Energy access is critical for sustainable development and therefore financing energy access is a necessity. The key is whether to focus on grants or public finance for sustainable development projects or move to a more diffused financing mechanism, involving investment grade financing sources like debt and equity. In other words, financing sustainable development action via grants is becoming a constraint. To address this constraint, it is important to consider the relationship between the nature and sources of financial flows. The concept of 'financial gradients' emerged while analysing the financial and business strategy developed for Lighting a Billion Lives (LaBL) campaign. This paper espouses the idea of 'financial gradients' which is a potential financial mechanism for sustainable development action. Financial gradients, can contribute in three different ways first, as an approach to analyse financial flows in projects; second, as a tool to generate a single, long term and stable inflow of finance; third, as a financial mechanism to help in creating long term strategies to sustain projects. This paper will concentrate on financial gradients as a potential approach to analyse financial flows in a sustainable development programme. (C) 2012 Elsevier Ltd. All rights reserved.