telluride (CdTe). Cadmium compounds are toxic, but studies show that such compounds cannot be emitted from CdTe modules during normal operation or even during fires. Industrial incineration temperatures, which are much higher than grassfires, are required to release the compounds from the modules.
Can solar modules change the microclimate underneath the modules and worsen invasive species, fungi, nematode, or other pest problems?

There have been relatively few studies on microclimate effects under solar modules, but current research results show there is little to no average impact. Air temperatures tend to be cooler under the panels during the day and warmer under the panels at night. One study found that air temperature, humidity, and crop temperature under modules were similar to conditions of full sun. This study found that soil temperatures at night under the modules were less than that of soil temperatures in full sun all day. There have been no studies linking solar development with pest problems, but studies have shown how native plants can thrive underneath solar installations.
Will solar modules heat up and dry out vegetation or crops under the modules?

Solar modules will cool crops and vegetation underneath during the day due to shading and keep them warmer at night. Studies have shown that these temperature differences cancel out and that means daily crop temperatures were similar under modules compared to full sun crops and there was no impact on crop growth rates. Modules can provide farmers the ability to grow shade-tolerant crops and to diversify crop selection, while also extending growing seasons and reducing water requirements. One study found that shading from solar modules produced lettuce crop weight equal to or greater than lettuce grown in full sun.
Can wild animals like antelope or elk graze under solar modules?

Yes, however, if desired, a security fence can keep out larger animals if they are deemed to be a damage risk to the modules. Fencing can be built to accommodate smaller animals such as kit foxes. Areas beneath the modules can be reseeded to provide habitat and forage to pollinators, birds, and other small species.
Can domesticated animals like sheep or cattle graze at ground-mounted solar facilities?

Sheep are commonly used for grazing for vegetation control at solar facilities in the United States and Europe as sheep do not climb on or harm the modules. Raising the PV modules in height is not necessary to accommodate grazing as vegetation is accessible beneath the modules at standard heights. Cattle grazing is generally not compatible with PV facilities due to the risk of damage to modules. Sheep grazing to control vegetation growth can benefit local shepherds, solar operators, and the land due to a reduction in mowing, herbicide, and other vegetation management needs.
Can you grow native vegetation or pollinator habitat underneath solar modules?

Yes, solar installations can support native vegetation and pollinator habitat species. Low-height plants can thrive underneath solar panels, avoiding the need for mowing and keeping the panels unshaded. Two states (MN and MD) have developed pollinator-friendly solar certifications to promote the planting of pollinator habitats underneath utility-scale solar projects. Pollinator habitats can benefit local farms and can also host beekeeping operations.
Will solar modules drive up the price of food?

There has not been any documented evidence of solar modules increasing food prices. Solar projects planted with pollinator habitats can help increase local agricultural yields through increased pollination and other beneficial insect services. Two states (MN and MD) have already developed pollinator-friendly solar certifications to promote the planting of pollinator habitats that can benefit local farms.

Is it safe to spray agrochemicals near solar modules?

Herbicide is currently sprayed around some solar modules to prevent weed growth. Agrochemicals should not present an issue. Care should be taken to not spray modules themselves, but if it occurs the modules can be washed off with water as they are made of glass and steel or aluminum and have been designed to withstand outdoor conditions.
Can solar modules power my irrigation equipment?

Yes, solar can power irrigation equipment. Solar can offset the power required for pumping and provide power to remote irrigation systems, requiring no grid connection. Solar irrigation pumps are currently in use in Africa, South America, and India.
I lease my farmland. Can I still install solar PV?

Depending on the current land use of the lessee, solar may or may not be allowed on the site. If current farming operations are suitable for solar or unused land exists, solar may be suitable.
I can't drive my tractor through or around solar modules. Are there ways I can still install solar?

Solar systems can be installed on marginal or salt-degraded land or at the margins of fields where no farming occurs. If there is a desire to grow crops underneath and in between solar modules, smaller tractors or hand management are options. There is no one-size-fits-all solar design and developers should account for land and farming needs in the design process.
I need to burn my fields every year. Can I still install solar PV?

You should not burn crops underneath or around solar installations; this could lead to electrical fires and damaged equipment. However, solar can still be installed at the farming site where no burning needs to occur. This need should be communicated to the solar developer upfront during the site selection process.
My farmland floods in the spring. Can I still install solar PV?

Solar can be installed in flood plains, but all electrical equipment will have to be installed above the projected level of flooding. Raising equipment could increase the cost of installation and may negatively impact the project's economics. Also, the cost of insurance will be higher for PV systems in a flooding area. An area that will not be flooded may be better suited for PV installation.
What are the impacts of dust on the performance of solar PV modules?

Various levels of power generation loss due to soiling should be incorporated into PV system generation estimates. NREL’s PV Watts soiling calculator uses an average soiling loss of 2%, but these losses are highly dependent on local weather and soiling conditions. Having vegetation underneath and around solar panels can reduce the levels of dust and soil on panels.
Can my land be converted back to agricultural land after the life of the solar system?

Land can be reverted to agricultural uses at the end of the operational life for solar installations. A life of a solar installation is roughly 20-25 years and can provide a recovery period, increasing the value of that land for agriculture in the future. Giving soil rest can also maintain soil quality and contribute to the biodiversity of agricultural land. Planting crops such as legumes underneath the solar installation can increase nutrient levels in the soil.
Are there trade-offs of raising solar modules to accommodate crop production?

Raising the height of PV modules can increase the cost of the solar installation. Due to the increased wind loading on higher structures, the length of steel foundational posts underground would likely need to be increased to accommodate the additional structural loading.

In addition, solar can provide several benefits to agricultural land managers that may offset the capital costs of installing solar:

Solar can be installed with zero upfront capital cost through leasing.
Solar can be installed on marginal agricultural lands and provide a different source of revenue for the farm. This different revenue stream can offset the operating expenses of the farm and provide economic resiliency in poor growing years.
Solar does not need to be installed on current or projected growing areas.
Co-location of solar and crop installations can be designed to optimize for both electricity and food production.
Shade under the solar modules can allow for planting high-value, shade-tolerant, and hand-harvested crops that may not normally be available in markets (i.e. lettuces in desert areas, etc.).

EV Charging

Who owns the units?

You do! As the site host, you own and operate the units collecting all revenue generated from your charging sessions.
What types of vehicles can use them?

All U.S. models can! in 2023 alone, 43 new models will hit the road in the U.S. accounting for nearly 15% of all new vehicle sales. Electron Charger designed their chargers to be universal across all U.S. vehicles including Tesla’s (with adapter).
How do I monetize my hardware?

Electron Charger’s universal software allows you to deploy multiple different strategies to generate revenue for your facility. T & T Solar will recommend a few that fit your use case in our service proposal.
How many chargers does my facility need?

That’s where T & T Solar comes in! Once we better understand the goals and use case for the facility, we will do an onsite energy evaluation and share our findings.
What if i want the chargers to be private?

No problem! Once we understand your use case, we will provide a solution that targets only the users you want to have access to the chargers.
How do I set up pricing rules for my facility?

T & T Solar will help here! When your units are installed, they will already be "smart." They will know what cellular network to use, what the desired monetization strategy is, and who can and cannot use the chargers. We will do a one-on-one software training with the facility director as part of our white glove service experience.
How do I get paid?

Electron Charger’s universal software allows you to "cash out" your charger-generated revenue monthly with the click of a button.