Week five featured two guest speakers and a planned lecture by James Mater on interoperability that was cut a bit short.
Our guests were:
Ken Dragoon – Ecofys-US
Lee Hall – Bonneville Power Administration
Both are deeply involved in NW smart grid projects, on different ends of a pilot project funded in part by a BPA program called technology innovation that is investigating use of DR for renewable integration. Lee Hall works to manage this project for BPA, and Ken Dragoon works for Ecofys, a dutch-based renewable energy consultancy that was the lead contractor.
Ken Dragoon – Role of Demand in Achieving a Low Carbon Grid
Ken has been an active proponent of wind power for many years, and a NW electricity industry expert longer still, having worked for PacifiCorp and BPA. Before joining Ecofys, he represented wind generators with the Renewable Northwest Project, and more recently worked as the lead for the Oversupply Technical Oversight Committee, part of the Wind Integration Forum at the NW Power and Conservation Council. So Ken knows wind, and he decided to share his knowledge in a book he published in 2010.
He started out by clearing the air of what he called toxic metaphors that he thinks shape many people’s conception of renewables and the electricity grid. Metaphor myths in bold and his answers following:
“We are running out of hydro system flexibility to integrate wind”
The reality here is a big improvement in recent years, integrating more wind while using fewer resources.
“We need to back up the wind.”
We back up load, not wind. We add and subtract resources to make sure load is served, not to “flatten” out wind generation.
“Power system operators must ensure that generation and load match at every instant.”
There’s not an operator in a control room watching every minute or every second to make sure supply and demand always match, conservation of energy makes sure that’s true.
Different people attach different meanings to this word. If you’re talking to someone about capacity, there’s a good chance that person is working with a different definition than you are.
I suppose I’m guilty of perpetuating these metaphors, having followed BPA’s travails with wind integration, used the “back up wind” and “load generation always must balance” comments many times in lay parlance. I completely agree about capacity definition ambiguity.
My comments on load/generation balance relate to my own initial misconceptions about how this really works, instilled from hearing many people voice that same line. Ken is right that there’s not an operator at the switch turning power plants up and down every few seconds to exactly match load. Utilities have automated systems that do this, called automatic generation control, sending signals to generators calling on them to expediently ramp up or down, but this doesn't quite get the grid all the way to supply/demand balance.
Instead it is indeed conservation of energy that does the rest, with the inertia in the spinning mass of many large synchronized generators that naturally absorbs and rejects energy, smoothing variations in supply/demand balance and stabilizing the system frequency. If we move toward a system that has fewer large central generators and more smaller units that have less spinning mass, (or none at all in the case of solar with with inverters) there will in likely need to be more of those second-to-second adjustments by the grid operator Ken was speaking of, usually called frequency regulation. Here is an electricitypolicy.com article that explains this in more detail.
Ken next showed the class a snapshot of BPA’s system over a typical week:
While BPA’s operators may not be making very many adjustments second-to-second, they certainly are over the course of an hour, the typical electricity interchange scheduling interval in the NW. A wind farm owner located in BPA’s balancing area that wants to ship power to California, a common arrangement, will submit a schedule to BPA prior to the start of the hour. As we know, the wind output is likely not to exactly match that schedule, so the enormously flexible hydro system BPA controls stands ready to ramp up and down as needed. That is to say BPA, as does every balancing area, holds in reserve the amount of generation that is expected to be required to handle not just ramps in wind generation, but fluctuations in load and contingencies such as unexpected loss of a power plant. As can be seen from the image above, there is often significant movement of both the total wind and hydro generation on BPA’s system.
Ever ongoing at BPA, it seems, is a process to determine how much money to charge that wind farm owner who relies on BPA to support an hourly schedule. Initiatives underway currently include scheduling every 30 minutes, and an option for the wind owner to self-supply this balancing energy. Notable and not mentioned in class was the recent FERC order 764 that will set in motion a move toward scheduling every 15 minutes, an effort to level the playing field for variable renewable resources by lessening balancing reserve requirements. BPA doesn’t have to follow FERC orders, however they are compelled to try. But that is another topic for another lecture.
Below is an image showing BPA’s balancing reserve deployment. Current BPA load, generation information is always available and I recommend everyone in the course check it out.
One more important concept on renewable generation before Ken got into solutions. Combining load to be served on an electric system with renewable generation produces a net load. The result is a decrease of net load at times of high renewable production, lessening the need to use conventional resources during those hours.
Going Beyond 20%
Ken talked about parts of the world that have set aggressive renewable energy goals, such as Denmark, Ireland and California. Denmark has 20% wind today, headed for 50% by 2025. The Danish wind energy accomplishments are often qualified by their advantageous location with transmission connections to both north to Norway and south to the broader continent, allowing support from both directions for wind balancing. I've heard numerous times Denmark is able to make use of Norwegian hydro resources for storage and shaping. Ireland on the other hand, has only weak transmission links to the UK, and decided not to invest in more lines or storage as they pursue 40% wind electricity. Instead Ken says they will rely on flexible natural gas plants and at times, wind curtailments.
Ireland All Island Electricity Grid Study:http://www.dcenr.gov.ie/Energy/North-South+Co-operation+in+the+Energy+Sector/All+Island+Electricity+Grid+Study.htm
Going beyond 20% will take more than incremental improvements in current grid operations, in Ken’s view; rather it will require “more concentration.”
Inspiration for some of the changes required can yet be taken from Demark, which has seen a major transformation in energy supply above and beyond wind power accomplishments. Denmark was once heavily reliant on coal and oil, and in response to oil price shocks in the 1970s made a move toward distributed combined heat and power (CHP) and district energy systems that today supply the bulk of heating and electricity in the country. 60% of all buildings there are connected to district heating systems. Further, the use of thermal storage disconnects heat use in many of them from the heat source. Ken recognizes the possibility to make greater use of wind energy in this way; hours of excess generation can be buffered by water storage tanks that can then supply heat in hours of deficit. Below is a picture of large insulated storage tanks that serves Copenhagen. They are today connected to a CHP plant.
Back in the NW, there are no tanks this size, and district energy systems are few and far between compared to the landscape in Denmark. Still, it may be possible to employ the same strategies by coordinating the use of many conventional tanks located in most homes. Ken also notes there are district energy systems in the region that could benefit from thermal storage, mainly in industry, military and university settings, including PSU. He said Ecofys is interested in partnering with a district energy system operator on a thermal storage project.
Like Conrad Eustis as PGE, Ken wants to organize use of hot water tanks such that they work as a large thermal battery, at a potential cost much lower than other energy storage technologies. The Ecofys technology innovation project has been investigating this plan, placing controllable water heaters and other thermal storage equipment in operation across the NW, exploring the capability of these units to support renewable integration. Also shared with Conrad is Ken’s thought that commercialization of water heater controls is best done at the factory for a minimal incremental cost. He gave a description of a future market he envisions for these appliances where homeowners in need of a new one can choose between a standard unit or one that’s ready to connect with utility signals, perhaps including a discounted price.
Concluding Ken’s talk were a few questions and discussion of whether anyone would want to have a utility or another entity controlling devices inside the home. It was clear most think not everyone would want to participate, and certainly no one should have to. Ken commented that participants in the Ecofys pilot largely did not have these concerns, mainly because they typically received the benefit of increased service from a more capable water heater. All the better if it comes with a discounted monthly bill or a check from the utility or other company that figures out how to best aggregate end users, manage interactions appropriately, and market this concept.
Besides water heaters, Ecofys is involved in DR projects for cold storage warehouses and data centers.
Lee Hall – Demand Response, Energy Storage and Smart Grid
Following Ken Dragoon’s talk that gave an introduction to wind in the region and in particular on BPA’s system, Lee Hall explained a bit more about Bonneville, part of DOE, that does not own dams, but markets power from the Federal Columbia River Power System. A striking statistic Lee mentioned right off the bat is the penetration of wind power capacity inside BPA’s balancing authority area, in proportion to peak load. It’s now about 40%, highest in the US, and fifth in the world.
Ken and Lee both showed a few of the same slides covering BPA’s wind growth and system management, including the image below, taken from the BPA website showing the astounding growth of installed wind capacity from about 2005 through the present.
BPA was an early leader in connecting wind farm developers to transmission lines, and in that way attracted many of them to the NW. As we've learned, dealing with all of that wind has been a challenge, so to best continue BPA’s mission of providing low rates to its customers, it has been open to all cost effective options for supply of balancing services. It certainly looks like smart energy management and DR will be among those low cost options going forward. But we’re not there just yet, a great deal of research still has to be done along with increasing the scope beyond pilot projects to a commercial scale.
There are also a number of benefits DR can deliver to BPA and the utilities it serves beyond wind integration. One that Lee cited a few times is the possibility to defer transmission investments through peak demand reduction. Since BPA is the region’s largest transmission operator, maintaining and building lines is a major cost center that could be more effectively managed if the right parties see the value of deferring payments to expand the system.
Testing BPA has recently completed, with Ecofys and other partners include:
- Commercial and public building load control
- Residential and commercial space heating energy storage
- Water heating energy storage and load control
- Industrial process load control and energy storage
- Large farm water management system load control and storage
- Small-scale battery storage
- Load increase using aquifer recharge opportunities.
From this experience Lee highlighted four areas of near-term benefit or BPA and utilities:
The rates BPA charges many of the utilities it serves include incentives to limit peak demand, done by instituting higher demand charges in recent years, so some of them are investing DR on their own to limit their exposure.
DR as a resource BPA can call upon for reserves to augment the hydro system and purchases of conventional resources.
Generation Oversupply Management
Springtime high river flows can reduce balancing reserves available from the hydro system. In past years, wind generation has at times been curtailed. DR could shift greater load toward the hours when this occurs.
“Non Wires” Peak Load Reduction.
Transmission investment deferment as described above. Transmission construction starts at about $ 1 million/mile.
In closing, Lee noted the need to effectively coordinate and communicate between all of the parties that are likely to be involved as DR scales up among NW public power utilities. There will be benefits to BPA, the local utility, and to the end use customer. Work on how best to structure the share of benefits between the participants is underway currently, and is likely to undergo refinements as projects are deployed and money is invested to go beyond the pilot stage.
James Mater – Smart Grid Interoperability and Standards.
James took a short time at the end of class to begin his lecture on standards. To start he referenced a National Institute of Standards and Technology (NIST) report that assessed the utility picture in the US with regard to standardization and interoperability. In short, there are over 3000 utilities, and many have traditionally done things their own way, with the exception of electrical standards such as plugs. The focus on physical standards has been at the expense of software and information standards, according to James.
He gave an example describing meter data management, which I’ll expand on a little. In the past, systems to collect and process data were customized, where one utility might have a completely different format than a neighbor utility. If these two utilities then decide they want to link meter data systems to their billing systems in different ways, perhaps for a new time-varying rate option, two customized upgrades are needed, perhaps by two separate vendors. That might be good business for the vendors and system integrators selling and maintaining proprietary systems, but it’s probably not in the best interest of the industry as a whole to continue doing business this way. If both utilities were using an industry-wide standard, many experts today think there’s a good chance the cost to make such an upgrade would be lower and the quality higher, since more robust competition would occur between sellers when the playing field has been standardized.
James described the Grid Wise Architecture Council’s Context Setting Framework, or stack. It’s inspired by the Open Systems Interconnection 7 layer reference model (OSI model) that separates networking communications functions into layers so as to break the whole system into components that work together.