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Modernizing a hydro plant’s assets is crucial for maximizing the plant’s lifespan and ensuring reliable and sustainable energy generation. By updating hydropower equipment and technologies, the plant’s performance can be improved, leading to increased generation, as well as compliance with regulatory standards and cost optimization.
It can be an opportunity to turn back the clock, returning to the optimal performance delivered on day one. But it can also go further, bringing facilities up to date and up to standard – with equipment that complies with today’s regulatory standards and technology that delivers new capabilities and capacity.
From reconditioning a single component to refurbishing parts of an installation, to full replanting, modernization can prolong the life of your assets, extending their productivity and protecting your investment.
New technology, new capabilities, new efficiencies—it’s all within reach.
It is possible to transform your hydropower plant with modern technology, optimizing performance for future demands. By integrating modern technologies and designs such as fully automated control systems, remote monitoring, and digital management, an installation can gain new capabilities and efficiencies. Key updates and upgrades not only enhance current operations but also future proof a plant for years to come. One area of this work is the upgrading of old mechanical governors to advanced digital ones, ensuring precise control and longevity of the equipment, as detailed here at the Hurricane Hydro Electric Plant.
Increased annual energy generation – Hurricane hydro plant.
The Hurricane Hydro Electric Plant, which is fed from the Virgin River diversion dam, was originally supplied and commissioned in 1987. Reliable operation of the plant is critical for operators Washington County District Water Conservancy (WCWCD), as its outflow allows them to meet their obligation to provide a set flow rate in the river for downstream consumers and wildlife. Gilkes were invited to review the system regarding upgrading the control system and governor to improve reliability following 30 years of operation.
Hurricane intake
The mechanical aspects of the turbine were found to be operating in good condition despite constant attack from the sediment laden water abstracted from the river. The Turgo turbine has a reputation for excellent abrasion resistance, and this was in evidence here. Many parts that are in constant contact with the water are still originals from when the turbine was supplied. The superior resistance to wear of the Turgo compared to other turbine types, and the regular inspections and maintenance from operators, has meant the turbine can expect to provide reliable duty for many years to come.
The original spear valve actuators had become unreliable and frequently needed maintenance; therefore, these were upgraded to modern modulating rotary actuators to provide reliable control of flow through the turbine.
A completely new control panel suite was proposed replacing the existing control and switchgear. The suite was custom designed to fit over the existing cable ducts and to accommodate a roof mounted building services transformer, a bespoke control philosophy was also developed to meet the specific needs of WCWCD. To aid them in meeting outflow obligations, turbine flow control was largely separated from the operation of the generator, which now allows them to pass flow through the turbine while the generator is shutdown.
New hydraulic control module
The deflector control arrangement was completely revised to facilitate the new control philosophy. The original electric actuator was removed, and a hydraulic ram put in its place. The ram is operated by a hydraulic control module featuring an accumulator to ensure safe shut down. Control of the deflectors is by a new digital governor, which works to precisely match the generators speed to the grid prior to synchronization. Generator start up is now possible at any turbine flow rate above the minimum flow of the system, including at full turbine flow.
Hurricane Scope of Supply
• Full control & switching panel suite.
• Electric spear valve actuators
• Hydraulic control module for deflector control
• Bespoke control philosophy
The new control system is fully automated, improving the annual energy production of the generator significantly, due to higher reliability and lower operator dependence.
New control panels
Replanting – the ultimate upgrade for a hydropower plant
One region currently undergoing modernization programs is the state of Alaska, where hydropower plays a significant role in the regions grid, providing over 20% of its electricity. Due to various incentives and grants being offered, operators of hydro plants are exploring the possibility of upgrading their current facilities.
Recently, Gilkes Engineers completed a comprehensive modernization program at the Blind Slough hydro plant for Petersburg Municipal Power & Light. This project included a full replant of the existing turbine with a new twin jet Pelton Turbine.
The original Blind Slough hydro site, constructed in 1921, featured two 400 kW units. In 1955, a larger 1600 kW single jet Pelton turbine was added in a separate powerhouse. After more than six decades of service, the electrical components on the 1955 Pelton Turbine were nearing the end of their lifespan. The runner had already been replaced once after 25 years and was now worn out again.
Runner
A consultant’s report evaluated various options and highlighted the risks associated with unplanned outages due to equipment failures and challenges in sourcing spare parts for repairs. Consequently, it was determined that upgrading the plant through refurbishment and equipment replacement would be a more cost-effective solution. This approach aimed to ensure the continued operation of the plant for an additional fifty years.
Commissioned Pelton turbine
The customer specified that the replacement turbine needed to manage 25 cfs flow rate. A Pelton turbine remained the most appropriate turbine type, and with a 900-rpm machine, would require a twin jet unit. A compact configuration was going to be necessary to fit the new equipment into the existing powerhouse. Consequently, a specially designed 2197kW Twin Jet Pelton Turbine with an 850mm Runner was selected for this project.
Read the case study for the full electrical & mechanical scope of supply and the challenges faced during commissioning.
With enhanced overall efficiency, the Blind Slough plant’s 2MW output plays a significant role in the regional grid, contributing 4% of its total power.
Additionally, the plant can be operated remotely and supplies around 25% of the power consumed by Petersburg.
