Chris Binnie has scrutinised the costs and benefits declared for the Thames Tideway Tunnel [IND04]. Within this report a breakdown is given in areas such as health and ecology and it was shown that benefits can be closely related to the assumptions behind them with his calculations showing benefits far less than those previously quoted.
Additional studies are needed to understand current benefits for any scheme. For example, a recent "aspects of fish benefit" report [IND09] concludes, noting report should be read for full listing:
A similar process needs to be adopted for BG solutions but, for appropriate comparisons to be made, all benefits need to be considered such as flexibility, immediacy and resilience together with all other by-products, such as better air quality, health, reduced pollution and employment opportunities - see "transforming our cities" bullet points on Home Page.