AFAIK Hydro-Quebec already does something like this.<p><a href="http:&#x2F;&#x2F;www.hydroquebec.com&#x2F;learning&#x2F;transport&#x2F;grandes-distances.html" rel="nofollow">http:&#x2F;&#x2F;www.hydroquebec.com&#x2F;learning&#x2F;transport&#x2F;grandes-distan...</a><p>Granted, there&#x27;s not much details :<p>« The technology used to transmit direct current is not the most common. However, it can be advantageous for isolating alternating-current systems or controlling the quantity of electricity transmitted. Hydro-Québec has a direct-current line (which goes from the Baie-James region to Sandy Pond, near Boston) as well as many direct-current interconnections with neighboring systems. »