What Is a Solar Energy System?
Solar energy is radiant light and heat that can be used to generate electricity.
Solar power is currently the fastest-growing source of energy worldwide.
Solar technologies convert sunlight into electrical energy to power homes and businesses. Some of these technologies store energy in batteries or thermal storage systems to continue generating electricity even when the sun is not shining.
Photovoltaic (PV)
Solar PV technology converts sunlight directly into electricity. This electricity can be used to power a device or sent back to the grid. In the latter case, it can be used to help provide energy to homes and businesses. The technology behind solar PV devices is based on the photovoltaic effect, first observed by French physicist Alexandre-Edmond Becquerel in 1839. The effect occurs when certain types of material, called semiconductors, absorb solar energy and convert it to electricity. The solar cells in a PV system consist of thin layers of a semiconductor material, such as silicon. As sunlight shines on the cell, it ionizes the semiconductor material, which in turn causes electrons to break free from their atomic bonds. When the electrons reach the pn junction (the point at which the two surfaces of a solar cell meet), they can no longer return to their original positions. The resulting electric current is direct current, or DC.
Solar cell efficiency has improved significantly since the emergence of thin-film technology in the 1980s. A new monocrystalline polysilicon technology called passivated emitter and rear cell (PERC) now dominates crystalline PV production. Efficiency levels continue to increase, with efficiencies currently exceeding 40%.
A PV system requires an inverter to convert the DC output to alternating current for use in electrical loads. Some PV systems are designed to be stand-alone, without connection to the grid. These systems may incorporate battery storage to ensure that electricity is available at night or when the level of solar irradiation is low.
Concentrating solar-thermal power (CSP)
CSP technology uses mirrors to concentrate sunlight on a power-generation engine that converts the sun’s heat into electricity. It can also store energy thermally for dispatchability during intermittent cloudiness or overnight. The most advanced CSP systems use molten salts or other materials to store solar heat. This allows the technology to compete with natural gas and PV combined-cycle plants for dispatchable power.
Solar-to-thermal conversion efficiency in a CSP plant is measured using the Carnot cycle, which includes all energy losses in the system. Real-world efficiencies are SOLAR ENERGY SYSTEM much lower, but improvements in technology can reduce the difference between projected and actual production.
A typical CSP plant uses rows of parabolic reflectors to focus the sun’s rays on a receiver pipe, which holds a heat transfer fluid (HTF) such as thermal oil or molten salts. The HTF is heated by the concentrated sunlight and then used to drive a steam turbine generator to produce electricity.
Historically, several CSP projects, including Khi Solar I and Ivanpah, were built without storage. However, the technology has since evolved, solar inverter generator and all new large-scale CSP facilities now incorporate some form of TES, increasing their dispatchability. The latest generation of concentrating solar power plants, such as those being built in Morocco, are designed to include 3 to 12 hours of thermal storage. This capability will help CSP compete with photovoltaics, natural gas and PV with batteries for flexible, dispatchable power.
Monitoring systems
Solar monitoring systems provide a window into your system’s performance, offering real-time data on energy production and consumption. They also help to pinpoint any issues that may arise, allowing timely interventions. This can improve your system’s overall energy efficiency, resulting in higher energy output and lower electricity bills – or even potential income from net metering billing.
These systems integrate with various components of your solar energy setup, including your panels, inverters and additional equipment like weather stations to gather comprehensive performance data. A system like Retgen, developed by Rast Teknoloji, for example, seamlessly integrates with both PV modules and inverters and allows users to view module-level energy performance data, identifying inefficiencies, determining solar shading impacts and understanding local weather patterns.
In addition to module-level production data, solar monitoring systems provide insight into your household energy consumption. You can use this information to reduce your energy consumption and make more efficient choices about your household electricity usage.
Choosing the right solar monitoring solution depends on your unique needs and system specifications. However, the most advanced systems offer a range of features that include live monitoring and analysis, workforce management, remote control and intervention, flexible action definitions and preventive maintenance services. Many of these systems are also cellular-enabled, meaning that they can transmit data independently of Wi-Fi networks and continue to operate when there’s no internet connection.
Solar batteries
Solar batteries allow homeowners to store their excess energy from solar panels for use at night or in low light conditions, or to backup essential systems during outages. They’re especially useful for those who aren’t eligible for full retail net metering or who live in areas with high utility time of use rates.
Most solar battery systems include an inverter to convert DC power from the battery into alternating current for use in the home or grid. The inverter also monitors the state of charge of the battery and can switch the load to the battery when it’s fully charged or back to the grid when it’s emptied.
The type of battery used in a solar energy system can impact its performance. For example, lithium batteries can deliver a high amount of energy in a short period of time while nickel-cadmium or redox flow batteries are more suited to longer energy storage. The Depth of Discharge (DoD) of a battery is another important factor to consider; using too much of its capacity before it’s recharged will significantly reduce its lifespan.
Solar batteries are available in a variety of sizes, ranging from 2kWh up to 20kWh. The size of a solar battery system depends on how much energy a household needs to power at a given time, and how often the system is expected to run.