Energy and Climate Change CommitteeWritten evidence submitted by Derek G Birkett (ISG 05)
Introduction
My name is Derek George Birkett resident in Highland Perthshire. I am a chartered electrical engineer having had extensive experience in the Electricity Supply Industry on installation, commissioning and operation, initially with the now defunct CEGB. For twenty years before retirement my employment was as a grid control engineer on shift with the North of Scotland Hydro Electric Board, becoming Scottish Hydro Electric on privatisation, subsequently Scottish and Southern and now SSE. This experience was preceded by control of hydro-electric plant over a four year period.
Since retirement at the millenium I have made a number of submissions to official bodies relating to renewable energy, acted as a witness at three public inquiries, two for wind farm applications and for the Beauly/Denny Transmission line application where I was an independent witness against the proposal. In July 2010 I had a book published by Stacey International titled “When will the lights go out?” warning of the risks being taken with energy supply by UK government policy on renewable energy.
This year I have given three public lectures, two of which were to engineering institutions.
Observations
My working experience has been entirely “hands on”. I have been dismayed by the absence of technical consultation over Government policy and where sought has been given by commercial organisations. Expertise with grid operation rests with a few score of individuals who are constrained to speak out unless retired. Policy has been politically driven, expropriating the time honoured practice of economic viability. Sufficient information has been made available from reports in the public domain, the problem rests with comprehension within the structures of government to implement sound policy.
Executive Summary
The approach taken in presenting this submission is to impress the long term need for secure, reliable and predictable energy supplies where tidal technology has an advantage of coming from an indigenous resource. Accommodation of any power source should relate to proximity of demand and long term economic viability with existing and prospective alternative generation sources. Current policy with wind resource is unaffordable, leading towards instability and reliance upon instantaneous imported supplies from distinct adjacent grid systems through subsea cable interconnections.
Evidence
1. Hydroelectric Generation. The characteristics of this technology surpass all other technologies. Long lasting, reliable, with rapid response and start up, such advantages are used to provide the dominant means for storing electrical energy by pumped storage, albeit at considerable capital cost and conversion loss. More conventional means have already been exploited, mainly in the Scottish Highlands and although some potential remains, further limited capacity is expected to come from “run-of-river” embedded sources. Where storage can be made available, significant increase of output becomes possible. There is considerable resource available from tidal barrages that if selectively developed in combination with promising tidal flow technology across the network, could yield consistent generation output over the twenty-four hour period. Such investment presents a significant opportunity by avoiding the lunar cycle and alleviating the instability problem from intermittence across the Grid system. Hydroelectric investment requires long term perspective that is not encouraged by restricted conditions of access to long-term finance.
2. Tidal Resource. The Severn estuary has the principal source of tidal energy available in the UK with a degree of output flexibility from a barrage having several lagoons. Other estuaries also have barrage potential with a tidal regime out of step with the Severn and further tidal resource could come from developing pockets of alternative tidal flow technology along the coastline. The effective exploitation of all these resources would require in depth studies to determine a coherent scheme of development enabling consistent and flexible power output for meeting the demands of the UK grid system.
3. Severn Estuary. The location of this tidal source is in proximity to the main transmission grid and demand centre of the GB Grid System in the South-East. There is limited grid generation capacity in the South-West to support the scale of consumer demand in that area. Current development of renewable wind resource, largely from Scotland and offshore, has to be transmitted over large distances and whose accommodation demands considerable transmission investment. This includes two “bootstrap” HVDC cables bypassing the Scottish border at considerable expense.
4. Security of Supply. This term covers a whole range of technical scenarios from sufficient controllable generation capacity to maintaining the stability of the Grid network. The Grid system is a dynamic entity, inherently unstable being profoundly different from the distribution network. Not only must generation be finely balanced with demand, reactive conditions must be continually adjusted to secure power flows. The rising proportion of wind resource on the GB Grid system presents a serious problem of managing intermittence that soon will become dependant upon imported power from continental sources through undersea cables (in addition the recent commissioning of an Irish connection would import their intermittency). Such interconnection would create a dependency upon our Euro neighbours that is essentially one way, given the much larger scale of the integrated continental grid.
5. Intermittence. The scale of planned wind resource to be installed is considered to be technically and economically unsustainable. Whilst a degree of mitigation can be introduced this comes at increasing cost at a time when most thermal generation capacity is rapidly ageing and experience has shown the dearth of availability with wind generation during times of freezing weather conditions. Wind resource is uncontrollable, not securely predictable, demands excessive transmission investment and has seriously underperformed on its promoted energy output. Crucially such capacity would never have been built without an excessive opaque levy on the electricity consumer, forced by parliamentary legislation.
6. Instability. The impact of a problem with instability would arise suddenly. Given the background circumstance of market imperatives, developing scenarios often over-ride technical good sense. In the middle of the last decade a moratorium on further wind installation was imposed in Ireland and overnight in Germany standby generation for operating wind capacity was raised from 60% to 90%. Fossil-fired thermal generation is an essential requirement for standby supplies and National Grid expect by the end of the decade an operating margin equivalent to a fifth of maximum demand will be needed to be available at all times to cope with the anticipated level of wind capacity.
7. Generation Mix. Renewable resources being developed are invariably intermittent except for biomass which has the problem of fuel supply. Conventional hydro is limited in scope for the GB Grid system, unlike continental circumstance where substantial capacity is available. The characteristics of nuclear power do not lend its use for variable output leaving the only available option for meeting fluctuating demand having to come from fossil-fired thermal sources given the scale required. Embedded generation from distribution networks and fluctuating wind and solar resource must also be accommodated. Any contribution from interconnection can only be marginal as costs rise exponentially and security of supply becomes an increasing issue. Undue reliance on any one technology has to be avoided. Currently there is a serious imbalance with age of the various technologies.
8. Fossil-fired Generation. There are three broad categories; oil, coal and gas. The first has become too expensive. Currently coal provides a third of power supply and where a third of this capacity is soon to be taken out of service by EU environmental regulation. Most coal capacity is from forty to fifty years of age but has a significant advantage of having coal capable of being stockpiled at site. Since privatisation only gas turbines have been introduced within these three categories and where its fuel supply has to be shared with industrial and domestic heating. Only 5% of annual gas use can be stored with limited expansion in prospect. The development of shale gas becomes an imperative to reduce imported supplies although its use for electricity generation dissipates half its heat value in conversion.
9. Contribution of Tidal Resource. Given the above constraints tidal power as part of a balanced strategy of generation provision would provide:
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As this list reveals, significant economic savings are made when viewed in wider perspective than a study for a single Severn project would indicate. Development of other tidal barrages would impact on any design for a Severn Barrage
Given the long term nature of exploiting such resource, reliance upon private initiative would be hazardous and some state organisation would be needed to assess all the implications. Starting with overall studies such a body could develop into a project organisation and operating concern well placed to influence, if not control other renewable development. The accumulated practical experience from this body would provide a source of advice and knowledge to government in formulating energy policy that has become so distorted since privatisation of the industry. Hindsight suggests the separation of generation and transmission at that time has led to the serious situation with electrical supply the nation now finds itself having to confront.
November 2012