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.