This article originally appeared in the SolareBusiness Newsletter, February 2015, Page 16.
FROM MONITORING TO CLEANING, ADMINISTRATION AND SECURITY, THE PROPER FUNCTIONING OF SOLAR DEPENDS ON THE MANAGEMENT ACTIVITIES OF MAINTENANCE AND CONTROL
The photovoltaic system is a power plant that can produce clean electricity in an autonomous way, saving on your bill. The initial investment supported for installation is recovered in a relatively short period of time when the structure works well, producing the energy needed to satisfy the user. For this to happen it is important that the plant was built to perfection and, later, to be managed correctly and consistently throughout its life cycle, which normally exceeds twenty years or more. Any drop in performance from failures and malfunctions may impede the productivity of the system, resulting in poor performance.
The attention devoted to the solar PV system varies depending on the type and size of the structure and can be divided into core activities, common to all sizes, and advanced tasks, to be studied case by case.
WHAT IS O&M?
The term operation and maintenance (O&M) means all activities relating to the management and maintenance of photovoltaic systems, to ensure the proper functioning of the system components and therefore energy production in line with initial forecasts.
Part of the O&M activities include the monitoring and control, the ordinary and extraordinary maintenance, security, and management of the paperwork related to incentives, tax deductions, relations with the Manager of Energy Services and banks.
For smaller installations, an audit can be performed by the owner in autonomy, with the request of the intervention of a specialist is necessary only if the extraordinary maintenance. For large photovoltaic installations instead, which are characterized as capital expenditures, as explained by Emanuele Tacchino, business development manager of Alectris, “you need a 360° approach that, starting from the aspects relating to maintenance and optimizing production, also supports the bureaucratic management of the plant. The larger the plant, and the higher the power generation climbs, along withthe number of installations, the more O&M becomes a complex operation.
The plant must produce at the highest level. It is not enough that it works. This is the service of O&M.” The words of Aldo Moretti, head of O&M of Enerray, effectively summarize the importance of the operations & maintenance.
A photovoltaic system that works well, taking advantage of all its potential, allows you to write off the cost of the investment schedule, avoiding huge economic losses. Any faults or problems that slow or stop the operation of the system may instead cause economic damage, of greater or lesser extent in relation to the size and mode of use of energy produced.
When the energy is used in self-consumption, as in the case of most of the plants of many residential and among those industrial and commercial, the loss of productivity generates a missed bill saving, because of the greater amount of electricity that is necessary to withdraw from the network.
If the plant has been made to sell the energy to the network, as in the case of many of the larger systems installed under the Energy Bill, this failure causes a loss of profit. The damage to the owner becomes even greater if the plant was financed through a bank loan, which will become more difficult to return. By setting a good service O&M the plant owner can avoid the loss of productivity, save on maintenance and, when necessary, to bring the plant to produce even more.
MONITORING AND CONTROL
The heart of the operations & maintenance is the monitoring or verification of the amount of energy produced by the plant every day and in different seasons. In fact, like any other electrical system photovoltaics also need to be constantly monitored, so that its performance will not suffer slowdowns than originally expected and, in case of failure, it is possible to act quickly to limit losses.
Operations monitoring and analysis of data on the initial estimate of productivity in relation to the actual production, are the basic tasks that are often performed by the inverter, which transmits the data through the display. In the market there are also innovative and user friendly solutions that allow you to collect and display data using special handsets or on PCs, tablets and smartphones, making it easier to control the performance of the owners of small plants.
A couple of times a year it is advisable to perform routine maintenance of the system, which consists of an inspection with control and verification of all components, to be made taking into account the relevant specifications and manuals.
Following this operation will proceed with any extraordinary maintenance, such as replacement of damaged or faulty components. Another activity to be carried out at least once a year is the cleaning of the modules, which can be washed even more frequently in the case where the photovoltaic system is in a particularly polluted area or is subjected to saline atmosphere. A plant cleaned regularly provides 10% more energy. Normally it is recommended washing with demineralized water, which is purified by the process of reverse osmosis. For work on modules particularly dirty with layers of dust, soot, pollen, bird droppings or moss, it is good to intervene with specific detergents. Instead we must not wash the panels with tap water in the hours of sun, because you could damage them. As explained Fabrizio Mellini, sales manager of ESApro, “for small plants, i.e. those generating power within the 100 kW, we can limit the O&M of these operations, combined with constant monitoring, will ensure production of electricity in line with expectations. ”
LARGE SOLAR PV SYSTEMS, GREAT SOLUTIONS
Large PV systems require a structured interlocutor who can handle all aspects of O&M, from maintenance and monitoring to safety management, asset management and possible improvements.
Services for large plants are studied on case by case basis according to the customer’s needs and structured in different types of offerings, from entry level, which includes monitoring and maintenance, up to all-inclusive packages that include the all-risk coverage or the replacement of all components of the system even if the guarantees were overdue. The monitoring is carried out by platforms able to perform control operations remotely through the reading and analysis of data, and report in real time possible malfunctions, allowing punctual and timely intervention in case of need.
The plant maintenance includes periodic inspections with specific tests such as thermal imaging, which allows you to see if excessive heating of the modules occurs, and to intervene with preventive actions to minimize anomalies panels and connections.
To protect the system against theft is then necessary to provide the structure with an alarm system that protects the perimeter, the cable ducts, modules and inverters, preferably supplemented by a video surveillance system. Finally operators of O&M offer asset management services, namely management of relations with the Manager of Energy Services, Enel and banks, and are also able to design and implement revamping, consisting in the replacement of parts of the facility or in the addition of devices capable of improving productivity.
Alectris is an international company present in Italy since 2012, where he currently manages O&M activities on a portfolio of approximately 45 MW photovoltaic systems. “We like to qualify for our customers as partners, rather than as mere service providers,” says the Alectris business development manager, Emanuele Tacchino. “Our proposal is focused on maximizing the performance of the system for the satisfaction and the economic return of the owner, turning what is normally an operating cost, O&M, into a source of additional revenue.” The heart of the added value offered by Alectris is the engineering, the ability to find better solutions tailored to each plant, in order to enhance the production of electricity and shorten the payback. Alectris also uses its own management platform complete ACTIS, able not only to monitor the operation of the plant, but predicatively analyze data, identify any problems and provide technical advance the solution to implement. www.alectris.com
GROWTH PERFORMANCE RATIO OF A SYSTEM OF FOGGIA AFTER INSTALLATION OF MONITORING SYSTEM
After about two years of operation, the four plants from 1 mW each installed in 2011 in the province of Foggia, recorded a production well below their potential. The solar plants, taken over by Alectris in mid-2013, have been equipped with the monitoring system ACTIS, which was able to highlight anomalies in the modules and inverters, and act quickly, bringing the performance ratio [parameter that defines the efficiency ratio the actual return from the theoretical] from the initial value of about 65% to 82%.