Photovoltaics (PV) a method of converting solar energy into direct current electricity using semiconducting materials.
Solar energy is the cleanest, most abundant renewable energy source available. The energy contained in solar irradiation that hits the earth by far exceeds today’s total energy consumption. To take advantage of this energy, solar radiation must be converted into a useful form and the output needs to be stored and distributed in order to overcome seasonal and regional variations. Solar radiation can be used passively through windows or other transparent façade systems. As for active systems, these fall into two groups – thermal use for heating and cooling purposes (solar thermal collectors) and the direct conversion of solar energy into electricity (photovoltaic modules).
Photovoltaics (PV) is the name of a method of converting solar energy into direct current electricity using semiconducting materials that exhibit the photovoltaic effect .Cities are installing photovoltaic (PV) solar electric arrays. PV becomes more cost-effective when conventional electric rates are high and ample incentives are offered by state government or local utilities. To achieve climate neutrality or deep cuts in GHG emissions, cities will need to transition as much as possible to carbon-free renewable solar energy technologies.
Large-scale installations also use combined technology, where steam is generated by concentrated solar heat, which then drives a turbine to produce power. Thermal storage systems (small scale in single buildings, large scale in communities or districts) help to bridge times without sunshine. Both photovoltaics and solar thermal systems are playing an increasingly significant role in the building sector, especially when aiming for zero-emission- and energy-plus-buildings.
Government,solar architecture and solar companies
What actions do you propose?
Install solar photovoltaic’s (PV) on Building
Solar photovoltaic technologies convert energy from sunlight directly into electricity, using large arrays of solar panels.
Solar photovoltaic technologies convert solar energy into useful energy forms by directly absorbing solar photons—particles of light that act as individual units of energy—and either converting part of the energy to electricity (as in a photovoltaic (PV) cell) or storing part of the energy in a chemical reaction (as in the conversion of water to hydrogen and oxygen).
Solar cells are devices that convert sunlight directly into electricity. Solar cells are made of layers of semiconductor materials. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity.
Solar cells are generally very small, and each one may only be capable of generating a few watts of electricity. They are typically combined into modules of about 40 cells; the modules are in turn assembled into PV arrays up to several meters on a side. These flat-plate PV arrays can be mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to capture more sunlight. For utility-scale electricity generating applications, hundreds of arrays are interconnected to form a single, large system.
Concentrated PV (CPV) Systems
Concentrated PV (CPV) systems concentrate sunlight on solar cells, greatly increasing the efficiency of the cells. The PV cells in a CPV system are built into concentrating collectors that use a lens or mirrors to focus the sunlight onto the cells. CPV systems must track the sun to keep the light focused on the PV cells. The primary advantages of CPV systems are high efficiency, low system cost, and low capital investment to facilitate rapid scale-up; the systems use less expensive semiconducting PV material to achieve a specified electrical output.
The amount of available sunlight is another important factor though PV can work well in all areas. Where there is less sun, compensate by adding panels to meet a given load. This adds cost and stretches out payback but it works. Where snow may cover panels during winter months, panels can be tilted to shed snow or PV array output can be pro-rated downward to allow for a number of weeks or months when output is nil. The performance of grid-interconnected PV is generally measured in terms of annual power production and most PV production occurs during the warmer months when days are longer and there is less cloud cover. In areas where winter days are cold and clear, angling panels to take advantage of those conditions becomes more important.
One of the world's first zero-carbon cities, called Masdar City, is being constructed in the Gulf emirate of Abu Dhabi, it is set to house 50,000 people. Construction began in February 2008. The desert city is designed to be powered entirely with renewable energy, including solar power and wind power. Construction of this large-scale project will occur in two phases. In phase one, a solar photovoltaic power plant will be built as a central energy source. Masdar is powered by a 22-hectare (54-acre) field of 87,777 solar panels with additional panels on roofs.
Who will take these actions?
Government, solar companies, industries, companies, private sector, and individual
Where will these actions be taken?
How much will emissions be reduced or sequestered vs. business as usual levels?
Once installed and operating, a PV system produces zero greenhouse gas emissions.
What are other key benefits?
The key benefits are:
- PV panels provide clean – green energy. During electricity generation with PV panels there is no harmful greenhouse gas emissions thus solar PV is environmentally friendly.
- Solar energy can be made available almost anywhere there is sunlight
- Solar energy is especially appropriate for smart energy networks with distributed power generation – DPG is indeed the next generation power network structure!
- Solar PV panels have indeed a highly promising future both for economical viability and environmental sustainability.
- Operating and maintenance costs for PV panels are considered to be low, almost negligible, compared to costs of other renewable energy systems
- PV panels have no mechanically moving parts, except in cases of sun-tracking mechanical bases; consequently they have far less breakages or require less maintenance than other renewable energy systems (e.g. wind turbines)
- PV panels are totally silent, producing no noise at all.
What are the proposal’s costs?
The cost of solar panels is a variable that actually depends on the time, place and scale of solar panel installation. Prices range between $1700-$2500 per Kw of installed photovoltaic (PV) panels (installed capacity). Other factors influencing the overall solar panel cost include the efficiency and life expectancy of the solar panels, installation costs including actual installation of the solar panels and electrical connections, additional equipment required such as inverters, batteries and cabling.
Within 1 year baseline survey
2 to 5 years manufacturing and installation of solar panels
Above 5 years cost benefit analysis.
How can smart technologies drive a rapid transition to zero-carbon cities?