Pushing the envelope for renewables

Australia has once again recorded a new record in the growth of renewables with 3GW of rooftop solar installed in 2021. This continued growth in solar along with the adoption of flexible resources such as electric vehicles, batteries to hot water systems is a positive sign that households and businesses are taking the lead to achieve energy independence instead of being at the mercy of rising electricity costs.

However, the growth in the adoption of distributed energy resources (DER) is a major challenge for network operators and energy retailers who want to have greater visibility and control over DER that are connected to their networks. The lack of visibility of DER can potentially de-stabilise the grid and the need to maintain flexibility within the grid to respond to network demands is a new and unique value stream that network operators want. An example would be how retailers are looking at the potential of virtual power plants as a way to stabilise the grid and to harness the energy of behind the meter batteries for grid stability and services.

A recent announcement that the Australian Renewable Energy Agency (ARENA) has provided funding to SA Power Networks, Simply Energy and AGL to develop and trial the capability of flexible exports to a network also known as ‘dynamic operating envelopes’ is an example of how we can unify the control of rooftop solar with smarter flexibility at an individual site level. 

ARENA’s funding towards the Flexible Exports Program builds on the successful trial that SwitchDin commenced in October 2020 with SA Power Networks and Ausnet Services where the SwitchDin’s Stormcloud and Droplet technology has been used as an alternative to the strict export limits that were imposed on rooftop solar systems in these networks.

Both SA Power Networks and Ausnet Services have grappled with a high uptake of rooftop solar and rather than implementing static export limits or imposing strict rooftop system sizes for newly connected photovoltaic systems to maintain system stability, flexible exports provides a solution that benefits both DER owners and network operators.

In this blog, we demystify what a dynamic operating envelope is and why it is beneficial to the grid as we address the rapid growth of distributed energy resources. 

What are Flexible Exports?

Using smart, internet-connected solar inverters, flexible exports allow households to automatically adjust how much unused solar energy is exported to the grid to match the available capacity within a network - essentially functioning as a dynamic operating envelope.

For example, a SA Power Networks customer can choose to have a flexible export limit of up to 10kW rather than having a reduced permanent fixed export option of 1.5kW per phase imposed if they wanted their rooftop solar system to remain connected to the network. This flexible export limit was introduced to suburbs that had an overload in rooftop solar systems to relieve congestion to the network.

Without flexible exports, existing customers would have their rooftop solar systems automatically curtailed to a 1.5kW limit. New solar customers who want to connect their rooftop solar systems have to agree to a flexible export limit to have their system approved for connection to the grid. 

What is a Dynamic Operating Envelope?

Australia leads the world in pioneering DER control and the application of dynamic operating envelopes. It essentially provides a boundary for the import or export of power at a given time interval for either individual DER assets or at a connection point. In Australia, it has been recommended that dynamic operating envelopes operate in five minute intervals to increase solar energy supply when resources are constrained or to capture greater value when the market is volatile. 

This safe operating envelope is calculated by a network operator to ensure that customers export and demand either from self operation or if it is part of a VPP, dynamic operating envelopes don't impact on the physical operation of the grid. By doing so, a dynamic operating envelope allows a network to operate safely and this defers the need for costly network upgrades. Besides optimising the use of self-generated solar energy, customers can realise more value from their DER.

Dynamic operating envelopes also support market efficiencies by making solar and battery assets available to reduce wholesale market prices benefitting both energy consumers and network operators. Customers receive efficient signals in a dynamic operating envelope and it informs them when to increase energy usage when more energy is available on the grid, reducing the need for infrastructure upgrades. This ultimately results in greater network efficiency in addition to providing greater stability to the grid during periods when excess solar energy is generated.

Without implementing dynamic operating envelopes, network operators will have to resort to banning new rooftop solar installations that are past a certain threshold, imposing limits on the size of new rooftop solar systems that are being connected to the grid, directing static export limits on new solar systems and making it less attractive to homeowners wishing to invest in renewable energy. The least desirable solution would be for network operators to automatically switch on/off connected inverters resulting in disruptions to rooftop solar systems that are generating clean energy for homes.

Consumer DER will stand to benefit from being part of a dynamic operating envelope. For example, households with solar and home batteries can defer the charging of their battery until peak periods of energy generation reducing their cost of grid electricity when needed. Electric Vehicles (EV) owners can secure value for their asset through vehicle to grid (V2G) charging by participating in frequency control markets and high cost ramping events.

All of these scenarios would result in having less solar energy on the grid and this is why dynamic operating envelopes is crucial for all electricity grids that are increasingly addressing a higher penetration of rooftop solar and the expansion towards supporting new assets such as batteries to electric vehicles.

What’s needed to build a Dynamic Operating Envelope?

Most Australian rooftop solar systems are not installed with smart, internet-connected inverters. Without a smart inverter, it is not possible for households to be connected to a dynamic operating envelope.

For eligible households who wish to participate in the Flexible Exports Program in South Australia and Victoria, SwitchDin has worked with a range of manufacturers such as Fronius, SMA, Growatt and FIMER to provide SwitchDin’s Residential Droplet hardware to support some of their inverter models to connect to the grid. 

SwitchDin has built a IEEE 2030.5 utility server platform and client side support for network operators to connect Droplets through the internet to deliver standards compliant dynamic operating envelopes. We have also helped some manufacturers to build their own native clients. As we look into the future, standards such as the IEEE 2030.5 for dynamic operating envelopes connections will be crucial in defining the implementation of dynamic operating envelopess. 

Network operators and regulators will need to have their customers’ buy-in for them to opt-in to participate in a dynamic operating envelopes. Ultimately, gaining control of their DER to support the grid requires adequate protections to be granted for their assets including providing them with adequate data or information that they are correctly compensated for their DER to be used, when or why their assets have been curtailed to the avenues they can take to redress any disputes with their network operators or energy providers.

Our Success Stories

SwitchDin bridges the gaps between energy utilities, network operators and energy end users such as households and businesses with rooftop solar, batteries, EVs and EV charging infrastructure. Through Stormcloud, a smart, digital platform that securely connects distributed energy resources all over the grid, portfolio owners can connect, control and communicate with a diverse range of assets to deliver a truly flexible and responsive grid.

We’ve worked closely with the industry to demonstrate the viability of dynamic operating envelopes across Australia with network operators to energy retailers. In addition to the Flexible Export Program, some of our earlier projects include Horizon Power’s Onslow DER Project, the Energy Queensland Lockhart River Microgrid to Project Symphony in WA.