ADVANTAGES OF GRID-TIED SYSTEMS
1. Save more money with net metering
Batteries, and other stand-alone equipment, are required for a fully functional off-grid solar system and add to costs as well as maintenance. Grid-tied solar systems are therefore generally cheaper and simpler to install.
Your solar panels will often generate more electricity than what you are capable of consuming. With net metering, homeowners can put this excess electricity onto the utility grid instead of storing it themselves with batteries.
Net metering (or feed-in tariff schemes in some countries) play an important role in how solar power is incentivized. Without it, residential solar systems would be much less feasible from a financial point of view.
Many utility companies are committed to buying electricity from homeowners at the same rate as they sell it themselves.
2. The utility grid is a virtual battery
Electricity has to be spent in real time. However, it can be temporarily stored as other forms of energy (e.g. chemical energy in batteries). Energy storage typically comes with significant losses.
The electric power grid is in many ways also a battery, without the need for maintenance or replacements, and with much better efficiency rates. In other words, more electricity (and more money) goes to waste with conventional battery systems.
Additional perks of being grid-tied include access to backup power from the utility grid (in case your solar system stop generating electricity for one reason or another). At the same time you help to mitigate the utility company`s peak load. As a result, the efficiency of our electrical system as a whole goes up.
Equipment for Grid-Tied Solar Systems
There are a few key differences between the equipment needed for grid-tied, off-grid and hybrid solar systems. Standard grid-tied solar systems rely on the following components:
· Grid-Tie Inverter (GTI)
· Power Meter
· Module Mounting Structure (MMS)
Grid-Tie Inverter (GTI)
What is the job of a solar inverter? They regulate the voltage and current received from your solar panels. Direct current (DC) from your solar panels is converted into alternating current (AC), which is the type of current that is utilized by the majority of electrical appliances.
In addition to this, grid-tie inverters, also known as grid-interactive or synchronous inverters, synchronize the phase and frequency of the current to fit the utility grid (nominally 60Hz). The output voltage is also adjusted slightly higher than the grid voltage in order for excess electricity to flow outwards to the grid.
Micro-inverters go on the back of each solar panel, as opposed to one central inverter that typically takes on the entire solar array.
There has recently been a lot of debate on whether micro-inverters are better than central (string) inverters.
Micro-inverters are certainly more expensive, but in many cases yield higher efficiency rates. Homeowners who are suspect to shading issues should definitely look into if micro-inverters are better in their situation.
Most homeowners will need to replace their current power meter with one that is compatible with net metering. This device, often called a net meter or a two-way meter, is capable of measuring power going in both directions, from the grid to your house and vice versa.
You should consult with your local utility company and see what net metering options you have. In some places, the utility company issues a power meter for free and pay full price for the electricity you generate; however, this is not always the case.
Module Mounting Structure (MMS)
Mounting your solar panel array is a crucial part of your solar system. The racking must meet local building code requirements, and be strong and durable enough to withstand the wind, snow, and whatever else Mother Nature throws at it for decades. Several options for mounting solar panels are available; they don’t always have to go on your roof. Ground mounting and pole mounting are available to move your solar array off the roof and expand your options.
Solar Array Racking for Roof
· Roof Mount (Raised mounting for required tilt angle)
· Roof Mount (Tilt angle as roof is)
· Flat Roof (No roof penetrations or ballasted)
Ground Mounted Solar Array Racking
· Pole Mount (top of pole or side of pole)
· Ground Mount (fixed tilt or seasonably adjustable)
Sun Tracker Solar Array Mounts
· Axis (single and dual axis)
· Seasonal Tracking