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Impact of Tidal Generation on Power System Operation in Ireland A. Garth Bryans, Member, IEEE, Brendan Fox, Peter A. Crossley, Member, IEEE, and Mark O’Malley, Senior Member, IEEE
Abstract—Tidal stream generation is a form of renewable energy that is predicable but variable in nature. The paper initially identifies the tidal resource around Ireland, utilizing the most appropriate and developed tidal energy technology, thus providing a potential magnitude and output profile. Methods of deployment and control, including the down rating of the generator relative to turbine size and operational output reduction, are suggested to reduce capital cost, increase the capacity factor and reduce the impact on the grid system. The combination of the potential resource and the application of control methods provide the basis to study the effect on the grid system in terms of ramp rate and the demand profile. The same inputs also provide the ability to analyze generator characteristics such as the capacity credit. Index Terms—Capacity credit, generator characteristics, ramp rate, system operations, tidal generation.
NOMENCLATURE EU TED IEDR OEDR NI NIE ESB TG TSO RoI UK
European Union. Tidal Energy Device. Installed Electrical Down Rating. Operational Electrical Down Rating. Northern Ireland. Northern Ireland Electricity. Electricity Supply Board. Tidal Generation. Transmission System Operators. Republic of Ireland. United Kingdom. I. INTRODUCTION
T
HE 1997 Kyoto Protocol has set down legally binding emissions targets for countries and groups of countries such as the EU, as of 2005 [1]. The EU Burden Sharing Agreement has allocated individual targets for its member states, under which the RoI and the UK have agreed to prevent their emissions exceeding 113% and 87.5% of 1990 levels by Manuscript received March 7, 2005; revised May 31, 2005. This work was supported in part by Northern Ireland Electricity’s SMART program (Sustainable Management of Assets and Renewable Technology), in part by the U.K. Department of Enterprise, Trade, and Investment (DETI), and in part by Sustainable Energy Ireland. Paper no. TPWRS-00133-2005. A. G. Bryans is with Queen’s University Belfast, Belfast BT9 5AH, U.K., and also with University College Dublin, Belfield, Dublin 4, Ireland (e-mail: garth.bryans@ ee.qub.ac.uk). B. Fox and P. A. Crossley are with the School of Electrical and Electronic Engineering, Queen’s University Belfast, Belfast BT9 5AH, U.K. (e-mail:
[email protected];
[email protected]). M. O’Malley is with the Department of Electrical Engineering, University College Dublin, Belfield, Dublin 4, Ireland (e-mail:
[email protected]). Digital Object Identifier 10.1109/TPWRS.2005.857282
2010 [2] respectively. Further targets have been set down by the European National Emissions Ceiling Directive (NECD), which is aimed at controlling acid rain through reducing emisand [3]. Most of the emission savings sions such as are expected from the electric power generation sector, so the EU has a target to produce 22.1% of its electricity by renewable generation by 2010. Within this target, the RoI has agreed to produce 13.2% and the UK 10% from renewables [4]. The main thrust of Ireland’s response to the EU target has been provided to date by wind generation, which currently supplies about 3% of the Irish demand. However, there is concern about the feasible level of wind generation that can be absorbed by the system, and there is a desire to achieve greater diversity of renewable energy supply. TG offers an energy source which is largely predictable. Also, tests on a medium-sized prototype have confirmed that the technology can deliver renewable energy at little extra cost to consumers [5]. Although other forms of ocean energy exist, such as wave, and ocean thermal, neither has been shown to be economically viable. Whilst further development of the technology may change this, wave energy is correlated to wind energy and so does not offer diversity. Also, Ireland does not benefit from the large temperature gradients required for ocean thermal energy production [6]. Tidal generation is expected to replace the marginal plant on the Irish system. These consist mostly of single and combined and . cycle gas turbines which do not produce much By contrast, the base loaded units which produce most of the and are unaffected by TG. Therefore, while TG will reduce emissions, it provides little benefit in terms of reand [7]. However, the prospect of reducing ducing emissions in proportion to TG, at a modest cost to the consumer, provides sufficient impetus to study the impact of TG on system operation and control. The transmission system on the Island of Ireland is operated as two areas: the NIE system in NI and the ESB system in the RoI. The NIE system comprises a 275-kV double-circuit ring with an underlying 110-kV system. The NIE demand ranges from 550 MW to 1750 MW. The ESB transmission system consists of a 400-kV grid with underlying 220- and 110-kV systems. ESB demand ranges from 1600 to 4400 MW. The systems are linked by a 400-MW inter-connector, with plans for reinforcement. The combined system is inter-connected to Scotland through the NIE area by a 450-MW HVDC link. Generation on both systems is in large units, relative to system size, of up to 400 MW. When considering a new form of generation for development and investment, it is important for TSOs to understand the
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challenges and advantages for system operation. The paper will identify the tidal resource available to Ireland, and the technology which is currently in the leading position to develop this resource (Section II). Methods of deployment and control will be considered to minimize the effect of a fluctuating generation source on the grid system and to provide the best possible return for capital investment (Section III). Both the tidal resource and the methods of control and deployment will be combined to study the potential effects on the grid system (Section IV) and the characteristics of tidal generation (Section V). Conclusions are given in Section VI. II. TIDAL RESOURCE Tidal energy is driven by the gravitational effect of the moon and the sun on the earth’s oceans. The earth rotates within this gravitational field, resulting in two high waters and two low waters each day. The tidal range depends on the location of the moon relative to the sun. When the moon and the sun are in line their gravitational forces produce a large spring tide, and when they are at 90 to each other they produce a much smaller neap tide [8]. The existing method of harnessing tidal energy is to capture the high water behind a barrage and then to exploit its potential energy by allowing it to flow out during low water [9]. However, this method prolongs the period of high water in the estuary, thus endangering the original estuarine ecosystem. It is also only able to generate power during low water. The capital cost of developing a barrage system is very high, forcing investors into an all or nothing gamble. The prospect of investing incrementally in a few small tidal energy devices is more attractive to them. Recent developments in tidal generation have focused on harnessing the kinetic energy of the tidal stream as the tide moves from high water to low water and vice versa. The resulting profile of power output has four peaks per day with a 14.7-day cycle over the spring neap period (see Fig. 1). Fifteen TED designs were investigated in this study including Stingray in Scotland [10], Hammerfest StrØm in Norway [11], TidEl in England [12], Verdant Power in New York [13], and Hydroventuri in San Francisco [14]. Only one developer was found to have a system with a full size prototype, with further funding to develop a commercial system that is scalable, generates power during both the ebb and flood tide and utilizes power from the entire water column. This TED, developed by Marine Current Turbines Ltd. (MCT), is based on a two bladed variable pitch horizontal axis turbine. Each unit consists of a pile driven into the seabed, with a horizontal support wing on the pile with a turbine on each end (see Fig. 2). This wing can be raised out of the water so that the turbines can be removed and serviced. MCT have developed this system to be viable in the areas of greatest energy density and minimum technical challenge to support the technology through its infancy. The MCT TED is considered viable in areas with a spring tidal current exceeding 2.2 m/s, in depths between 20 and 40 m [15]. The resource assessment around the Island of Ireland was based on an oceanographic database containing data with a grid square resolution. The key criteria were: maximum 405 spring current velocity; maximum neap current velocity; sea
Fig. 1. Power profile resulting from the velocity profile during a spring neap cycle.
Fig. 2. TED system developed by MCT [16].
bed depth; maximum probable wave height in 50 years; seabed slope; significant wave height; and the distance from land. The potential power output from each grid square was approximated from the velocity at a given time according to the following equation: (1) where blade area; efficiency; current velocity; site feasibility factor; water density. The velocity was estimated at 15-min intervals during a spring neap cycle by assuming a sinusoidal variation between the spring and neap tides, whilst the semi-diurnal variation was driven by a 12.4-h rectified sinusoidal pattern [8]. The blade area was based on a maximum rotor diameter of 15 m. Unlike wind turbines, which have to accept wind coming from any direction, TEDs only have to accept the tide from two directions, therefore they should be installed in rows. Devices have been given minimal spacing between each other along these rows. The spacing between these rows was limited to 15 rotor diameters. No limitation was put on the ratio of row length to number of row. Until measurements have been taken of current flow around a full-scale commercial turbine, it is not possible to develop a reliable assessment of optimal turbine spacing
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Fig. 3. Areas found to be viable for an MCT system limited to a spring velocity > 2:2 m=s in 20 to 40 m of water. TABLE I
Fig. 4. Energy lost as a result of IEDR or OEDR applied as a cap on net TG output.
TIDAL STREAM RESOURCE AVAILABLE TO IRELAND CONSIDERING THE CURRENT TECHNOLOGY AND POTENTIAL DEVELOPMENTS IN THE FUTURE
capital cost (Section III A). Secondly, the electrical down-rating (EDR) of individual TEDs can be supplemented operationally by system TG curtailment (Section III B). It will be seen below in Section III C that this supplementary control may be necessary when EDR is applied to TED’s located to avail of tidal phase superposition. Control interactions were investigated by using the theoretical outputs of one or more identical turbines based on the velocity profile shown in Fig. 1 and (1). A. Installed Electrical Down Rating (IEDR) and density. The turbine efficiency was set to 40% [5] and the site feasibility was set to 60% to account for obstacles to development not seen on the coarse grid resolution used [5]. The factors limiting the development of a site for a TED (in this case the MCT system) were tested against the database criteria and those grid squares found to be viable were noted. These are shown in Fig. 3. The power available from the TG resource was found to be 72 MW on average over a year, with a maximum output of 374 MW during a spring tide–see Table I. This is about 2% of the current Irish electrical energy demand. The authors expect that, as the technology matures, developers will increase rotor diameter and deploy the TEDs in deeper water. Such developments would significantly increase the power output from a single turbine and may make operation in a lower current speed viable. Therefore such scenarios have been included in Table I. III. TED DEPLOYMENT AND OPERATION The operational and control methods which enable the developer to maximize return and the system operator to limit any adverse effect of tidal generation on the system were identified and included within studies on system impact and TG performance. Two methods, described in this section, of controlling the TED systems have been considered. First, TED energy production cost can be reduced by spilling energy at times of peak tidal current in order to reduce installed TED electrical rating and
The power output from a turbine, harnessing all the power available to it, reaches its maximum output twice a month (see Fig. 1). By feathering the blades during spring tides, it is possible to decrease the rating and cost of the support structure, the drive train, the generator and grid connection. For example, with an IEDR of 40%, only 10% of the available energy is lost (see Fig. 4)—this down-rating would probably be cost-effective. B. Operational Electrical Down Rating (OEDR) The net output of all the tidal generators on the system may be controlled by applying operational curtailment beyond IEDR. For example, the system operator may deem the additional ramping on the system to be excessive at times when the tidal ramping is in opposition to the demand ramping. C. Tidal Superposition Most tidal forcing in shelf seas and gulfs is driven by the tides in the deep ocean. These establish standing waves near coasts. As with any standing waves there are nodal points of zero tidal range, known as amphidromic points. The tidal induced wave rotates around these points due to the earth’s rotation. If two TED clusters were placed at points of identical tidal resource 3.1 h (90 ) out of phase with each other, it would be possible to reduce the semi-diurnal variation in the generation profile. Four TED clusters 1.55 h apart would further reduce daily variation (depending on cut-off speed). Note that this will have no effect on the power variation caused by the spring neap cycle. Whilst
BRYANS et al.: IMPACT OF TIDAL GENERATION ON POWER SYSTEM OPERATION IN IRELAND
Fig. 5. Effect of IEDR and OEDR on the theoretical net power output of four identical TED clusters with identical tidal resource 1.55 h apart.
this approach may be possible in many other parts of the world, the major areas of tidal resource around Ireland offer a maximum phase difference of just 1.25 h. In areas where it is possible, it may seem sensible to implement both IEDR to optimize the economics of TED plant, and tidal superposition to reduce the semi-diurnal variation experienced on the system. A study of four similar TED clusters with identical resource situated 1.55 hours out of phase was undertaken. With no EDR, the power output variations from the dispersed TED clusters cancel (Fig. 5, no EDR). When IEDR is applied, output capping of some clusters reduces the smoothing effect of superposition (Fig. 5, 50% IEDR). This may increase the necessary ramp rate of conventional generation. However, it is possible to reduce this “spiking” by introducing OEDR, as shown in Fig. 5 (50% OEDR). The addition cost of utilizing OEDR can be seen in Fig. 4, which demonstrates the decreased energy production. IV. EFFECT OF TIDAL GENERATION ON THE SYSTEM The shape of the demand profile gives a good indication of the level of marginal generation which has to be run during peak times, as well as the rate of demand change. The recorded generation data for 2003 was scaled to 2006 using an annual demand growth of 1.8% for NIE and 3.2% for ESB, with house load of 4% subtracted [17]. The theoretical tidal profile available to the system, following application of IEDR and OEDR, was subtracted from the combined ESB and NIE demand data to give the demand profile that conventional generation has to supply (Fig. 6). The profiles with and without TG were then compared to assess the effect on system ramp rate and on the demand profile. Tidal generation has its greatest effect during a spring tide when the tidal flows are strongest. Although the time of high water moves forward by 50 minutes each day, the time of high water during a spring tide occurs at about the same time of day. Thus the average annual energy depends on the time of day, as shown in Fig. 7. This correlation of tidal flows with time of day,
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Fig. 6. 2006 winter day net demand profile with (dashed) and without (solid) a 72 MW (average) tidal resource during a spring tide.
Fig. 7. Average annual power output from 100 MW (average) tidal generation and the average Winter demand over 24-h period.
and hence system demand, reflects the sun’s influence on the tidal pattern. Fig. 6 illustrates the effect of a 72-MW average TG resource on a 2006 demand profile during a spring tide. It was found that the TG results in a delay in the morning rise and exaggerates it. However peak TG also coincides with peak demand. Generation must ramp up and down to match system demand. A concern of TSO’s relating to variable forms of generation is the maximum ramp rate to which the system is exposed – see the demand variation in Fig. 6 between 5 and 10 h. To quantify this effect, 2006 seasonal demand profiles were considered. The maximum ramping up and down rates for each season were determined for a tidal resource with an average generation of 100 MW. The exercise was repeated with the TG profile stepped forward by one day up to seven days. This phase shifting of the TG over seven days provides a complete picture of long-term effects. It was found that an average tidal generation of 100 MW caused the maximum ramp-up rate to increase by a few megawatts per minute or 16% (see Fig. 8). This is due to the TG causing a steeper morning demand rise (see Fig. 6). However,
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Fig. 8. 2006 system ramp rate with no tidal generation and following the addition of 100 MW (average) of tidal generation. Fig. 10. Availability factor versus EDR. Note that in one TED area the availability factor is equal to the capacity factor.
duced. However, if IEDR is applied to these systems, the resulting spikes in the net power output, as seen in Fig. 5, cause the combined ramp rate to increase from the profile seen for two TED areas under OEDR to that seen one TED area under IERD (Fig. 9). V. TIDAL GENERATION PERFORMANCE CHARACTERISTICS It is useful for the system operator and developers to have an understanding of tidal generation characteristics, including TED capacity factor (average TED power output/rated TED power output), availability factor (average TG power output/maximum TG power output), and TG capacity credit. Fig. 9. Maximum TED ramp rate following EDR applied to the TEDs individually and to the net output. In cases with two TED clusters each area is assumed to have the same resource magnitude as the single cluster (while this may appear to double the capacity it should be remembered that these are generating at different times).
the only noticeable effect on the rate of ramping down was an increase during the summer. The potential benefits from IEDR in terms of reducing ramp rate were studied by determining the net generation ramp rate from the theoretical outputs of two similar TED clusters with identical resource sited 3.1 h out of phase (superposition). With tidal superposition the ramp rate would decrease (see Fig. 9). However, the level of IEDR required to cause this was considerable because the point of maximum ramp rate occurs mid way down the power curve (see Fig. 1). The decrease occurs in a stepwise manner because no one point remains the maximum point continually as the EDR is increased. Instead, a particular point during the season is found to have the maximum ramp rate. If the EDR is increased until this point is removed, then a new point is found, so the ramp rate is decreased in steps. Further studies of the effect of IEDR on the system ramp rate for the predicted Irish tidal resource indicate that this stepwise effect is very prominent due to variations in the demand profile. In systems with tidal superposition, the ramp rate will initially be much lower because the diurnal variation has been re-
A. Capacity and Availability Factors The “capacity factor” is the average generation of an individual turbine as a fraction of its rated output. This is an important consideration for investors and developers. With conventional generation the capacity factor could also be used in conjunction with the expected down time, by the system operator, as the probability that the generator will be available to the system. However, with tidal generation, the availability of the overall TG is different from the capacity factor of individual TEDs, due to tidal superposition. Therefore, this has been termed the “availability factor”. Both the capacity and availability factors were studied using two TED clusters. The capacity factor of a single turbine cluster increased from an initial value of 0.19 to 0.6 as the EDR increased from 0 to 90% (see Fig. 10). The improved system availability factor obtained by locating the turbines at complementary tidal phases can be seen in Fig. 10, with the availability factor at an EDR of 0% increasing to 0.37. However this benefit to the system is reduced if IEDR is applied without OEDR, due to the “spiking” seen in Fig. 5. This is similar to the ramp rate in Fig. 9. B. Capacity Credit The capacity credit that a generator offers the system is a measure of how much extra demand could be supplied while maintaining the permitted annual period of load shedding (8 h/year
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weekly patterns are significant because the spring neap cycle has a period of 14.7 days. Hence, the peak power output will occur on the same day on alternate weeks for a number of weeks. The effects of this were studied by phase shifting the TG in increments of one day up to seven days. When the spring tide occurred during weekends over the peak period, TG capacity credit decreased to 10% of installed capacity. C. Cut-Off at Minimum Velocity Much like wind turbines, it is expected that tidal turbines would have a minimum operating velocity below which the turbine would be switched off. The effect of this on TED performance was studied by setting the cutoff velocity to 1 m/s. This had a minimal effect on any of the results including the resource, because cutoff applies when power output is low. The effect on energy production is negligible. Fig. 11. 2005.
Capacity credit offered the Irish grid system by tidal generation during
VI. CONCLUSION on the Irish grid system [18]). While increasing demand uniformly by a base amount is less realistic than increasing it by a multiple, it is more compatible with previous studies of capacity credit which assess the amount of generation that can be displaced from the system [18]. Therefore, the demand was increased using a constant base amount. Each generator on the system has a probability of unscheduled outage, typically between 0.01 and 0.10, and the percentage of time it must be taken out on scheduled maintenance. A maintenance profile was developed for each season, to maintain as steady a level of generation capacity as possible throughout the season, while giving all generators their seasonal outage period in one block of time each season. The Monte Carlo method was used to simulate forced outages by giving each generator a random on/off setting weighted to its unscheduled outage probability [19]. This can be repeated for each time step in the year’s demand data. The demand was then incremented until the permitted load shedding occurred, giving the capacity credit. The capacity credit offered by TG was assessed for the Irish system during 2005 (due to availability of generator data), first with no EDR, and then with IEDR of 50%. The results showed that with no EDR, an average additional demand of 17.9% (see Fig. 11) of the installed capacity of tidal generation could be supported. With IEDR of 50% this increased to 19.3% of the installed capacity. However, it must be noted that the installed capacity of a TED is taken after IEDR, and that the energy available per installed megawatt increases as the IEDR is increased. To quantify the benefit that Ireland may gain through having maximum spring tide generation at the time of peak demand (see Figs. 6 and 7), a study was run with no EDR and with the tidal generation phase shifted by three hours (impractical for Ireland, but equivalent to shifting Fig. 7 by 3 h). In this case TG was found to support on average an additional 11.7% of TG capacity (see Fig. 11). Therefore the benefit gained from the coincidence of maximum tidal generation with peak demand is that capacity credit increases from 11.7% to 17.9% of TG capacity—an increase of 53%. There is a weekly as well as a daily demand pattern, with weekends having a much lower demand than weekdays. The
The TED under development by MCT was deemed to be the most likely tidal generation system to be deployed commercially. Ireland was found to have a resource available to the first generation of TEDs of 374 MW of turbine capacity, giving an average power of 72 MW with no down-rating. While the concept of tidal superposition would reduce daily variation, most of the tidal resource around Ireland is separated by 1.25 h at most, limiting such use. However the electrical down-rating of turbines offers both economic advantages to developers and reduces the effect on the system. The times of maximum tidal generation occur immediately before the morning rise in demand. This leads to an increased maximum system ramp rate through delaying and hence exacerbating the morning rise. The addition of a 100-MW (average) tidal resource is predicted to cause the maximum ramp-up rate for the Irish system to increase by 16% on the basis of 2006 demand profiles. Spring tidal generation in Ireland coincides with the system demand peak. This enhances the economic value of the resource. TG was found to provide capacity credit equal to 17.9% of its installed capacity when the spring tide occurs on a weekday during the period of peak demand. Ireland is fortunate in the location of its tidal resource, had the resource been located in an it would have reduced areas where the time of high water is the capacity credit of TG from being able to supply 17.9% of its installed capacity to 11.7%. However, the capacity credit will drop to 10% of its rating when the spring tide occurs during a weekend over the peak period. Tidal energy is therefore seen as a form of renewable generation that will provide a modest amount of generation on the Irish grid system in the near future. The effect of such levels of tidal generation on the system is acceptable. Methods have been presented to moderate these effects if necessary. ACKNOWLEDGMENT The authors are grateful for the support provided by Queen’s University Belfast and University College Dublin in hosting and supervision for the project. The authors thank the Danish
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Hydrographic Institute for providing the tidal modeling software “Mike21,” Kirk, McClure and Morton, and Northern Ireland Electricity for providing data and guidance, and the British Oceanographic Data Centre for providing wave data. REFERENCES [1] United Nations, “Kyoto Protocol to the United Nations Framework Convention on Climate Change,”, United Nations. FCCC/CP/1997/L.7, 1997. [2] “EU: Council decision of 25 April 2002 concerning the approval, on behalf of the european community, of the Kyoto protocol to the United Nations framework convention on climate change and the joint fulfillment of commitments there-under,” Offic. J. Eur. Commun. (2002/358/EC), 2002. [3] “EU: Directive of the european parliament and of the council of 23 October 2001 on national emission ceilings for certain atmospheric pollutants,” Offic. J. Eur. Commun. (2001/81/EC), 2001. [4] “EU: Directive of the european parliament and of the council of 27 September 2001 on the promotion of electricity produced from renewable energy sources in the internal electricity market,” Offic.l J. Eur. Commun (2001/77/EC), 2001. [5] T. Whittaker, P. L. Fraenkel, A. Bell, and L. Lugg, The Potential for the Use of Marine Current Energy in Northern Ireland: DETI, 2003. [6] G. T. Heydt, “An assessment of ocean thermal energy conversion as an advanced electric generation methodology,” Proc. IEEE, vol. 81, no. 3, pp. 409–418, Mar. 1993. [7] A. G. Bryans, E. Denny, B. Fox, P. Crossley, and M. O’Malley, “Study of the effect of tidal generation on the Irish grid system: Resource and emissions,” in Int. Council on Large Electric Systems (CIGRE) Symp., Athens, Greece, 2005. [8] T. G. Pugh, Tides, Surges and Mean Sea-Level. Chichester, U.K.: Wiley, 1987. [9] J. P. Frau, “Tidal energy: Promising projects–La Rance, A successful industrial-scale experiment,” IEEE Trans. Energy Conver., vol. 8, no. 3, pp. 552–558, Sep. 1993. [10] The Engineering Business.. [Online]. Available: http://www.engb.com. [11] Hammerfest StrØm (2002): Tidal Power Plant in Kvalsundet – The Installation of the Prototype has Started: Hammerfest StrØm, 2002. [12] SMD Hydrovision: TidEl. Data Sheet. Newcastle upon Tyne, U.K.: SMD Hydrovision, 2004. [13] New @ Nature, Nature: Tidal flow to power New York City London, U.K., 2004. [14] Hydroventuri.. [Online]. Available: http://www.hydroventuri.com. [15] Marine Current Turbines.. [Online]. Available: http://www.marineturbines.com. [16] M. Wright, “Seaflow tidal current turbine,” in Wave and Tidal Technologies Symposium, London, U.K., 2004. [17] “ILEX Energy Consulting Ltd.: Operating Reserve Requirements as Wind Power Penetration Increases in the Irish Electricity System,” Sustainable Energy, Ireland, 2004. [18] “Transmission System Operator Ireland: Generation Adequacy Report 2004–2010,” Transmission System Operator, Ireland, 2003. [19] J. Fitzgerald, Generation Adequacy in an Island Electricity System. Dublin, Ireland: The Economic and Social Research Institute, 2004.
A. Garth Bryans (M’05) received the B.Sc. degree in marine biology and oceanography in 2003 and the M.Sc. degree in applied physical oceanography from the University of Wales, Bangor, U.K. He is currently pursuing the Ph.D. degree at Queen’s University Belfast, Belfast, U.K., and University College Dublin, Dublin, Ireland. Since October 2003, he has been studying the feasibility of large-scale tidal energy development in Ireland.
Brendan Fox received the B.Sc. and Ph.D. degrees from Queen’s University Belfast (QUB), Belfast, U.K., in 1966 and 1969. Following a period in the electricity supply industry, he joined Ulster Polytechnic, Ulster, U.K., in 1972 and QUB in 1980, where he is currently a Reader in Electrical Engineering. His teaching and research interests are in power system engineering, with a particular interest in the operational integration of renewable energy on a large scale. Dr. Fox is a Member of the IEE.
Peter A. Crossley (M’92) was born in the U.K. in 1956. He received the B.Sc. degree from the University of Manchester Institute of Science and Technology (UMIST), Manchester, U.K., in 1977 and the Ph.D. degree from the University of Cambridge, Cambridge, U.K., in 1983. He is a Professor of electrical engineering at Queen’s University Belfast (QUB), Belfast, U.K. He has been involved in the design and application of protection systems for 26 years, first with GEC, then UMIST, and now with QUB. He has published over 100 papers, and his research interests include power system protection, embedded generation, and condition monitoring.
Mark O’Malley (M’86–SM’96) received the B.E. and Ph.D. degrees from University College Dublin, Dublin, Ireland, in 1983 and 1987, respectively. He is currently a Professor at University College Dublin and Director of the Electricity Research Centre, with research interests in power systems, control theory, and biomedical engineering. Dr. O’Malley is Chairman of the United Kingdom Republic of Ireland Power Engineering Society Chapter.
