To provide all countries with clean energy and deliver it to anywhere in the world - all this can
Only 1.11% of global energy consumption in2019 received from solar energy. The sun has a huge energy potential, so researchers are looking for a way to make the best use of its full potential.
At first glance, solar energy is a simpleand the obvious choice. Unlike fossil fuels, their production does not emit greenhouse gases that accelerate global warming. Competition for water resources and territories is also not a problem.
More politically, solar energyone of the safest sources of alternative energy. Large conflicts took place over the right to dispose of oil and coal reserves. In this sense, solar energy is universal, it belongs to everyone and no one at the same time.
Why is it not efficient to receive solar energy on Earth?
According to NASA, approximately 29% of solar energyreflected back from the earth's atmosphere and scattered into space. On top of that, another 23% of solar energy is absorbed by water vapour, ozone and dust as it passes through the atmosphere. After all, only 48% of solar energy reaches our planet.
Therefore, solar panels on Earth receive inat best, half the energy of the original amount. But there is still a problem in the batteries themselves, their maximum efficiency is about 22%: we are talking about non-laboratory conditions. And most importantly, solar panels only work during daylight hours. Therefore, you need to have an idea to receive energy directly from the Sun, while not being on Earth.
How does space solar power work?
Space Solar Power (SBSP) is an ideacollecting solar energy in space using satellite solar panels. Then it wirelessly gets to the Earth. According to the European Space Agency (ESA), light from the Sun is 11 times more intense outside the atmosphere. Therefore, satellite solar panels can provide a huge amount of energy that humanity can not even spend.
In addition, satellite panels are not threatenedbad weather and sunset. From space, these devices will be able to transmit energy to any place on Earth, so you only need to put the satellites into an optimal orbit.
How to deploy a solar panel in space?
To make space solar poweraffordable, two basic technologies are needed. First, launch vehicles for delivering materials into space must be inexpensive and environmentally friendly. Most of the rockets currently used to deliver payloads are very expensive and polluting. Several private companies, notably SpaceX, are now developing cheap, reusable rockets.
The second point is the construction of solar satellitesin orbit. To harvest the required amount of energy, satellite solar panels would need to be much larger than the ISS. In fact, it will be a huge spaceship. On the other hand, space panels are easier to assemble than the ISS.
What are solar satellites?
According to researchers from the MinistryUS energy, there are two types of satellites that can be created to collect space energy. Both of these types will consist of solar collectors, reflectors and a transmitter. Reflectors are large mirrors that will direct radiation to small panels - collectors - which then convert solar energy into microwave or laser energy to transmit it to Earth. Receiving stations on Earth will collect, store and distribute energy.
- Satellites with microwave transmission
The larger of these two structures will be the satellites,transmitting microwaves. They will be made from huge solar reflectors that direct solar energy to the center of the satellite, from where it is then transmitted to Earth in the form of microwaves. Satellites transmitting microwave signals will orbit the Earth in geostationary orbit at an altitude of about 35,000 km - that's just under one-tenth the distance from the Moon.
However, all such constructions willhuge. The solar reflectors alone will weigh over 80,000 metric tons with a diameter of up to 3 km. Thanks to their sheer size, microwave satellites could generate gigawatts of power and power the world's major cities. In addition, the wavelength of the electromagnetic spectrum is relatively large, so the transmission of energy from such a satellite will be as fast and intense as sunlight reaches the Earth.
Launch, assembly and operation of satellites,transmitting microwaves - all this is very expensive. Their value is estimated at tens of billions of dollars. Due to the large size, it will take 40 to 100 launches to deliver all the materials. In addition, the size of receiving centers on Earth should be scalable to the size of satellites in space—about 3 to 10 km in diameter. And such large tracts of land are difficult to develop and maintain.
- Satellites with laser transmission
The second type of solar satellites are satellites withlaser transmission - they will be only about 2 m in diameter. To transfer energy back to Earth, they will place a diode-pumped alkaline laser. A laser can be about the size of a kitchen table and radiate energy to Earth with over 50% efficiency.
Satellites with laser transmission will launchgroups into low Earth orbit (LEO) for about 400 km, as they are small. The production of such devices is not as risky and requires less time than satellites transmitting microwave signals. Cost estimates for laser satellites range from $500 million to $1 billion.
But there are also disadvantages.Satellites with laser transmission are less powerful: each unit will generate only 1 to 10 MW of power. Even if many devices are launched at once, they will not be able to match the power provided by satellites with microwave transmission. And since the power is lower, it will be more difficult to transfer energy through heavy clouds and rain.
Launching solar panels into space will help solvenot only energy problems, but also social and political conflicts. Currently, many countries are dependent on fossil fuel supplies, and limited supplies of oil and carbon are causing serious international conflicts. Solar energy will help ensure energy independence. Also, this energy can be exported to almost anywhere in the world.
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