It's so hot that solar power can't take off? Hello, head

bright and quick Xiao Xiao From the Aofei temple
qubits | official account QbitAI

Let's say how crazy this hot weather is .

Some people even moved to buy solar energy , To power your own air conditioner .

HN There is also a lot of voice on the ,“ We need a lot of solar panels ” It has also become a hot topic among the people , The degree of discussion has reached 809.

In this weather , The British 7 On the first day of the month, the solar power generation reached 66.9 Givash , Can meet the national 8.6% The needs of , Germany is also said to have reached a one-day high in solar power generation .

Do I mean , Extreme high temperature can really “ One hundred evils and one benefit ”？

BUT, So sorry , You may think too much .

Solar power , In fact, I'm afraid of high temperature ！

Too high temperature , The efficiency of photovoltaic power generation has decreased

It also has to start with solar power generation equipment .

The principle of solar power generation , It is essentially produced by irradiating semiconductors with light Photovoltaic effect （ Photovoltaic effect ）, Convert light energy directly into electric energy .

say concretely , By shining sunlight on P Type a semiconductors and N Type semiconductor contact PN Knot up ,PN After the junction absorbs the energy of photons , Excite electrons and holes （ Move in the opposite direction ）, Thus, different sign charges accumulate to form positive and negative poles , generate voltage .

From this point of view , More light energy does produce more electricity .

BUT, The high temperature It's not equal to More light energy （ Even if there is no sunlight , The ambient temperature can also be very high ）.

More Than This , It will also seriously affect semiconductor Work efficiency .

Affected by its own nature , The temperature stability of semiconductors is extremely poor , Must be kept at 20℃~30℃ It can work normally within the range , If the heat dissipation is not timely , Directly burned out the circuit .

besides , High temperature will also produce hot spot effect and PID Effect, etc .

Hot spot effect , It refers to that some components in the series branch are “ shelter ”, Not only can it not generate electricity , It will also be used as a load to consume the energy generated by other branches .

Once a hot day occurs , Excessive local temperature will be aggravated , Strengthen the hot spot effect , Directly lead to the aging of the module battery board 、 The condition of the damage .

After all, as exposed “ A big board ”, Photovoltaic panels will inevitably be polluted , If present Bird shit etc. .

Put it in normal time , Bird droppings cause a small resistance , But as soon as the high temperature appears , will exacerbate Its impact , It is very easy to burn components .

besides ,PID effect （ Potential induced attenuation ） It will also intensify with the high temperature and humid environment .

Because hot weather is often accompanied by humidity , So a lot of water vapor in the air , It will enter the interior of the component through edge sealing silicone or backplane , As a result, a large amount of charge inside the module accumulates on the surface of the battery , Cause serious performance degradation .

Taken together , The best temperature for solar power generation is 25℃, Too high temperature will affect power generation .

and , High temperature may be right New energy power generation Have a more serious impact .

For example, some nuclear power plants have recently reduced power generation , Because the temperature of the discharged cooling water is too high , It will pose a threat to marine life .

For example, at the end of last year , The tones nuclear power plant in Britain had to be shut down urgently , Because of the high sea water temperature, a large number of jellyfish are flooded , That directly blocked their cooling water outlet .

Also in these years , California, USA 、 Japan 、 Some seawater cooling nuclear power plants in the Philippines and Israel , Also because of the way of seawater cooling , Cause a large number of jellyfish to reproduce and cannot continue to run .

that , If the high temperature will lead to the decrease of solar energy efficiency , Is it feasible to use heat energy ？

What other ways of using the sun to generate electricity ？

as everyone knows , China is a hot country that can heat black brothers to heatstroke .

Such a good thermal energy resource , Of course we have to make use of it .

So in addition to solar photovoltaic power generation , There are many new power generation methods using solar energy in China .

It is often compared Solar thermal power generation .

In China, Dunhuang has the installed capacity of Asia Maximum 、 Global single machine spotlight area Maximum Molten salt tower photothermal power station .

This year, 6 month , Its power generation exceeds 3379 ten thousand kWh, Single continuous uninterrupted power generation 262 Hours , The average daily power generation in sunny days exceeds 185 ten thousand kWh.

As mentioned above Photovoltaic power generation Different , It does not need expensive silicon crystal photoelectric conversion process , In principle, it is similar to traditional thermal power generation .

Simply speaking , Is to use a big mirror to gather sunlight , Through the heat exchanger “ The boiling water ” Generate steam , Then push the turbine to generate electricity .

Because the principle is similar , It can even be directly connected to traditional power plants .

Its biggest advantage is when there is no sunlight , Can continue to generate electricity .

Through the energy storage system , The solar thermal power station can first collect the heat energy when there is the sun , Call again when the light is insufficient .

This avoids photovoltaic power generation , The problem of stopping when there is no sun , It can also adjust the peak according to the downstream power demand .

meanwhile , The heat conducting working medium used in the optical thermal power station is recycled , Almost no emissions .

More importantly , The main reason we mentioned above that photovoltaic power generation is vulnerable to high temperature is Solar panels On , This component is not used in solar thermal power generation .

therefore , Cope with extreme high temperature , Solar thermal power generation may have more advantages ？

But solar thermal power generation also has disadvantages , That's the light 、 The floor area requirements are higher , It is not a technical route suitable for miniaturization .

For example, the total area of the mirror field of Dunhuang optical thermal power station has reached 140 Over 10,000 square meters .

all the time , Its construction cost is also high , It can achieve photovoltaic power generation 4-5 times .

Except on land , Solar energy can also be used to generate electricity on water , It can also solve the problem of high temperature of solar panels .

This is floating surface photovoltaic power generation .

Simple understanding , Let the solar panel float on the water , Water as a high heat capacity substance , It can provide favorable conditions for heat dissipation of photovoltaic panels .

And this kind of power plant , It can be directly built on the surface of lakes in the suburbs of the city .

For example, in Dingzhuang Town, Dezhou, China , The floating photovoltaic power station with the largest monomer capacity in the world , The total installed capacity is 320 mw .

It is true that “ Lying down can generate electricity ” 了 .

One More Thing

that , Open the pattern more , Can we launch solar panels into space ？

After all, the solar energy that can be received on earth , Not only has it been reflected and scattered by the atmosphere , The air quality in various regions will also affect the efficiency of solar power generation .

In space, , In theory, solar panels can do 24 Hours Keep working , There is no influence of night .

So in 20 century 70 Around the time , It was suggested that Space based solar energy （Space-based solar power） Power generation method .

Um. , Is to launch satellites into space , Collect the energy of the sun in space and send it back to the ground .

It needs to carry photovoltaic cells on the satellite , Convert solar energy into electricity , Then transmit microwave through the antenna , Transmit electric energy to the ground receiving station .

There have been research plans in this field at home and abroad .2008 year , Japan proposed to take space solar energy as a national goal , Also developed a corresponding commercialization roadmap ;2014 year , Xi'an University of Electronic Science and technology also proposed OMEGA（ Spherical membrane energy collection array ） plan .

However , Limited by launch costs , Space based solar research is not on fire .

Until these years , With the reduction of launch cost ,NASA Also began to reconsider “ Space based solar energy ” The prospect of this technology .

According to the SpaceNews news ,NASA This matter has been discussed with some technical institutions , The plan will result in this year 9 International Astronautical Congress in August （IAC） On display .

however , As early as 2012 year , Musk just roast that this is a “ Stupid enough ” Things about .

Do you think this method of power generation is feasible ？

Reference link ：
[1]https://www.cnbc.com/2022/07/26/surging-temperatures-are-good-for-solar-panels-right-the-answer-is-its-complicated.html
[2]https://fortune.com/2022/07/19/europe-solar-panels-lose-efficiency-in-high-temperatures/
[3]https://caseyhandmer.wordpress.com/2022/07/22/were-going-to-need-a-lot-of-solar-panels/
[4]https://en.wikipedia.org/wiki/Space-based_solar_power
[5]https://news.ycombinator.com/item?id=32197012
[6]http://ex.chinadaily.com.cn/exchange/partners/77/rss/channel/cn/columns/8hk2q2/stories/WS62a92f05a3101c3ee7ada95b.html
[7]https://www.reddit.com/r/space/comments/r0yeu6/elon_musk_called_spacebased_solar_power_the/