The sector is uniquely positioned to help advance Canada's clean energy future and provide, as the throne speech aspires to, clean, affordable power in every Canadian community.
Canadians and Americans share a highly integrated electricity grid, connected by more than 35 high-voltage cross-border transmission lines. Our members also engage in bidirectional electricity trade with the United States and work with American counterparts to keep the grid reliable and secure.
Trade integration forms the backbone of a highly positive and mutually beneficial cross-border electricity relationship, which provides economic, environmental, resiliency and security benefits to Canadians and Americans and contributes to affordable and increasingly clean energy for customers on both sides of the border. Overall, the binational integrated electricity system exemplifies the advantages of partnership and collaboration and benefits both countries.
In recognition of these mutual benefits, CEA and its U.S. counterpart, the Edison Electric Institute, submitted joint comments to negotiators on both sides of the border during the renegotiations. These joint comments highlighted our shared view that the existing cross-border trade relationship works well and the importance of preserving it. For more than 25 years, NAFTA has provided stability and predictability to our shared interconnected grid. Its value is underpinned by NAFTA's guarantee of tariff-free electricity trade, and it is positive that the Canada-United States-Mexico free trade agreement maintains this integral guarantee.
CEA also supports the greater integration and interdependence of North American energy systems and was pleased to see the inclusion of a CUSMA Canada-U.S. energy side letter on regulatory measures and regulatory transparency.
Over 70 terawatt hours of electricity flowed across the border in 2018, representing an electricity trade relationship of over $3 billion. Approximately 30 states engage in electricity trade with Canada each year, with Canadian exports to northern border states being particularly robust. This two-way exchange enables electric supply to meet demand in the most efficient manner, increases resilience, boosts affordability for customers and helps regions meet policy and business goals. Many Canadian and U.S. electricity companies own assets in both countries.
Canadian export volumes are high relative to import volumes, as Canadian generating capacity generally exceeds requirements. In 2018, net exports were 48.2 terawatt hours, which represented a net value of $2.4 billion Canadian. We have additional surplus supply as well as rich resource development opportunities.
From a Canadian perspective, electricity trade provides system reliability and resilience and economic and affordability benefits. While exports represent a valued source of revenue for many Canadian electricity companies, that is only half of the story.
From the American perspective, particularly for northern border states, our electricity is an affordable, reliable, safe, secure, clean supply option that contributes to national energy security, environmental goals and economic success. Given our abundant clean electricity profile and rich clean resource development opportunities, Canadian electricity imports contribute to the shrinking of the U.S. carbon footprint and can also serve as backstop energy to support the development of U.S. variable renewable resources such as solar and wind.
This relationship is more than powering homes and businesses. National energy security has also been a major Canadian preoccupation throughout the negotiation of the agreement. The interconnected nature of the North American grid means that its reliable and safe operation is a shared responsibility. Canada and the U.S. have worked together to develop effective institutions in support of a safe, secure, reliable electricity system to the benefit of both Canadian and U.S. businesses and communities.
The Canadian electricity sector is an active participant in cross-border institutions and programs that aim to secure the grid, such as the Electricity Subsector Coordinating Council, which enjoys participation of senior government officials in the sector and electricity industry CEOs from both countries. The electricity sector and the government also participate in major cross-border security incident response exercises like GridEx, which was held this past November across Canada and the U.S.
To this end, Canada and the U.S. work very closely on the protection of critical infrastructure. Cybersecurity and physical security are top of mind for industry and government alike. While there is good collaboration between our governments and industries, there is always opportunity to strengthen cyber protocols.
All things considered, there are further opportunities to leverage the positive electricity partnership between Canada and the U.S. The ratification of CUSMA will help provide the stability and predictability to our shared interconnected electricity system to help forward this valuable partnership.
We'll keep working to make North America the world's leading energy region by promoting energy security and affordability, strengthening energy and infrastructure protections and achieving environmental goals.
Thanks for your time.