Part of EE Times’ Energy Needs a Smarter Approach Special Report

Microgrids, microinverter-based battery and solar systems are now a business real-world reality. They are becoming a manifestation of the energy as a service (EaaS) model of business designed to replace traditional utility services.

There are also microgrid networks which offer connections to the energy system and connect to a variety of kinds of traditional and renewable energy sources. These microgrids connected to networks can hook directly to loads in the building like a massive industrial motor. This means that they’re extending renewable energy sources beyond cable-fed fields and rooftop installations. 

ADVERTISING

Microgrid networks comprise a network of microgrids with smaller sizes that can accommodate different technologies that include solar PV batteries, hydrogen storage, and hydrokinetic. (Source: Siemens)

However, before discussing microgrids installation, it’s essential to comprehend the anatomy of microgrids.

Microgrid’s primary building blocks

Sam Abdel Rahman, the systems architect of Residential Solar and Energy Storage Systems at Infineon Technologies, outlined the five fundamental design components — or elements of microinverter-based microgrids. In the first place, microinverters are tiny, grid-tied inverters, which are placed on every solar panel. These devices transform DC power generated by solar panels to AC power.

Microinverters are not only becoming more powerful however, there are the latest multi-photovoltaic (PV) microinverter panels, as well as panel-based designs that allow for higher power production in a microgrid as per Abdel-Rahman.

“From a microinverter design perspective, this pushes designers to adopt new package and chip technologies to fulfill the new trends and requirements.” For instance, the latest microgrid designs are able to capture efficiency and lower costs by using wide-bandgap (WBG) technologies including gallium Nitride (GaN) as well as silicon carbide (SiC) power switches for topside cooling on surface mounts and low-inductance packaging.

The second is that Energy storage devices (ESSes) keep the excess energy produced during periods that are high in production. They then release it in times of peak demand. “It’s a major ingredient of the microgrid that stores excess energy generated and discharges it during the low solar production,” Abdel-Rahman explained. “Microgrids cannot be energy independent or reliable without storage.”

Thirdly the power management system, which is a central control system, manages the flow of power through the microgrid. It controls demand and power production and regulates the ESS.

Fourth, communication systems such as sensors or smart meters allow communication between the various components of the microgrid. They allow the remote control and monitoring.

In the end, protection systems such as breakers, fuses and surge protectors assure the security and stability of the microgrid, by preventing damage to equipment in the event of a malfunction or surge.

Microgrid design examples

In analyzing microgrid applications that make use of these blocks of construction to build distributed grids and assets, consider the case of the 11.34-MW microgrid that is being constructed within John F. Kennedy (JFK) International Airport’s brand new Terminal One. It is aiming to provide immediate reductions in greenhouse gases of 38% by using grid-generated energy, which is enough to power 3,370 standard U.S. homes for one year. Additionally this rooftop solar system is expected to comprise more than 13,000 solar panels and the power generated by the solar array is enough to power 1 039 typical U.S. homes for a year.

The microgrid currently being constructed on the site of JFK Airport comprises four “power islands,” and each island is an integrated local energy system, incorporating storage, sources of energy generation advanced control and automation. The microgrid will comprise 7.66 MW of solar panels on rooftops, 3.68 MW of fuel cells and 2-4 MWh of storage for energy stored in batteries. In addition, it uses recycled heat to create chilled water as well as hot water.

Annette Clayton, CEO of Schneider Electric North America, states that microgrids will help solve two of biggest problems with one solution that is resilient and decarbonization. Schneider Electric, which designs and builds, as well as manages, and operates custom-designed energy infrastructures that will offer the microgrid via its collaboration with its joint venture AlphaStruxure together with the global firm Carlyle.

The 11.34-MW microgrid located at JFK Airport will be delivered via the EaaS solution. (Source: Schneider Electric)

The medium-voltage microgrid situated in the industrial zone in Marjamaki, Finland, presents another instance of the creation of an energy network that is decentralized in its production in renewable power. It is complete with ESS as well as a grid automation system which allows an efficient and sustainable energy system while also ensuring the safety of electricity. Microgrid controllers ensure an efficient monitoring and control system and blackout security.

In this microgrid it will generate energy through two solar panel fields which will generate an annual output of electricity at 3,600 MWh. It will have more than 15,000 panels, 6 gas motors, as well as fuel cells.

the first sustainable energy story of success in the field of energy

Renewable energy is a topic of discussion in the political spotlight at the moment as well as a lot of discussion of SiC as well as GaN semiconductors as the key catalysts in this technological endeavor. But it’s important to remember that microgrids, often referred to by the name smart grids represent the first significant success story in the quest for the reduction of greenhouse emissions of greenhouse gases.

Microgrid technology has developed continuously over the past decade. The advancements in the design of power semiconductors and their packaging will surely boost microgrid infrastructures in the coming years. This will also help EaaS initiatives and create new opportunities for investment and entrepreneurship in the tech sector.