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Wind and solar energy generation both are weather-dependent technologies. The decreased wind or lack of sunshine will make generated power drop, respectively. For example, in June 2018, heat waves covered Europe. The "wind drought" happened. It meant that wind turbine nearly stayed idle for 9 consecutive days. For summer 2018, wind power generation was less than ideal.
The wind farm installation rose by 10% year over year, but the share of power that they generated fell from 12.9% in 2017 to 10.9% this summer. Thus, experts pointed out that diversified green energy and energy storage system are both very important.
The wind and solar power generation in UK both reached a milestone for green energy, respectively in 2017. For instance, in 2017, the electricity generation for the wind and solar surpassed that of nuclear power for the first time ever. During one of the day, coal power stations didn't have output at all while wind power generation broke a new record.
By contrast, in summer 2018, wind became considerably weaker in UK, so wind power generation dropped remarkably. Thus, gas turbine power generation has to step into the break. Foreign media pointed out that softer wind made turbine blades stay idle. Because renewable energy is considered clean, this summer the power supply is less "clean".
The falling output of renewable energy made people question whether renewables can be the main sources of electricity. Luke Clark of RenewableUK replied, to evaluate wind power, we should observe for a longer period of time, rather than only for the short summer. In 1Q18, UK's wind power supported 19.1% of UK electricity. In the future, wind energy is predicted to provide 30% of annual electricity supply.
The bio-mass energy, solar power and hydro power can help fill in the gap that is caused by weak wind. On cloudless days, solar power plants can help generate electricity for UK power grids. Pascal Storck, Director of Renewable Energy at Vaisala (an environmental measurement company), expressed that wind power and solar energy might seem to compete against each other. However, in reality, a diversified mix of green energy could solve multiple issues for variable renewable energy.
In UK, wind power generation takes a huge share of renewable power generation. Aside from wind power, the UK has also been developing other types of renewable energy. In 1Q18, renewable energy took a 35% share of total supply. Among the UK renewable energy, 28% was from offshore wind power, 26% was from biomass, 5% was from PV energy and hydro power.
Generally speaking, heat wave does not reduce offshore wind power as much as onshore wind power. Clark expressed that the more offshore wind turbines are installed, the more stable future wind generated electricity will be for the UK. His team devoted to researching for floating offshore wind turbines. They hope to capture more wind power in the future.
UK is currently expanding installations of power battery storage systems. For example, Danish offshore wind farm developer Ørsted cooperated with Britain power firm ABB in 2017, to build the first offshore wind power storage system in UK. Another example is in Scotland. The world first floating offshore wind farm "Hywind" was installed with the battery storage system "Batwind".
For weather-dependent variable renewable energy (such as solar energy and wind power), there will be days without wind or without sunshine. However, with energy storage systems, the ever-changing weather will not prevent these types of renewable energy from output power in the future. This measure will significantly enhance the stability of power grid. British Department of Energy hopes that its power system can develop into low-carbon smart grid. With new technologies, the DOE can effectively manage energy and lower electricity price.
Reference:
- UK Wind Sector Defends Calm Summer Performance
- UK summer ‘wind drought’ puts green revolution into reverse
(Image credit: nosha via Flickr CC BY-SA2.0. Article by Daisy Chuang)
