Solar modeling report : solar resources mapping in the Maldives

Abstract

1 SUMMARY Background This Modelling Report presents preliminary results of the project Renewable Energy Resource Mapping for the Republic of the Maldives. This part of the project focuses on solar resource mapping and measurement services as part of a technical assistance in the renewable energy development implemented by the World Bank in Maldives. It is being undertaken in close coordination with the Ministry of Environment and Energy (MEE) of Maldives, the World Bank’s primary country counterpart for this project. This project is funded by the Energy Sector Management Assistance Program (ESMAP) and Asia Sustainable and Alternative Energy Program (ASTAE), both administered by the World Bank and supported by bilateral donors. Objective and method The objective of the project, in Phase 1, is to increase the knowledge of solar resource potential for solar energy technologies by producing a comprehensive data set based on satellite and meteorological modelling. In Phase 1, SolarGIS approach is used in the preliminary mapping. The satellite-based and meteorological models are used for computing solar resource and meteorological data. These data are validated with ground measurements, available in a wider region representing this climate zone. Geospatial data are delivered in a format suitable for Geographical Information Systems (GIS), and also as digital maps. For four sites, representing variability of climate in Maldives, we delivered site-specific time series and Typical Meteorological Year (TMY) data. Data validation results are presented in the Model Validation Report 129-02/2015. Data delivery The following data parameters are resulting from this solar resource and meteorological modelling: • Global Horizontal Irradiation (GHI) and Global Tilted Irradiation: for assessment of photovoltaic technology • Direct Normal Irradiation (DNI): for Concentrated Solar Power and Concentrated Photovoltaics technologies, also important for accurate simulation of flat plate PV systems • Air temperature: this parameter determines efficiency of solar power plant operation. For site-specific data we delivered also wind speed, wind direction, and relative humidity data. • Photovoltaic electricity potential. The data products that are delivered as part of this preliminary solar modelling: 1. GIS data and digital maps for the whole territory of the Republic of the Maldives, representing long- term monthly and yearly averages. In addition hourly data values are delivered in specific data format: • Raster digital data layers for Geographical Information System (GIS), representing monthly and yearly values • High resolution digital maps of annual values for poster printing • Medium resolution digital maps of annual and monthly values for presentations • Digital image maps of yearly values for Google Earth and GIS • Support maps in a vector data format for GIS Page 10 of 98 World Bank, Global ESMAP Initiative, Renewable Energy Resource Mapping: Solar − Maldives (Project ID: P146018) Solar Modelling Report – Preliminary Results 2. Site specific data at hourly resolution are prepared for 4 representative sites: • Time series, for detailed solar resource analysis • Typical Meteorological Year (TMY), for use in solar energy simulation software. 3. NetCDF files with hourly data for the complete period 1999 to 2013 The deliveries for Phase 1 are designed to help effective development of solar energy strategies and projects in their first stages. The innovative features of the delivered data are: • High-resolution, harmonized solar, meteorological and geographical data computed by the best available methods and input data sources; • The data represent a continuous history of last 15 years (1999 to 2013); • The models used are extensively validated by GeoModel Solar and by external organizations. The data are supported by two expert reports: • Solar Modelling Report (129-01/2015, this report), describing the methods and results of Phase 1 activities; • Solar Model Validation Report (129-02/2015), describing the methods and results of the data validation. Phase 1 delivers data computed by SolarGIS model without any support of regional measurements. This phase will be followed by two additional phases: • In Phase 2 we will deploy and operate approx. four solar measuring stations in Maldives to collect high- quality site-specific solar and meteorological time series for adaptation of solar and meteorological models and for detailed analysis of solar climate at representative sites. This Phase is planned for a minimum of 24 months; • Phase 3 aims to combine site measurements with models, and to deliver a new version of the modelled database with reduced uncertainty. Copyright for the delivered data is © 2015 GeoModel Solar. Results This Solar Modelling Report is divided into twelve chapters. Solar radiation basics and collection of solar radiation data from different sources are described in Chapter 2. Characteristics and challenges of using modelled and ground-measured solar parameters are compared in Chapter 3. Chapter 4 describes measurement and modelling approaches for developing reliable meteorological data at any site. Chapter 5 provides a link between solar resource and meteorological parameters and relevant solar technologies. An emphasis is given to photovoltaic (PV) technology, which has high potential for developing larger-scale projects close to larger load centres, as well as deployment of smaller PV hybrid systems and minigrid applications for electrification in islands. Chapters 6 to 8 present developed solar resource and meteorological data in the form of maps. Four representative sites are selected to show potential regional geographical differences in the country through tables and graphs. Chapter 6 introduces some support geographical data that may help in PV development strategies. Chapter 7 summarizes geographical differences and seasonal variability of solar resources in Maldives. Chapter 8 presents PV power generation potential, calculating theoretical specific PV electricity output from the most commonly used PV technology: fixed system with crystalline-silicon (c-Si) PV modules optimally tilted and oriented towards the equator. The expected data uncertainty based on the validation exercise is summarized in Chapter 9. The complete methodology and detailed results can be consulted in the Model Validation Report 129-02/2015. The provided solar resource information, evaluated in the context of other location criteria (demographic, infrastructural, logistic and other constraints and priorities) is a good starting point for building solar energy strategy in Maldives. Chapter 10 outlines the best practices of solar data use in all stages of a project development and operation. Chapters 11 and 12 summarize the technical features of the delivered data products. Page 11 of 98 World Bank, Global ESMAP Initiative, Renewable Energy Resource Mapping: Solar − Maldives (Project ID: P146018) Solar Modelling Report – Preliminary Results Conclusions This Solar Modelling Report is supported by the results of preliminary modelling. The maps and site data for four representative sites, serve as an input for knowledge-based decisions targeting development of solar power. The Phase 1 outcomes show very good potential for exploitation of solar resources in Maldives, indicating very good opportunities for photovoltaics, predominantly small to medium size ground-mounted and roof-top systems. Concentrated photovoltaic is not recommended because of its space requirements and lower DNI in the equatorial climate zone.