The Project aimed to determine and demonstrate the extent of capability for wind farms of similar design and functionality to the Hornsdale Wind Farm Stage 2 (HWF2), and operating in similar conditions, to provide Frequency Controlled Ancillary Services (FCAS) to the National Electricity Market (NEM). A subsequent objective was to gauge necessary adaptation to the registration/dispatch processes, enabling better integration of renewable generator on the FCAS Market. AEMO provided significant support to materialise this and enable HWF2 to participate in these markets.
Highlights of HWF2’s performance in the market trial included:
- High quality provision of regulation services during the Market Trial period;
- Operation of HWF2 FCAS in conjunction with the Hornsdale Power Reserve FCAS to reduce otherwise high FCAS prices during planned maintenance of the Heywood Interconnector on 14 January 2018. Regulation prices peaked at $248/MW on this date compared to an average of more than $9000/MW during previous Heywood Interconnector outages; and
- Autonomous response to a range of frequency excursions (both as a part of the Market Trial and during normal market operation following its conclusion).
How the project works
Undertaken by NEOEN, (the owner and operator of the Hornsdale group of projects) in conjunction with AEMO, the FCAS trial ran from August 2017 to February 2018 and was comprised of the following stages:
- Technical modelling of plant performance and demonstration of capability via on-site plant testing;
- Review of modelling and on-site test results leading to registration of HWF2 as an ancillary service generating unit; and
- In-market demonstration of FCAS delivery for all registered services through 48 hours live of bidding and dispatch under a range of wind conditions.
The Project intended to increase the value delivered by renewable energy in Australia by ultimately reducing the cost of electricity to Australian electricity consumers, while contributing more actively to system security. It materialised the opportunity for wind and solar generators to fully participate in the NEM’s energy and FCAS markets by providing frequency control services in addition to generation.
The trial also demonstrated the technical capability of type 4 wind turbines to be remotely controlled by AEMO. This allows AEMO to assess modifications that may be required for wind forecasting, bidding and energy management systems.
Area of innovation
The FCAS trial is the first in-market technical demonstration of FCAS provision from a wind or solar farm in the NEM. It has provided a critical proof of concept to the market and investors on the ability of wind farms to provide FCAS.
The success of this trial and growing interest from other wind farms in providing frequency control services is compelling evidence of the commercial and technical maturation of wind energy technology. AEMO advised they expect utility scale wind and solar technology will continue to take on a larger role in providing essential ancillary services in the NEM. The ability to offer frequency control services to the market is no longer a novel concept for pilot projects; it is an important and flexible tool in the operational kit of utility scale renewable generators that provides value to the generator and to the power system.
The original operational concept for Hornsdale Stage 2 did not consider participating in the FCAS markets. To continue operating in the FCAS markets some upgrades to the communication and control systems are required for practical reasons. These reasons are:
- flexibility, the wind farm needs to be able to select the mode it operates in;
- agility, the market operator needs to be able to take advantage of changing market conditions; and
- reliability, operator at this point does not have the ability to set the wind farm to the correct modes seamlessly.
The most complex issue to resolve is the participation of wind generation in the fast raise/lower FCAS market. Some optimisation may be possible to improve the performance of the wind farms in this regard. It may also require a relaxation by AEMO of the requirement for the wind generation to provide R6 service where there is a concurrent voltage and frequency events.
This trial was completed using the Siemens turbine (direct drive) that was installed already at the Hornsdale Wind farm. They are now looking into the impacts (durability and guarantee) on the wind turbines themselves to determine if there is any extra wear and tear while providing FCAS or if any extra service and maintenance is required if the FCAS services are provided on a permanent basis.