Article - Issue 20, August/September 2004
Letters to the Editor
Energy policy and electricity costs
There is nothing surprising about the fact that the various renewables are more expensive than fossil fuel fired generating technologies, nor that the natural gas fired CCGT is the cheapest. However, the decisions as to which sources and technologies are to be preferred for future electricity generation need to be made in the context of an overall sustainable energy policy and not simply, as hitherto, on which is the cheapest for one particular part of the energy mix.
We are now at a time when both oil and natural gas will begin to become scarce and increasingly expensive commodities in the foreseeable future – oil probably sometime after 2020 and natural gas about twenty years later. Also, with the exception of biomass, all renewables are delivered in the form of electricity, at a cost at least four times as great as for fossil fuels, remembering that at present only about ten per cent of delivered energy is electricity and ninety per cent for heat and engine fuels. We are approaching an era of much more expensive, and much more capital intensive, energy supply and use. I suggest therefore that the first consideration must be to minimise energy waste. One way of doing this is to use each source judiciously with maximum efficiency and the special qualities of each used most effectively.
When I consider how to make best use of the special qualities of natural gas, its gaseous nature makes it particularly suitable for widespread piped distribution to a multitude of small outlets, such as domestic/commercial heating, where it can be delivered with low energy cost and a use efficiency of more than 80 per cent. Another application in which its special qualities are used is in a compressed form as an internal combustion engine fuel. However, in this application its efficiency of use is much lower. As a source of energy input to power stations, its special qualities are not exploited, and its overall efficiency of delivered energy use is well below the efficiency of use as a domestic source of heat. Coal on the other hand is unsuitable in its solid form as a domestic fuel, but is most appropriately used in major generating plants and other big industrial units, particularly where its high carbon content can be used as a reducing agent.
It was this kind of thinking which, in the 60s, led to the policy of using natural gas primarily as a source of space and water heating, with industrial application being on the basis of interruptible supply only. Unfortunately that policy, based on sustainable development reasoning, was abandoned with the ‘dash for gas’. As a result the long term availability of natural gas for its most appropriate and efficient use has been greatly reduced, and its overall efficiency of use has been considerably lowered. Another important disadvantage of this present policy is that we are in danger of becoming excessively vulnerable by being dependent on imported natural gas for a substantial part of both our heating and our electricity needs.
In spite of the attractive low cost of CCGT generation, I hope that the Government will allow no further gas fired CCGT stations to be built; but instead follow the sensible policy of the Chinese by adopting coal fired IGCC technology for some of the base load generation which will be needed in partnership with renewables. By so doing coal will be used with maximum efficiency as a source of base load electricity within environmental constraints for sustainability. The higher generating costs can easily be offset by improvements in the efficiency of energy use, remembering that for sustainable development it is the total system efficiency of production, distribution and use which must be maximised and not only supply and distribution.
John D Davis FREng
How do practising engineers learn?
Sir David Brown’s question in the May/June issue of Ingenia is an important and on-going question for all involved with engineering. Fortunately there is now an almost universal commitment to CPD. But are we too complacent in just accepting the commitment without understanding how it can best be accomplished?
Engineering CPD is presented as the responsibility of the individual who should plan and report on his/her CPD. Some jurisdictions, for example several Canadian Provincial Professional Engineering Associations, recommend that engineers spend at least 240 hours on CPD over a three year period.
When you ask experienced engineers about their own learning post qualification, the answers come from first hand experiences while ‘doing’. These are usually memorable experiences with lots of emotion. And these were not part of a planned CPD activity. However CPD does encourage a learning and questioning attitude, which is essential for making sense of experiences.
Can engineers learn from other professions and activities? American teachers have found that creating a ‘learning community’ results in teachers being more committed to on-going learning as well as being more effective for individual learning.
On a similar theme, Peter Senge in his book The Fifth Discipline: The Art and Practice of the Learning Organization emphasizes how managers can develop their own learning skills in a ‘learning organization’. He points out that we learn in a cyclic pattern – cycling from action to reflection. The best results come from what he calls ‘skillful discussion’. This calls on the skills of imagining others’ viewpoints, listening, observing and questioning.
Sir David points out that putting knowledge to work is what generates competitive advantage. So how does the mind store CPD and then recall it so that it can be used effectively? Cognitive scientists and psychologists are trying to answer questions like this. Jens Rasmussen in Denmark and James Reason at Manchester have presented human decision making activity in three levels: skill-based, rule-based and knowledge-based. Should not engineers and their learned societies learn from those who are studying learning?
While engineering CPD is a personal commitment, are others helping? Most organisations will claim they are – but is this just lip service? There are organisations that still question library budgets, save money by cutting journal subscriptions, consider attendance at conferences to be perks and limit Internet access.
As Sir David points out, IEE’s INSPEC provides a good database. Similarly the IMechE provides web access to a wide range of standard engineering textbooks. But Sir David’s question how do practising engineers learn has only been partially answered to date. There is plenty of scope for the Institutions and Royal Academy to explore this question in more depth. Maybe, after technical presentations, we should ask the authors what have you learned from the work you have presented? This might help generate a ‘skilful discussion’ and a ‘learning community’.
One scenario does not a level playing field make
A quick glance at Richard Ploszek’s article (‘Electricity costs – start with a level playing field’ Ingenia, May/June) shows that there is something missing from the recent PB report issued by the Academy. If the question had been the cost of electricity last Thursday, perusal of ‘the books’ might well have given a single point answer. But if the report claimed to be looking at the medium term, the relative cost of differing technologies is clearly going to depend on background events which are currently uncertain. At the launch meeting of the Report, some present accused the report of using assumptions that favoured nuclear energy. That is to miss the point. In a level analysis, nuclear deserves its favourable scenario, just as might gas, coal or renewables. However the resultant synthesis would have resulted in much wider ranges for costs than we see from PB. Since working with margins is bread and butter to engineers this would have been no bad thing for a report covering the views of a whole Academy. Irritatingly, a lack of transparency in PB’s calculations inhibits any recalculation under different assumptions.
David Fisk BP/FREng
Professor of Engineering for Sustainable Development, Imperial College London