SEVERN BARRAGE v WIND TURBINES and WIND TURBINES v NUCLEAR
Looking at these options briefly but objectively:
Severn Barrage, the location in terms of generation to natural electricity demand sync, is probably the most favourable as there is an all ready constructed 400kV double circuit transmission line within reasonable access, so minimal cost of National Grid connections but more importantly it would reduce the high transmission losses for the normal power flow direction Scotland to England. Secondly, a contractual arrangement could be set up favourably with the pumped storage power stations at Dinorwig and Ffestiniog where these stations pump at low cost energy overnight and generate at high cost during the day time. These pumped storage stations also provide very efficient frequency control and reserve services both in the generation and pumping modes. Also, generators in a barrage system could provide frequency and reserve duties whilst operational. So there are several additional major advantages that can be obtained to having a Severn barrage. Other major advantages of building the Severn barrage are road and rail links and whilst we all ready have these, it would certainly reduce the road and rail routings directly between those areas and provide a significant upgrade to the future for the current networks/crossings. A barrage would also be very aesthetically pleasing in comparison to wind-turbines. There would be a significant carbon footprint to the build but ‘if-in-the-future’ we need to build more rail and road links this carbon footprint cost would be reduced significantly. There are two other downside factors and that is the reduced mud flats for birds at times of low tides and the possible dredging requirements from mud build up.
Wind-turbines, their locations are in the majority of cases not favourable because they will incur increased costs of connection and high order transmission losses for those being constructed off-shore, particularly in the north of Scotland. In the extremes of Scotland, the eventual power flows to England will cause power flow energy losses of the order of 15%, this energy waste should not be ignored because these costs are added to the overall balancing system charges that are included in the Energy Suppliers charges in our electricity bills. There are planned east and west high voltage submarine cable interconnections between England and Scotland and it will be interesting for National Grid to state how there increased budgetary costs for these connections are going to be charged when these extremely high cost of connections will run into billions of pounds. If the major transmission submarine cables for the wind-turbines are going to be charged directly to the electricity consumers through the electricity Suppliers charges then these additional costs should be factored against the wind-turbines directly as a comparison to other generation developments. The carbon footprint of these additional interconnections should also be factored directly against these wind-turbines. Another very important factor against wind-turbines is the visual harm that it is doing to our spectacular landscapes and seascapes for they are a heavy burden aesthetically for the times when the human needs are to escape from the urban sprawls to see natural open countryside or the seaside’s. There must be a loss factor to add here for tourism. A major consideration to building any more wind turbines must be the fact that their intermittancy and unpredictability are causing double generation capacity build costs. Additionally, it can be proven (along the lines of the Dutch Schipol report) that adding any further wind turbines generation will not reduce any further carbon emissions and if the carbon footprints of their build plus the double capacity factor of build for other generation sources are taken account of then carbon emissions are in fact becoming a resultant negative. This means that for any future wind-turbine builds they cannot claim to have any green credentials and are therefore not fulfilling any claim to climate change improvement.
Nuclear Power is the one source of energy that can be proven as very low carbon emission, even taking account of the carbon footprint build element. The other major benefit is that the majority of National Grid power lines are all ready in existence to build new nuclear power plants on existing sites, and therefore very minimal cost of connections. Also, because the existing locations, particularly around the southern coasts, the transmission of power losses will be minimal. The only drawbacks with nuclear are the nuclear waste containment and the minimal accident risks. It will however take of the order of fifteen years to fulfill a nuclear replacement program. This was planned in CEGB days, twenty years ago to continue on from Sizewell B PWR.
What has to be done in the short-term? It seems the only answer is to reducing carbon emissions is to stop building any more wind-turbines and deploy a second round of ‘the-dash-for-gas’. This should be very manageable as existing gas-fired power stations can be refurbished or replaced with completely new installations in a matter of two-years and would not need any significant planning consents. So if the shale gas exploitation should take place internationally, including the UK, as has all ready happened in America, then gas prices should reduce by 50% and we have time to replace our time-expiring power plants without the need for panic.
George Wood, retired Power Systems Operations Expert.