Solar leasing contracts and PPAs may seem more complicated than a solar loan or cash purchase due to the additional terms included in them, but they usually offer leasing companies flexibility in the event of a change in circumstances. While the terms “Solar Lease” and “Solar PPA” are used interchangeably on this page and are very similar in practice, there is a decisive difference between the two. With a solar lease agreement, you agree to pay a fixed monthly “rent” or lease calculated based on the estimated amount of electricity the system will produce in exchange for the right to use the solar installation. With a solar ECA, you agree, instead of paying for the “rent” of the solar module system, to purchase the electricity produced by the facility at a price determined per kWh. . . .