It is a certainty that we will
have a deeply distributed power supply infrastructure and a densely built out
super conducting power grid with loads also operating with similar technology
to truly minimize loss.
The weak point in this rapidly
emerging rosy power picture is the necessary transformer part of the equation
which has always been a serious drag.
Here we get a taste of the changes beginning to emerge although they
appear to still be tentative. They are
working out protocols as the customers line up.
I suspect we will see a new super
conducting entrant shortly out of the Far East . It is to obvious and so necessary.
The Networked Grid: Can Solid-State Transformers Shape the Future of
the Grid?
Advances in higher-voltage power electronics could usher in a new
distribution grid architecture, underpinning the future smart grid.
One of the panels that I will be moderating this afternoon, on day one
of Greentech Media's Networked Grid conference, focuses on the emergence of
solid-state transformers. Though countless challenges exist, the advent of
these new systems has the potential to be the most interesting story in the
smart grid over the coming decade. The concept of solid-state transformers is
not new (EPRI and traditional transformer vendors such as ABB, GE, Siemens and
others have been researching this for years), but as with many other
breakthrough technologies, timing may be everything. The industry seems to be
witnessing a perfect storm of events that could finally take solid-state transformers
from the R&D lab to live distribution grid circuit deployments in the next
three to five years. What simultaneous industry events are occurring to help
make this a reality?
1. The sheer availability and volume-based cost reduction of capable
silicon carbide semiconductor components (MOSFETs and IGBTs). As an example,
Cree (which is represented on today's panel) is currently working on bringing a
number of these devices to market.
2. The shift from centralized to distributed power generation, and in
this case, primarily the proliferation of distributed PV. When select circuits
in the distribution grid reach 20% to 25%+ PV penetration, the potential for
grid instability, the ability to effectively manage voltage regulation, etc.,
become real issues. I met with one major IOU recently that is capping the PV
penetration on any given circuit at 15%, given these concerns. This is at odds
with meeting RPS requirements, enabling renewables to scale, and the industry
is actively looking for solutions, of which solid-state transformers may be one
of several.
3. Power layer grid infrastructure and assets are largely monolithic
and unmanageable. With these devices representing the true core of the
networked grid, this makes little sense going forward, especially as nearly
every other surrounding smart grid technology is taking advantage of embedded
intelligence, network connectivity and remote manageability.
4. To a lesser extent today, but still a potential issue in the next
three to five years and beyond is the growth of EVs and their associated load
profiles. In some cases, the load of an EV can equal that of an entire home
connected to a distribution transformer. I think you can see where this is
going. Some IOUs are actually already doubling legacy transformer capacity in
pockets of dense EV deployment. Though this is a viable band-aid solution right
now, is it really the smartest approach going forward?
The promise for this new class of grid assets is immense, though so is
the number of challenges that must be addressed in bringing them to market.
Skeptics will ask many relevant questions. Can these devices be designed and
manufactured to be cost-competitive with today's legacy transformers? Can a
system based on solid-state electronics, presumably with a complex software
control architecture, meet the efficiency and reliability metrics of existing,
downright simple distribution transformers made largely with copper, iron and
well-understood packaging techniques? These are certainly very fair questions,
but as the industry starts to dig deeper into the functions performed by
solid-state transformers, it will find that comparing them, metric-for-metric,
with legacy transformers is ultimately comparing apples to oranges.
The industry needs to start thinking about these devices in an entirely
different way, and that is not going to happen overnight. This is not
transformer 2.0; it's an entire new class of grid asset that needs to be
introduced to the market and positioned as such. It's going to take time and market
education, as with any potentially disruptive technology.
Too often, when people first think about solid-state transformers, the
initial benefit that comes to mind centers around footprint (size and weight).
It's true that these new devices can reduce footprint by an order of magnitude,
significantly helping with inventory management and operations costs (in
many cases the installation cost of a distribution transformer is 10x the
capital cost), but this is only the tip of the iceberg.
With the advent of solid-state transformers, voltage transformation
(the primary function of a transformer to step up/down voltage) becomes only
one of many new features. When you start to consider many of the other
potential features surrounding voltage regulation (CVR, programmable output
voltage, OV protection for PV-centric circuits, etc.), power quality (reactive
power compensation and harmonic filtering), management and telemetry
(integrated remote management, real-time load management, active line analysis,
etc.), and other functions (such as the option for integrated storage), it
becomes evident that these new integrated devices are much more than
yesterday's transformers.
As you can see, comparing the capital cost of a legacy transformer with
that of a solid-state transformer, with many more integrated features and
embedded intelligence, becomes an uneducated comparison. Nobody that is serious
about solid-state transformers is claiming they can be introduced to the market
at the same price point of a traditional transformer, and the industry needs to
start understanding why this is the case given the additional benefits (and
associated systemic-level cost reductions) that can be realized. Beyond cost
and features, true innovators in this market are also meeting efficiency and
reliability metrics, that naysayers may be skeptical of, defined by the DOE.
Lastly, another important point to understand is that proponents of
solid-state transformers are not suggesting a rip-and-replace strategy for
existing transformers. The strategy for the introduction of solid-state
transformers will center around strategic benefits related to the 'green
circuit' of the future, rolling out devices on feeders with high PV penetration
and EV load. In addition, most utilities have a relatively well-known annual
replacement strategy (often in the 2% to 4% range) for aging transformers,
failures, etc., providing another opportunity to introduce smarter devices,
enabling a beneficial network effect as more devices are rolled out over time. The
idea is to get the initial devices in place where pain points exist and then
build a more intelligent platform over time. Also, international markets may
provide significant greenfield
Despite advances in AMI and other early smart grid deployments, it's
becoming clear that we are in the very early stages of a truly intelligent
grid. Until the embedded intelligence of these higher-layer control plane
architectures is integrated into grid assets sitting in the power plane, the
grid is only partially intelligent. Although there are enhanced sensors
and monitoring technologies being introduced into the power layer of the smart
grid, it's only the beginning, as true real-time decision making and actuation is
what will ultimately be required. Solid-state transformers, and the many
additional features and benefits they bring, have the potential to be a
cornerstone device for such functionality.
Attendees at The Networked Grid are looking forward to learning a lot
more about this topic in today's panel, titled Distribution Grid 2.0: The Dawn
of Solid State
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