by Richard Morgan, ND Metering Solutions
Keeping the U.K.’s lights on requires a delicate balancing act.
Every second of every day, National Grid, which owns and maintains the high-voltage electricity transmission network in England and Wales-Scotland has its own networks-must ensure that electricity supply and demand are perfectly matched.
If more electricity is supplied than is being used, equipment could be damaged.
If demand outstrips supply, the country could encounter blackouts.
This is where grid balancing comes in.
Some 1 percent of the average domestic bill goes toward paying the costs for balancing the network every year.
In 2012-2013, the total cost of balancing the network was 803 million pounds ($1.3 billion).
Grid balancing is important to the country because 15 percent of the U.K.’s total electricity demand is met through grid balancing.
In addition, experts predict demand in the U.K. will increase 25 percent by 2020, putting more pressure on grid balancing and prices.
Traditionally, grid balancing has been performed by dedicated power stations’ adjusting supply in response to changing demand.
As more intermittent generation such as wind energy is added to the grid and reserve margins become tighter, it becomes more difficult for National Grid to balance the grid and keep the costs down.
National Grid, therefore, constantly is exploring new technologies from smart meters to electricity storage to find new opportunities for large and small consumers to help it balance the system.
Demand response programs are a big part of National Grid’s grid-balancing strategy, and it works with several companies to implement demand response programs.
One of those companies is Open Energi, which supplies a demand-balancing service that is different from traditional demand response services.
From Reactive Supply to Dynamic Demand
It’s not difficult to see the disadvantages in using dedicated power production to address imbalance from the supply side, and it’s not surprising that demand response technologies have developed to counter it from the demand side.
Traditional approaches to demand response (nondynamic), such as frequency control by demand management (FCDM) and short-term operating reserve (STOR), focus on explicit requests from National Grid to shut off or generate at times of low frequency and typically maintain the interruption for at least 30 minutes (see sidebar).
Dynamic demand response, on the other hand, goes a step further, continuously and autonomously monitoring the grid to react to low-frequency events by reducing demand and high-frequency events by increasing demand.
Open Energi’s demand response technology, Dynamic Demand, is cheaper, cleaner and provides a quicker answer to energy supply fluctuations than running a power station at subcapacity.
In return for providing this balancing service, National Grid makes payments to Open Energi that are shared with customers who have installed the technology, and assets turn into revenue streams.
Open Energi has received funding from the Carbon Trust and Ombu Group and has a portfolio of customers among the U.K.’s major energy consumers in the private and public sectors, such as Sainsbury’s supermarkets, Aggregate Industries and the National Health Service.
Open Energi’s Dynamic Demand service is based on patented software that operates across a range of applications, creating smart devices that react instantly to imbalances in electricity supply and demand.
Unlike other demand response services, Dynamic Demand makes subtle, rules-based adjustments to the timing of an asset’s electricity consumption.
The technology respects an asset’s control parameters so it does not affect performance or interrupt service.
For example, if a refrigeration unit must maintain an internal temperature within set parameters, then Dynamic Demand could not override these so that the device warms above the recommended 3 to 5 degrees Celsius.
It is a fully automated and autonomous solution that requires no interaction or behavioral change. Dynamic Demand may be used alongside other energy-saving programs and, under certain circumstances, other demand response services.
Although it provides grid-balancing services to National Grid, Dynamic Demand is installed at the premises of energy users.
It operates with a range of electricity-consuming devices but is ideally suited to equipment that stores energy, usually for heating or cooling.
Once installed, it reads the balance on the grid and makes minute adjustments to the time at which the equipment draws power while ensuring no loss of performance.
In return, equipment owners receive a payment from National Grid for their contribution toward balancing the grid.
By using Dynamic Demand, Open Energi’s customers can generate revenue from their existing assets and identify potential energy savings and intelligently manage their assets using the energy data the system harvests.
“Ours is an interesting business model,” said David Perry, operations director at Open Energi. “National Grid is our end customer, but we depend on relationships with big energy consumers who actually install Dynamic Demand on their premises. It’s another kind of balancing act that has to be carefully managed.”
From Early-stage Commercialization to Established
National Grid requires Open Energi’s meter data to be accurate and specific.
It’s how the company proves to National Grid that it has the power available within its customers’ equipment. Metering, therefore, is a critical part of the Dynamic Demand technological and business model.
Metering data provides the basis on which Open Energi can sell that load.
What cannot be measured cannot be managed, and a demand response system can be as good only as the data it draws on.
Moreover, meter data can provide further added value for customers.
The benefits of submetering for energy efficiency and management are well-documented, and the harvested data can be used to feed into users’ wider energy programs.
Gaining visibility into usage patterns provides opportunities for savings.
For example, a firm might discover it is using far too much energy during weekends or see strange consumption spikes on Monday afternoons.
The meter data can make users aware of such savings opportunities, and if the opportunities are taken, then the additional savings compound the revenue generated by Dynamic Demand.
Initially, Open Energi developed its own submeters alongside the Dynamic Demand technology.
But in early 2012, the company concentrated its efforts on Dynamic Demand and worked with a specialist provider for submetering and other related technologies.
The company moved its platform to a Tridium Java Application Control Engine (JACE), which allowed it to look constructively at other potential standardized components.
“We were building up interesting leads and prospective relationships, and we needed more flexibility in our offering than we could develop by ourselves, so it felt like the right thing to do,” Perry said. “By getting in experts to deliver their components, we could apply our own expertise to integrating the various elements and to developing our own technology and client base.”
A Relationship for a Sustainable Future
Open Energi began the search for the right submetering partner, and after extensive assessment of the market, it selected ND Metering Solutions.
Its meters are Internet Protocol (IP)-based and fit into Open Energi’s existing infrastructure. In addition, the use of such a widely used standard made it easier to connect and transfer data in standard-file formats to energy management solutions or data analytics packages and ensured information remained accessible from a standard Web browser.
ND Metering Solutions also provided the depth of information that Open Energi was looking for at a highly granular level of detail and the right speed.
Speed is crucial with this type of balancing and defines the service, Perry said. To provide continually adjusted demand rather than the slower, FCDM-style extended interruption, Dynamic Demand must respond within 2 seconds and deliver full power within 10. To achieve this, the submeters must be able to handle high volumes of data and track second-by-second changes in demand to a high level of accuracy as it responds to grid frequency. Open Energi had to ensure it could meet these requirements across a dispersed network of assets that range from bitumen tank heaters and computer room air conditioning units to half-kilowatt boilers and small fans.
Submeters also contain data verification algorithms that improve the reliability and accuracy of the data they send out.
A Solution Designed to Fit
Much of Open Energi’s work involves retrofitting at existing plants, often in different conditions. ND Metering Solutions offers a modular design that allows a single meter to monitor up to 20 circuits, which helps save space and minimizes some of the challenges of retrofitting.
Since opening the company to this more collaborative approach and working with ND Metering Solutions, Open Energi has been able to better help National Grid balance electricity supply and demand. Together these companies are playing a vital role in the development of a global energy future that is reliable, affordable and secure. They also are helping numerous energy users unlock new revenues through a smart approach to commercializing their energy loads, improving their energy management and supporting their sustainability goals.
National Grid’s Frequency Response Services
System frequency is a continuously changing variable that is determined and controlled by the second-by-second, real-time balance between system demand and total generation. If demand is greater than generation, the frequency falls; if generation is greater than demand, the frequency rises.
National Grid has a license obligation to control frequency within the limits specified in the Electricity Supply Regulations. It must ensure sufficient generation, demand or both are held in automatic readiness to manage all credible circumstances that might result in frequency variations.
There are two types of frequency response: dynamic and nondynamic response. Dynamic frequency response is a continuously provided service used to manage the normal second-by-second changes on the system. Nondynamic frequency response is usually a discrete service triggered at a defined frequency deviation.
The two types of nondynamic frequency response are:
Frequency control demand management (FCDM). FCDM provides frequency response through interruption of demand customers. The electricity demand is automatically interrupted when the system frequency transgresses the low-frequency relay setting on-site. The demand customers who provide the service are prepared for their demands to be interrupted for 30 minutes, where statistically interruptions are likely to occur between 10 to 30 times per annum. FCDM is required to manage large deviations in frequency, which can be caused by, for example, the loss of significantly large generation. The service is a route to market for demand-side providers and complements other nondynamic service provisions.
Short-term operating reserve (STOR). This is a service for the provision of additional active power from generation or demand reduction or both. STOR is needed because at certain times of the day National Grid needs reserve power in the form of either generation or demand reduction to deal with actual demand being greater than forecast demand, plant unavailability or both. Where it is economic to do so, National Grid procures part of this requirement ahead of time through STOR.
Richard Morgan has 13 years’ experience in energy management and submetering and has been responsible for some of the largest global submetering rollouts, including having installed tens of thousands of submeters across numerous continents. After graduating with a degree in energy management systems, Morgan joined EnergyICT in 1999 and quickly progressed to director level. He joined ND Metering Solutions as sales director in 2013.More PowerGrid International Issue Articles
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