Tag Archives: hybrid power

Red 5 taps Zenith Energy for hybrid power options at King of the Hills gold project

Red 5 Ltd has entered into a Power Purchase Agreement with a subsidiary of Zenith Energy Ltd that will see the growing Australia-based power producer build, own and operate approximately 30 MW of hybrid power generation capacity to service the needs of the King of the Hills (KOTH) project in Western Australia.

The power inputs as part of the BOO agreement comprise high efficiency reciprocating gas fuel power generation together with a 2 MW photovoltaic solar farm (an example from Zenith’s other work shown above) and a battery energy storage system.

Power supply to the site is planned to commence in the March quarter of 2022 with an initial term of 10 years. The contract includes provision for a potential future upgrade to the power station to support increased plant throughput beyond the initial planned 4 Mt/y run rate, Red 5 says.

Gas will be supplied from the Goldfields Gas Pipeline, 12 km west of the mine, under separate contracts, the company clarified.

Red 5 Managing Director, Mark Williams, said the award of the agreement marked another important construction milestone for the King of the Hills project while, at the same time, helping to achieve one of the company’s environmental, social and governance commitments to reduce the carbon footprint of the project.

“We are pleased to have signed the Power Purchase Agreement with Zenith, an experienced power producer which provided us with a compelling hybrid thermal and sustainable power solution that includes renewable energy,” he said. “Zenith’s combination of a gas and solar power station, supported by a battery energy storage system, provides the efficiency and stability required for the processing plant and infrastructure to enable King of the Hills to be a long-life, low-cost gold producer.”

The KOTH project is an open pit and underground gold deposit with a projected mine life of over 16 years. This could see the company produce 176,000 oz/y of gold over the first six years, according to a recent feasibility study.

KPS to leverage ETC tech in hybrid power conversion at Iluka’s Jacinth Ambrosia mine

Pacific Energy Ltd’s wholly owned KPS subsidiary has signed a contract to convert its 10 MW diesel power station at Iluka Resources’ Jacinth Ambrosia mineral sands mine in South Australia to a hybrid facility.

The facility will incorporate electric turbo compounding (ETC) technology, which, the company says, allows generators to maintain the same power output using less fuel and producing lower CO2 emissions.

The conversion and upgrade will have a meaningful impact on lowering emissions and fuel costs for Iluka, Pacific Energy claims.

KPS has operated the 10 MW diesel power station at the Jacinth Ambrosia site since 2009. Under the new contract, which runs for an initial term of seven years, KPS will:

  • Install 3.5 MW of solar power generation;
  • Integrate the solar array with the diesel power station; and
  • Introduce ETC technology to each of the 10 1 MW generators.

ETC technology makes generators work more cleanly and effectively by recovering waste energy from the exhaust to improve power density and fuel efficiency, the company explained.

Juwi Renewable Energy Pty Ltd, the Brisbane-based subsidiary of juwi AG, is to construct the medium penetration solar/diesel hybrid power solution for Jacinth Ambrosia, with KPS owning and operating the hybrid project. After completion, it is expected to deliver almost 21% of the mine site’s annual electricity needs.

Pacific Energy Chief Executive, Jamie Cullen, said: “This is an exciting development for both Pacific Energy and Iluka Resources in what we believe is a world first – integrating solar and ETC technology with an existing fossil fuel facility. The reduction in diesel consumption and improvement in fuel efficiency is expected to save over 2 million litres of diesel and over 5,500 tonnes of CO2 per year, every year, for at least the next seven years.”

Aggreko to energise Gold Fields’ Salares Norte mine with hybrid power solution

Aggreko, a leading provider of mobile and modular power solutions, has signed a contract with Gold Fields to provide a 25.9 MW hybrid solar and thermal power solution to the Salares Norte open-pit mine in Chile.

This “ground-breaking solution” has been designed to provide power for the entire mine, which sits at an altitude of 4,500 m in the Andes mountain range and is 190 km from the nearest town, Aggreko says.

The hybrid system will comprise both tailormade high-altitude performance diesel gensets and Aggreko Solar Power units, optimised for off-grid applications and ready to meet the extreme wind conditions these units will experience.

The gensets will each deliver 772 kW (for 16 MW of power in total) and will incorporate spinning reserve and cold reserve units to efficiently manage peaks in demand, the company says. This diesel generation system will be integrated with solar units, which, once installed, will provide 9.9 MW of emission-free power.

“The system will deliver a reliable, modular power supply across all five of the mine’s distribution points, whilst surpassing the Chilean government’s environmental standards as well as Gold Fields’ requirement for a minimum of 20% renewable power generation for mining operations,” Aggreko said.

Once complete, it will achieve $7.4 million in cost of energy savings over the next decade and a further $1.1 million in carbon tax offset over the Aggreko project lifetime in addition to 104,000 t of carbon emissions savings, Aggreko estimates.

“The modular rental solution also supports a consolidated capital expenditure outlay, allowing for greater cost control and variable commitments whilst ensuring continued operational excellence at the mine,” it added.

The deployment of this hybrid solution follows Aggreko’s recent launch of Aggreko Solar Power, which will be deployed to provide power at the site. This solution is designed for weak or off-grid energy applications, providing clean and efficient power supply to a range of operations without long-term financial commitments.

Pablo Varela, Latin America Managing Director from Aggreko, said: “As the energy transition continues to gather pace, our customers are increasingly looking for more flexible power solutions which can reliably support operations whilst reducing carbon emissions and lowering costs.

“Hybrid products, such as the one we are deploying for Salares Norte, enable a reliable and flexible power supply whilst reducing carbon emissions, thanks to the incorporation of Aggreko Solar Power units as part of the system. Having a standardised product such as this provides the kind of consistency and reliability which our customers have come to expect from us.”

The 10-year contract between Aggreko and Gold Fields for power generation at the mine represents the strong working relationship between the companies, reinforced with the recent installation of one of the world’s largest renewable microgrids at Gold Fields’ Granny Smith mine in Western Australia.

First production from the mine is set for early 2023, with Salares Norte having an 11.5-year life of mine with a production average of 450,000 oz/y for the first seven years of operations.

Optimising energy management at B2Gold’s Fekola mine

The delivery of a cutting-edge 17 MW/15 MWh energy storage platform and Wärtsilä’s advanced GEMS system is optimising energy management at B2Gold’s Fekola gold in Mali, Luke Witmer* writes.

Since B2Gold first acquired the Fekola gold mine, located in a remote corner of southwest Mali, exploration studies revealed the deposits to be almost double the initial estimates.

A recent site expansion has just been completed, and while the existing power units provide enough power to support the increase in production, the company sought to reduce its energy costs, cut greenhouse gas emissions, and increase power reliability.

The addition of a 35 MWp solar photovoltaic (PV) plant and 17 MW/15 MWh of energy storage to the existing 64 MW thermal engine plant was decided. This new energy mix is anticipated to save over 13 million litres of fuel, reduce carbon emissions by 39,000 t/y, and generate a payback in just over four years.

Such an elaborate hybrid configuration needs a powerful brain to deliver on all its potential: Wärtsilä’s GEMS, an advanced energy management system, has been set up to control the energy across the fleet of power sources, thermal, renewable, and battery storage. The integration, control, and optimisation capabilities provided by GEMS allow the thermal units to be run at the most efficient rate and enable the battery storage to handle the large load step changes and volatility of the solar PV generation assets.

Integrated hybrid energy solution

In the context of the Fekola mine, which is an off-grid electrical island, the battery is performing a lot of different services simultaneously, including frequency response, voltage support, shifting solar energy, and providing spinning reserves. The energy load is very flat, with a steady consumption rate around 40 MW as the mining equipment is operating consistently, 24/7. However, if an engine trips offline and fails, the battery serves as an emergency backstop. The controls reserve enough battery energy capacity to fill the power gap for the time it takes to get another engine started, and the software inside each inverter enables the battery to respond instantaneously to any frequency deviation.

The reciprocating engines operate most efficiently at 85-90% of their capacity: this is their ‘sweet spot’. But if there is a sudden spike in demand, if a little more power is needed, or if mining equipment is coming online, then another engine needs to be run to meet the extra load.

With the battery providing spinning reserves, the engines can be kept running at their sweet spot, reducing the overall cost per kilowatt hour. Moreover, with the solar plant providing power during the day, three to four engines can be shut down over this period, providing a quiet time to carry out preventive maintenance. This really helps the maintenance cycle, ensuring that the engines operate in a more efficient manner.

Solar PV volatility can be intense. On a bright day with puffy clouds passing by, a solar farm of this size can easily see ramps of 25 MW over a couple of minutes. This requires intelligent controls, dynamically checking the amount of solar that can be let into the grid without causing an issue for the engine loadings or without overloading the battery.

Conducting the orchestra

The GEMS intelligent software provides the optimisation layer that controls all the power sources to ensure that they work together in harmony. The user interface (UI) gives access to all the data and presents it in a user-friendly way. Accessible remotely, all operations are simulated on a digital twin in the cloud to verify the system controls and simulate the most efficient operating scenarios to lower the cost of energy.

This is an important software feature, both during and after commissioning as it allows operators to train on the platform ahead of time and familiarise themselves with the automated controls and dynamic curtailment of renewables. The UI provides the forecast for renewables and the battery charge status at any given moment, it can provide push email or phone notifications for alerts; telling operators when to turn off an engine and when to turn it back on.

The software is constantly analysing the data and running the math to solve the economic dispatch requirements and unit commitment constraints to ensure grid reliability and high engine efficiency. Load forecasting integrates the different trends and patterns that are detectable in historic data as well as satellite based solar forecasting to provide a holistic approach to dispatching power. The Fekola site has a sky imager, or cloud tracking camera with a fisheye lens, that provides solar forecasts for the next half hour in high temporal resolution.

To ensure that operators really understand the platform, and have visibility over the advanced controls, the UI provides probability distributions of the solar forecast. Tracking the forecast errors enables operators to see whether the solar is overproducing or underproducing what the forecast was expecting at the time and provides visibility to the operators on the key performance indicators. This feedback is an important part of the machine/human interface and provides operators with insight if an engine is required to be turned on at short notice.

Automated curtailment enables the optimisation of the system providing a reactivity that people cannot match. By continually monitoring the engine loadings and battery, the system is ready to clamp down on solar if it gets too volatile or exceeds some spinning reserve requirement. For example, if a large, unexpected cloud arrives, the battery is dispatched to fill the gap while the engines ramp up. Once the cloud disappears, however, the engines remain committed to operating for a few hours, and the solar power is transferred to recharge the battery.

Over time, as load patterns shift, the load forecasting algorithm will also be dynamically updating to match the changing realities of the load. As mining equipment hits layers of harder rock, increasing the power load, the system will adjust and dispatch the engines accordingly.

The new gold standard

The Fekola mine project incorporates the largest off-grid hybrid power solution in the world, demonstrating the growing case for clean energy and its sustainable and economic potential for mines in Africa and beyond.

As the cost of batteries and solar panels continues to become more competitive, hybrid solutions are proving to be a realistic and effective means for increasing energy reliability and lowering operating costs in any context, thus freeing up resources to improve the human condition; whether through cheaper materials and gainful employment, or by providing broader access to reliable electricity for healthcare, education, and improved quality of life.

*This piece was written by Luke Witmer, General Manager, Data Science, Wärtsilä Energy Storage and Optimization

Solar hybrid power plant pays off for B2Gold at Otjikoto in Namibia

B2Gold has provided an update on the solar power plant working at its Otjikoto gold mine, in Namibia, in its 2018 financial results, confirming that the installation is making savings when it comes to heavy fuel oil (HFO) use and power generation costs.

On May 29, the company celebrated the official opening of the solar plant, one of the first fully-autonomous hybrid plants in the world.

At the time, B2Gold said it would allow the company to significantly reduce fuel consumption and greenhouse gas emissions from the site’s current 24 MW HFO power plant. The shift to an HFO solar hybrid plant was, at that point, expected to reduce Otjikoto’s HFO consumption by approximately 2.3 million litres and reduce associated power generation fuel costs by approximately 10% in 2018.

B2Gold selected Caterpillar and Cat® dealer Barloworld for the 7 MW solar power solution. The full system included Cat photovoltaic solar modules and the Cat microgrid master controller.

In the company’s 2018 results, B2Gold said the plant was now providing approximately 13% of the electricity consumed on site.

And, the plant had also achieved its expected HFO consumption and power generation fuel cost results: “Changing the power plant to an HFO solar hybrid plant reduced Otjikoto’s HFO consumption by approximately 2.4 million litres and reduced associated power generation fuel costs by approximately 10% in 2018,” B2Gold said.

Diesel power up and running at Tanami gold project, Zenith Energy says

Zenith Energy says it has achieved completion on the diesel portion of its 62 MW power station for Newmont Mining’s Tanami gold mine in the Northern Territory of Australia.

The remote power generation specialist said it had energised the 42 km 66 kV interconnect between the Dead Bullock Soak and Granites sites, enabling transmission of power for the site in line with previous estimates.

The agreement between Zenith and Newmont – a build, own and operate (BOO) contract for a 62 MW power station at the mine – is the largest such power purchase agreement Zenith has signed to date. It is for an initial 10-year term, with an option to extend the contract for a further 10 years.

“Zenith is also delighted to confirm that the supply commencement milestone of Q1 2019 has been successfully achieved, with numerous complex design, engineering, logistics and construction challenges met and overcome, resulting in the on‐time, on‐budget and safe completion of this landmark project by Zenith’s world‐class team,” Zenith said.

The power station comprises 52 MW of gas‐fired and circa 10 MW of diesel (back‐up) power generation. Zenith said: “To put the scale of the power station in perspective, the average Australian household consumes circa 25 kWh/d of power, whereas the Tanami facility will produce upwards of 864,000 kWh/d.”

With the completion of this facility, Zenith has 428 MW of total generation capacity under control.

The design and construction phase for Tanami required the transport of three 150‐t Wartsila 34DF generators by road train from Fremantle in Western Australia; a 3,000 km journey (pictured) taking more than one week to complete, according to Zenith.

Managing Director of Zenith Energy, Hamish Moffat, said: “The construction of our 62 MW power station at Tanami, on time and within budget, is testament to the capability and commitment of the entire Zenith Energy team. As the largest BOO hybrid gas‐diesel project we have undertaken, completion of the Tanami power station is a major milestone for Zenith.

“Diesel-fuelled electricity supply from the facility has commenced and gas supply is imminent. We look forward to delivering cost‐effective, reliable power to Newmont’s Tanami operation for years to come.”

Newmont’s Tanami underground gold mine produced 419,000 oz of gold (attributable to Newmont) in 2017.