Tidal Resource Assessment for Wavehub

The Wavehub is attempting to understand whether there is any potential for deploying tidal energy devices at their location and they have hired you to do tidal resource assessment for them. They propose that you base your assessment on the 15 kW URdreaming device. The 8 m radius UR device has a cut-in speed of 0.2 and has a linear power curve up to its rated power (100 kW) which is achieved at 1.1 m/s. The UR device can rotate and auto adjusts so oriented directly into the folow. You are free to determinethe optimal depth for turbine emplacement but reminded that Trinity House will require 8 m clearance between the lowest sea level and the top of the turbine.

They are providing you with over 60 days of bottom mounted ADCP data recorded every 10 minutes from an RDI 600 kHz Workhorse Monitor. The Wavehub engineers have taking the original Matlab file and removed non-essential information, converted time into a useful format and saved this information as MAR512_tidal_data.mat. They are also giving you a script file which demonstrates how one might manipulate and plot the data (read_data.m). The Wavehub staff have carefully reminded you that ADCP data closer to the surface than 1/10th of the water depth is unreliable.

Wavehub staff request that you review the data, determine an appropriate period to perform the assessment, and do so.

• Information on the directionality of tidal currents
• information on the vertical variation in tidal currents
• A justified decision of at what depth the hub of the device will be deployed
• A justified decision of at what depth the hub of the device will be deployed
• Total velocity exceedance curve for the deployment location
• The total annual potential energy available for the deployment location
• An estimate of the total annual energy generation for the UR device at this location

1. T-tide and U-tide are very commonly used packages to do harmonic analysis on tidal signals. Respectively they are available at:

In addition to the minimum price contract (50%) for these products, additional payments will be provided for steps beyond the minimum. These include:

• Explanation of processing steps
• Clear statement of and justifications for assumptions made.
• Extension of the analysis beyond a single depth
• Clearly explained uncertainty estimates
• Use of depth variations in power calculations
• Extension of the analysis beyond the period of data collection
• Exploration of non-tidal forcing

The report is written and presented to a very high standard and includes analytic expressions for all the analysis performed on the data. Any data used for the analysis will have been cleaned in a fashion which maximizes data coverage, minimizes data of questionable quality, and is fully justified. A site characterization will be presented include basic information like depth, tidal range and mean spring and neap peak velocities and estimates of random flow fluctuations. The data analysis will include a harmonic analysis and subsequent extension of the tidal data to a virtual two year span throughout the water column. A proper process to estimate power across the entire turbine which accounts for depth variations in magnitude and direction will be developed and this will be used to generate exceedance velocity and power density graphs. The optimal vertical location will be determined and a total annual enery output will be provided. First Class Bonus (> 70%)

The report is written and presented to a very high standard. A process of data inspection and basic data cleaning will be performed. Some site characterization is presented which might include basic information such as depth, tidal range and/or mean spring and neap peak velocities. The data analysis will present a proper process to estimate power across the entire turbine which accounts for depth variations in magnitude and direction. Exceedance velocity and power density graphs will be developed. A vertical location and for turbine position will be provided along with a total energy output for a specified period of time.

The report is well written and presented. Data inspection and cleaning will be discussed. The data analysis will estimate power production along with providing exceedance velocity and power densisty diagrams. Variations indepth and direction will be discussed.

The report is written and presented in a fashion which permits comprehension.The data analysis will estimate power production along with providing exceedance velocity and power density diagrams.

The report is largely incomprehensible. No credible estimate of power production is provided and velocity exceedance and power density diagrams are substantially incorrect or absent.