General ESM FAQs

What is emergency solar management?

Emergency solar management (also known as ESM, Distributed Photovoltaic Management or DPV management) refers to the management of rooftop solar systems. Put simply, ESM is the ability to turn down or turn off the capability of rooftop solar systems to generate solar energy remotely.

Presently inverters are not technically able to be turned down via remote management and so if ESM measures are required, rooftop solar systems will only be able to be turned off. In the future, technology may also allow inverters to be turned down.

Who does ESM apply to?

ESM applies to all customers who install or upgrade their rooftop solar systems after 14 February 2022 which have an inverter capacity of 5kW or less and participate in the Distributed Energy Buyback Scheme (DEBS). These customers include:

• most residential properties (customers that consume < 50MW hours per annum)
• any customer that is a school, university or other educational institution or a non-profit making organisation

Why do rooftop solar systems need to be remotely managed?

Distributed rooftop solar is an important source of low cost and low emission power. However, WA’s main electricity grid was not designed for the large uptake of renewables that has occurred in recent years. Large amounts of rooftop solar energy are making the electricity system more vulnerable and increasing the risk of electricity supply interruptions.

As a last resort measure, emergency solar management could assist in managing the current risks to the electricity system and allow rooftop solar systems to continue to be installed and connected to the grid as we transition to a more sustainable energy future.

How often and for how long will household rooftop solar systems be remotely managed?

ESM was introduced as a last resort measure to help protect the SWIS (WA's main grid) and is only to be used in emergency operating conditions, during extreme ‘low load’ events.

EPWA, the State Government's energy policy agency, expects that these ESM low load event days, and the subsequent need for remote management under the ESM arrangements, will occur in the SWIS infrequently and for short periods.

The Australian Energy Market Operator (AEMO), the operator of the South West Interconnected System (SWIS) (the main electricity system in WA) will inform Western Power and Synergy of emergency operating conditions. As instructed by Western Power, Synergy will temporarily turn off (and back on again) rooftop solar systems subject to ESM requirements to manage the risk to the electricity system.

Synergy will also periodically undertake compliance tests to ensure that the systems and onsite hardware for rooftop solar systems can be remotely managed to ensure that appropriate actions can be taken in an emergency solar management low load event.

 

Does emergency solar management only cover the SWIS (South West Interconnected System)?

At this stage, this only applies to the SWIS – the electricity network operated by Western Power.

How will emergency solar management affect my electricity supply and use?

Emergency solar management will not affect a customer’s electricity supply and use as when impacted rooftop solar systems subject to ESM will be temporarily turned off and back on again as required. Customers impacted will continue to have access to electricity supply from the grid in such cases but will not be able to generate solar energy for this period.

What is low load and why is it an issue?

On mild, sunny days (usually weekends), the energy output from rooftop solar systems is generally high while demand for electricity is low. The stability of the electricity system requires the supply and demand of electricity to be balanced. When generation from rooftop solar systems is high and electricity demand is low, it becomes more difficult to keep large-scale generators online which help provide essential services for maintaining a stable electricity supply in the system. As a result, the electricity system becomes vulnerable to unexpected events – this raises the risks of widespread electricity supply interruptions in the grid.

AEMO has released a report titled 'Renewable Energy Integration – SWIS Update'. The report states that whilst the rapid adoption of rooftop solar systems by Western Australians is encouraging, it is also contributing to low load risks. Read more about how low load is challenging WA’s main electricity system here.

What is an export limit and how does it work?

An export limit refers to the maximum amount of solar energy generated by a rooftop solar PV system, in excess to personal consumption, that is permitted to be exported to, or feed back into, the electricity grid. The purpose of export limiting is to help ensure that the grid remains stable and safe.

For the solar PV system to be export limited, at installation a sensor is attached to the inverter that determines the amount of current being sent to the grid (an export limiter).

The inverter converts solar energy into electricity. This solar generated electricity offsets consumption at the property first at the time of generation and then anything in excess is exported to the grid. The export limiter controls the amount that can be exported to the grid.

The offset of solar generated electricity against your personal consumption will help to reduce your electricity costs as you are not drawing electricity directly from the grid.

Export limits are set in accordance with Western Power’s Basic Embedded Generator Connection Technical Requirements.

How to apply: 

An application to install or connect a solar PV system that cannot meet ESM requirements and is required to be subject to an export limit cannot be completed online. To apply, please complete the Distributed Energy Systems Application for renewable energy system with an inverter capacity of up to 30kW form.

What other measures is the WA State Government considering undertaking to resolve low load issues in the SWIS?

The introduction of ESM and the delivery of the WA State Government’s Distributed Energy Resources Roadmap, a plan to integrate solar PV, batteries, electric vehicles and other energy devices into the SWIS, are part of WA's Energy Transformation Strategy (ETS) to provide a blueprint to ensure the delivery of secure, reliable, sustainable and affordable electricity to Western Australians for years to come.

Planning is underway to reduce the need for ESM (or DPV management) in the future. This includes proposed changes to the electricity regulatory framework that will allow new technologies, such as battery storage, to assist to manage low load risks in the future.

As part of the ETS, the WA State Government is already undertaking a number of other actions intended to improve the resilience of the electricity system to low load, including considering the use of virtual power plants, investment in large-scale and community battery storage and planning for the integration of electric vehicles into the grid. ESM represents a stepping stone to reaching this future, to assist in maintaining system security and reliability and to enable renewable generation to continue to be installed in the grid.

Why is the WA State Government responding now to low load issues?

A report by AEMO has found that risks associated with low load in the network have increased due to the accelerating uptake of rooftop solar systems. In 2020 the installed capacity of rooftop solar increased by over 300 MW (or 24%) in the SWIS. The installation rate of rooftop solar in the SWIS has consistently exceeded forecasts, including those from AEMO.

The WA State Government has implemented ESM arrangements so that the electricity system can better manage periods where there less demand for electricity or 'low load' in the future. ESM (or DPV management) requirements apply to rooftop solar systems that are installed or upgraded after 14 February 2022 with an inverter capacity of 5kW or less.  ESM has been introduced following a recommendation from AEMO.

What can my household do to assist with low load risks?

Days where low load risk typically occurs are on weekends when the weather is sunny and mild. On these days, all households, whether or not they have rooftop solar installed, can help to mitigate low load risks by:

• running appliances, such as the dishwasher and washing machine around lunchtime
• charging devices such as laptops and phones in the middle of the day
• setting timers on hot water systems and pool pumps to operate in the middle of the day
• charging EVs in the middle of the day
• setting batteries to commence charging at midday so that they are not full when there is excess capacity in the network from solar

Check out our blog for more tips to maximise your rooftop solar system and assist with low load risks.

Who can I contact if I have any questions about ESM?

All queries regarding ESM can be directed to Synergy’s residential contact centre on 13 13 53, between the hours of 7am to 7pm, Monday through to Friday, excluding public holidays. 

For enquiries specific to your rooftop solar system, it is recommended that you speak with your solar installer.