Large turbine halls and macro grid systems cannot fulfil every need for increased electricity demand
The transition of the world’s energy infrastructure is the product of a combination of mass electrification, a rapid move to dominance by renewables and a shift in the way we consume energy so that waste can be minimised.
This is happening amid surging demand from industry. By 2050, it is expected that the 40,000 TWh of electricity used by the planet will be predominately generated from renewable sources including wind, solar, biomass, and nuclear.
According to research each year industry is the single largest user of electricity on earth. Statista reports that industry accounted for over 41% of electricity used in 2018.
The US Energy Information Administration says “The industrial sector uses more delivered energy than any other end-use sector, consuming about 54% of the world’s total delivered energy. The industrial sector can be categorized by three distinct industry types: energy-intensive manufacturing, nonenergy-intensive manufacturing, and nonmanufacturing.” (2)
Any industry using a power system that relies primarily on 500MW – 5GW power stations, coupled to a legacy grid pushing electricity over long distances, with its related with large losses, knows that it must seek alternatives.
Users with requirements for 100MW-300MW need energy independence and energy security even as they seek a path to net zero.
They are turning to local power generation delivered via 100MW+ microgrids. Today, such developments are being discussed, modelled, planned and built.
Some microgrids will operate with grid supply and some without.
The opportunity is to build industrial scale microgrids which are integrated with existing grids or operate independently.
They will fill the gap between traditional large remote turbine halls and today’s reliance on on-site local power back up for specific applications.
Today all energy intensive industry sectors are evaluating their microgrid options. These include data centres, manufacturers, process, transport and energy itself.
This trend is global. Private wire alternatives to large scale national grids are being considered in territories with established grids and mature relationships between generators and DSOs (Distribution Systems Operators) and TSOs (Transmission Systems Operators) and across developing economies where grid development using microgrids are being established to reach remote, rural and other communities.
Challenges to microgrid developments are both technical and economic.
The technical challenges include the need for power conditioning, voltage stabilisation and frequency.
At this level the primary requirements for a stabilisation system are to rapidly react to active power fluctuations and to correct these so that the frequency is maintained at a constant value.
Such as system ensures short-term reactive power on demand and thus maintains the voltage at a constant value for the load.
To provide one example, maintaining constant frequency is vital. Frequency changes occur both when too much surplus power is generated and too little. Fluctuations in power generation have a big effect on the active power balance of the network and therefore frequently lead to frequency fluctuations. The energy sources, (a main grid, a large genset or a renewable system) and their control systems, are usually not able to adjust the output power to the new situation (such as disturbances or rapidly rising and falling load demand) within a few seconds, so that fast-acting stabilization systems are needed to promptly restore the power balance and with it the frequency.
This grid gate acts as a ‘choke’ which offers many possibilities for the subsystem to import or export power and manage output.
Factors such as regulation, planning, geography, power availability, access to renewables, existing grid stability and capacity, nature of the use case application and load… (the list goes on) mean there will be no one size or one design choice to fit all.
The range of stakeholders involved and complex factors are doing nothing to slow the growing trend of data center, commercial and industrial users seeking alternative electricity sources that are independent of traditional grid supply. 100MW – 300MW microgrid projects are becoming part of critical industrial infrastructure.
In some locations large hydrogen ready generators are being deployed for primary baseload. Elsewhere big tech companies are building microgrids to supply data centres which are directly connected to solar and wind farms or are running microgrids powered through biomass renewable natural gas. A remote mining operation that needs 300MW of power is unlikely to have a choice of connecting to a reliable grid.
Whether the load sits in an industrial plant, large mine, processing plant or digital infrastructure facility, whether it is connected to an existing grid or operating independently, whether using gensets and batteries or renewables and fuel cells, users know they need to fill the 100-300MW power gap with reliable, stable supply.
Among these variables what is clear is that the future of industrial power supply is local.
What can be stated with confidence is that to successfully fill the gap any industrial scale microgrid design must be able to guarantee frequency and voltage stability.
This article first appeared on Datacenterdynamics in April 2023