Load Sequencing Panels: Monitor and Reduce Energy Use for Residences
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- Apr 23, 2021 4:45 pm GMTApr 29, 2021 4:51 pm GMT
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Load sequencing panels (LSPs) are a new device that will change the way residential customers consume electric energy. LSPs will allow residents to track their energy use in kilowatts, kilowatt hours, or both, while monitoring the price of energy set by host utilities. This will allow consumers to accurately track their electric bills in real time and alter their usage based on the cost of energy. LSPs will be capable of reducing residential load by up to 40%, which in turn will reduce monthly bills and greenhouse gas emissions.
LSPs will also benefit host utilities. Once in place, LSPs will eliminate the need for conventional rotating outages (a.k.a. rolling blackouts) when consumer demand exceeds energy supply. LSPs will also improve the financial stability of energy producers and host utilities by reducing their investment in new infrastructure. Plus, consumers will support host utility recovery from failures that, in the past, would result in wide area blackouts. However, before utilities can implement LSPs, updates must be made to traditional billing practices.
Let’s take a deeper look at how these new devices will influence the future of the electric utility industry. But first, let’s look at the updated billing practices that will be necessary for LSPs.
The Need for Updated Billing Practices
To effectively use load sequencing panels, electric energy providers must update their billing practices. Current KWH billing is not a sustainable revenue stream for host utilities, especially once distributed renewable energy sources and LSPs become commonplace. Instead, each host utility should base monthly bills either on maximum electric power demand in KW without consumption charges, or on maximum electric power demand and consumption charges in KWH.
For example, in a demand-based model without consumption charges, a utility could charge $10 per KW based on a customer’s maximum electric power demand. No charge would be applied for KWH usage. In a demand-based model that includes consumption charges, a utility could charge $6 per KW plus a usage fee of $0.04 per KWH. Both models should provide electric utilities with a sustainable income to maintain infrastructure across the grid while delivering reasonably priced electricity to consumers.
With this updated model for billing, energy consumers will know ahead of time the exact cost of their energy, and can set their maximum price point monthly. This is where LSPs come into play.
Load Sequencing Panels Explained
Load sequencing panels are devices that will connect to individual homes and residences as a replacement for traditional circuit breaker panels. A LSP is a combination of a circuit breaker panel and a switching panel, where the flow of power is directed by a microprocessor. Each on/off switch will be connected in series with a circuit breaker; the LSP’s microprocessor turns each switch on or off based on customer preferences, energy costs, and system conditions. LSPs will be programmable via app, and will have two modes of operation: monitoring and mitigation.
Monitoring Mode of Operation
When in monitoring mode, load sequencing panels will monitor each individual residence’s energy use in KW and KWH. LSPs will communicate with the app, allowing residents to track their usage and bill from their smart phones.
On the app, residents will select maximum KW, KWH, and monthly bill values that they are willing to pay. LSPs will ensure that residents can stay below their set price point. To do this, microprocessors in their LSP will monitor demand and consumption within range of the monthly price point. Host utilities will notify residents of the set price of KW once per year, as well as the cost of energy in KWH every fifteen minutes, as this price point can vary. Consumers will be able to monitor these pricing changes via the app, and can adjust their monthly maximum price point if needed.
The app will alert consumers as they are nearing their monthly maximum price point. It will also display monthly bills and yearly bills before each transaction is finalized. Through monitoring of power consumption, residents should be able to track and curb their usage of certain devices before the maximum price point is reached. This will help residents form power-saving habits while paying a consistent electricity bill.
Categories within Monitoring Mode
Residents will use the app to categorize each circuit in their residence as essential, preferred, or interruptible. LSPs will be programmed to always provide power to circuits categorized as essential, regardless of the cost, to continue powering vital devices such as refrigerators. LSPs can either maintain or stop the power flow to preferred circuits when costs exceed their highest price point, depending on the setting selected by the consumer. LSP will stop power flow to interruptible devices before the maximum price point is reached. Table 1 summarizes LSP categories and power flow strategies.
Once consumers have been alerted that they are nearing their price point, they can use the app to shut off power to interruptible circuit breakers. This way, residents can continue to power their essential devices while reducing electricity consumption. Once the maximum price point is reached, LSPs will automatically shut off power to interruptible circuits and preferred circuits according to the consumer’s settings.
Residents can select nuanced settings in the preferred and interruptible categories. For example, a preferred circuit may power a washing machine, and could be programmed to stop power to the circuit once the wash cycle is complete. Circuits that power indoor lights could be programmed to activate only after sunset and before a preset bedtime.
In-home climate control is another place where nuanced settings are necessary. The climate control panel could be categorized as either preferred or interruptible, with settings in place to prevent the home from reaching too high or too low of a temperature. Residents could program their LSP to override the maximum price point and send power to their air conditioner if the indoor temperature is above 850F, or their preferred temperature. Residents would then pay the market price for power, which may exceed their usual maximum price point. However, the home temperature would be maintained within safe living conditions, which would be vital during a heat wave or winter storm.
Host utilities will also have the ability to open the circuit to all preferred and interruptible loads if the resident fails to pay the energy bill. This ability would not apply during extreme weather conditions.
Event Mitigation and Recovery
In addition to the monitoring capabilities outlined above, load sequencing panels will monitor grid voltage and frequency. Whenever frequency drops below 59.2 Hertz (60 Hertz reference) or voltage drops below 95%, the circuits to interruptible and preferred loads will be opened, stopping the flow of energy. This ability to selectively turn off residential loads will eliminate the need for conventional rotating outages that impact businesses as well as residences. Rather than de-energizing entire strips of the power grid, LSPs will be able to shed load from specific points.
When this happens, residents may not have outdoor lighting, but they will have a working refrigerator. Businesses will be able to continue as usual, since LSPs are designed to shed load from residences only. Traffic signals will continue operating, restaurants can continue to do business, and factories will continue producing when LSPs actuate to reduce peak demand.
Furthermore, when facilities are repaired, LSPs will assist recovery by delaying the restart of interruptible and preferred loads when voltage is less than 90%. This will prevent “cold load pickup” (when every air conditioner, water heater, refrigerator, etc. restarts simultaneously once voltage is restored) from causing further drops in voltage. Cold load pickup can increase load by as much as 200% of normal, and can persist for hours. If voltage is less than 90% when voltage is restored, then cold load pickup could lead to a further outage.
To prevent this, LSPs will use their grid voltage and frequency monitoring function to determine when certain loads should be re-energized. LSPs can gradually re-energize loads across the grid after a prolonged outage, starting with preferred loads and moving to interruptible loads once voltage returns to normal. This will prevent the worst impacts of cold load pickup, while allowing load shedding when needed.
Load Sequencing Panels and the Electric Power Grid
Additional updates to the electric power grid will be necessary to prepare the grid for updated electric energy generation, namely from distributed renewables. Electric powerways will include necessary updates to existing transmission lines; electric serviceways will include similar updates to distribution lines. Electric warehouses will be updated substations that contain storage modules in addition to traditional substation components.
LSPs will be necessary in the updated electric power grid because they will aid in the efficient transfer of energy from distributed renewables located at individual residences. My vision for the updated electric power grid, including LSPs and other next generation components, is outlined in figure 1. The figure also includes updated communication channels, which will be necessary as utilities update their billing practices and LSPs become commonplace.
Figure 1 illustrates the updated electric power grid, including load sequencing panels and other new components. LSPs will communicate directly with host utilities to ensure consumers always know the cost of electric energy. They will also assist in efficiently transferring energy from distributed renewables into the power grid.
Additional Benefits of Load Sequencing Panels
Load sequencing panels will reduce maximum KW demand and minimize residential consumption when market prices are very high. This will reduce residents’ monthly electric bills and prevent future sky-high bills like those seen in Texas this past February.
Host utilities will have the ability to selectively reduce load when predictable, rare events, like the winter storm in Texas, occur. Had they been in place, LSPs may have prevented the almost statewide power shutdown in Texas by selectively shedding load when power demand exceeded supply. Residential consumers would have maintained power to their electric heat or specific outlets for space heaters, as well as ovens and refrigerators for food preparation.
LSPs will also allow host utilities to eliminate expenditures for equipment that may only be needed for a few days each year while repairs or maintenance work is underway.
Change is on the Horizon
A few years before I began my career, the Northeast Blackout of 1965 occurred, and host utilities implemented underfrequency load shedding schemes to mitigate underfrequency events that occur once a decade in the United States. More recently, host utilities used the underfrequency load shedding database to select circuits to interrupt when load was predicted to exceed energy production.
Now is the time to implement new technology for advanced load monitoring and selective load shedding. Load sequencing panels will provide the electric power grid with advanced technology so that consumers can manage their own electricity usage and bills, and host utilities can be prepared for the inevitable occurrence of electric power demand exceeding supply. LSPs will benefit host utilities and consumers, and assure that essential services are not interrupted. LSPs can also be part of the solution to climate change because they will eliminate the need to run inefficient, outdated generating equipment when the cost of power increases significantly.