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This paper provides an international policy review on energy efficiency retrofit in owner-occupied homes and recommendations to apply best practices to the UK.

This working paper presents a review of policy design and implementation in OECD countries for increasing uptake of energy efficiency retrofitting in medium to high-income, 'able to pay' owner-occupied households. Renovation measures to help improve energy efficiency and decarbonise homes can include loft and cavity wall insulation, heat pumps and solar PV.

The review uses a rapid evidence assessment of academic and grey literature to address the following research question: Which internationally applied, good practice policies have the most potential to accelerate quality, energy efficiency retrofits of owner-occupied, 'able to pay' households in the UK?

The review reveals that residential energy renovations in OECD countries are mostly shallow single measures, with a small portion comprising multiple measures or deeper renovations. Although some countries such as France, Germany, the UK and the US have retrofitted millions of single measures to homes, this review has not identified any countries which have delivered deep home energy retrofit at a widespread scale.

We identify various review studies on policy instruments which have been applied in different countries and are considered important for implementing residential energy renovation. Policy instruments most commonly emphasised are regulations, financial support and information provision. Most reviews also include policies to develop workforce skills and competencies, supply chains and quality assurance.

Drawing upon our review of international and UK evidence, we make a series of policy recommendations for an effective home energy retrofit policy framework in the UK, with a focus on medium to high-income owner-occupier households:

This document is a summary for the project titled 'Band Structural Engineering of TiO2 for Efficient Solar Cells'.

This project is aimed at increasing the energy conversion efficiency of Titanium Dioxide which can be applied to cheaper materials, such as glass, plastics etc, using deposition to create solar cells. Currently the material can only convert 5% of the suns energy into electrical energy, the amount of the solar spectrum photovoltaic cells can absorb is called its band gap and TiO2 can only absorb ultraviolet irradiance. This project explored the possibility of using the process of doping to narrow TiO2's band gap thereby increasing the amount of the suns energy it can absorb to up to 50%. Doping is the process of is the process of introducing impurities into an extremely pure semiconductor (in this case TiO2) to change its electrical properties. The effectiveness of using such a technique for narrowing Titanium Dioxide's band gap was explored both through theoretical modeling and computer simulations. This doped TiO2 material was then fabricated in a laboratory as part of the project

This project has led to two applications for patents and a spin off company. Prof. Shao has also received a further £933,050 funding from the Technology Strategy Board to continue his research into low cost, highly efficient photovoltaic solar cells. As a result of the possible applications of the research two companies involved in the project, Kleentec International Plc and Crowberry Energy, are working on a related project with funding (£10,000) from Metric.

This document is a report for the project titled 'Capacity Ten-Seven'.

Project Capacity Ten-Seven sought to bring together leading UK industrial expertise in the required disciplines to "define the parameters for the design of a new solar cell process plant with a capacity about 10MWp per annum and establish the optimum substrate size, cell configuration and junction structure and include the necessary research to confirm that these key characteristics are suited to high volume low cost production."

The project objectives were addressed through six interrelated technical work. Activities each with its own sub-objective and work plans. These were:

1. Fundamental Studies
2. Front Contact Deposition
3. Semiconductor Deposition
4. Rear Contact Deposition
5. Cell Isolation
6. Initial Design Study

The project achieved its overall goal of positioning ICP Solar UK to proceed with detailed design of a Capacity Ten-Seven production facility that will meet with future expansion plans.

This document is a summary for the project titled 'Deposition Techniques for Thin Film Ternary Semiconductor Solar Cells'.

In the UK, the government has set up ambitious targets for the production of electricity from renewable sources, 10% of electricity by 2010 and 15% by 2020, and solar power is expected to make a significant contribution to this. Therefore the development of low-cost, efficient and environmentally friendly photovoltaic technologies will be of enormous benefit to society as a whole. It will also provide significant business opportunities internationally as countries strive to move towards more sustainable ways of generating electricity. The development and manufacture of solar cell modules for the production of electrical power is a growth industry with considerable wealth-creating potential for North West UK manufacturers during the next century.

This project extended previous work carried out at the University of Salford on pulsed DC magnetron sputtering (PDMS), a technique used to deposit thin films of a material onto a surface, for use on CIS solar cells. The purpose of which is to establish whether PDMS offers a realistic approach for the industrial production of CIS solar cells. The project also involves experiments to replace some of the materials used in CIS cells with more efficient or less toxic alternatives.

The Electra-Clad project sought to utilise existing steel based building cladding materials as a substrate for direct fabrication of a fully integrated solar PV panel of equivalent design to the ICP standard glass based panel. This would represent a major step forward in BiPV panel manufacture if achieved and open up the substantial BiPV cladding market for later exploitation of the technology. It was planned that this would be achieved by the further development and productionisation of the Electra Clad technology, working in partnership with cladding manufacturers to develop a facility capable of producing at least 20MWp p.a. The time scales to achieve this were expected to be less than 5 years and no more than 10 years.

The nominal 3 year programme was progressed from January 2002 to August 2005, though with a 1 year suspensions due to the liquidation in December 2002 of the Lead Contractor, Intersolar / British Photovoltaics Limited (BPL). The work has progressed under 5 interrelated Activities as follows:

The project was successful in achieving most of the Activity objectives.

1. Introduction
2. Technical Background
3. Experimental Work
4. Results
5. Discussion
6. Lessons Learned
7. Conclusions
8. Recommendations
9. Acknowledgements
10. Figures
11. Appendix
12. Annex

Summary of the results of the project:

In order to offer a cost effective production Solution for a Photovoltaic (PV) Roof system cosmetically similar to standard Slate roofs, the following Objectives were highlighted as key areas:

The design specification of the Electra-Slate has been finalised and prototype parts produced to prove the concept in both installation and manufacturing. The desired manufacturing costs of the product can be achieved with conversion to a large scale manufacturing set up.

Realising a sustainable hydrogen economy requires a breakthrough in the production of hydrogen. Photoelectrochemical conversion of solar energy to energy in hydrogen at viable efficiency isa long term goal needed to usher in the Hydrogen economy worldwide. The twin cell technology based Tandem Cell^TM tackles a number of challenges faced by single photoelectrochemical cell based water splitting and offers a novel way of utilising complimentary parts of the solar spectrum in two cells. The overall process results in a complete system driven by solar energy that splits water into hydrogen and oxygen.

This program included 12 technical tasks:

1. Studies on spray nozzle parameters
2. Studies on spray solution parameters
3. Investigation of the mechanised doctor blading technique
4. Investigation of spray pyrolysis techniques
5. Performance of scale-0up electrodes in Tandem Cell^TM
6. Alternative photocatalytic materials
7. Alternative electrolytes
8. A desk study on substrate materials
9. A lab study on substrate materials
10. Alternative design configuration
11. Quality control procedures
12. Fabrication of Tandem Cells

The main conclusions resulting from this DTI-assisted project were:

1. Introduction
2. Experimental Work
3. Results
4. Discussion
5. Conclusions
6. Recommendations
7. Acknowledgements
8. Figures
9. Appendix

This project had two primary goals; the first to develop the next generation of multicrystalline silicon ingot growth system capable of producing ingots up to 90cm square and weighing up to 500kg. The second goal was to develop equipment which could be used to automate the ingot-to-block processes and to minimise the levels of manual handling required, especially for the heavier blocks of sizes 150mm and above.

The crystal growth system operated successfully during growth trials and the quality of silicon produced met photovoltaic standard requirements. The testing of the growth system was undertaken through a series of growth trials, each designed to progressively test the system's capabilities. The first trials tested the functionality of the graphite furnace, power supply and coil arrangements; only minor optimisation was required to obtain efficient coupling. Heating trials were the undertaken to prove the operation and robustness of the furnace design. The susceptors and insulation showed no damage or problems at the completion of the tests. Work was undertaken in parallel to assess the effectiveness of a pyrometer for both temperature control and monitoring but the repeatability between runs in the existing set-up was inadequate to allow it be used in production and thermocouples were retained.

The project has successfully develop the crystal growth system and block process line as set out in the initial proposal. The use of 3D CAD and finite element analysis (FEA) has been successfully implemented on this project and has greatly reduced the time and costs associated with the development of operation systems by identifying and resolving potential problems before components were put into manufacture.

1. Introduction
2. Project Objectives
3. 90cm Multicrystalline Silicon Growth System
4. Block Process Line Equipment
5. Acknowledgements

The objectives for this project are:

The project has undertaken the design and development of the next generation of multicrystalline silicon ingot growth system, capable of producing ingots up to 90cm square and weighing up to 500kg. This project has also covered automation of downstream ingot processing equipment. The developed processes include block chamfering, inspection and packaging.

The project has successfully developed the larger crystal growth system and automated block process line as set out in the proposal.

Microgeneration in individual homes has been the subject of increasing policy and industry attention in recent years. Although there are only around 100,000 microgeneration installations in the UK, the Energy Saving Trust believes that microgeneration could supply 30-40% of UK electricity demand by 2050 (Energy Saving Trust, 2005b). If adopted by large numbers of households in this way, microgeneration could bring about fundamental change to our energy system. Many consumers would become energy producers, leading to a breakdown of the traditional distinction between energy supply and demand. Established regulatory frameworks and energy infrastructures could need to change radically to deal with a fundamental decentralisation of power and control.

This project investigated how microgeneration might be deployed in the UK and its possible implications for domestic consumers, energy companies and the energy system as a whole. Working closely with industry and government it identified technical, regulatory and institutional changes that might stimulate the market uptake of microgeneration technologies. The aims of the project were set out in the original proposal. The main objective of the research is: to work with industry and government to help tackle the main challenges associated with microgeneration. Its more specific aims were:

These aims and objectives have largely been fulfilled by the project. A number of challenges affected the fulfilment of the objectives. Section 7 of the End of Award Report Form provides further details of these and their impact on the project.

1. Background
2. Objectives
3. Methods
4. Results
5. Activites
6. Outputs
7. Impacts
8. Future Research Priorities
9. References

• Appendix 1 - Schematic of main project activities and outputs
• Appendix 2 - Members of the Project Advisory Group
• Appendix 3 - List of interviewees
• Appendix 4 - Full list of project outcomes

The aim of this project was to understand how microgeneration might be deployed, and to explore policies to support investment by consumers and energy companies. The research was undertaken by an interdisciplinary team drawn from three universities: University of Sussex, University of Southampton and Imperial College. It was carried out in parallel with significant policy developments, notably the government Microgeneration Strategy, the Climate Change and Sustainable Energy Act and the wider Energy Review.

The research found that it was important for policy makers support a diversity of routes to microgeneration deployment, with incentives for both householders and energy companies. The project analysed three different models of microgeneration deployment to explore the possibilities and implications. This included 'Plug & Play' deployment by individual consumers wishing to assert their independence from established suppliers; 'Company Driven' deployment by incumbent energy companies that shift their focus towards the delivery of energy services rather than energy supply; and 'Community Microgrid' deployment as part of decentralised microgrids.

There are significant opportunities to build microgeneration into new construction developments. The Climate Change and Sustainable Energy Act is important since it encourages local authorities to set targets for this. In addition, the research found that it will be desirable to include flexible service areas and space (e.g. as cellars) in new buildings so that future developments in micro-generation and home energy automation can be accommodated. If sustainable visions for larger developments such as Thames Gateway are to be realised, strong intervention is likely to be required by government. This is because such developments are substantially different from the UK's current energy system. In the absence of strong intervention, an opportunity for the implementation of more pervasive local energy systems based on Community Microgrid models linked to new district heating networks could be lost. Energy regulation has a role to play here too. The Registered Power Zone scheme developed by the regulator, Ofgem allows electricity network companies to experiment with new network concepts and recover costs from consumers. So far, the rules governing this scheme have proved to be too restrictive to rebuild capacity for innovation with the electricity network companies.

Overall, the research showed that microgeneration can make a potentially powerful contribution to a sustainable energy future - in terms of carbon reductions and wider social impacts. Microgeneration can be both a result of ongoing changes in existing energy systems and the cause of potentially radical change. Our research has also underlined the interdependence of technical, institutional and social factors that inhibit or enable the diffusion of sustainable technologies. Technically, energy networks will have to be able to cope with two-way flows. Policies, regulations and institutions will need to change and to acknowledge that the distinction between energy supply and demand is not as sharp for micro-generators. Finally, consumers could have a new position in the energy system - whether as hosts of microgeneration installed by company or as 'co-providers' of their own energy services.

Low or zero carbon energy sources are increasingly being installed in buildings, e.g. small scale and micro CHP units, photovoltaic panels and building mounted wind generators. The development of performance standards and suitable guidance on satisfactory provisions, on e.g. structural measures, weatherproofing and location is needed, also compliance with ADL and any relevant provisions of the forthcoming Electrical AD. This desk study will also take account of the Energy White Paper and the EU Energy Performance of Buildings Directive (EPBD).

The overall aim of this project is to develop suitable performance standards and guidance for the installation of low or zero carbon energy sources in buildings.

It is proposed to include a specified list of low or zero carbon energy sources as alternatives to energy conservation and energy efficiency measures in order to achieve target carbon emissions for different building types. The extent to which LZC energy sources can contribute to achieving the carbon emissions target should be limited to a given level or percentage.

Since the proposal is to include LZC energy sources as an alternative to further energy conservation or energy efficiency measures there is no strict requirement to calculate the cost effectiveness of each for the purposes of regulatory impact assessment. However, an assessment of cost effectiveness has been undertaken to provide ODPM with:

The assessment of cost effectiveness shows that few LZC technology/application cases achieve a positive NPV and hence none are recommended to be considered for mandatory inclusion.

The objectives of this project are:

This document is a summary for the project titled 'Third generation Solar Cells based on Quantum slicing by Rare earth doped Silicon nanocrystals'.

Current commercially available silicon solar cells are typically 10-20% efficient at converting sunlight into electricity. The main limitation in these materials is that they absorb nearly all the light that falls on them creating electrons, but they waste 80-90% as heat when the electrons lose excess energy on absorption. If one could convert the short wavelength (Blue) sunlight that falls on them to an equivalent amount of energy in the infrared, the electrons would lose almost no energy on absorption and the efficiency of the devices could almost double. Such a "quantum-slicing" technology has been the goal of solar cell research for many years. Recently it was reported that rare earth elements such as erbium or neodymium when incorporated into silicon oxide containing tiny clumps of silicon (nanocrystals) could be made to emit two infrared "photons" of light for each incident blue photon. This is very attractive as an industrial technology as silicon oxide can be formed on silicon solar cells by merely heating them in oxygen. However, the rare earth element used in these experiments was erbium whose emission is not suitable for harvesting with silicon. This project investigated the incorporation of a different element - neodymium in such materials. They will deposit optimised neodymium doped silicon oxide layers containing nanocrystals onto prototype silicon solar cells to demonstrate improved efficiency. Doping is the process of introducing impurities into an extremely pure semiconductor, in this case silicon rich oxide (SRO), to change its electrical properties.

The project builds on an EPSRC grant (value £192k) which funded the work that developed the original technology and is effectively a three way collaboration between the University of Manchester, the University of Surrey and McMaster University. The work carried out on this project led on to a £1.5m multicentre grant award (ESPRC) to follow up the underlying IP. An additional £200k was also awarded by ESPRC to investigate biosensing applications of the technology.