The difference between solar and solar microgrids

Solar power set-ups come in different forms. Most commonly, solar panels are used to collect solar energy and are connected to a major grid. For example, most residential solar set-ups operate in this way, enabling the solar panels to feed or draw from the main grid dynamically depending on energy collection and usage levels. In order to operate independently of the main grid, the individual home would need extra equipment like a battery and a specialized solar microgrid inverter.

A solar microgrid is an integrated, independent network that can operate completely separately from the main grid. So, while all solar microgrids are supplied by solar, not all solar energy is linked to a microgrid.

However, many microgrids are linked to main grids as well as having the capability to operate independently, and they can be either connected or disconnected at will depending on the circumstances. This can further improve reliability and has been very helpful in helping to maintain energy supplies after unforeseen events, such as earthquakes, where a major grid has been damaged.

What are the advantages of microgrids?

The main benefit of using a solar microgrid is the added reliability it can provide to those connected to it. As mentioned above, having an independent system that is capable of “islanding” energy production and distribution is incredibly helpful when the main grid is damaged or unavailable.

This reliability is particularly significant in rural and isolated areas, and in those where the main grid can be unreliable. For example, many rural communities in places like India can struggle to access energy even at the best of times, with unreliable major grid networks and isolated locations posing many challenges. Add in the incidence of destructive events like fires, earthquakes, and floods, and it’s a recipe for disaster. Having access to a microgrid can give such communities an energy lifeline, helping hospitals, homes, and schools keep the lights on at all times. It can also ensure that basic infrastructural equipment such as water pumps remains operational.

Additionally, solar microgrids are an excellent way to reduce reliance on fossil fuels on a community-wide level. This can not only reduce greenhouse gas emissions and contribute to fighting climate change, but can also shield people from fluctuations in energy pricing (such as the huge price surges seen in many parts of the world in recent months) and supply chain issues with traditional fuel sources.

How do solar microgrids work?

Solar microgrids can vary greatly in complexity and size, but they all follow the same basic concepts. Typically, a solar microgrid would look something like this:

• To begin with, a group of solar panels (or photovoltaic array) captures energy from the sun. The type of panels used can vary, but a microgrid will generally consist of high-quality equipment to maximize efficiency. Monocrystalline panels, for example, can achieve efficiency of 20% or more, making them a popular choice for microgrid arrays.
• These panels are connected to a solar charge controller, which acts to regulate the voltage and current of the incoming electricity. This regulation is vital as it converts the electricity into a usable form that won’t damage the equipment in the microgrid, such as batteries.
• All of the energy is then transferred to a combiner box which also works to protect the rest of the system. Additionally, it can reduce energy loss and allow engineers/computers to monitor the performance of the system. It also consolidates all the energy that is being produced into one connection.
• Via this connection, all the energy is channeled to an inverter. This converts the energy from direct current (DC) to alternating current (AC), which makes it suitable for a range of everyday uses such as to power machinery, household appliances, and more. Hoymiles microinverters, for example, can be used effectively in microgrids when paired with a storage system.
• If an excess of energy is being generated at a given time, some of it will be stored in batteries for later use. This step is key in helping communities achieve energy independence. It also eliminates reliance on the main grid and reduces the chance of fluctuations in supply during periods of low production (such as overnight or in bad weather). In some systems, excess energy may be fed into the main grid to maximize efficiency.
• The energy leaving the inverter runs through one or more meters, which track usage of the community or individual users. These meters may be used to determine the pricing for each user.
• From here, it is transported to end users such as individual households, industrial buildings, other business premises, and so on.

In many modern solar microgrids, the entire grid can be connected to or isolated from a larger grid on demand. This ability helps users access power more efficiently and reliably than if they were just connected to either one of the grids.