Ocean energy conversion has been of interest for many years however factors such as increasing awareness of global warming, high energy prices and concern over energy security have renewed interest in the topic. Other marine renewables such as offshore wind and ocean current energy converters are far more mature than wave energy converters, however it has been recognised that there is a huge potential for wave energy to become a fully developed energy resource; with a UK offshore resource of between 600-700TWh.
Business Perspective: Some Fun Facts.
- The UK is committed to reducing its carbon emissions, with the first target set at 15% renewable, low carbon electricity generation by 2015.
- The National Grid does not expect wind farms to generate enough electricity for all our needs, meaning other sources are needed for a low carbon future.
- The energy in ocean waves is a significant resource with economically recoverable power capacity between 14% and 26% of 2008 UK con-sumption.
- The areas richest in ocean wave resource around the UK are the north western coast of Scotland and the South Western coast of England.
- Ocean WECs are currently amongst the most expensive electricity pro-ducing devices, the best being at around 7p per KWh, while wind farms produce at about 4p per KWh.
Given that Europe receives a large quantity of energy per m width of wave front (amounting to 2TW of power), it is safe to assume that wave power can make a significant contribution to our energy needs even with the low generation efficiencies (typically around 10%).
This project aims to test, optimise and develop a sustainable business/ddevelopment model for the wave energy converter produced in the Wave Project 10/11. There are a range of improvements which must be made to the device before it can begin to be tested. One area that required most development that of the instrumentation and measurement.
The following will be measured during the course of testing:
- Vertical acceleration experienced by the device (and hence velocity, displacement),
- Rack and pinion output shaft rotation speed (and hence mechanical output power),
- Electrical Power output from conversion system (a bicycle dynamo).
The instrumentation is being designed to operate effectively during dry tests and in a wave flume environment. In this con-fined space, only a 9V battery will be available. Voltage Regula-tor circuitry on a custom PCB (currently in the process of manu-facture) will provide the necessary supply voltages for:
- ADXL335 3-axis silicon accelerometer (3.3V)
- HOA2001 Optoschmitt sensor (5V, 1.6V)
- Sparkfun “μLog” low speed datalogger and Sparkfun Lo-gomatic mk2 high speed datalogger boards. (3.3V)
Custom Board Layout
Objectives for the project
- Test and optimize a rack and pinion based energy converter
- Determine the technical and commercial viability of full-scale deployment
- Generate an understanding of the theory behind a rack and pinion wave device designed to operate at a depth of 40m in open water for 30 years
- Gain an understanding of the commercial capability and costs of such a device
- Look into previous designs and gain an understanding of the market (legislative/competition/raising capital)
- Understand how to deploy a device on a macro scale and develop a successful full-scale business model
- Ensure existing device is working as expected by eliminating critical problems such as leaks
- Obtain experimental data on performance of existing device using wave flume, purpose-built instrumentation devices and power generation scheme
- Make mechanical improvements based on research i.e., try to eliminate or minimise the effect of specific weaknesses
- Obtain new experimental data by testing again using the same apparatus and conditions, thus determining effectiveness of alterations
With the completion of this project it is hoped that the wave energy converter will have a suitable business and development plan. Alongside this the power generation of the wave converter will be optimised following the aquisition of reliable testing data and there will be suggested improvements to the rest of the device, in areas such as optimised bouyancy, and heave plate improvements.
This will potentially allow for further research to be focused into the optimisation of the device to allow it to compete with other existing technologies and establish itself as the chosen wave energy conveter technology.