The study described has taken the researchers far and wide in the field of sustainability and it would be remiss if this report did not include some personal observations of the researchers:
1. Sustainable Design.
The genesis of this study was a challenge laid down by Howard Liddell, (an RIAS 4 star accredited sustainable design architect and winner of an RICS sustainability award in 2003 for the Glencoe visitor centre) to be more explicit with regard to the costs associated with
sustainability. This research has made significant progress towards a standardised methodology and some of the work has been incorporated into the BSI/BCIS publication mentioned above. However, rules of thumb are difficult to evolve except to say that on-site, micro energy solutions are difficult to justify on economic grounds. On the other hand many innovative design solutions have been used to substantially reduce a project’s carbon footprint. These design solutions do not need to cost more; it is a gross oversimplification to say that a sustainable design will add 10% or 15% to the cost of the building. This logic comes from ‘addition thinking’ i.e. here is a designed office building, house or school, how much extra will it cost to modify the design to include for example convection powered ventilation? Design has to be based on a clear briefed concept and a value system dictated by the client; ‘addition thinking’ is entirely the wrong approach.
Examples reflecting sustainable value in design were seen at Arup’s Solihull Campus, at Gaia’s Glencoe visitor centre for the National Trust for Scotland, at King Shaw Associates’ Innovate Green office project at Thorpe Park Leeds and at Keppie’s design for Great Glen House, Inverness, the headquarters building for Scottish Natural Heritage. These three examples demonstrate a
sustainable design solution to a clear brief backed by an explicit value system. The cost of these solutions has to be viewed from a value for money perspective calculated on LCC principles. Comparisons with design solutions where sustainable design was not a feature of the client’s value system could in theory be made but the calculations and logic are complex.
Conclusion
2. Embodied energy
This was initially an objective of the original research proposal but has proved too difficult to accurately model. It was unfortunate in some ways to focus on aluminium products as a trial study. Bauxite is mined in a number of countries worldwide and transported to smelters. Whilst aluminium requires huge amounts of energy in the smelting process a significant proportion (83% in the case of Alcan) of this electricity is sourced from local hydro schemes. The carbon footprint of this smelting process is very small. Finally, the carbon cost of transport and fabrication, further transport and the installation of the final product became so product and site specific that generalisations were completely invalid. Added to this was the maturity (in relation to many other materials) of the aluminium recycling industry. These facts resulted in the embodied energy objective being abandoned. However, the lesson learned was the importance of undertaking specific case studies at least to clarify the accuracy of the perception of a number of designers that for example, metal is bad and wood is good.
3. Micro energy
A lengthy study of micro-energy was undertaken which is reflected in the findings in appendix 3. There are many sources of information and some of these have been referenced. At the end of the study the researchers concluded that although many micro energy products are sold based upon economic advantages, some of which are reported in appendix 3, that the benefit of micro energy has to be based upon a value judgement. Currently, a properly undertaken option appraisal study using the rules advocated by this research is unlikely to prove any economic benefit from a micro energy solution even with the current levels of government grants and current prices paid by electricity companies for surplus generated electricity.
Conclusion
On-site generated micro energy is difficult to store, hot water less so than electricity. Three approaches are available for dealing with electricity generated in excess of the domestic requirements at the time of generation; dumping waste energy (usually as heat), installing batteries and an inverter for on-site storage or connection to the electricity grid. Batteries are a low demand supplier of electricity suitable for example for low wattage lighting but unsuitable for sustained high demand required for example by an electric oven. Selling surplus electricity back to the energy supplier is an effective way of dealing with excess generation. Electricity companies will buy such electricity at about 3p per unit (Jan 2008).
Economic benefits from grid connected exported micro electricity generation accrue to electricity companies from sale of the electricity and sale of Renewable Obligation Certificates (ROCs). ROCs are awarded to accredited generators of eligible renewable electricity produced within the UK – solar energy (including photovoltaics), hydro, wave power, tidal energy, geothermal energy, biofuels (including energy crops) and on and offshore wind. ROC’s are traded amongst electricity generating companies such that those companies which fall below their renewables obligation can buy from those companies who have exceeded their renewables obligation.
ROCs are not to be confused with international green certificate trading. The latter is an offsetting device whereby those who wish for various reasons to present themselves as zero carbon can purchase green certificate offsets. The current price of green certificate offsets is approximately £20 per tonne of CO2.
In summary therefore investing in micro energy generation is done for reasons other than any economic advantage.
4. New technology products:
It is difficult for manufacturers to predict the longevity of innovative products and their components. Additionally, many of the innovative products are produced by new companies which are more prone to failure, takeover, etc and these companies have difficulty offering credible long term guarantees that parts will be continue to be available over the estimated life of the product. Even in fairly established technologies such as wind generators, installation in a new environment can lead to problems for example, in 2007 it was reported that 12 out of 36 turbines off Herne Bay, on the Kentish Flats suffered major failures after one year in service.
Conclusion
6.3 Recommendations for further research
Demands for cost planning, budgeting, tender evaluation and audit on a life cycle cost basis are increasing. There is a necessity for rules and guidance on best practice which this research has addressed in part. ISO 15686 gives clarity to applications and definitions and the BSI/BCIS publication is expected to influence rules and methodology. This work has majored on rules and methodology using sustainability as the subject. The research has uncovered many different approaches in the evaluation of sustainable options on a life cycle cost basis. This current situation is unacceptable. There are three significant pieces of work which are required under the sustainability banner,
1. Case study research is required to illustrate in some detail a proper approach to embodied energy. Existing theories of embodied energy need to be robustly examined and tested and an explicit method developed for the measurement of embodied energy in construction components.
2. Sustainability needs its own currency. Whilst energy remains relatively inexpensive evaluation solely on economic grounds will tend to favour the status quo. A suggestion for further research is the development of a shadow “taxation” system. The research would answer the question, how high must taxation be on existing carbon based technologies before a tipping point is reached and sustainable design and
sustainable energy become the preferred option. A parallel situation exists currently in the innovations in site waste disposal to avoid landfill tax.
3. Finally, a method needs to be established for the explicit statement of value for money in the context of sustainability. It can be anticipated that in the not too distant future tenders will be judged on value for money where a major part of the value equation will be sustainability. How will this value for money be credibly calculated?