In the wave of global energy transition, photovoltaic power plants are not isolated "substitutes", but "synergists" that complement and coexist with traditional energy sources such as thermal power, hydropower, and wind power. This "new old combination" model not only leverages the clean advantages of photovoltaics, but also compensates for the intermittency of photovoltaics with the stability of traditional energy sources. While ensuring the safety of the power grid, it steadily increases the proportion of clean energy and becomes an intelligent choice that balances efficiency and safety in the process of energy transformation.
1 Photovoltaic+Thermal Power: A Stable Partner for Stabilizing Fluctuations
The rapid peak shaving capability of thermal power and the volatility of photovoltaics form a natural complementarity. In a coal-fired power base in northwest China, a 100MW photovoltaic power station and a 300MW thermal power unit form a joint power generation system, which achieves real-time coordination through an AGC (Automatic Generation Control) system: when the photovoltaic output decreases due to a sudden drop in light intensity, the thermal power unit increases the load within 10 minutes to fill the power gap; When photovoltaic output surges, thermal power reduces output and coal consumption. The data shows that the system has reduced the photovoltaic power abandonment rate from 15% to below 5%, reduced coal consumption for thermal power by 8 grams per kilowatt hour, and reduced annual carbon dioxide emissions by 120000 tons.
The combination of photovoltaic and thermal storage thermal power goes further. In a project in Inner Mongolia, photovoltaic power is stored in a molten salt tank through resistance heating during noon surplus; When the photovoltaic output is zero at night, the thermal storage system provides steam to the thermal power unit, reducing coal consumption. This mode increases the flexibility of thermal power units by 40%, achieves a 100% absorption rate of photovoltaic electricity, and saves 50000 tons of standard coal annually.
2 Photovoltaic+Hydroelectric: An Ecological Combination of Water and Light Mutual Aid
The seasonal complementarity between the wet season and dry season makes photovoltaics and hydropower a perfect match. Along the Dadu River in Sichuan, a 500MW photovoltaic power station and a hydropower station form a "water solar complementary" project: during the rainy season (June September) when hydropower is in full swing, the photovoltaic power station will reduce its output appropriately to avoid water abandonment; During the dry season (October to May of the following year), hydropower output decreases, and photovoltaics operate at full capacity to make up for the power gap. This system increases the proportion of clean energy in the regional power grid to 85%, while utilizing the reservoir regulation capacity of hydropower stations to control the daily fluctuations of photovoltaics within ± 5%.
For runoff hydropower stations (without regulating reservoirs), photovoltaics become a "supplementary power source" during the dry season. The "Photovoltaic+Runoff Hydropower" project in the Lancang River Basin of Yunnan Province generates 30% of the daily photovoltaic power generation during the dry season (November to April of the following year), increasing the power supply guarantee capacity of the hydropower station by 25% and ensuring the stability of downstream agricultural irrigation and residential electricity consumption.
3 Photovoltaic+energy storage+multi energy complementarity: building a resilient energy system
In the power grid with a high proportion of new energy integration, the multi energy complementary system of "photovoltaic+energy storage+traditional energy" has become the mainstream mode. The 10 million kilowatt new energy base in Hainan Prefecture, Qinghai Province integrates 4000MW of photovoltaic, 1000MW of wind power, 500MW of solar thermal (thermal storage), and 2000MW of coal-fired power. It is centrally scheduled through a smart energy management platform: photovoltaic and wind power provide basic electricity, solar thermal storage stabilizes intraday fluctuations, and coal-fired power should cope with long-term power shortages under extreme weather conditions. This system ensures that the proportion of new energy generation reaches 60%, and the reliability of power supply in the grid remains at 99.98%.
In isolated power grids such as islands, this collaborative mode is even more important. A certain offshore island in Zhoushan, Zhejiang Province, has achieved energy self-sufficiency through a "5MW photovoltaic+2MW/4MWh energy storage+1MW diesel generator" system: photovoltaic power supply is prioritized, energy storage stabilizes fluctuations, and diesel generators only start on continuous rainy days. After the system was put into operation, diesel consumption on the island decreased by 60%, electricity prices dropped from 1.5 yuan/kWh to 0.8 yuan/kWh, and carbon emissions from ship oil transportation were also reduced.
The synergy between photovoltaics and traditional energy has broken the binary thinking of "either or" and demonstrated the gradual wisdom of energy transformation. This model can not only utilize existing traditional energy infrastructure to reduce transformation costs in the short term, but also gradually increase the proportion of clean energy such as photovoltaics, providing a smooth transition "buffer zone" for the power grid. With the advancement of technology, this collaboration will move from simple output complementarity to deep mechanism integration, ultimately achieving a historic leap from "traditional energy as the mainstay and photovoltaic as the supplement" to "photovoltaic as the mainstay and traditional energy peak shaving".