Below, we list some of the most common:

Financial

As the cost of solar panels has fallen significantly over the past decade, many Cyprus residents have been able to save money with solar panels.

Environmental

Much of the electricity used in Cyprus comes from power plants that burn fossil fuels. When fossil fuels are burned, they produce emissions that contribute to air pollution, as well as producing carbon dioxide, a greenhouse gas which causes global warming. Solar panels can reduce the need for electricity production from fossils fuels and thereby decrease the emission of greenhouse gasses.

Energy Independence and Resilience

Some Cyprus residents choose solar because they want to be more independent and produce their own power, or because they are far from the power grid. Residential solar systems can be either off-grid (not connected to the electric grid) or grid-connected. To be completely independent of the grid requires investing in a standalone inverter system and installing battery storage. Most people who go solar don’t choose an off-grid system. A grid-connected PV system will not function in the case of an electricity outage unless the home has an accompanying electricity storage system and the ability to “island” (completely disconnect from the grid). But even a simple grid-connected system provides some cost independence as it reduces the amount of electricity purchased from the grid and therefore subject to utility rate fluctuations.

Energy Efficiency First

Energy efficiency should always come first. It is usually more cost efficient than solar; it reduces the cost, size and footprint of the final solar system. Installing insulation in the attic and walls, adding weather-stripping, using energy efficient lights (such as LED lighting), and using energy efficient appliances can provide energy savings month after month while also reducing the size of the desired solar system. Every home is different, so homeowners should have a complete home energy audit conducted to guide the energy efficiency effort. The size of a solar system is often based on the total amount of electricity used in a year; for the most accurate results, the energy impacts of efficiency measures should ideally be tracked for a year to determine the correct new baseline for solar array sizing. Alternatively, the new energy baseline can be estimated given the old baseline and the estimate of energy savings from the energy efficiency measures.

What Is a Solar PV System?

 Photovoltaic (PV) systems convert sunlight into electricity. Sunlight strikes the solar panel material and frees electrons, creating electricity. The electricity produced in a photovoltaic system is direct current (DC). Other than some off-grid homes and specialized appliances, homes use alternating current (AC). The PV system changes the DC into AC through the use of an inverter. The output of the inverter is then connected to the home’s electrical system so that the electricity produced by the PV system can power the home. PV systems have few moving parts and are generally very reliable. They require little maintenance. Understanding the components of a PV system can help you decide whether to go solar, and how.

The Solar Cell and Panel

The basic electricity producing structure is the solar cell, which is normally comprised of silicon and electrodes. Cells are strung together in a module (often called a panel). A number of panels connected together electrically (in series) and fed into the inverter (described below) is known as a string. The entire system, consisting of one or more strings connected together in parallel, is referred to as the solar array.

The output of a panel is measured in DC-watts. The nameplate output of a panel represents the amount of power produced under rated conditions. Lower output panels have fewer cells and come in smaller sizes. Choice of panel size, output and shape will usually depend on the installation method and location. Solar panels are available in varying colors, shapes, power outputs, efficiency and appearance.

Materials

The external components of a solar panel include the cover (usually glass with an anti-reflective coating), composite backing, aluminum frame along the perimeter and sometimes along the back, and wiring to connect the panel to the rest of the system. A back frame, when present, helps to support the weight of the panel under snow loads. Inside the panels, different kinds of cell materials are used to generate electricity. Currently, the most widely used material is a polycrystalline silicon, which is inexpensive to manufacture and can be recognized by subtle shades of blue and blue-black in the cells. Another, more expensive option is to use monocrystalline silicon, which uses purer silicon grown into a single crystal structure. This material results in a uniform color and slightly increased output efficiency. Another option is thin film manufactured cells, which are less expensive to manufacture but are also less efficient. This material is used in a wide range of installations, including flexible panels and roofing materials. Building-integrated panels (BIP) refer to solar panels that replace the need for conventional walls and roofing and are used both as the weathering surface of a building and for solar generation. These and other emerging technologies currently in commercial development may result in new opportunities in the future.

Racking and Mounting

Racking and mounting systems secure solar panels together and attach them to the building structure or to the ground, usually as part of the system’s electrical grounding. (Proper grounding is required by electric codes to ensure safe system operation.) Since most panels are warrantied to last 25 years and will likely last longer, it is good to have quality racking that can last at least 25 years without corrosion or other degradation and can withstand wind, ice, and snow loading. Racking is comprised of several parts. Panels are clipped to the racking rails (primarily aluminum) and the rails in turn are secured to mounting units. These units secure the system to the support structure (either a roof, pole or the ground). The racking can also provide channels for wiring, offering protection and aesthetic benefits for the system. Some racking is available in different colors to match roofing and panel composition (such as silver and black). In a roof-mounted system, the mounts are usually secured to underlying rafters and include multiple layers of waterproofing and flashing to protect the roof from water damage and leaking. Mounting is a critical component to protect the roof and ensure the long-term viability of the system and the home. Homes with standing seam metal roofing can have the solar panels clipped directly onto the metal roofing, avoiding the need for any roof penetration or flashing. Roofing material, age, and quality can affect the choice of racking and mounts. In some cases, a ground or pole-mounted system is a better option than a roof-mounted system. Some roofs may be old and in need of repair/replacement, or they may not be strong enough to carry the extra weight of the panels; orientation or shading may limit the output of a rooftop system; or there could be an aesthetic concern. In these cases, solar arrays can be mounted directly to the ground using racking systems manufactured for this purpose. Ground systems may also be mounted on the side or top of a pole. Although ground-mount installations can increase the installation cost due to additional construction time and materials, as well as the added cost of running connecting wiring to the electricity panel, it may provide greater flexibility in location. It is critical to ensure the ground-mounting solution matches the site’s soil bearing capacity and is secured at a sufficient depth to prevent frost heaving (vertical ground movement caused by freezing and thawing of the moisture in the soil). For ground-mounted systems, it is necessary to consider the average snowfall in the area when determining the minimum height of the lowest solar panel as snow sliding down from the panels can build up and block the lower level of the panels. Ground mounted systems (both pole and rack types) are available that allow the panel tilt to be seasonally adjusted to maximize solar production. These systems are usually adjusted two to three times a year and can increase annual solar production by about five percent.

Trackers

Some pole-mounted systems use trackers to keep the panels pointed toward the sun on a daily basis. Tracking systems track on either one or two axis. Single-axis trackers (moving the panels east to west over the course of a day) can increase output by up to 20 percent over a fixed system. Dual-axis trackers move both east and west and up and down to keep the panels always pointing directly at the sun. These trackers can increase output by up to 30 percent over a fixed system. Trackers increase the installed cost of a system and, because they involve moving parts, they require additional maintenance. Consumers should carefully weigh the benefits and costs of such systems when deciding what type of system is best for their needs.

Wires

A PV system will require wiring between the panels, from the array to the inverter, and from the inverter to a building’s electrical panel. Wiring that runs outdoors has different specifications than normal building wiring. The wiring must last a long time and should be enclosed in conduit when necessary to protect it from the elements and from rodents (especially squirrels). Running wiring along racking underneath the panels can ensure a clean looking installation and protect the wiring from the elements. Plan for additional wiring if the PV system might be expanded in the future.

Inverters

The inverter changes the direct current (DC) power coming from the panels (or from a battery) to alternating current (AC). The inverter includes protective devices such as fuses, breakers, and the necessary components to automatically disconnect from the grid in the case of a power outage. Inverters can include heavy-duty enclosures that allow them to be installed outdoors. There are two primary types of inverters: central inverters and micro-inverters. Central inverters manage parallel strings of panels. Because the panels of a string are wired together in series they work together as a single unit, and shading on one panel will impact the efficiency of the entire string. With micro-inverters, each panel is individually managed by its own dedicated inverter. While this means that shading of individual panels will not affect the entire array’s output, it comes with a higher monetary cost. Individual panel output can also be monitored through the use of micro-inverters. If your system will be impacted by partial shading, it may make sense to consider micro-inverters. Ask your solar contractor if using DC-DC optimizers or micro-inverters are worthwhile given your specific installation conditions. Inverters generally don’t last as long as solar panels, so inverters may fail and need to be replaced during the life of a solar system. The failure of a central inverter will stop the output of the entire solar array; if micro-inverters are used, the failure of a single micro-inverter will only stop the output of the individual panel.

A DC-DC optimizer matches the output characteristics of a solar panel, or a string of solar panels, to the input requirements of the inverter. While this improves the performance of the central inverter and the solar system as a whole, it comes with an added monetary cost.

Meters

When you install a PV system, the utility company may install a second electric meter to measure the output of the solar array. This would be in addition to the regular electric meter provided by the utility company to measure electricity usage and provide reliable service. In some cases, the utility will simply install a meter that can run backwards, depending on the direction of power flow.

Including Storage—On-grid and Off-grid Options

Off-grid solar systems always require energy storage to provide electricity when the sun is not shining. For grid-connected systems, battery storage is an option that can provide some electricity when the grid fails during storms or other events. This can be especially appealing if a home experiences frequent outages, or if there are essential systems, such as medical equipment, that need to operate at all times. With storage comes some additional equipment and cost. Additional components and monitoring will be required to ensure the battery system is maintaining its proper charge and system functionality. Charge controllers, specialized inverters, and batteries are the major components of a system with electrical storage. If you are interested in having storage, you should work with a system designer/installer that specializes in storage-based systems. Several battery systems are designed to be low or no maintenance and relatively easy to operate. Some of these newer systems benefit from advances in battery materials and technology. They are sealed, produce no off-gasses, and do not require electrolyte levels to be checked.

Solar Photovoltaics vs Solar Thermal

This guide focuses on using sunlight to make electricity with PV panels. Sunlight can also be used to make things hot, including heating water for household hot water use. PV panels and solar hot water panels are sometimes side-by-side on the same roof, but they function completely differently. Solar hot water panels can reduce water heating bills. Some installers have experience with both PV and solar hot water panels. Another option for heating hot water sustainably is to install a highly efficient electric heat pump water heater and power it with electricity from PV panels. Heat pump water heaters pull ambient heat from the surrounding environment into a storage tank where it is used to heat water. Heat pumps are an added expense, but might save money in the long run through reduced fuel costs. Some utilities offer an incentive for heat pump water heaters.

Battery Storage

Battery storage comes in two primary forms. For most off-grid systems batteries are DC-coupled, meaning the direct current from the solar panels is fed directly to the batteries, and the batteries can run both AC equipment (through an inverter) and DC equipment (if your home is equipped with such equipment). Most grid-connected systems use the alternative, an AC-coupled system, which is connected directly to the AC electrical system in your home and uses a bi-modal inverter that can both supply AC power from the batteries or produce DC power to charge them. These systems operate in standard “grid-connect” mode until utility power fails at which point they disconnect (island) from the utility and draw power from the batteries to power a home. Some battery-based systems can be structured to accommodate additional energy sources, such as diesel generators.

These bi-directional meters may also allow for time-of-use billing, an optional rate structure in which the cost of electricity changes during the course of a day. Consider asking the advice of the utility company or an energy advisor when selecting an electrical rate structure, such as a flat rate or time-of-use rate (if offered).