By Anthony Allard, Executive Vice President and Head of North America, Hitachi ABB Power Grids
Placing electricity at the heart of the reset
The impact of the global COVID-19 pandemic has presented North America with a golden opportunity to focus growth investments on modernizing its aging energy infrastructure. The North American electricity grid, whose origins are more than a century old, needs to become more resilient and flexible to enable a carbon-neutral future. The grid is under pressure to integrate growing amounts of variable renewable energy, adapt to shifting electricity demand patterns and more electrification (transportation, infrastructure and buildings sectors), and withstand changing environmental patterns (e.g. extreme weather conditions). These challenges need to be addressed in parallel to stimulating the American post-pandemic economy and the time to act is now.
In the US, President Biden is taking very encouraging steps with his proposal to spend $100 billion on grid resilience, underscoring the fact that electricity will be central to the economic reset and to meeting climate targets. I welcome this increased focus on electricity infrastructure spending and call on the wider energy industry to build on this momentum and make its investment commitments.
Economic and financial consultants, The Brattle Group, estimates that this modernization and expansion requires investments of up to $690 billion by 2050. The great news is that the technology to address these challenges is ready and available and the investments will create jobs.
Connecting renewables in bulk
The most pressing shift concerns the integration of renewables as electricity producers are adding gigawatts of green energy. North America, like other regions across the world, has ambitious targets to increase green electricity production. Canada plans to source 90 percent of its electricity from clean energy sources by 2030, and President Biden aims for the US power sector to be carbon-free by 2035, leading to a net-zero emissions economy by 2050.
This fast-paced growth in renewable energy needed to support the 2030 carbon-free goal poses several new challenges to the North American power system.
Firstly, their variability brings stress to the transmission network, which was built on centralized, baseload electricity generation that was largely predictable. The influx of wind and solar resources, which cannot be produced on demand, also reduces the network’s inertia because, unlike traditional, thermal power plants, they are connected to the grid through power conversion systems based on power electronics and do not have the same kind of large, rotating turbines that produce grid inertia. Changes within the power generation mix which may lead to lower levels of grid inertia may result in a faster decrease in frequency when grid disruptions occur, which significantly reduces the resiliency of the grid.
Hitachi ABB Power Grids has, for example, provided such a technological solution to a wind farm in Mexico, where a static compensator helps maintain high-quality electricity and stabilizes the network.
Secondly, high-quality renewable energy resources are often located far away from demand centers, such as mountain ridges in remote areas or offshore. A study by the American Council on Renewable Energy has shown that the 15 US states between the Rocky Mountains and the Mississippi River account for 88 percent of the country’s wind potential but are home to only 30 percent of expected electricity demand in 2050. This geographical mismatch between supply and demand creates a need for building both new intraregional transmission lines as well as expanded connections between the grid interconnections, which are not synchronized and require high-voltage direct current (HVDC) to exchange power.
Deepening grid connections also addresses the third grid challenge posed by growing renewable energy: addressing the timing mismatch between production and demand. For example, peak solar production around the middle of the day does not coincide with the traditional peak of daily power demand in the early evening. Again, it is electrical engineering that is the answer here as HVDC transmission can help transport electricity over long distances with very few efficiency losses and its ability to control load flow, to places where it is needed at the time of production.
Another way of handling excess renewable electricity is to store it. Hydroelectric dams offer one way to do this. Managing reservoir levels, by pumping water into a reservoir and releasing it when electricity is needed, is a traditional method of bridging supply and demand gaps. Pumped hydro storage represents the bulk of electrical storage on the grid today. This method is working well on the north-eastern border between the US and Canada, but North America can apply it even more widely. As well as offering storage capability, the use of hydro and solar and wind power to operate pumps to fill storage reservoirs provides a carbon-neutral alternative that is in line with North America’s various strategies to cut greenhouse gas emissions.
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