Photovoltaics, or PV for short, is a Solar Power technology that uses Solar Photvoltaics systems' or Solar cells to provide electricity for human activities. Photovoltaics is also the field of study relating to this technology.
Solar panel cleaning is a vital component of any solar operation and maintenance (O&M) program. Experts agree, dirty panels, or as solar asset managers in the North East discovered this winter – solar panels covered in snow, produce less electricity than clean, unobstructed panels.
In some areas, without adequate solar panel cleaning, photovoltaic (PV) performance can degrade as much as 25% according to the National Renewable Energy Laboratory. This can increase a solar arrays pay back time by three to five years!
To maintain optimal energy production, solar arrays require periodic solar panel cleanings especially in those areas of that are prone to high airborne particulates such as pollen, exhaust, dust, industrial processes, coastal salts, organic debris, and in certain regions in the winter — snow.
Why Clean Solar Panels
To understand why solar panels need to be kept clear of airborne debris, it’s important to know a bit about how a solar array works. A solar array contains several solar modules wired together. Each solar module, also know as a solar panel, consists of solar cells mounted collectively in a frame and covered by a protective glass coating. Solar cells are made of semiconductor materials like silicon. One side of a solar cell is positive and the other is negative. When sunlight hits a solar cell, it excites the electrons in the semiconductor material. This energy is captured as electricity. Pollution, dust from traffic, bird droppings and leaves or other organic debris prevents sunlight from reaching the solar cells in the solar panels thereby reducing the amount of energy generated.
Solar panel cleaning is so important to ensure maximum energy production from a solar array that some solar panel manufacturers are now even making panel cleaning a condition of their warranty.
When to Clean Solar Panels
O&M companies that have years of experience in solar maintenance will layout a preventative maintenance plan that includes, amongst other things, a detailed cleaning schedule for the solar array.
In addition to the predetermined, Preventative Maintenance schedule, solar operation and maintenance companies have two methods to determine if and when the panels need to be cleaned. They will visually inspect the solar panels on a periodic basic and/or use a monitoring system. Most commercial O&M companies will do both.
What Happens During a Solar Project Inspection
During a physical inspection of a solar project, panel cleanliness is not the only thing that technicians are reviewing. Other components of the array will also be inspected by the skilled technician including, but not limited to: the mounting, cabling, the inverters and connecting boxes, shading and vegetation growth, water drainage, fencing, the security of the area, and wildlife or pest activity. A physical visual inspection can often detect potential hazards or smaller problems that could turn into major headaches down the road. Identifying and making repairs or adjustments before they interfere with energy production is key to a successful O&M plan.
How Solar Monitoring Systems Work
A solar monitoring system connected to a commercial solar array is an extremely helpful tool for Asset Managementkeeping a watchful eye over a solar project, twenty-four hours a day, seven days a week, three hundred-sixty-five days a year. And, what’s even better — this monitoring can happen from any where in the world or within feet of the array itself.
A solar monitoring system is basically a computer program that accesses, compiles and reports on data generated from a solar array. Through thorough and regular analysis, operators can determine if the solar array is, among other things, meeting or exceeding performance projections. It will also indicate when the array or part of the array is offline or if it’s not performing as expected.
What Determines the Amount of Energy an Array Generates
Every solar array has a projected amount of energy that it will produce each month based on several factors including:
Solar Panel Efficiency
Size of Panels and System Size
Solar radiation in the Region
Angle of the Sun to the Solar Panel
Weather and Seasonal Variations
Pitch and Orientation of the Solar Panels
Before any solar projects commencement, the positive and negative results of these factors are compiled. Energy projections over the life of a solar farm are made to determine the long-term costs and potential revenues the project will generate. Solar financing depends heavily on these energy projections and investors do too.
Whenever a solar array is under-producing, or offline not generating energy, it means its costing investors money. And, as stated earlier in this article, soiled panels can degrade PV performance up to 25% which can increase the pay back time by three to five years. An undetected outage could have even more dire consequences over the long haul. Which is why Emergency Solar Services for offline outages are extremely important.
No matter what the cause of the under production or outage, the faster the solar array returns to normal operational levels, the better.
How to Detect System Events
Should a solar farm be underperforming or offline, key personnel will receive automatic emails of events affecting the system performance. Additionally, monitoring systems have the capability of running remote and/or onsite diagnostic programs to narrow down system failures to a particular string, inverter or other issue to expedite repairs. In the instance of panel soiling, as expected, data trends will show a declining production in energy as more and more soiling occurs on the surface of the solar modules.
Cleaning Solar Panels
There are several methods to clean solar panels, all of which are relatively easy; however, the sheer volume of panels in a commercial solar array adds a level of effort, which can be beyond some company’s limits, which is why utility scale solar power plants typically enlist the help of an O&M company.
Miller Bros. Solar (MBS) is a chosen leader in operations and maintenance (O&M) solutions due to the company’s project expertise, full construction capabilities, and 160+ pieces of heavy equipment. MBS is one of the few electrical contractors that can simultaneously self-perform multiple utility scale solar projects while exceeding client expectations, controlling costs and adhering to timelines and customer schedules.
Miller Bros. Solar provides O&M services for solar projects in the following states: Connecticut, Delaware, Ohio, Georgia, Indiana, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia, and West Virginia.