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Health Condition Monitoring of Small Scale Tidal Generators Using Miniature Torque Sensors

Periodic Reporting for period 1 - TidalHealth (Health Condition Monitoring of Small Scale Tidal Generators Using Miniature Torque Sensors)

Reporting period: 2015-03-01 to 2015-08-31

By 2050, the size of wave and tidal energy is expected to reach an installed capacity of 100GW, which will be able to power 66 million European homes and also enable the EU to meet its target of reducing emission of green-house gases by 80-95% below 1990 levels. Tidal generators are installed in very harsh environments of the sea-bed, where saline water, unpredictable tidal flow, marine debris and suspended particle impact can cause serious damage to generator blades and gearboxes. In addition, the unpredictable changing nature of load demand causes stresses on the tidal components. The primary objective of the TidalHealth project is to commercially produce a direct torque measurement device attached to tidal generator shaft for overall condition monitoring of tidal power plants remotely. This will result in the reduction of operations and maintenance cost of the plants and thus improves the return on investment for tidal technologies.

The objective of the TidalHealth technology is to develop a health monitoring system of tidal generators using torque sensors attached to the generator shafts. This system will be able to reduce the O&M cost of the tidal power plants and thus successfully commercialize the tidal energy market. The system targets a potential 796 billion Euro market of marine energy market with some special features USP (Unique selling point) like optimal mounting method of RF antenna for data communication, miniature sensors that take measurement from torque input directly.

More specific the objectives of the project were:

1. Development of detailed design specifications: For proper output of SAW sensors, they need to be directly attached to generator shafts. This study will test and implement optimized solution for different angles and methods for attachment of the sensor to shafts. TidalHealth system will be associated with optimized fuzzy logic algorithm and more accurate, control rules to use direct torque measurements as input. In the feasibility study the design parameters and regulations will be optimized for cost efficiency and better performance. Primary target can be fully operational efficiency for maintaining 10 MWh power generation plants which would be scaled up to 10 GWh power generation within first 5 years.
2. Feasibility study of data communication and signal processing of sensors: The sensors must have RF antennas coupled for signal processing and data communication. Parameters such as antenna positioning, range, data transmission protocols, channel for data communication and positioning of the receivers will be tested and implemented in this feasibility study for efficient optimization of the TidalHealth system. 100% data transmission efficiency is the goal of the study.
3. Planning a test rig: We will study the cost and implementation of a test rig with our TidalHealth technology. We are expecting to apply for SME instrumentation Phase 2. This complete study will help us to adapt the up-gradation. The goals will be to i) Reduce generator downtime (maximum 1 hour downtime for each generator of a plant), ii) Increase yearly power output (10% increase of power generation at the end of year 1).
4. IP protection: We have one patent in USA and two in Turkey. We also have applied for few other patents covering some specific aspects of our ideas on SAW sensors, fuzzy logic based control and signal processing algorithms. We currently plan to manufacture the devices at our own. But, we will study the monetary benefit of giving license of using our IP to some OEMs.
5. Identification of suppliers: In this feasibility study we plan to identify different components of the system and identify the potential suppliers for future negotiations. Supply components include SAW sensors, control systems, testing services for marine environment, automation related services and supplies control solutions etc. We will discuss with different component suppliers to obtain quote and to create a list of different component suppliers. We believe by expanding our component supplier search across the globe and by utilizing negotiating skill, we can keep the manufacturing cost down to €1.5 million.
6. Market research: The primary objective of market research is to study the nature of two different sections of market: tidal power generating bodies and original equipment manufacturers for tidal power plants. In order to reach the potential clients effectively, we need to study their need in detail. We will also research on possible extension of our market. Tidal Sense Demo, Epsilon Optics, Akoostix and SKF group are our potential competitors. We will make detailed study about them and try to recognize other potentials.
7. Risk analysis: We need to investigate different risks associated with the business plan, e.g.
• Failure to encourage the consumers to invest in TidalHealth technology.
• Dissatisfaction among users and switch to competitor products.
• Higher market penetration by the major competitors.
• Failure to assess generator health in more challenging regions.
• Failed data communication by the antenna attached with sensors.
8. Developing a Business Plan: By integrating the above mentioned objectives in the phase 1 study, we will develop a solid business plan for the commercial exploitation of this TidalHealth technology. This will include market opportunity (size, growth, needs), value proposition, commercialization strategy, IP strategy technology/solution description, , and financial projections
PARS Makina (Turkey) and Transense Technologies PLC (UK) have conceived a new condition monitoring solution for rotating shaft tidal stream generators that could help to establish predictive maintenance operation and thus operation reliability and endurance for this class of renewable energy device subject to harsh environmental conditions. The device as presently conceived is specified in section 1 and this report represents an analysis of the commercial suitability of such a development for the two companies.
Global energy demand is forecast to increase by 60% over the next 25 years and European energy demand is rising at a similar rate. To counter global warming and climate change, the EU has set a target for 20% of its energy requirements to be supplied from renewable sources, amongst which tidal energy is currently viewed as an emerging and leading technology with large European potential. By 2050, wave and tidal energy is expected to reach an EU installed capacity of >100GW – sufficient to power 66 million European homes, helping the EU to meet its target of 80-95% reduction in greenhouse gas emissions below 1990 levels. However, tidal power plants have not yet been fully commercialised and are currently driven through government or public sector subsidised projects. SI Ocean (supported by the EU Intelligent Energy Europe programme) has listed the primary challenges of commercialization of tidal power generation:
i. Enabling technology
ii. Risk management
iii. Technology fragmentation and design consensus
iv. Grid access, connectivity and infrastructure
v. Economic perspective
vi. Establishing equitable environmental mitigation measures.

Risk is, in this context, the probability of component failure within the service life of the
Tidal generator while reliability is the probability of the sytem components not
failing during service.These challenges have resulted in the high cost of installation, operation and maintenance of tidal power plants. Currently, Operations and Maintenance (O&M) represents 30% of the total cost of energy production in tidal based plants .

Sudden grid connectivity problems, generator shutdown and malfunctions are a regular occurrence with current generator technology. Grid synchronisation problems of power electronics are common and are mainly linked to insufficient advanced metering infrastructure including online torque data and maintenance and repair is expensive and time consuming due to marine supply logistics. This can lead to significant downtime or unavailability of the generator, with lost revenue. At a selling price of tidal energy equal to its production cost, (about €0.36 /kWh ), a single typical 1MW capacity generator loses ~€9K/day when shutdown, making private sector finance for tidal projects currently commercially unattractive. The average O&M expenditure on tidal turbines is typically 30% of production costs, i.e. €0.1/kWh. Global installed tidal capacity by 2014 produced 63TWh per annum (average capacity of a tidal plant ~9 GWh and ~7,000 tidal plants, many single generators, worldwide). The total O&M cost thus amounts to over €6Bn per year.

A Feasibility report has been produced in order to study the attachment of SAW sensors and optimised control rules for torque measurement system on generator shafts and the commercial plan to realise an economic initial deployment. This feasibility study sets out to examine the validity of a commercial solution to tidal generator health monitoring based on Surface Acoustic Wave (SAW) torque transducer device attached to a generator shaft, providing sensitive and real data on the performance of the tidal plant for optimised predictive maintenance intervention. Also, focuses on examining the implementation of optimised solutions for different angles and methods for attachment of the sensor to the shafts. In the feasibility study the design parameters and regulations will be examined for cost efficiency and performance.
TidalHealth aims to reduce the operations and maintenance costs associated with the production of electricity by tidal generators. For proper maintenance of these generators, the information regarding their operating conditions should be complete and accurate. TidalHealth will provide this information on generator health with a rigour and accuracy unmatched by any other commercially available system, and relay the information to a remote control centre removing significant need for on-site presence. Torque measurement provides direct monitoring of the crucial mechanical functioning of the generator and turbine shaft in the harsh environment encountered by tidal devices and thus provides the most important part of condition monitoring data. Coupled with sensitive electrical measurements of the power delivery a large proportion of the generator health is monitored. Thus, our device is capable of reducing by 10%-50% the O&M cost (total cost for a generator is around €0.1/kWh) of tidal generators. These savings will approach €300K per year for a typical 8.76GWh power plant (1MW operating 24/7). The payback period for a typical €40K sensor system installed on a 1MW generator would thus be on average about 2 months. In practice several sensors may be needed per generator but the plant should recover the installation cost within one year and generate cost savings for the remaining lifespan of the plant. O&M cost savings for generator customers using accurate direct strain health condition monitoring with wireless control, and increased generator reliability and thus investor confidence are our two unique selling points.

TidalHealth promises to effect significant disruption of the market for tidal power. Lack of detailed, long-term performance data on the reliability and operational efficiency of the myriad of different designs created to tap into this major renewables resource is hampering the uptake and large scale investment into tidal power. In the face of global warming the requirements of replacing up to 90% of global total energy needs from renewables by205060 and estimates of supplying 5% by tidal stream resources are warmly welcomed and commercial development programmes such as EMEC are significantly assisting progress with standardisation procedures, performance measures, planning and financial investment, but to accelerate uptake and meet EU climate targets of 20% renewables by 2020, financial confidence must be firmly established - now. TidalHealth condition monitoring can make an immediate contribution to this. By 2050 the EU target of 90% greenhouse gas emissions reduction from 1990 levels will be assisted by an estimated 100GW of installed tidal capacity.

A reliable health conditioning system will drive tidal power engineering development. The multitude of different generator designs will become dominated by a few designs that can demonstrate, early on, a high figure of generation revenue/operation cost ratio. Advanced designs have tended to focus on generation efficiency, neglecting operation costs, and it is here that TidalHealth will make an impact – efficient configurations such as CoRMAT will be engineered to be operated more reliably by the addition of SHM. The consolidation of tidal conversion variants into a few market-dominant types (Type III perhaps) will not only reduce development costs but financially reward both those engineering companies involved and the market investors in their systems. The market will move from exploratory one-off engineering to large scale production of more standardised systems competing on price.

It has been estimated that there are currently around 7,000 tidal generators globally which is expected to grow to 16,500 by 204057. The marine energy industry, consisting of wave and tidal based power, is expected to be of worth €800Bn in Europe, Canada and selected sites around the world. The development of TidalHealth is very timely. Commercialisation of the TidalHealth sensor will take advantage of the fact that tidal energy generation will increase significantly over the next 5-10 years as the production costs of tidal energy are declining and technological developments arise. Wave and tidal energy is expected to be deployed on a commercial scale due to large available resource and high market potential.
Quantified Global Resource of 25GW
Lab Experimental Setup
System Components Schematic