خرید داوطلبانه انرژی سبز: کشش قیمت و تجزیه و تحلیل سیاست

Green Power schemes offer electricity from renewable energy sources to customers for a higher price than ordinary electricity. This study examines the demand characteristics of Green Power in Australia and policies which could increase its sales. A sample of 250 pooled time series and cross sectional observations was used to estimate a statistically significant elasticity of demand for Green Power with respect to price of −0.96 with a 95% confidence interval of ±68%. The wide variation in market penetration between jurisdictions and between countries for Green Power, and the low awareness of Green Power found by surveys indicate that Green Power sales could be increased by appropriate marketing and government policies. The most cost effective means to increase sales was found to be advertising campaigns although only one Australian example was found, in the state of Victoria in 2005. It was also found that full tax deductibility of the Green Power premium to residential customers, exemption from the Goods and Services Tax and a tax rebate for Green Power are all probably less cost effective for promoting sales than direct government purchase of Green Power, in terms of cost per unit of increased sales.

Global warming from the human-generated increase in greenhouse gases in the earth’s atmosphere is increasingly accepted by the public and the scientific community as a threat, not only to the world economy, but possibly also to civilization. The Stern Review (Stern, 2006) has highlighted the grave likely economic consequences of global warming and the relatively small costs in reducing its impact to acceptable levels. The world electricity supply industry must play an important part in greenhouse gas abatement. It is estimated that this industry will need to reduce greenhouse gas emissions by 60% by 2050 if atmospheric carbon dioxide is to be kept to the recommended tolerable maximum of 550 parts per million (Stern, 2006).The current level is 379 parts per million (IPCC, 2007). In 2002 Australia accounted for 1.2% of world energy consumption(British Petroleum, 2003)which, per capita, is about 3.6 times world average. Green Power schemes are a means of countering global warming by encouraging growth in the generation of greenhouse-gas-neutral renewable energy. Renewable energy sources include solar, wind, small-scale hydroelectricity and biomass. Green Power can be defined as electricity that is produced from renewable sources and that has been differentiated from other electricity products and marketed as being environmentally friendlier (Salmela and Varho, 2006, p. 3669). Green Power customers voluntarily pay an additional premium which covers the additional cost of generating the customers’ electricity from renewable energy sources. Green Power schemes use a technique to reduce greenhouse gas emissions which differs from both the carbon tax and cap-and-trade regimes. Green Power relies on the good intentions of consumers to pay for the additional costs of clean generation of electricity. If successful, Green Power could be an important means of reducing greenhouse gas emissions at minimal cost to governments and to the rest of society, paid for willingly by people. If it is found that global warming is not caused by human activities, the risk that the expenditure on abatement is futile is borne by the purchasers of Green Power. These advantages of Green Power schemes highlight the need to study the economics of Green Power, including what determines the demand in this market and how the Green Power market can be made to function so sales are maximised. The objectives of this study are: (1) To identify and quantify factors affecting supply and demand in the market for Green Power in Australia; (2) Using what is learned about the Green Power market to assess which government policies should be adopted with regard to Green Power. To achieve these objectives, data were gathered on renewable energy generation capacities and costs and on Australian Green Power sales and prices. Regression analyses were conducted with quantity of sales of Green Power as the dependent variable, to determine which explanatory variables have statistically significant coefficients. This enables an estimate to be made of the elasticity of Green Power demand with respect to own price. The findings of these statistical analyses inform the policy analysis that follows. The empirical investigation in this study concerns identification of factors driving demand for Green Power in Australia using price information, where available, for the various Green Power schemes, sales information from published audit reports and other data. This study differs from the other studies by (a) using actual Green Power sales as the dependent variable, (b) price for each scheme as an explanatory variable and (c) not relying on data on stated preferences or survey data on attitudes. The main contribution of this study is an estimate of the elasticity of demand for Green Power with respect to price from revealed preferences while attempting to discern other factors that may affect the market. No studies have been found which estimate a statistically significant elasticity of Green Power with respect to own price using revealed preferences. There are no empirical studies of the elasticity of demand for Green Power in Australia, so this study adds to empirical understanding of the Green Power market. The plan for this work is as follows. After a survey of the literature on quantitative studies of the Green Power market, regression analysis techniques are used to identify which variables are likely to have the most effect on Green Power sales (based on sales data from published Green Power audits and price data from various sources). The price elasticity of demand with respect to own price for Green Power is estimated and then used in an analysis of the likely consequences and effectiveness of a number of government policy options to increase Green Power market penetration.

While demand for Green Power may be influenced by sociological factors such as conformity and ‘ethical’ behaviour (Nyborg et al., 2006), this study shows that Green Power sales are responsive to price. From a sample of 250 observations, the elasticity of demand up to December 2005 for Green Power with respect to own price has been estimated to be −0.96 with a 95% confidence interval of −1.53 to −0.39. This estimate of elasticity is a stronger response to price than that estimated by others for demand for ordinary electricity, although with a small overlap of confidence intervals the difference between elasticities was not shown to be statistically significant. Because this estimated elasticity is for total Green Power sales, it gives no information on the separate price responses of sales to business in contrast to residential customers. However, it can be reasoned that, since a large proportion of business sales are to governments, that residential sales would be more responsive to price than business sales. It could therefore be expected that most of the response to price for Green Power comes from residential customers. Also the age of a particular scheme and promotional activities were statistically significant in explaining the level of Green Power sales, and introduction of retail contestability in electricity sales was associated with increases in sales of Green Power. The wide variations in market penetration between states and territories and between countries indicate that the full potential for Green Power sales is not being realised. Willingness-to-pay consumer surveys have predicted much higher levels of sales of Green Power than have occurred and may indicate low awareness of Green Power by consumers (ABS, 2002). On the question of what measures to take to maximise Green Power sales, of policies to increase the market penetration of Green Power the most cost effective policy was found to be advertising campaigns. However, this is based on only a single example from Victoria. Using the estimated price elasticity of demand for Green Power, the most likely costs to government of (a) full tax deductibility of the Green Power premium to residential customers, (b) an exemption of the Green Power premium from the Goods and Services Tax and (c) a tax rebate for the Green Power premium were all found to be greater per unit of induced sales than the cost of direct government purchases of Green Power. Suggestions for further research would include: • Observation and analysis of more recent price and sales data for Green Power. • Analysis of the probable effects of various designs of emissions trading schemes on Green Power sales, particularly on whether Green Power sales are additional to, or included in emissions reductions targets. • Effects on the Green Power market of the enlarged renewable energy target. In conclusion, Green Power sales respond to the level of the Green Power premium and therefore appear to represent value to consumers as well as a ‘no regrets’ tool of governments to reduce greenhouse gas emissions. The deferral of the introduction of an emissions trading scheme by the Australian government may enhance the usefulness of Green Power as a functioning policy on climate change. Alternatively, if the problem of global warming becomes increasingly accepted by most people and governments are successful in putting an appropriate price on greenhouse gas emissions, this ‘no regrets’ advantage of Green Power may lose relevance.