IRENA Solar City Simulator: Georgetown

Overview

The SolarCity is a web-based simulator application created to help households, businesses and municipal authorities evaluate their prospects for generating electricity using rooftop-mounted solar photovoltaic (PV) systems.

For homes and businesses, the simulator provides the means to calculate likely savings from rooftop solar PV compared to other power sources and based on a cash flow financing model.

For municipal authorities, the simulator supports assessments of different policy incentives – such as generation or capital subsidies – on each city’s rooftop solar PV market.

The SolarCity simulator combines ultra-high-resolution three-dimensional building footprints with solar irradiation data, computed at one metre (m) grid cells. It is one of a series of web applications developed by the International Renewable Energy Agency (IRENA) as part of the Global Atlas for Renewable Energy.

User Guidance

The Setting section presents the capacity of solar PV panels that can be accommodated on a single (or multiple) rooftop(s) as well as the self-consumption of a single (or multiple) building(s).

The Set Input tab allows users to adjust some of the parameters of the analysis. This window comprises two sets of parameters:non-alterable and alterable.

The non-alterable parameters– such as the PV capacity, surface area, number of buildings and annual consumption – are precalculated by the SolarCity simulator based on the user’s chosen configuration and area of interest. The annual consumption figure responds to user interaction via the consumption subsection of the tuner.

Alterable parameters, such as storage capacity, PV efficiency, system cost, interest rate, loan, loan period, emission factors, average consumption, tariffs, tax credits and subsidies can be adjusted as required. The SolarCity simulator recalculates the outputs of the ‘Financing’ and ‘Environmental (and Social) Benefits’ sections of the ‘Output’ panel.

For instance, by inputting values for subsidies or income tax credits, the SolarCity simulator can assess the economic feasibility of rooftop solar PV systems. This assessment is based on a simplified model that assumes a solar programme aiming at full utilisation of all suitable rooftop spaces.

Note that the output metrics comprise the direct accounting costof the subsidyor income tax creditsto the municipal or central authorities and the prospective value created by these interventions. This first approximation does not estimate the indirect costs of implementing the schemes or measure the positive and negative externalities that may arise from their implementation.

All outputs from the SolarCity model can be downloaded by clicking on the ‘Get report’ icon in the ‘Results’ section.