Emirates solar is a site that is dedicated to encouraging people all round the world to make the move towards green energy.
This will be updated in the future to allow us to get feedback on how and where solar power is used in Alaska.
Solar Energy
Solar energy is clean and virtually limitless energy.
Most forms of green energy are solar in one form or another. Wind Energy is energy from the sun causing the air to move via temperature changes. Hydro Power is energy from the sun evaporating water into the air which then comes down as rain into the rivers. The earth receives 174 petawatts per day. (1 petwatt is enough to supply all of New York City for 10.5 years!) Solar energy flow has a share of more than 99.9% of all energy converted on the planet. However solar energy currently accounts for only 0.04% of the energy used by people on the planet today. However, this is predicted to increase significantly over the next decade. Solar power production is one of the fastest growing areas of technology and the cost of electrical energy per kilo watt hour from a solar source is rapidly going down.
There are several applications for solar power e.g. individual installations for a single house, large solar power plants using photovoltaic cells, large power plants using solar towers and even solar power generating glass that is used for large sky scrapper structures.
The rest of this article describes different uses of solar power in the world today.
Individual Installations
There are two types of individual installations. These are Standalone Systems and Utility Interactive Systems.
Stand Alone Home Systems
A stand alone system is one that does not require support from the national grid. Its energy can be wholly generated by solar cells. Stand alone systems require a battery storage system. Full stand alone home power systems that will cater for all the needs of a modern house have been around for a while now and the technology for them gets better every year. By using an inverter they can provide an AC power supply. However, some people use a DC system and buy DC appliances.
In some situations solar home systems are already the least costly method of house-hold lighting and electricity.
Utility Interactive Systems
In this system there is no need for on-site storage. Your solar installation is one that feeds energy back up to the national grid when your photovoltaic cells produce more power than you consume. The power company will then buy it back from you at an agreed price. Before you take this option make sure the power company is willing to offer this option. With this system the national grid also acts as a backup power supply for when you do not produce enough power.
Solar Power Stations
These are becoming popular and tend to fall into various types.
Solar Towers
Solar central power towers generate electric power from sunlight by focusing concentrated solar radiation on a tower-mounted heat exchanger (receiver). The system uses hundreds to thousands of sun-tracking mirrors called heliostats to reflect the incident sunlight onto the receiver. These plants are best suited for utility-scale applications in the 30- to 400-MWe ranges. In a molten-salt solar power tower, liquid salt at 290°C (554°F) is pumped from a “cold” storage tank through the receiver where it is heated to 565°C (1,049°F) and then on to a “hot” tank for storage. When power is needed from the plant, hot salt is pumped to a steam generating system that produces superheated steam for a conventional Rankine-cycle turbine/generator system. From the steam generator, the salt is returned to the cold tank where it is stored and eventually reheated in the receiver.
Photovoltaic Panel Farms
This is effectively a large set of solar panels put up in a location.
Solar photovoltaic cells convert sunlight into electricity and many solar photovoltaic power stations have been built.
11 megawatt Serpa solar power plant on 90 acres in Portugal
Solar Updraft Tower
The solar updraft tower is a proposed type of renewable-energy power plant. It combines the chimney effect, the greenhouse effect, and the wind turbine. Air is heated in a very large greenhouse-like structure around the base of a tall chimney, and the resulting convection causes the air to rise and escape through the tower. The air current from the greenhouse to the chimney drives turbines, which produce electricity.
Solar Buildings(Skyscrapers)
Here photovoltaic panels are clad around a large tower building.
One such example is the CIS Tower in Manchester, England. This total peak power of the solar panels is given as 400KWp which provides 200,000KWh per year.
Urban Areas
Solar energy has also plenty of potential in urban areas for the following applications, amongst others:
As an alternative form of energy where the national grid is unreliable. i.e.providing yourself with energy via a standalone system.
As a boost to the national grid using utility interactive systems.
As an energy source for neighbourhood lighting. E.g. street lighting, porch lighting etc. Many people have security lights in their neighbourhood/street. The cost of this lighting is normally shared amongst the residents of the neighbourhood. It can be annoying collecting the fees from each member. With solar lights, once the lights are put in place there are no energy bills to pay.
Alternative Energy Supply For Devices
Solar power will provide an alternative energy supply to burning various fuel types (e.g. kerosene, diesel, wood etc.) to provide energy for light, cooking and warming. There is a large market in solar variations for small appliances, e.g. lanterns, lamps, water heating, portable air conditioners, fans, cookers, fridges, freezers and so on.
In the developing world rural households that currently use kerosene lamps for lighting and disposable or automotive batteries for operating television, radios and other small appliances, comprise a large market for solar home systems. Families are spending up to thirty dollars per month on home energy services, depending primarily on income levels and fuel prices. A 1993 World Bank study from a dozen countries found that the average monthly expenditure for lighting and entertainment communications alone ranged between $2:30 and $17:30 for a month’s supply. Even back then it was found that the average cost to provide the same lighting and entertainment using solar power was around $10 per month. Today, thanks to new methods of production, solar cells and the new LEDs used in place of light bulbs, the cost is much less than $10 and it keeps falling.
Water Pumping For The Home And Irrigation
The solar powered water pumping is another area where solar power is showing great potential. These pumps are becoming increasingly popular especially now solar cells are becoming more efficient. Water pumping is a great application of solar power as the water can be pumped into a tank in the daytime and then used throughout the night. There is therefore no need for a battery to store any energy to pump water during the night.
The Advantages Of Solar Power
There is no shortage of products to produce the solar cells, mirrors or the other raw materials needed to generate solar power. Silicon cells are one of the most used types of solar cell and 27.7% of the earth’s crust is composed of silicon. There are also new innovations which have come out recently which allow solar cells to be printed onto materials like aluminium. This will allow for even cheaper and more efficient cells.
Unlike fossil fuel and nuclear energy, solar power has no nasty by-products.
It can be used for both small scale portable applications, e.g. solar lanterns, as well as large scale systems like power stations.
It allows people to feed surplus energy back into the national grid and get paid for it!
Unlike wind and hydro power systems, solar power systems do not kill birds or fish or require the destruction of huge areas of natural wild life habitats.
The cost of solar power keeps falling. Thanks to the new printed solar cells, there is talk of solar energy competing with conventional forms of power generation.
The Disadvantages Of Solar Power
There are some parts of the world where the sun does not shine for several months although this may be a good thing as half the time there is constant sun and there is no need for a battery (well perhaps a small battery for cloudy days).
The solar system can realistically only be charged up in the daytime.
Solar power for many applications will need to be stored as it is only available in the daytime.
If everyone were to use a utility interactive system, we could end up with an unstable sytem as on cloudy days everyone would withdraw power from the system and on sunny days everyone would sell power to the national grid. However, as power storage innovations move forward, this should not be a problem.
Recent Points Of Interest
Solar Power is now used by many countries for street lighting.
In hot countries it is often used for air conditioning.
However it is not yet common for domestic house hold systems.
