Thursday, 25 February 2016
At low technology readiness level, before tank tests and numerical models have been done, it is very difficult to estimate the levelised cost of energy. Indeed, this is not so much an estimate as complete guess work– we don’t know the optimum system size, nor relative subsystem size.
I’d like to propose a different early stage metric: the revenue to cost ratio. Both revenues and costs can be expressed as engineering parameters (such as loads, power, stroke or time). The ratios of these parameters can be informative and insightful. The most well-known example of the gain to pain ratio had been around for decades: the ratio of mean to extreme. Revenue is a function of the mean; costs are a function of the extremes. This ratio can give insights into a whole bunch of design choices. For example, it indicates that low variability can be a more important consideration than average power when choosing a site for installation. As the gain to pain ratio can be applied to many types of renewable energy, we can also use this perspective to ask: what are the design requirements for wave energy to be competitive with wind?