Jane Chen and Brian LaMorte joined us recently for our Weekly Wednesday Free CEU webinar Series.
If you missed this session, want to rewatch it, or share it with a friend or colleague, you can now do so, as the recording and article on the topic are available below.
Overall, respondents reported learning a great deal about electrical load management, especially that service upgrades are often unnecessary when smart load management devices are used. Many highlighted a new understanding of the 80% rule for panel sizing, the difference between voltage and amperage, how to calculate loads, and how panels are typically underutilized in real-world conditions. Participants were particularly struck by the idea that 100–150 amp panels are often sufficient for electrification (including EV chargers) when load prioritization and demand management are applied, and that subpanels do not increase service capacity. Several learned what load management devices are, how they integrate with main and subpanels, and that code-permitted demand management can “zero out” new loads in capacity calculations. There was also appreciation for practical alternatives to costly 200A upgrades, including products like Stepwise and other smart or add-on systems. Remaining questions centered on when full panel upgrades are truly justified, how load managers are physically wired and installed, how to assess older homes (including whether rewiring is required), how to interpret utility peak demand data versus calculated loads, and the cost, rebates, and installation considerations associated with these systems.
Q&A
Question: Does adding a subpanel increase total capacity, or just “space?” In other words, could you add 50 amps to a main panel that is 100 amps by adding a subpanel?
Answer: Adding a subpanel increases physical space for breakers, but does not change the overall “ampacity” that is available in the panel.
Question: The graphic showing all the loads is better expressed in kW than in kWh – power draw vs. energy used.
Answer: Totally fair, thanks for the input. We’ll try to update the visual in the future. I completely agree that capacity is the more important metric; most consumers are more comfortable thinking in total energy consumed since they’re used to looking at the electric bill.
Question: Beyond the install cost, are there any ongoing issues with oversizing the panel?
Answer: Oversizing the panel does not lead to issues for the homeowner, but could lead to overall electricity price increases for everyone in the long run. When home electric panels are upsized, that will also trigger transformer upgrades to occur. Any utility infrastructure costs will be rate-based in higher residential electricity prices.
Question: Is there a way to calculate how much electricity is continually drawn by smart appliances which are constantly drawing energy? For example, older appliances didn’t have things like digital clocks, but now they are standard. Over time all those little things add up. Even though tech advances, now devices require constant connection to WiFi, or our Alexa’s are always running. Is it minimal or does it add up?
Answer: The electricity you’re talking about here is very minimal in comparison to the types of capacity spikes we talk about.
Question: So can you make the panel bigger (200A) without a service upgrade, if the house has more potential than the panel accesses?
Answer: Yes, you can make the panel ampacity feel bigger by allowing the panel to use its full capacity without actually doing a service upgrade. Imagine a line graph shaped like a curve. Think of electricity usage as the area under the curve. Capacity (“ampacity”) is a measure of the amplitude of the curve. With load management, we can use more of the total area under the curve while ensuring the amplitude never gets beyond its current limits.
Question: For older houses, when the panel is upgraded for household electrification purposes, does the entire house have to be re-wired?
Answer: When the service is upgraded (i.e. from 100A to 200A), the wire from the meter to the panel often has to be sized up to accommodate the increased electron flow. The interior of the house does not need to be rewired UNLESS you’re dealing with a knob and tube system that is not code compliant. The reason that it is a lot of manual work to do the panel upgrade is because you have to replace the existing panel with a new one and reconnect all the wires, which also means tracing back the breakers to the appliances and manually taking stock that everything is connected correctly.
Question: Can you speak to peak load/startup load? I have a GSHP that I believe draws more heavily on startup and then I think it levels off… is that possible and how do you account for or possibly taper that off?
Answer: As Brian mentioned, most modern appliances no longer have a massive upfront startup peak, but if you did have a system with the peak, you could add a soft start device to manage the spike (usually ~$400).
Question: I have a 2018 200A electric panel. I would like to have a smart panel. How much would switching out the panel cost? Are there other options to gain smart capabilities with an existing panel?
Answer: A traditionally smart panel upgrade would cost ~$8K-$10K all in. Load management is a more cost effective way to manage important circuits and gain the same type of data intelligence as a smart panel for ~$1K per circuit.
Question: Cost for the Load Manager (LM)?
Answer: Hi Jane, the MSRP for the Stepwise Tap Load manager is $780. Contractor and Volume Discounts are available. Link to the store: https://getstepwise.myshopify.com/ and more overall information at www.getstepwise.com
Question: I had purchased a load management tool from SENSE and had electrician install – horrible experience that had a lot of trouble getting any data – are there tools that you recommend?
Answer: Sense is not actually considered a load management tool because it only has the ability to monitor but cannot enable control of a circuit. I can’t speak to the experience of getting access to data across the different energy monitors out there, but I would trust Reddit for its recommendations. If you are looking for control capabilities as well, then I would recommend taking a look at load management solutions.
Question: How to best convert kW to Amps? Is there a best rule of thumb?
Answer: Yes, you can think of them as being interchangeable. For instance, the measure of power is usually kWh (which is kW x time), but it is also referred to as Amp hours.
Question: I’m curious what Brian’s heating system setup is, as well as climate zone. We’re pretty far north and have some folks switching to air source heat pumps, some of which are all-electric systems.
Answer: Brian has a 2 zone heat pump for a 3500 sq ft home. He’s based in Ithaca, New York.
Question: Is there a lifetime on the devices, do they update automatically or have to be replaced every 10 years or so?
Answer: The devices can be updated over the air if they are connected to WiFi, meaning that the software program can be updated like your smart phone. You can assume the hardware part has the same lifespan as a panel, so 10 years is a good assumption.
Question: If we use historical peak demand to determine whether a panel upgrade or load management solution is needed, but a panel upgrade is being anticipated due to planned electrification, how can you be sure sizing for past peak demand will meet future peak demand?
Answer: We use historical peaks and then layer on the future loads. For instance, if peak load when looking at the previous 3 months is 30A on a 100A panel, and you’re adding an EV charger, you can assume that you would need to add in up to 48A of additional capacity during peak. If the historic load + new load is <80A, then you can add the planned project without worrying about the panel. If the new load cannot be supported by the additional panel capacity, then you could consider load management.
Question: Please DO address “smart” panels such as SPAN panels!
Answer: Smart panels are one form of load management. They are particularly suitable for new builds where it’s more cost effective to swap out a whole panel. A typical SPAN full installation costs about $8-10K in total, which is more than the cost of a dumb panel upgrade and can be difficult for many individuals to swallow as an upfront investment. The best way to select for the appropriate load manager is to think about your application and your electrification plans. If you are looking to do one off installations one at a time, then a circuit level controller offers more flexibility. If you are pursuing a whole home electrification project and have access to financing, or if you’re building a new home, a smart panel could make sense to get access to full panel controls.
Question: Are load management devices universal in terms of voltage across world zones?
Answer: Yes, in the residential context they are compatible with 240V appliances.
Question: Could the data from Stepwise help to decide how much backup storage battery capacity you need?
Answer: Yes, it could help inform battery capacity since you would know how much energy and the peak capacity the home is actually using.
Question: If the home has no EV charger, no battery, what are examples of other appliances/loads that might have the load decreased/turned off? If, for example, a home converts to a heat pump and installs load management system instead of a panel upgrade, what would the LMS “dial back” to allow the heat pump to work properly?
Answer: Any 240V appliance in the home could be controlled to be turned off. Examples include induction stoves, water heaters, snow melts, hot tubs, and heat pumps. The only caveat on heat pumps is that we would encourage you to first find other things in the home to turn off first as most people like to have control over their heating/cooling controls. Adopt the mindset of “making room for the heat pump” by putting a load manager on something else in the home.
Question: A smart panel like the SPAN solution may avoid having to increase the service upgrade.
Answer: To be clear, a SPAN panel or a smart panel install is often akin to getting a service upgrade. The only difference between a smart panel upgrade and a service upgrade is whether the utility needs to be involved to increase the service to the home. The labor involved is roughly the same and may have a higher price tag because of material costs.
Question: Are there commercial applications here as well, or strictly residential-size applications?
Answer: Yes, there are commercial applications, but because you are dealing with 480V in many commercial settings and the wiring set up is a bit more complicated, those cases would need to be dealt with on a case-by-case basis.
Question: Great, Stepwise is the name of the company?
Answer: Yes, Stepwise Electric Inc is the full name of the company. www.getstepwise.com
Question: How can you tell how much electricity your heat pumps used in a year to disclose when trying to sell your house?
Answer: You can monitor the heat pump circuit using an energy monitor or a load manager.
Question: What would you estimate the marginal cost of adding an additional 8/10 slot sub-panel to be, compared to having existing space in the main panel to add additional breakers?
Answer: On average, a subpanel could cost ~$2K and tandem breakers to make room in an existing panel would be $100-200.
Question: When doing a panel assessment in this use case described, is it prudent to validate the Earth ground copper & rod, validate the service wire conductor size related to observed load prior to sign off the inspection?
Answer: Yes, always helpful to validate the earth ground and the service wire.
Question: How are ELECTRICIANS and CODE OFFICIALS being educated on this topic?
Answer: We are conducting training sessions with inspectors and electricians both on our own and in partnership with some utilities. If you have any organizations that would benefit from education please connect us. You can email me holly@getstepwise.com
Question: Can you provide a list of good load management devices with links?
Answer:
- Simpleswitch – https://simpleswitch.io/
- DCC – https://rve.ca/en/dcc-solution/
- Span – https://span.io/
- Schneider smart panel – https://www.se.com/ca/en/work/campaign/local/qosmartpanel/
- Stepwise Tap – www.getstepwise.com
Question: Are arc fault parts an impact?
Answer: Cannot agree more! That’s why we believe education on the concept of load management should be widespread across all electrical and building professionals.
Question: So, if a home has 100A service, and the panel is in good condition but physically full, you could get a subpanel and a load management system. Is that generally going to cost under $2,000 or so with labor?
Answer: Yes, that is a good ballpark, although the exact price will depend on what region of the US you live in.
Abstract
As homes transition toward electrification to reduce carbon emissions and improve energy efficiency, the residential electric panel has emerged as a perceived bottleneck. Conventional wisdom often assumes that electrification—adding heat pumps, electric cooking, EV charging, and other high-load appliances—requires costly panel or service upgrades. However, a deeper understanding of residential electrical demand, load calculation methods, and emerging load-management technologies reveals that most homes possess substantial untapped electrical capacity. By integrating monitoring-based load management strategies, homeowners and contractors can frequently electrify existing buildings without major electrical service upgrades. This article clarifies how electric panels function, explains the limitations of traditional load calculations, and outlines when load management can safely and economically enable electrification while avoiding unnecessary infrastructure expansion.
The Electrification Challenge and the Role of the Electric Panel
Residential electrification is accelerating as buildings transition away from fossil-fuel combustion toward electric heating, water heating, cooking, and transportation. Yet the shift raises a practical concern: can existing homes support these additional electrical loads?
The electric panel—the central distribution point for household electricity—often becomes the focus of this concern. It aggregates all circuits and defines the maximum amperage available to the home. When major electric appliances are added, contractors frequently recommend upgrading from a 60- or 100-amp service to 200 amps or more. This recommendation is commonly driven by code-based load calculations that estimate potential simultaneous electrical demand.
However, these estimates rarely reflect real-world usage patterns. Most households operate well below theoretical peak loads, meaning significant capacity often exists within existing panels. Understanding this discrepancy is key to enabling cost-effective electrification.
Understanding Electric Panel Capacity and Load
An electric panel’s rating, expressed in amperes (amps), represents the maximum current the service can safely supply. The main breaker defines this limit, while branch breakers distribute power to lighting, appliances, and equipment throughout the home.
Residential systems in North America typically provide both 120-volt and 240-volt power. All homes receive 240 volts from the utility; standard outlets use one leg (120 V), while large appliances such as heat pumps or EV chargers use both legs (240 V). Panel upgrades therefore relate primarily to amperage—not voltage.
Electrical load represents the total current drawn by all active devices at a given time. Large electrification loads—heat pumps, electric ranges, dryers, and EV charging—dominate residential demand compared with lighting or plug loads.
To ensure safety, electrical codes require that calculated load remain below approximately 80 % of panel capacity. When calculated demand exceeds this threshold, traditional practice mandates a service upgrade.
The Limits of Traditional Load Calculation
Code-based load calculations are intentionally conservative. They assume worst-case simultaneous use of multiple appliances, regardless of real occupancy patterns or behavior. The result is often a substantial overestimation of true demand.
Field monitoring data consistently shows that actual peak usage is far lower than calculated values. Even fully electrified homes with EV charging often remain well below panel limits most of the time.
This gap arises because households rarely operate all major loads simultaneously. For example, laundry, cooking, space heating, and EV charging seldom coincide at full power. Consequently, calculated load may suggest the need for a 300-amp service while real peak demand remains near 100 amps.
The implication is profound: many homes possess substantial unused electrical capacity that conventional calculations fail to recognize.
What a Service Upgrade Really Entails
Upgrading electrical service is often assumed to be straightforward, but in practice it is complex, disruptive, and expensive.
A true service upgrade typically requires:
- Replacement of the service entrance conductors
- Installation of a new meter enclosure
- Coordination with the utility company
- Permitting and inspections
- Temporary power shutdown
- Potential trenching or conduit replacement
Underground services may require excavation to the transformer or utility connection point, which can involve driveways, landscaping, or structural barriers. In some cases, site conditions make upgrades impractical or prohibitively expensive.
Costs commonly range from several thousand dollars to well above $10,000 depending on region and installation complexity.
Even when technically feasible, service upgrades impose broader system impacts. Increasing individual home service sizes drives the need for larger neighborhood transformers and distribution infrastructure, raising system costs and ultimately electricity prices.
Oversizing and Its System-Level Consequences
Historically, electricians often oversized services to accommodate future electrification needs. While this approach avoids immediate constraints, it can produce unintended consequences.
Oversized services encourage higher instantaneous demand, even if rarely used. When many homes adopt larger services simultaneously, utilities must upgrade upstream equipment such as feeders and transformers. These infrastructure investments are shared across ratepayers, increasing long-term electricity costs.
Therefore, avoiding unnecessary upgrades is not only economical for individual homeowners but beneficial for grid efficiency and affordability.
Real-World Demand Versus Theoretical Capacity
Monitoring data offers a more accurate perspective on residential electrical demand. Whole-home monitoring or utility smart-meter data can identify the highest recorded peak load over time, revealing true capacity needs.
Measured peak demand often falls far below calculated values. Even large, fully electrified homes with EV charging frequently remain well under 200-amp service limits.
This observation demonstrates that electrification is often feasible within existing panels—especially when combined with load-management strategies that ensure safety during rare high-load intervals.
Load Management: Concept and Function
Load management provides a practical method to use existing electrical capacity more efficiently. Fundamentally, it acts as a traffic controller for household electricity.
A load-management system performs two essential functions:
- Monitoring real-time household electrical demand
- Controlling selected loads to keep total demand within safe limits
By continuously measuring current draw, the system can automatically reduce or temporarily interrupt specific appliances when the panel approaches capacity.
This approach ensures that electrical demand never exceeds panel ratings while enabling additional electrification loads to be installed.
How Load Management Works in Practice
Load-management devices may be installed at several points in the electrical system—within the main panel, a subpanel, or directly on a circuit serving a specific appliance. Sensors monitor incoming service conductors to determine total household load.
When demand approaches a preset threshold, the system acts automatically. For example, an EV charger may temporarily reduce charging rate or pause operation during peak household use. Once demand falls, full operation resumes.
The process is largely invisible to occupants because peak coincidences are brief and infrequent. For most homes, load management operates only occasionally as a safeguard rather than a routine control.
Types of Load-Management Solutions
Load management can take several forms depending on project scope:
- Circuit-level controllers for individual appliances
- Smart breakers or panels controlling multiple loads
- Whole-home energy-management systems
- Integration with solar or battery systems
Smart electrical panels represent one comprehensive implementation, monitoring and controlling each branch circuit. Circuit-level devices provide a simpler alternative when adding a single load such as EV charging.
The appropriate solution depends on whether electrification involves a single appliance or whole-home transformation.
Integration with Renewable Energy and Storage
Load management also plays a role in homes with solar generation or battery storage. During grid outages or limited battery capacity, the system can prioritize essential loads and defer discretionary ones.
For example, heating may take precedence over EV charging during backup operation. This dynamic prioritization offers flexibility beyond fixed “critical load panels,” enabling more adaptive energy use during outages or peak conditions.
Safety and Code Compliance
Modern load-management systems are recognized within electrical codes as energy-management systems. When properly listed and installed, they are fully compliant and acceptable to inspectors.
By actively preventing panel overload, load management enhances electrical safety. It ensures that total demand never exceeds design limits, reducing risk of overheating or fire while enabling electrification without service expansion.
Economic Advantages
Avoiding service upgrades produces significant cost savings. Load-management installation typically costs a fraction of a full upgrade, often near one-quarter or less of the expense.
Beyond direct cost reduction, load management shortens project timelines. Service upgrades require permitting, utility coordination, and inspections, whereas load-management installation may be completed rapidly without utility involvement.
These advantages make electrification accessible to more homeowners, especially where upgrade costs are prohibitive.
When Load Management Is Appropriate
Load management is most effective when additional electrical demand occurs only occasionally or for short durations. Typical examples include EV charging, electric cooking, or intermittent appliance use.
In such cases, existing panels often possess sufficient capacity for most operating conditions, with load management handling rare coincidences.
Many homes can achieve full electrification on services as small as 150 amps when real usage patterns and load management are considered.
When a Service Upgrade Is Still Necessary
Load management does not replace all upgrades. Certain conditions require increasing service capacity:
- Severely undersized or unsafe existing service
- Obsolete or damaged panels
- Extensive simultaneous high-load equipment (e.g., pools, workshops, multiple heat pumps)
- Commercial-scale or continuous heavy loads
If multiple large loads operate frequently and concurrently, relying on load management alone would cause frequent interruptions or reduced performance. In such cases, increasing service size remains appropriate.
Policy and Incentive Considerations
Public policy increasingly recognizes the value of load management in enabling electrification without infrastructure expansion. Some jurisdictions provide incentives for electrifying homes without panel upgrades, reflecting the grid benefits of efficient capacity use.
Federal and state rebate programs may also support load-management installations alongside electrification measures, further improving project economics.
Toward Smarter Electrification
Electrification need not be constrained by existing electrical panels. By shifting from conservative theoretical calculations to data-driven demand management, the industry can unlock unused capacity in millions of homes.
This approach aligns economic, environmental, and grid objectives:
- Lower homeowner costs
- Faster electrification adoption
- Reduced infrastructure expansion
- Improved grid efficiency
Load management therefore represents a critical enabling technology for large-scale residential decarbonization.
Conclusion
The perception that electrification requires widespread electrical service upgrades is often overstated. Traditional load calculations significantly overestimate real residential demand, leading to unnecessary infrastructure expansion and cost.
Monitoring-based load management provides a safe, code-compliant method to utilize existing electrical capacity more effectively. By dynamically controlling loads during rare peak conditions, it enables most homes to adopt electric heating, cooking, water heating, and transportation without major panel upgrades.
For sustainability professionals, builders, and contractors, understanding this distinction is essential. Smart electrification depends not only on efficient appliances but also on intelligent use of existing electrical infrastructure.
Key Takeaways
- Most homes use far less electrical capacity than traditional load calculations assume.
- Electrical service upgrades are costly, disruptive, and often unnecessary for electrification.
- Load-management systems monitor demand and automatically control appliances to prevent overload.
- Many homes can fully electrify on existing services—often as low as 150 amps—with load management.
- Upgrades remain necessary only when loads are frequent, continuous, or structurally unsafe.
- Avoiding unnecessary service expansion benefits homeowners and the broader electric grid.
