Demand Side Management

A Demand Side Unit (DSU) consists of one or more Individual Demand Sites (IDS) and can be instructed by EirGrid to reduce its electricity demand. 

This might be required during peak consumption periods or reduced generation availability. DSUs that are available for demand reduction are eligible for a capacity payment in the Single Electricity Market (SEM).

A DSU must have at least 4 MW of capacity to be registered in the market, as per Grid Code. 

Multiple IDS's can be aggregated into a single DSU, these are combined by a DSU Aggregator, which is a third-party company specialising in demand side participation.

An IDS is a site (typically medium to large industrial premises) capable of reducing its electricity consumption. This reduction in energy consumed can be achieved through on-site generation, plant shutdown or a combination of the two.

An IDS with a capacity of greater than or equal to 10 MW can be a standalone DSU but cannot be aggregated with other IDS's.

What is Demand Side Management?

Demand Side Management is a way of controlling electricity demand. It encourages customers to reduce their electricity use, either during peak hours or their overall use. It can offer significant benefits for customers, including lower bills.

Demand Side Management is key to system security for Ireland. It helps us to manage the power system efficiently, including:

How to Participate

Electricity consumers can participate in Demand Side Management through tariff-based schemes. Examples include: Economy 7 (Northern Ireland) and NightSaver (Ireland). 

Medium to large electricity users can also participate in a Demand Side Unit (DSU) or Aggregated Generating Unit (AGU).

Eligibility

Demand sites can register as a DSU, whether or not they have a Maximum Export Capacity (MEC). A DSU must have a demand reduction capacity of at least 4 MW.  

A demand site with more than 10 MW demand reduction capacity cannot be aggregated but can register as a stand-alone DSU. 

The company registering the DSU must be a licensed supplier registered in the SEM. The company is not required to be the supplier of the individual demand sites. 

We issue dispatch instructions to each DSU using the Electronic Dispatch Instruction Logger (EDIL). The DSU Aggregator then coordinates the reduction from the individual demand sites. DSUs use a combination of on-site generation and plant shutdown to reduce their demand. 

We require real-time communications with the DSU. DSUs must be available 24 hours a day year-round. This is to ensure we have a secure power system and can issue dispatch instructions quickly. The exceptions are a breakdown or an agreed outage.