The new technologies and innovations featured in this special report range from civil innovations to cloud-based monitoring systems. Learn more about these technologies and potential applications.
I used to buy in to that way of thinking that says hydropower is a “mature” technology, that not much changes from year to year in terms of new products or innovations. After all, why mess with what works? And, honestly, we weren’t hearing about a lot of flashy new technology or applications.
|Carbon fiber-reinforced polymer (photo courtesy QuakeWrap Inc.)|
Well, working on this article has changed my way of thinking. In researching, I uncovered a plethora of both new technology and innovative ways existing technology is being used at hydropower facilities worldwide. It was honestly rather astonishing and, I think, a reflection of a renewed interest in hydropower coupled with the need to make sure hydro stays competitive with some of the newer forms of generation that are changing the landscape (i.e., solar and wind).
This article only brushes the surface of the innovations out there, but we had to start somewhere. Read on to discover technical information, and applications if available, about 10 new technologies or applications of existing tech. I’m sure some of these will be useful and relevant at your hydropower facility or dam.
Penstock replacement alternative
Carbon fiber-reinforced polymer (FRP) is a viable repair alternative for large structures and pipes at hydroelectric facilities, as evidenced by the recent application of this technology to repair a penstock in Arizona in the U.S.
FRP has been in use since the 1980s and consists of a polymer reinforced with fibers. FRP is anisotropic, meaning the strength is different in the x and y direction and depends on the amount of reinforcing fiber present in each direction.
Carbon FRP can be used to repair and strengthen pipes and penstocks made out of all materials — including steel, concrete, fiberglass and even wood — with the resin- saturated fabric applied externally or internally to the deteriorated pipe. The carbon FRP extends the expected service life and adds pressure ratings that allow them to increase the volume of water that can flow through, thereby boosting electricity generation at the facility, according to manufacturer QuakeWrap.
Carbon fabrics — with a thickness of about 0.02 to 0.03 inch — are typically supplied in 24-inch-wide rolls hundreds of feet long.
Carbon FRP was used on a 10-foot- diameter, 5/8-inch-thick riveted steel penstock at the 10-MW Mormon Flat project on the Salt River in Arizona, U.S. The penstock had lost as much as 50% of its thickness in areas, and owner Salt River Project decided to repair the pipe with carbon FRP. Strengthening of the pipe included application of up to five layers of FRP, with a final abrasive-resistant coating sprayed over the FRP for protection against any small debris that may enter the penstock.
Challenges of this application were a repair area that included two 96-inch-diameter pipes about 15 feet long that merged into a single 120-inch-diameter, 45-foot-long segment; a drop in elevation of nearly 20 feet halfway through the repair section; and rivets that were longer than anticipated, adding difficulty in smoothing those regions. The repair has been completed and should provide a long-lasting, maintenance-free penstock, QuakeWrap says.
Satellite for greenhouse gas monitoring
GHGSat is using satellite technology to measure emissions of greenhouse gases from hydroelectric facilities. The company’s demonstration satellite, called Claire, captures 200,000 atmospheric measurements around an industrial facility in a few seconds. These measurements are processed to produce a “heat map” of GHG concentrations from the facility. Using weather data and these concentrations, GHGSat can estimate the rate at which an industrial facility releases GHGs into the air.
Claire, a low-cost nanosatellite, has been used to detect methane emissions from the 30-MW Lom Pangar hydro facility under construction at the existing Lom Pangar Dam on the Sanaga River in Cameroon. This marked the first time emissions from hydro plants were detected from space, GHGSat says.
|“Heat map” of greenhouse gas emissions from Lom Pangar hydro facility.|
The company then worked to acquire local data to validate the measurements, and continued to perform satellite measurements of the facility to monitor emissions rates over time. Electricite de France built this facility and manages it with Cameroon’s Electricity Development Corporation, and the partners are providing average wind data and details of dissolved methane concentration in water on both sides of the dam to help GHGSat personnel validate the measurements from Claire. This work is ongoing, and preliminary indications are that measurements were realistic and within a plausible range. It also confirmed that considerable degassing is taking place when water is released from the dam.
In the coming months, EDF will have a team at the facility with a weather station to provide accurate wind data, as well as the ability to measure methane concentrations in the water. GHGSat plans to work closely with that team to coordinate data gathered with future observations based on the satellite data.
GHGSat is building two new satellites that will incorporate lessons learned from Claire and enter service in late 2018 and early 2019.
Cloud-based asset management
Uptime is a cloud-based application developed by Uptime Analytics that allows hydro project owners and water managers to integrate data from multiple sources (such as ERP, CMMS, sensor, IoT and Excel) and use predictive models to aid in maintenance decisions.
Plant owners can understand the current state of the facility, including availability trends, top failure models and lost revenue due to failures. They can access data related to the maintenance plan, such as maintenance tasks grouped by frequency and skill and maintenance tasks associated with identified failure modes. The system can be used to monitor variables and understand failure behaviors or find failure patterns.
Uptime says that Chilean utility Pacific Hydro has used this system at its hydropower facilities for a variety of purposes, including optimizing the current maintenance plan, incorporating inspection tasks to anticipate asset failures, identifying the need to purchase critical parts, and definition of a continued improvement maintenance process.
Specifically, the Uptime equipment model was used for a 110-MW hydroelectric plant, and in defining failure modes Pacific Hydro realized there was a potential failure mode based on flooding the first floor of the plant. This was evaluated as a high risk, and one mitigating task was to plan to relocate the electronic equipment to second floor and to order spare parts needed for repairs in case of failure.
Two months later, the first floor of the plant was flooded. The electronic components had not yet been moved to the second floor, so they were damaged and the plant was shut down for repairs. Because the replacement parts had been ordered, downtime was two weeks rather than three months. Uptime says that understanding this failure mode and its criticality saved Pacific Hydro more than $3 million in lost revenue.
Energy recovery system
Generating electricity using the potential available in water pipelines and conduits is a definite trend in the U.S. Rickly offers a technology to do this, called the nCONDUIT-Hydro System. This “pipe-to-power” system uses a small turbine to capture hydroelectric potential at variable flow and head.
The system can be used at the outlet of existing dams and in municipal waterways, Rickly says. Turbine options include turgo; PROPEL, an axial flow turbine with a permanent magnet generator and adjustable guide vanes; and pump as turbine. The selection is based on a combination of design flow, design head and variability in flow.
The system is arranged to easily flange into existing infrastructure and has a standard control system to simplify the design. A remote monitoring function allows monitoring and simple adjustments, or the system can be integrated with the plant remote access system.
|nCONDUIT-Hydro System installed at a dam in Colorado, U.S.|
A 24-kW nCONDUIT turbine is operating at Beaver Park Dam in southern Colorado. The Colorado Department of Parks and Wildlife, which owns the facility, is using the turbine to generate electricity from water discharged from the dam via a cone valve, which previously was simply wasted potential. Electricity generated is used to power on-site automation, lighting and heaters.
Optical communication technology
The OceanLink free-space optical communication technology for Ethernet applications is being used by the German Research Center for Artificial Intelligence on its autonomous underwater vehicle Flatfish, but Sidus Solutions says OceanLink has applications for hydroelectric power.
Optical communication involves using light to communicate over long distances. Free-space optics is a point-to-point, line-of-sight technology that uses light propagating through free space to carry bidirectional data between two points, Sidus Solutions says. Free-space optics propagates through a vacuum, air, underwater, glass windows and other transparent objects.
|ROV view of intake riser at Cherry Lake Dam|
Benefits of using this technology include simple and fast installation, easy deployment of temporary installations, no government regulation or spectrum license or frequency coordination required, completely immune to radio frequency interference, secure with respect to outside intrusion, and low data latency.
Sidus Solutions says users can transmit sensor and video data through a water column, where normally they would have to install submersible conduit for electrical wires. This could be in the areas of penstocks, dealing with trashgates, or fish ladders — anywhere you need to get data and video from one point to another and running cable is expensive or completely unavailable.
Sidus says the best application to date for OceanLink involves its use for long-term submersible autonomous unmanned underwater vehicles (AUUV). These vehicles do not have to be tethered to the surface and complete their missions without human operators. The data required to complete its task is “beamed” to the AUUV through OceanLink wirelessly at the docking station. It will complete its task, return to its docking station to recharge, and upload the data wirelessly using OceanLink. The German center has integrated OceanLink with its Flatfish AUUV, designed to inspect oil and gas subsea structures.
Acoustic monitoring system
To detect and classify a wide range of mechanical phenomena in machinery, including hydroelectric turbines, acoustic monitoring is proving useful. This technology capitalizes on the fact that moving parts — whether solid, liquid or gas — produce a unique sound pattern and when something in that movement changes, the sound changes as well.
3DSignals is using this technology in its Predisound sound-based predictive maintenance system. Industrial-grade airborne ultrasonic-connected microphones, five times more sensitive than the human ear, are placed next to the machine. They have a sensing range of 0.1 feet to 10 feet. The sound is transmitted in real time via a secure connection to a cloud environment. Learning algorithms then analyze the audio signal, detecting anomalies and classifying them. The data can be accessed through a web app from any device.
3DSignals says the system can be used to identify irregular behavior, empowering the maintenance team to identify and address surfacing production problems, as well as identify the root cause. Use of the system can reduce unplanned downtime and critical equipment failure. Many failure types can be detected: stuck or broken valves, cracking or wear in bearings, shaft misalignment or bending, cavitation and much more.
Enel Green Power in Italy is using this technology for monitoring its hydroelectric generators. 3DSignals says Enel has complex processes wherein one power generation unit sound like one machine when in fact it’s a large collection of machines — generator, bearings, peripheral systems, electrical motors, hydraulic systems, and valves. With the Internet of Things, hundreds of sensors may be needed to get the full picture of process flow and condition. Instead, 3DSignals’ technology can monitor systems with fewer than 20 sensors per plant. The company says it will be installing its Predisound technology in some of Enel’s U.S. hydropower plants as well, based on the results obtained.
Underwater dam inspections
Inspections of embedded structures at depths of 250 feet is a challenge, and one Deep Ocean Engineering was able to overcome using its Phantom T4H ROV.
The unique package used to inspect the intake riser at Cherry Lake Dam in California consisted of the use of a third-party dynamic positioning-capable triple pontoon boat with a forward-mounted ROV launch and recovery system. This boat deployed the Deep Ocean Phantom T4H ROV to the coordinates of the intake riser, where it scanned the area with an Imagenex 88a Sonar. It descended 258 feet to the intake riser and flew inside, where it employed LED and HID lights from Deep Sea Power and Light.
The ROV inspected the structure and observed the dam’s internal condition. The dam was built in 1956 and has provided water and power to the San Francisco Bay Area and to the Modesto and Turlock irrigation districts for more than 60 years. The structure has not been seen since its construction, Deep Ocean says.
The video images were seen with such clarify that the dangers of using saturation divers and further intervention were completely unnecessary, the company says. Using the data collected, the San Francisco Public Utilities Commission was able to determine the state of the intake riser and is preparing for major rehabilitation construction later this summer.
Deep Ocean says 258 feet is about a quarter of the ROV’s rated capability.
Modular construction technology
Use of modular precast elements to build hydropower facilities and dams can reduce the cost of this work by half, says French Development Enterprises. The company says physical civil construction is the largest single component of new hydropower development cost, from 40% to 90% of total capital cost depending on the project size.
To address this situation, FDE has developed a technology, called the French Dam, that is based on modular components manufactured off-site in a controlled environment. These modules can be secured to the riverbed using underpinning and interconnected with adjacent modules to complete a dam.
The French Dam technology was developed through funding provided by the U.S. Department of Energy to advance the manufacturing and installation of hydro facilities with low environmental impact. In fact, FDE’s chief executive officer was part of the task force that completed DOE’s Hydropower Vision report in 2016. And FDE is part of DOE’s new Standard Modular Hydro task force.
To date, the company has only built test dam systems. This includes completing the design of a low-head cast-in-place dam in Rhode Island and building and testing a 16-foot-by-24-foot French Dam prototype in 3.5 hours. However, FDE is currently bidding on two projects, a 1-MW powerhouse and a privately owned high-hazard dam that is 200 feet long and 20 feet high. So, a practical application is expected in the near future.
Partial discharge monitoring
On-line monitoring of partial discharge (PD) can be a valuable asset management tool. Continuous monitoring of PD can help plant owners identify mechanisms responsible for the deterioration of stator winding insulation in motors and generators. Weak points in the insulation can be detected at an early stage and machine failures avoided through the early implementation of condition-based maintenance and repair measures.
Omicron recently released MONGEMO, a permanent monitoring system. The technology offers synchronous, four-channel PD data acquisition, noise suppression and fully automated PD cluster separation, recording of raw PD data at selected intervals, and “seamless integration” of third-party monitoring devices and SCADA systems, Omicron says.
|French Dam modular precast construction technology|
It has been used to monitor hydroelectric facilities in Austria, France, Germany, India and the U.S., the company says.
Water quality measurement
EOMAP GmbH & Co. KG uses an operational physics-based monitoring system for Earth observation that provides globally harmonized measures of water quality parameters — including turbidity, chlorophyll and organic absorption — from a number of satellite sensors.
The system is applied for daily monitoring in coarse resolution (500 m) and in a resolution of 10 m to 30 m with up to three-day sampling intervals. The results are continuously published over EOMAP’s eoApp service, a web application allowing easy online access to daily measurements and time series at freely selectable virtual stations for any location worldwide.
EOMAP also offers the eoApp 2.0 web application and easy API interfaces that directly stream various satellite-based environmental information into the client’s geospatial or decision-making environments.
The system has been used to monitor river sediment and turbidity in the Mekong River near Xiaowan Dam in China, EOMAP says. Xiaowan Dam impounds water for a 4,200-MW hydro facility. The client was the Southern Institute for Water Related Resources Vietnam. Use of EOMAP allowed the client to perform impact assessment 30 years back in time, the company says.
Elizabeth Ingram is managing editor of Hydro Review.