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Solar energy resource depends on solar irradiation of the geographic location as well as local issues like shading. Initially, solar resource assessment can be done based on satellite data or other sources, but as the project development moves forward, ground-based measurements are desirable to provide an increased level of confidence. Energy yield is a critical parameter that determines (along with the capital costs and the tariff) the financial viability of the project. Probability-based energy yield (for example P50, P75, P90) are modelled over the operating life of the project. A thorough analysis of the solar resource and projected energy yield are critical inputs for the financial analysis. Details on the methodology, solar data sources and key issues to be considered when estimating the energy resource and project energy yield.Site selection is based on many considerations, such as whether the PV plant is close to the grid, and whether the process for obtaining a grid connection agreement is transparent and predictable. Close cooperation with the grid company is essential in obtaining a grid connection agreement. The agreement, as well as applicable regulations should clearly state the conditions of the PV developer’s access to the grid, and provide the guidelines for design, ownership, and operation of the grid connection. Access to land is also a basic requirement for project development. Project land must be purchased or leased for longer than the debt coverage period; a minimum of 15–20 years is desirable, although a 40–50 year lease is often signed. In addition to the project site, the developer needs to secure access to the land over which the grid connection will be laid out. Land use issues are reviewed along with the technical aspects of site selection. Permits and licensing is often a very bureaucratic process involving multiple agencies in the central and local governments which may not coordinate their procedures and requirements. The list of permits/agreements needed is usually very long and differs from country to country. Typically, at least the following are needed: 1) Land lease agreement; 2) Site access permit; 3) Building permits; 4) Environmental permit; 5) Grid connection agreement; and 6) Operator/generation license. Understanding the requirements and the local context is essential. Consultations with the relevant authorities, the local community, and stakeholders are also important for a smoother approval process. Environmental and social assessments should be performed early in the project planning process and actions should be taken to mitigate potential adverse impacts. Grid connection agreement is critical to ensure that the PV plant can evacuate the power generated to the grid.



PV systems are installed on rooftops of residential buildings (typically 10–50 kW) and commercial/industrial buildings (up to 1–2 MWs). From the design and construction point of view, key aspects are: optimal orientation and shading from adjacent (present and future) buildings and plants. Permits are easier to obtain, but they differ from large utility-scale PV plants, as different agencies are involved (mostly local authorities). Depending on the regulatory framework affecting such installations, net metering or gross metering may be available; this is something that (along with the regulated tariff for electricity sold to the grid) will determine the payback period and overall attractiveness of the project. However, purchasing the PV system is not the only option for the owner of a building. As a company we invest and offering the plants under lease agreements or installing the PV plant and paying the owner of the building a rental. Under such agreements, electricity may be sold to the building owner at below-market prices.

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