PPAs have become increasingly popular in recent years, particularly among large eco-oriented companies that do not have the physical space to install their own renewable energy systems. Companies such as Google, Facebook, Amazon and Apple are just some of the modern solar-PPAs users who enable them to achieve their strict environmental goals without taking on the operational risk of maintaining their own systems. When a statutory subsidy to an existing plant expires, AAEs are a means of providing follow-up funding for the operation of the facility. This could include operating costs such as maintenance and leasing. These are examples of this type of PPP that are listed below. AAEs have been subdivided into AAEs that are more relevant to smaller and more rural energy projects, and more complex AAEs, relevant to large projects in developing countries. In the case of decentralized production (where the generator is on a construction site and the energy is sold to the building occupants), commercial PPAs have developed as a variant allowing companies, schools and governments to source directly from the generator and not from the distribution company. This approach facilitates the financing of distribution-related production facilities, such as photovoltaics, micro-turbines, alternative piston engines and fuel cells. The AAE is considered binding at the time of signing, also known as the reference date. Once the project is built, the validity date ensures that the buyer buys the electricity produced and that the supplier does not sell its production to others other than the buyer.  Tanzania – An abbreviated version of relatively simplified airing agreements for small electricity generators in Tanzania -Ppa standardized for main grid connection and standardized PPPA for isolated mini-grids, with standardised tariff methods for each case and detailed tariff calculations, all available on the EWURA website. See also guidelines for the development of small energy projects.
The installer designs the system, indicates the components of the system and can track the life of the photovoltaic installation. To install the system, the solar service provider can set up an in-house team of installers or have a contractual relationship with an independent installer.