The Basics of a Solar Energy System
Solar energy is a renewable resource that can be used to generate electricity. It can also be used to heat water for homes and businesses.
Every hour, enough sunlight strikes the Earth to meet all of the world’s energy demands for a year.
This energy can be converted into electrical power with a solar system that includes a number of components.
Solar Panels
The large black solar panels you see on roofs and at places like stations are made up of many small solar cells. These are silicon semiconductors that create an electric current when they absorb sunlight. The more light they absorb, the more electricity they produce. These solar panels generate power which can be used in the home, stored in a battery or sent back to the grid.
The cells are connected together to form modules and strings of modules can be connected in parallel to achieve the desired voltage (or output) capacity of the system. The module electrical connections are made with conducting wires that take the current off each panel and may include blocking diodes or bypass diodes depending on the configuration of the system.
Blocking and bypass diodes are incorporated into SOLAR ENERGY SYSTEM the panel design to deal with partial array shading that degrades performance. In a series connection, blocking diodes prevent current from flowing backwards through shaded modules to short-circuit the rest of the string; bypass diodes allow current to flow around them.
Solar panels are expensive to buy and install so it’s a long-term investment for homeowners. Some solar companies offer leasing options (a solar lease or PPA) that allow homeowners to enjoy the benefits of solar at minimal upfront costs. However, these options don’t make the homeowner the owner of the system and they can’t claim solar tax credits or incentives.
Solar Batteries
Solar batteries help you capture and store the energy generated by your solar panels, even in overcast conditions. The extra electricity would otherwise flow back to the grid via a process called net metering. With a battery, this power can be used at night or when sunlight isn’t enough for your home.
The silicon semiconductors inside a solar cell absorb and transform the sun’s energy into an electric current outdoor post solar lights vendors that flows in one direction through metal contacts. This DC current passes through an inverter to be changed into AC electricity for your appliances, then into a solar battery to be stored. The battery stores this energy in a chemical state until it is needed again.
Solar batteries come in a variety of sizes based on your household energy consumption and your preferences. The size is measured in kilowatt-hours (kWh). When choosing a solar battery, you should also consider its depth of discharge rating. Exceeding this limit will dramatically shorten the battery’s lifespan.
The most common solar battery type is lithium-ion. Lithium-ion is the same technology that powers many everyday electrical devices, such as phones, laptops and electric cars. It is safe, environmentally friendly and cost-effective. Other battery options include flooded lead acid, VRLA (valve-regulated lead-acid) and nickel cadmium batteries. There are also newer technologies such as lithium iron phosphate and redox flow batteries.
Solar Charge Controllers
Sunlight contacts solar panels and generates DC electrical power that is delivered to a charge controller. The solar charge controller regulates the amount of energy that flows to your battery system and prevents your batteries from getting overcharged.
When the battery voltage is too high, a solar charge controller opens the circuit and halts the flow of electricity to the load. This protects the batteries from damage, but it also stops any excess power from flowing back into the solar panels at night and allows the system to use battery power.
The most common solar charge controllers on the market are PWM, or pulse width modulation, controllers that operate by chopping up direct current from solar panels into a series of voltage pulses. This method wastes some of the solar panel output and is not very efficient. MPPT, or maximum power point tracking, controllers are more advanced and can be up to 80% more efficient than PWM controllers.
All charge controllers have a rating of how much current they can handle, and it is important to stay within this limit. Exceeding this limit can burn out the wiring inside of your charge controller and create safety hazards. We recommend choosing a controller that can safely work with the type of batteries you plan on using, as well as your solar array size.
Solar Inverters
The solar inverter is the piece of equipment that turns the DC energy coming from your panel into 230V AC electricity that you use to power your home. Depending on your installation requirements, you can choose from different inverter options that are normally recommended by reputable installation companies like HIES (Hire a Local Energy Service).
There are two types of solar inverters: string inverters and microinverters. A string inverter does all of the DC to AC conversion at a single location, and it’s often installed on the side of your house for easy access. Since the inverter is centrally located, it can be easier to maintain and repair when something goes wrong. However, this also means that if one of your panels is shaded or obstructed, the whole string suffers performance loss.
In contrast, a microinverter does the conversion at each individual solar panel, allowing you to monitor each panel’s output and mitigating the effects of shading. Some research suggests that the higher reliability and longer MTBF of microinverters compared to string inverters make them the better choice. Combined with the ability to retrofit your system with battery storage, they’re ideal for homeowners looking to maximize their home energy savings. A good installer will help you decide between a microinverter or string inverters for your particular circumstances and install the option that suits you best.