ONSITE SOLAR
FAQs and popular topics about onsite solar
Most roof mounted solar arrays have few or no roof penetrations. Racking systems that require penetrations are either flashed or sealed by a professional roofer to warrant against leaks (pending wind zones and roof type, many attachments can simply be heat-welded with no penetrations). Pivot works with the roof manufacturer or existing roofer of record to ensure that the necessary steps are taken to uphold and maintain the current warranty. In some cases that may involve special padding under the racking, and inspections. Adding solar to your roof can actually help to extend the lifespan of roofs, given the very nature that panels shield the roof from hail or UV degradation.
Pivot offers O&M services for solar systems with system monitoring and annual inspections as part of a preventative maintenance plan.
Solar energy projects are static state, meaning there are no moving parts which reduces the most common maintenance concerns of mechanical failure (some ground mounts, however, do include tracking systems). Cleaning entails spraying down the modules with water and using a soft brush and squeegee. Depending on the local conditions, the modules typically need to be sprayed down with water once or twice a year.
Pivot only uses top-tier UL-listed equipment, and all arrays are installed according to the most up-to-date standards of the National Electric Code published by the National Fire Protection Association. This includes necessary setbacks established by the local authority to enable appropriate roof access. All work is inspected by the local permitting authority, and key components are labeled to communicate safety issues clearly. In addition, the work will be inspected by the utility to ensure proper interconnection.
The owner of the solar array (either the building owner or the third party owner) will need to insure the solar array. In many cases, adding coverage for the solar array results in no increase in premiums. In the case that it does increase rates, the annual cost will typically range from 0.25% to 0.5% of the total installed cost of a project. Additionally, in some states, solar is not permitted to increase insurance premiums and property taxes.
Hail can damage a solar panel, although this is rare. Solar panels are built using tempered glass for durability and safety and are designed and tested to withstand 1" hail and high winds. It is common practice for Tier 1 module suppliers to test their panels with steel balls dropped from a height reflective of hail reaching terminal velocity or alternatively testing by shooting hail balls at the panels.
Solar modules have a long life and typically carry a 25-year power production warranty. However, it is normal for a solar module to degrade slightly over time and those warranties factor in that degradation. While warranties vary, the typical annual degradation is about 0.5% year over year, and all of our energy production projections incorporate this factor.
Pivot follows all industry best practices and applicable codes when it comes to structural engineering for roof mounted solar PV systems. As part of the permitting process, we created stamped structural drawings which show that the solar array weight is within the reserve capacity of the roof.
Solar arrays are not as heavy per square foot as most rooftop equipment, and we have multiple racking options, so it is rare that a structure would need reinforcement to accommodate a solar array. Most flat-top roofs like those with TPO or EPDM membranes require ballasted arrays that may add up to 4 - 6 lbs./SQFT whereas a metal roof solar application may add as little as 2- 4 lbs./SQFT. Most rooftops have enough headroom to accommodate these additional loads and when that is in question, Pivot Energy will conduct a thorough structural analysis.
Pivot works with the racking manufacturer to receive wind loading engineering information, including the required ballast to keep the array safely pinned down on the roof. Wind loads are calculated by a qualified engineer and must be approved by the corresponding AHJ. Where ballasting becomes too heavy, we tether or secure the system to the building’s structure. Having designed for Florida and high roofs in the past, we have experience with high wind engineering requirements. Safety is our primary concern when engineering solar arrays.
Solar arrays are not as heavy per square foot as most rooftop equipment, and we have multiple racking options, so it is rare that a structure would need reinforcement to accommodate a solar array.
Grid-tied solar arrays require a special interconnection agreement with the utility. Most states have some sort of interconnection policy that requires utilities to allow customers to install power generation equipment. However, those policies may vary widely on the size of the installation and conditions of the agreement. The Database of State Incentives for Renewable and Efficiency (DSIRE) is the best source of information on these policies, as well as other rules, regulations, and financial incentives.
Net metering is a billing mechanism that credits solar energy system owners for unused solar energy sent to the utility grid. There may be times when a solar PV system produces more power than is needed. In these circumstances, the excess power is exported to the utility grid. The utility monitors the amount of energy exported to the grid and credits the customer.
Seasonal variations in energy production and demand may generate excess energy in a given month, while in other months your demand is exceeding solar production. Some states allow customers to carry over excess energy from month to month, which also enables them to become net-zero consumers more easily. Other states require the net-excess generation to be paid out monthly, usually at a fraction of the retail rate.
The solar industry has grown dramatically in the last five years, and the cost of equipment has dropped significantly during that period. Solar module manufacturers continue to develop greater efficiencies in power production output, however, they continue to use the same basic materials and technology to produce that power.
Crystalline silicon wafers dominate the solar industry. There are variations in the technology and manner in which the materials are designed, assembled, and manufactured that have resulted in gains over the years, but the gains are relatively modest. While module wattage continues to increase so does the size of the average panel, so higher efficiency is not 100% linear. There continues to be a wide investment in alternative technologies, but there is no “game-changer” on the horizon.