The development of renewable energy is growing rapidly, of which the solar energy is slightly better and the abundant sunlight can meet the needs of mankind each year. However, there are still three major problems that prevent the rapid development of solar energy.
1 battery cost
Varun Sivaram, a science and technology specialist at the not-for-profit think tank, said that if the sun is to supply 30% of the world's electricity, its price per watt must drop from a dollar to 25 cents.
Dr. Sivaram believes that to reduce the cost of solar energy is the perovskite cell (perovskite cell) commercialization, the current mainstream of solar cells on the market is still a silicon cell, but its cost is higher; perovskite battery manufacturing temperature Lower than the silicon cell batteries, the price is cheaper, the light conversion efficiency from the beginning of the development of 3.8% to now can reach 25%.
In addition, perovskite solar cells can be rolled into flexible color film, widely used, the United States on the team to research on the use of vitrinite material developed solar window.
However, perovskite solar cells from commercialization is still some distance, and stability is one of the major shortcomings it must overcome, perovskite crystals easily decompose in humid environment, affecting the stability of the battery; the other problem is the battery volume The size of the current perovskite solar cells only nail-like size, scientists have not yet developed a large volume while maintaining high efficiency of the battery.
Dr. Sivaram added that while the prospects for perovskite solar cells are promising, the research and development funds invested in the energy industry are too scarce to push them to the commercial market.
Only 1% to 2% of energy companies invest in research and development, and semiconductor companies to invest in R & D funding is about ten times as many energy companies. The federal government annual investment in renewable energy research budget of only 5 billion US dollars, so the speed Probably by 2020 China's energy research funding beyond.
2 power management
Solar energy is an intermittent source of energy, and its power generation peak demand is usually not high, but in the time of the highest electricity but lower power generation. The lack of power grid also makes too much power must be distributed to other countries; to California For example, solar power accounts for 10% of the state, and whenever there is too much power in the grid, the excess electricity needs to be sent to other states.
One solution is to use a large-scale energy storage system, but the battery cost is still high, it is difficult to achieve large-scale. According to the US Department of Energy data show that the battery only accounts for 1.7% of the grid energy storage, the rest are Pumped storage power station processing.
Ramez Naam, an Lecturer in Energy and Environment at Singularity University in California, said that the most immediate solution to this problem is to build a more decentralized and larger power grid. In the United States, for example, there are three major grids including the east, The western and Texas grids, ideally, connect these grids to new high-voltage boxes, but this may create chaos in management responsibilities.
3 indirect costs
Some people think that it is a technical issue that hinders the development of solar energy. However, the "soft cost" of setting up solar power plants is also quite high, including project design, construction approval, site selection and grid connection.
The U.S. Department of Energy estimates that indirect costs account for 64% of the total cost of solar power plant construction, while the rest is spent on solar cells and solar hardware itself.
But if the battery is combined with rooftop solar panels, consumers can generate electricity in their own homes Tesla starts building solar cells and components at Gigafactory 2 in Buffalo, NY in October 2017. However, current roof solar panels and batteries The price is still too high, even if the future price decreases, the public may still want to have a backup power grid.
