Energy from microgeneration : sustainability and perceptions in the UK

• Main Author: Balcombe, Paul
• Other Authors: Azapagic, Adisa; Rigby, Daniel
• Published: University of Manchester 2014
• Subjects: 333.79; Microgeneration
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.634848

The drive to meet climate change and energy security targets has led the UK government to incentivise microgeneration, with 2 GW now installed, the vast majority of which is solar PV. However, this only represents 0.2% of UK energy supply and greater uptake is not guaranteed since FIT rates were cut for solar PV in 2012, reducing the financial incentive to install. Thus, other consumer motivations must be focussed on by industry and the government in order to further increase uptake. Additionally, microgeneration may be able to contribute to a sustainable and reliable UK energy mix, but such a contribution is not guaranteed. For example, there is concern that above 10 GW of installed solar PV, the electricity grid will experience balancing problems due to uncontrolled exporting to the grid. With higher intermittent solar PV generation, there will a greater load requirement on variable-load plants such as coal and gas generation plants. This research investigates the above issues by contributing to the question: How can microgeneration contribute further to UK climate change and energy security targets? Firstly, this research determines the consumer motivations and barriers associated with the decision whether or not to install microgeneration, in order to find ways of further improving uptake. A comprehensive literature review was carried out, followed by a survey using the ‘best-worst scaling’ approach to determine the relative importance of each motivation and barrier across existing adopters, those currently considering installing and those who have decided not to, rejecters. The most important motivations were to earn money, to increase self-sufficiency and to guard against future energy bill increases. The greatest barriers were high capital costs, not earning enough money and the risk of losing money if they moved home. Whilst the Green Deal was designed to remove the capital cost and risk of losing money barriers, it may actually increase the risk of losing money if they moved home as homebuyers are reluctant to purchase a house with an attached Green Deal loan. The desire for self-sufficiency is more important for considerers and rejecters than adopters and greater emphasis on increasing self-sufficiency could help improve uptake. Secondly, an option to increase household energy self-sufficiency whilst mitigating the grid balancing problems associated with solar PV exports was investigated: a combined solar PV, Stirling engine CHP (SECHP) and lead-acid battery household system was simulated and used to carry out a cost-benefit analysis and life cycle assessment compared to a conventional household system using the electricity grid and gas boiler for heating. The system provides 72% of a household’s energy demand and reduces grid demand variations by 35% with a 6 kWh battery. However, the system is only cost-effective for households with large electricity demand, 4,300 kWh/yr. If uptake of such a system is to be encouraged, it must be incentivised: a 24% capital grant would be required for the average household (£3,600). The environmental impacts of the system are reduced by 35-100% compared to the conventional system for 9 out of 11 impacts. However, depletion of elements is 42 times higher largely due to the use of antimony for the battery manufacture. Environmental benefits vary greatly across households and those with the largest energy demand achieve the greatest benefits from the system. Appropriate battery sizing is essential in order to maximise environmental benefits, with 10–20 kWh capacity being optimum for the households considered. Overall, this research has identified numerous ways to increase microgeneration uptake, but this is likely to be at a cost to the government and, ultimately, the tax payer. UK microgeneration policy over the last decade has frequently changed and created uncertainty for consumers and the industry. A more continuous, simple and transparent policy environment would provide security for both industry and consumers, allowing more stable growth in a quickly maturing market.