Renewable Energy Options


HOW AFFORDABLE ARE LOW AND ZERO CARBON


(LZC) RENEWABLE TECHNOLOGIES


IN NEW PROPERTY DEVELOPMENT?


Kevin Joyce


The most effective and efficient renewable energy technologies or combination of technologies options will vary from scheme to scheme, and could be strongly influenced by considerations such as the location and aspect of a development, the costs and convenience of access to fuel sources, availability of grant, or the opportunity to make savings on usage by feed-in tariffs back to the grid. Solar thermal and solar photovoltaic installations for example, will maximise heat generation if fitted to south facing roofs, with energy generation being at its highest in summer months.


Wind turbines generally operate more effectively in rural areas rather than in urban environments where wind flows are buffeted by buildings. A high profile illustration of this was in 2007 when David Cameron installed a small wind turbine to his Notting Hill town house, which attracted fairly scathing comments in the national press about the limited level of energy generated. (1)


Developers will appraise the renewable energy options available to their projects on the basis both of the energy saving outputs which can be achieved and the capital cost of the technologies and their installation or emplacement, which costs can vary quite significantly. The benefits and limitations of different technologies merit consideration.


Commercial and residential property developers generally have a quite daunting array of challenges to meet to successfully deliver new development projects. This includes a need to obtain planning consent and secure project finance at the outset, allow for Section 106 costs attached to planning approval, possibly remediate contaminated land, develop within cost and timescale parameters, and cross their fingers for either a pre-let with commercial developments or a healthy level of


end-buyers interest in new housing notwithstanding any constraints on the availability of mortgage finance.


For public sector procurement bodies, the challenge is to procure projects such as new hospitals and schools in a fiscal environment where capital investment strategies are having to be increasingly curtailed following a tightening of capital investment public purse strings.


An emerging and increasingly costly additional challenge for both private and public sectors is a requirement to meet sustainable development standards in new construction geared to the UK’s requirement under the Climate Change Act 2008 to reduce carbon emissions by 80% by 2050. In May this year, the benchmark for investing in clean energy was raised further with the Energy and Climate Change Secretary, Chris Huhne, announcing new targets to cut emissions to 50% between 2023 and 2027.


As no right-minded developer would knowingly build to show a loss on a project, there is pressure on developers now to design and build utilising a combination of low and zero carbon technologies which address sustainability targets but without making their projects financially unviable.


Thermal Insulation. Retrofitting of poorly or uninsulated properties with thermal insulation, which can reduce both heat loss from buildings in cold weather and heat gain in summer months, is considered to have the capability to provide the largest contribution to carbon dioxide savings in the UK.


Insulation formats can range from surface treatments and liquid foam, to small fibres, flexible rolls and large panels, with insulation materials being naturally occurring, such as wool, hemp, cob (clay, straw and earth mix), straw bales, or synthetic, such as glass mineral wool and rigid plastic insulation panels. The most commonly used insulation materials are synthetic, primarily mineral wool and glass mineral wool in roll or batt form laid in roof spaces, and polyurethane foam pumped into cavity walls or sprayed on the underside of slate and tile pitched roofs. (2)


Solar Photovoltaics. Solar photovoltaics (PV) is a system of generating electricity from light, distinguished from solar thermal technology which uses the sun’s energy to heat buildings and provide hot water. PV cells have at least two layers of semi-conductors, one positively charged and one negatively charged, with typical silicon PV cells being doped with a small quantity of boron to give the cells a positive character and a thin layer of the top of the cell being doped with phosphorus to give a negative character. The cells work through light shining on the semi-conductors to create an electric field across the junction between the layers which causes electricity to flow. The more intense the light, the greater the flow of electricity. (3)


Early photovoltaic panel installations attracted some criticism on the grounds of being visually unsightly. A new generation of solar PV roof tiles has now been developed though, designed to fit almost seamlessly with standard roof tiles on buildings. A variant on these more aesthetically integrated systems is a Nu-Lok Roof system, which combines electricity


THE TERRIER - Autumn 2011 15


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