In response to your question, I have put several links to resources below.
I worked in another group at Siemens for many years (now retired), but I was occasionally was briefly involved with projects that used HVDC transmission lines as well as a related technology, Flexible AC Transmission Systems (FACTS). Some additional explanation is below.
With AC transmission on the grid, the power follows the path of least resistance (some say, it goes where it wants to). DC transmission can be dispatched like generation to control the amount of power that goes down an HVDC transmission line. FACTS (really a family of technologies) uses power electronics to dispatch AC transmission.
Also, there really are not any great new developments in either HVDC transmission or FACTS in the last ten years, just incremental improvements. These are described in the two Siemens brochures linked below. Also there have been several major new application for HVDC, mainly connecting offshore wind projects to coastal terminals and ultimately the grid. Also transmission lines that need to cross bodies of water are now much more viable using the technologies described in the first link below.
Financing is provided by the incremental payback a given project provides for the grid (described for one project below), or in the case of linking offshore wind (described below) whether it is the best fit (it generally is).
The link below is a link to a brochure on Siemens Latest HVDC technology “HVDC Plus”. Further below I link a paper I wrote over a year ago that describes how this technology is used in both of the above applications.
The link below is to a Siemens Brochure on FACTS:
Siemens is a leader in the above complex technologies because they are a full spectrum provider, providing consulting on how to best utilize these technologies on the grid, and training for utility personnel. There are links to these services below.
A link to a paper published on Energy Central over a year ago. In section 4.2 it describes how an underwater HVDC Transmission cable now provides 40% of San Francisco’s demand. Section 5 in this paper suggests a new project to link this cable to a huge set of offshore wind farms north of San Francisco. The second link below is to the Transbay Cable site.
And finally, when I wrote the above paper, I was not aware that the arear I proposed for the windfarm (and the terminal in San Francisco) in the above linked paper had already been identified by a NREL study. Since California offshore wind is starting to heat up, I posted a paper last week (linked below) In section 1.2 it identifies the five possible areas for offshore wind development in California, including the one north of San Francisco. By the way, as of this year I started posting papers in PDF format, which means that you will need to go to the site linked below, and then click on the “Publication” button.