As solar photovoltaic power generation continues to become more popular, more and more residents have installed photovoltaic power systems on their roofs. The principle of solar photovoltaic power generation is to convert light energy into electrical energy. It is a green new energy that many countries focus on promoting.
Mobile phones, computers, and WiFi emit radiation, so will there be radiation from a home solar power system installed on the roof of a house? Let’s take a look at the detailed explanation below.
1. What is radiation？
The definition of radiation is very broad. Light is radiation, electromagnetic waves are radiation, particle flow is radiation, and heat is also radiation. So clearly we are exposed to all kinds of radiation. What kind of radiation is harmful to people? What people generally call "radiation" refers to the radiation that is harmful to human cells, such as causing cancer and has a high probability of causing genetic mutation. And this kind of radiation generally contains shortwave radiation and some high-energy particle flows.
In fact, everything contains radiation. Radiation can be divided into two types: ionizing radiation and non-ionizing radiation. What is harmful to the human body is ionizing radiation.
In 1895, German physicist Röntgen discovered X-rays. The unit of measurement for ionizing radiation is millisieverts. Taking a chest X-ray meaning exposed to about 0.2 millisieverts radiation. For CT scans of different parts, the highest radiation is about 10 sieverts. For the human body, it is safe if the cumulative does not exceed 100 millisieverts in one year.
The ionizing radiation of a banana is about 0.0000778 millisieverts, which means that it is safe to eat no more than 1.28 million bananas in a year. Is eating 1.28 million bananas a year a lot? If a person sleeps 8 hours a day and eats bananas for the remaining 16 hours, he or she needs to eat an average of 3.652 bananas per minute.
Therefore, the ionizing radiation we encounter in daily life can be basically ignored. Regarding ionizing radiation, we cannot talk about its harm without numbers.
2. Do solar power systems produce radiation?
Photovoltaic power generation is non-ionizing radiation. It converts light energy directly into DC power through the characteristics of semiconductors, and then converts the DC power into AC power that can be used by us through an inverter with 12v battery.
When the photovoltaic module itself generates electricity, it does not undergo any chemical changes or nuclear reactions, so it does not produce any electromagnetic radiation.
For photovoltaic power generation, the power generation mechanism of solar modules is completely direct conversion of energy. During the energy conversion in the visible light range, no other products are generated, so no additional harmful radiation is generated.
Solar inverters are just general power electronic products. Although they contain IGBTs or transistors and have a switching frequency of dozens of K, as long as the inverters have metal shielding casings and comply with global electromagnetic compatibility regulations, there’s no need to concern about the radiation. For further information, you can check the top 10 solar inverters for reference.
3. Is solar power generation harmful to the human body?
It is impossible to say that solar power generation has no radiation. In fact, solar photovoltaic power generation contains some electromagnetic radiation. The amount of this radiation is very little. If the solar photovoltaic power generation equipment is qualified, the radiation generated will not cause harm to the human body, and this radiation will not affect or interfere with other equipment.
Photovoltaic power generation uses the characteristics of semiconductors to directly convert light energy into direct current, and then converts the direct current into alternating current that we can use through an inverter from 500w inverter to 3000w inverter.
The photovoltaic system consists of photovoltaic modules, brackets, DC cables, inverters, AC cables, distribution cabinets, transformers, etc. The brackets are not charged and will naturally not produce electromagnetic interference. Photovoltaic modules and DC cables contain DC current, which does not change direction. They can only generate electric fields, not magnetic fields.
Although the output transformer uses alternating current, the frequency is very low, only 50Hz, and the magnetic field generated is also very low. An inverter is a device that converts direct current into alternating current. It contains power electronic conversion, generally at a frequency of 5-20KHz, thus generating an alternating electric field and therefore electromagnetic radiation.
However, there are strict standards for the electromagnetic compatibility of photovoltaic inverters. Compared with household appliances, the electromagnetic radiation of photovoltaic inverters is similar to that of laptop computers, and lower than induction cookers, hair dryers, refrigerators, etc.
We talked about ionizing radiation before, now let’s talk about non-ionizing radiation. Cell phones, computers, humidifiers, WIFI, hair dryers, etc. are almost all contain 0 millisieverts radiation. If you must calculate, you could calculate the value of their electromagnetic radiation. The unit of measurement is μT or microtes L. Generally, it is several to more than 10 μT.
The ionizing radiation values of these items are all added together, and are not as high as the μT value obtained by going out to bask in the sun. Therefore, all animals and plants on the earth are basically not affected by these values.
4. WiFi vs. solar power system, which one emits more radiation?
We all know that Wi-Fi radiation has always been criticized, and many pregnant women avoid it. In fact, Wi-Fi, as a wireless device, has a transmitter itself, which does produce electromagnetic radiation around it.
However, the working power of ordinary Wi-Fi is only between 30 and 500 milliwatts, which is smaller than the power of ordinary mobile phones (0.125 to 2 watts). At the same time, compared with mobile phones, wireless routers and other equipment, photovoltaic power generation systems are usually built on rooftops and are much farther away from users, which means that the power density of radiation received by people is much smaller.
Therefore, the radiation caused by photovoltaic power generation systems is actually smaller than that of electronic devices such as mobile phones. The environment we live in is full of radiation, both harmful and harmless. Although solar photovoltaic power generation emits radiation, it is within the safe radiation range. So we don’t have to worry about radiation from solar panels.
After scientific identification, when a photovoltaic power station is installed on the roof, the electromagnetic environment is lower than that of common household appliances. The amount produced will not affect human health. Non-ionizing radiation cannot directly act on the interior of living organisms and cannot ionize.
At most, it only acts as surface heating. Just like when we are basking in the sun outside, we may feel hot; while we can’t even feel the heat when we stand next to most of these electrical appliances.