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Today solar energy is regarded as complementary, but not an alternative, to oil.
We do indeed need all energy resources to fulfill the demanding energy needs. Our liquid sources, like oil, are necessary for certain applications and fossil energies in general will continue representing a large part of the world energy mix, even if the latter is subject to progressive evolution.
For about ten years now, photovoltaic solar energy has greatly reduced its costs and is becoming more and more available. In numerous countries, the grid parity has been reached, meaning that electricity generated by photovoltaic solar energy is the same cost as the average cost of electricity sold in this country, making it an economically-attractive choice.
In some very-sunny countries which are presently obliged to import energy, photovoltaic solar energy allows them to manage their own electric production thanks to a cost decrease. In Chile for example, the number of photovoltaic plants are increasing and helping the country's energy-independence.
Yes, today it's possible for a house to be fully supplied in electricity thanks to solar energy. However, an energy self-sufficient house is still the combination of several factors:
1. A perfectly insulated building as if the inside isn't fully insulated there is the risk of heat loss,
2. Using low heat-consumption equipment (ex: A, A+++),
3. Being very aware of energy consumption, adopting all the good reflexes such as turning off lights and electrical equipment when not being used,
4. Having fairly efficient photovoltaic panels. The solar energy allowing to generate electricity in a house obviously depends on the available surface area to install the solar panels,
5. Having a storage system to ensure using electricity, notably at night.
1. Reducing the thickness of silicon wafers. When photovoltaic cells operate, electrons circulate all around the wafer thickness. Therefore, if wafers are too thick, the probability of impurities increases and the risk of electrons touching these impurities becomes greater. By reducing wafer thickness, the impurity rate decreases therefore the light-to-energy conversion increases. Presently, wafer thickness is about 190 microns but some laboratories have already managed to make wafers with a 20-micron thickness. Nevertheless, this is still difficult to implement from an industrial standpoint as it means ensuring no ultra-thin wafers break during the various handling activities.
2. The multi-junction solar cells. On photovoltaic cells, each junction absorbs a certain part of solar radiation. The principle of multi-junction technology is to superimpose several photovoltaic junctions, able to absorb each of the various light rays. This increases the light-to-energy conversion. Nevertheless, this technology leads to additional costs so it’s essential to check that the balance between the efficiency gains and costs remains attractive.
3. Groundbreaking technologies. By definition, groundbreaking technology doesn’t exist yet but many researchers are working hard in laboratories hoping to find a totally innovative and never-before-seen technology. This starts by constantly monitoring developments to stay updated with all innovations, and identifying intriguing leads for the solar industry.
Within a concentrated solar energy plant, solar radiation is used to produce heat and indirectly to produce electricity from a turbine.
Using reflecting mirrors, the aim is to concentrate the solar radiation onto a fluid to heat it up to 300-400° C. This high-temperature fluid can then generate steam, driving a turbine to produce electricity.
The concentrated solar energy is therefore different from photovoltaic energy which directly uses sunlight to generate electricity.