Any power production technology should be able to demonstrate that it’s able to comply with current and future environmental regulation and that it demonstrates a considerable surplus in the energy balance being a part of the entire power system. This means that the energy used throughout all the lifecycle stages; from provision of materials over manufacturing of components and assembly, to deployment and use and eventually the disposal stage, is considerably less than the energy produced by the device during its use/production stage. With this paper, Wave Dragon is the first wave energy developer to publish figures of the energy balance of its technology. An LCA conducted at the Technical University of Denmark demonstrates that the energy consumed during Wave Dragons life cycle may be returned 20 times throughout its anticipated lifetime of 50 years, according to the EDIP LCA method. But if Wave Dragons power production is compared to production of electricity using fossil fuel the energy can be returned 50 times. Introduction Exploitation of the energy bound in ocean waves is making technological and economical progress with different emerging concepts and devices. The potential of harnessing near shore waves is to supply up to 50 % of the World’s demand for electricity. Still, the different wave energy converters need to show more modest production costs in order to be able to compete with other matured renewable energy technologies. Wave Dragon Wave Dragon is a floating wave energy converter functioning by extracting energy principally by means of waves overtopping into a reservoir. A 1:4.5 scale prototype has been tested for 21 months in corresponding sea conditions at a less energetic site between 2003 and 2005. Figure 1: The Wave Dragon principle Figure 2: Wave Dragon prototype. Approaching waves are concentrated by the reflector towards the ramp Figure 3: Wave Dragon in good waves (left) and in smaller waves (right) The LCA method In early 2005, the company Black & Veatch (on behalf of the British Carbon Trust) made a review of the entire concept including a first attempt to provide an “embedded carbon assessment” and in the autumn 2005, this study was followed by a full LCA conducted at the Technical University of Denmark. Both studies are based on a rather time consuming process of modeling the life cycle of Wave Dragon and obtaining the required data. It can be done in a program called GABI, where it’s organized in “plans” and “processes”. The LCA assessment is following the EDIPmethodology, including normalization and weighting. The functional unit is 1kWh like in other power plant LCA’s, in order to make the assessments comparable. All electrical power used and produced is based on a process called Danish power grid mix by consumption, 2001. Figure 4: Flow chart of the life cycle of Wave Dragon LCA results The following graph represents the normalized and weighed values of the environmental impact potentials and the resource consumption for the basic scenario for the entire life cycle. Separate graphs exist for all four stages. Bulk w aste Hazardous w aste Nuclear w aste Slag and ashes Ecotoxicity w ater acute Ecotoxicity w ater chronic Human toxicity air Human toxicity soil Human toxicity w ater Acidif ication Global w arming Nutrient enrichment Ozone depletion Photochemical oxidation Ecotoxicity soil chronic -0,00007 -0,00006 -0,00005 -0,00004 -0,00003 -0,00002 -0,00001 0 Target person equivalent (PET) Figure 5: Weighted environmental impact potentials for the whole life cycle The weighted values for the environmental impacts are all negative. From the bar chart in Figure 5, it can be noticed that the most serious avoided impacts are: global warming, human toxicity soil, bulk waste and acidification. The reason for negative values is that the electricity production from Wave Dragon circumvents both consumption of various fossil fuels and contributions to other environmental impacts like emissions of greenhouse gases, bulk waste and dangerous chemicals. The following graph Figure 6 represents the normalized and weighted values of the environmental impact potentials and the resource consumptions for the basic scenario over the entire life cycle. Concerning the consumption of resources, tin is by far responsible for the most serious impact. Tin is a constituent in bronze, which will probably be used for the turbine propellers. Bronze is almost completely recyclable but according to the available “processes” in GABI tin will not be recovered. Similarly nickel is not recovered though it might be recycled as stainless steel. Aluminum Copper Crude oil Hard coal Iron Lignite Manganese Natural gas Nickel Tin Zinc -0,000003 -0,000002 -0,000001 0 0,000001 0,000002 0,000003 0,000004 0,000005 0,000006