Bring more solar and wind power – but have backup power and energy storage
Like many utilities, the Omaha Public Electric District has a net zero goal by 2050 – something it hopes to achieve by increasing the use of green energy. And like all power companies, Omaha’s plan includes the use of flexible energy sources that can start when the sun stops shining.
Everyone already knows that wind and solar are intermittent fuels. They need to be bolstered by energy storage or quick-start production, ideally also carbon-free. Most often, natural gas is used as a safety net. But generator set manufacturers are now creating engines and turbines that are versatile, durable and capable of running, for example, on hydrogen.
“To build a sustainable future, we need to decarbonize step by step,” says Håkan Agnevall, Managing Director of Wärtsilä Corporation, in a Zoom conversation with this writer from his office in Finland. “Some of the major solutions will be wind and solar. But they have challenges. So you need “balancing power”.
“There are different technologies: pistons and battery storage are two of the major solutions,” Agnevall adds. “The good thing is that they are flexible and can move up and down quickly. They adapt well to intermittent sources and they can also be flexible in terms of the types of fuels they use. In two minutes you can increase by 10 megawatts. It’s quick.
Today, for example, Wärtsilä engines can incorporate up to 25% hydrogen mixed with natural gas. But the company is working hard to ensure that these engines can run entirely on hydrogen – and ideally on “green hydrogen” which is produced from clean energy sources. Engines will be “future-proof,” meaning utilities will have no stranded assets a decade from now. Other manufacturers of power generation equipment are General Electric, Siemens, and Mitsubishi Heavy Electricals.
As for the Omaha Public Power District, its backup generation is a 156 megawatt multi-fuel power plant. It will develop this facility with 400 to 600 megawatts of large-scale solar generation that connects to the grid. It has just signed a contract with Wärtsilä for the emergency plant to start operating in May 2023. Already, Wärtsilä has installed a total of 74,000 megawatts of power plant capacity in 180 countries. It has also installed 80 energy storage systems around the world.
How big is the flexible energy market – fuels that can firm up intermittent fuels? In the most developed countries of the world known as the G20, more than 3,500,000 megawatts of such flexibility are needed to achieve 100% renewable energy, according to the Wärtsilä 100% Renewable Energy Atlas. This includes 933,000 megawatts of flexible natural gas electric capacity.
At the same time, Wärtsilä offers advanced energy storage services. It has just installed 200 megawatts of such a capacity in Texas: the energy storage plants of Madero and Ignacio, for example, will support the Electric Reliability Council of Texas, which controls production sources and operates the network of much of the state. The systems are expected to be fully operational in January 2022.
“Battery storage is growing rapidly in the United States, Australia and Asia,” says Agnevall of Wärtsilä. “It provides shorter support – between four and eight hours. We use lithium-ion batteries. They bring real added value: if you have this power, it can be sold to other buyers when demand is high. Combustion engines used as back-up are for long-term oscillations.
In the meantime, those economies of scale are getting stronger: Tesla Inc. is investing $ 5 billion in a battery storage manufacturing plant while Xcel Energy has received hundreds of offers to help it integrate energy storage. in its wind and solar energy networks. It shows that battery technology is becoming competitive with conventional production and that these prices, in general, are falling.
To boot, the Federal Energy Regulatory Commission issued an order in 2018 that allows storage resources to participate in wholesale markets – where electricity is purchased directly from generators before selling that electricity to homes and businesses. Under the ruling, storage operators are paid in the same way as traditional electricity providers. A federal appeals court upheld the commission’s order.
The need for flexible resources has never been greater. Consider that there are now 100,000 megawatts of solar power and 140,000 megawatts of wind power – a number that will grow exponentially. And while back-up generation and energy storage are both essential to achieving net zero goals, so too is a modernized and extended transmission network. The US Department of Energy network reliability study says the current US grid can be prepared for additional renewables. But by 2030, more high-speed, long-haul transmission lines will be needed.
And California will be the ultimate test. It incorporates 20,000 megawatts of wind and solar resources, a number that could increase by 15,000 megawatts by 2030.
“We understand their variability,” referring to wind and solar power, says Elliot Mainzer, general manager of ISO California, which is the state grid operator that controls the supply of electricity and directs then those electrons where they belong. “We’re good at planning and sourcing and you can get ahead of that curve… The strategy is to put in place clean energy and clean distribution capacity to replace (natural gas) production. ”
The network operator is therefore turning to flexible electrical systems. Beyond energy storage and back-up power generation, it also uses demand response, distributed generation and micro-grids, not to mention a real-time wholesale platform where Western participants can buy and sell energy. If renewables are to thrive and the United States is to become carbon neutral, all of these technologies and platforms will be needed.