A revolving loan fund is a source of money from which loans are made for multiple sustainable energy projects. Revolving funds can provide loans for projects that do not have access to other types of loans from financial institutions, or can provide loans at a below-market rate of interest (soft loans). The fund gets its name from the revolving aspect of loan repayment, where the central fund is refilled as individual projects pay back their loans, creating the opportunity to issue other loans to new projects. Revolving funds for sustainable energy provide financing to parties to implement energy efficiency, renewable energy, and other sustainability projects that generate cost savings. These savings are tracked and used to replenish the fund for the next round of investments, thus establishing a sustainable funding cycle while cutting operating costs and reducing environmental impact. The London Green Fund is a good example of a revolving loan fund. The definition can be found on the ManagEnergy website.