A Fleeting Ray of Sunshine – a Stable Energy Supply
Making solar power available 24/7
Power generated by the sun is the ultimate in clean, free energy. But however sunny the location, there’s a catch: Nighttime. For a conventional power plant, the time of day is irrelevant, but for solar, no sun means no power. Energy storage is therefore necessary to make solar power available around the clock. In converting this to usable electricity, vacuum pumps from Busch play an essential role.
Solar panels supply electricity to the grid only when the sun is shining on them – limiting their output to daylight hours on non-cloudy days. Without a viable means of energy storage, other forms of power generation, usually using non-renewable fossil fuels, are left to fill the gap in the grid. One solution is to make solar power generation more like a conventional power plant – by converting it to thermal energy.
Heating for a rainy day
Storing thermal energy is much easier than storing electricity. Consider the simplicity of an insulated flask that keeps your tea hot compared to the number of batteries you would need to boil an electric kettle without a power connection. While conventional solar panels convert sunlight directly to electricity, solar thermal power plants add an extra step: converting it into heat that can be more easily stored and drawn from when needed.
From heat to electricity
The key to solar thermal energy is concentrating the sun’s rays. Rather than flat panels, a solar thermal power plant is made up of concave mirrors that reflect the rays onto a collector. The collector contains a fluid, either molten salt or a synthetic oil, that is heated by these concentrated rays. The heated fluid can then be stored at temperatures of between 400 and 600 °C in insulated tanks.
When the electricity is needed, the fluid is used to heat and evaporate water to steam. The steam is directed through a turbine that drives a generator. A vacuum pump is connected to the condenser, where the steam returns to water. Before starting the turbine, the vacuum pump evacuates air and other non-condensable gases. This improves the efficiency of the condensation process by eliminating the insulating effect of the air, which would otherwise prolong the process. It also minimizes back pressure on the turbine, making the energy transfer from heat to mechanical energy more efficient. Once the turbine has been started, the vacuum level is maintained by continuously removing any air that leaks in. By using vacuum in this process, the free, clean energy won from our sun can be used to its maximum potential.
Heating for a rainy day
Storing thermal energy is much easier than storing electricity. Consider the simplicity of an insulated flask that keeps your tea hot compared to the number of batteries you would need to boil an electric kettle without a power connection. While conventional solar panels convert sunlight directly to electricity, solar thermal power plants add an extra step: converting it into heat that can be more easily stored and drawn from when needed.
From heat to electricity
The key to solar thermal energy is concentrating the sun’s rays. Rather than flat panels, a solar thermal power plant is made up of concave mirrors that reflect the rays onto a collector. The collector contains a fluid, either molten salt or a synthetic oil, that is heated by these concentrated rays. The heated fluid can then be stored at temperatures of between 400 and 600 °C in insulated tanks.
When the electricity is needed, the fluid is used to heat and evaporate water to steam. The steam is directed through a turbine that drives a generator. A vacuum pump is connected to the condenser, where the steam returns to water. Before starting the turbine, the vacuum pump evacuates air and other non-condensable gases. This improves the efficiency of the condensation process by eliminating the insulating effect of the air, which would otherwise prolong the process. It also minimizes back pressure on the turbine, making the energy transfer from heat to mechanical energy more efficient. Once the turbine has been started, the vacuum level is maintained by continuously removing any air that leaks in. By using vacuum in this process, the free, clean energy won from our sun can be used to its maximum potential.
Read more – Solar panels in space
In space, the sun shines 24 hours a day. As a result, vacuum-coated solar panels are the main power source for almost all satellites and probes, as well as for the International Space Station (ISS). What if we could use this constant stream of solar energy down on the Earth’s surface? The feasibility of this concept is what the European Space Agency’s SOLARIS project is hoping to prove. If the project goes ahead, solar plants would be sent into geostationary orbit around 36,000 km above our planet’s surface and beam down the energy they capture via microwaves. The scale of the project is enormous: To generate each gigawatt of extraterrestrial power, an area of 5 km2 of solar panels is necessary in space. And the receiving station here on the surface needs to be even bigger at 25 km2, just slightly larger than Manhattan Island, the urban center of New York City. Although there are many technological challenges involved to be overcome before the project can be realized, the result would be a giant leap for mankind: 24/7 clean, green energy from space with the help of vacuum.
In space, the sun shines 24 hours a day. As a result, vacuum-coated solar panels are the main power source for almost all satellites and probes, as well as for the International Space Station (ISS). What if we could use this constant stream of solar energy down on the Earth’s surface? The feasibility of this concept is what the European Space Agency’s SOLARIS project is hoping to prove. If the project goes ahead, solar plants would be sent into geostationary orbit around 36,000 km above our planet’s surface and beam down the energy they capture via microwaves. The scale of the project is enormous: To generate each gigawatt of extraterrestrial power, an area of 5 km2 of solar panels is necessary in space. And the receiving station here on the surface needs to be even bigger at 25 km2, just slightly larger than Manhattan Island, the urban center of New York City. Although there are many technological challenges involved to be overcome before the project can be realized, the result would be a giant leap for mankind: 24/7 clean, green energy from space with the help of vacuum.