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Are Your Load Profiles for Solar Customers as Accurate as You Think?

Posted by Gwen Brown on Jan 24, 2018 6:47:34 PM

It’s a typical day at your solar installation company. You received an inquiry from a prospective customer who is thinking about installing solar on their house, so you sit down to put together a design and quote. As a savvy designer, you’re already using cutting edge remote design tools to assess the solar access potential of the home and create a custom solar installation.

You begin the process by getting a sense of the customer’s energy consumption in order to design a PV system sized to their needs. As is often the case, you don’t have copies of the customer’s actual electricity bills, just the bill amounts they’ve provided.

In most cases, this is a fine starting point—as long as you know the utility rate, tools like Aurora’s estimator can translate that total bill amount into an estimated energy consumption amount. These tools can even generate a representative load profile (also known as a consumption profile) depicting the amount of energy the customer uses throughout the day and year. Aurora builds a profile based on the typical patterns of energy consumption in a particular area.

Given the bill values and utility rate you have from this customer, and their location in Southern California in a suburb of Los Angeles, a typical profile would look something like this:

A typical load profile (consumption profile) for an electric utility customer in Southern California, generated by Aurora Solar. Aurora's interactive Consumption Profile tool estimates a customer's load profile based on the typical consumption patterns in their geographic area, as well as heating and lighting types, and whether they have amenities like AC, a pool, or an electric vehicle. 

Unfortunately, this particular customer isn’t as typical as you may have expected. Little could you tell from their electric bill amount, but this is what their load profile actually looks like:

A load profile (consumption profile) for a prospective solar customer that is very different from a typical profile in the region. This customer's load profile is actually quite different from typical energy consumption patterns in Southern California. As you can see from the shape, the bulk of their energy consumption is between 10am and 6pm. 

It turns out this customer is a startup founder, feverishly work to launch the next Snapchat. They don’t yet have an office, so they spend most of their waking hours—into the late evening—working from their home. These late nights also mean that most days their small team gets a late start, ramping up their work around 10am. With multiple computers and electronics running, they have sizeable energy consumption during hours when most residential households would be out of the house at work or school.

The end result of this customer’s unusual energy consumption patterns is that they’re actually consuming a lot less energy than a typical customer paying this amount on their electric bills—they’re just paying more per kilowatt hour.

Why is that and why does it matter?

This is because the customer is on a time of use rate, which charges them different amounts for electricity depending on the time of day that they use it. On this customer’s rate, peak hours—when electricity is most expensive—span from 10am to 6pm, precisely when they are using the most. As a result, this customer’s energy consumption is less than than most customers with equivalent monthly bills.

In this case, the difference between the customer’s actual annual consumption and the typical consumption for these bill amounts is over 1000 kWh per year! As you can imagine, this has big implications for developing an appropriate solar design. Without knowing the breakdown of their energy consumption throughout the day and how much they consume during peak hours, the estimate of their annual consumption is far too high.

If the customer’s load profile wasn’t verified with greater accuracy before installation, this could lead to designing a system that’s larger than their needs. Or, if the mistake were to be discovered before project completion, it might require a change order that costs your company considerable time and money.   

Creating a More Accurate Load Profile

While this is an extreme example (not all of your customers are trying to build the Next Big Thing in their living room!), it illustrates the critical importance of an accurate load profile to creating an appropriate design and accurately estimating the customer's savings from solar.

Recognizing that the utility bill information that contractors receive from customers can vary widely, both in level of detail and structure of the information, we’ve been hard at work here at Aurora to give you a variety of options for arriving at an accurate load profile.

New Consumption Profile Entry Options.pngAurora is rolling out new options to make it easier to generate an accurate load profile for prospective solar customers. 

Traditional Approaches to Load Modeling

As we discussed above, one option for developing a load profile is to use software tools to generate an estimated load profile based on monthly energy consumption or bill amount. This is a great option for customers with typical consumption patterns, but as demonstrated, it has limitations when the customer’s patterns of energy use are outside of the norm.

Alternatively, if your customer’s utility company offers Green Button data—a type of standardized file of their energy consumption throughout the day—software like Aurora lets you upload that file to generate a perfectly accurate historic model of their energy consumption down to 15-minute intervals. Unfortunately, only a limited number of utilities offer Green Button data. For these reasons, additional modeling options can be helpful.

Green Button Data is currently available from selected electric utilities in the U.S.Green Button data is currently offered by a handful of electric utility companies around the United States. Source: Green Button Alliance

New Tools for Accurate Load Profiles

Starting next week, Aurora is excited to unveil some additional tools that offer solar designers greater ability to create an accurate load profile.

First, if you have copies of the customer’s bills, you can now manually enter their consumption information in much more granular detail than just entering their monthly consumption or bill charge. Specifically, if the customer’s utility rate includes different time of use periods or different rates in different seasons, you can enter the amount of energy or the portion of their bill that corresponds to each billing period. This will allow you to manually generate a representative profile of how much they consume during those different periods.

Aurora Solar offers a manual input option to accurately model a solar PV customer's consumption profile (load profile)

Aurora’s new Direct Input option allows you to manually enter a customer’s energy consumption during different time of use periods in order to generate a more accurate load profile.

Additionally, we’re now making it easier to enter consumption information from the customer’s utility in different formats than Green Button data. If the customer’s utility offers it, you can now upload a CSV file of the customer’s historic energy consumption. Like Green Button data, this option allows for the entry of a customer’s energy usage over different time spans, such as 15-minute or 1-hour intervals. This also provides greater flexibility for modeling load profiles of customers in international markets.

Clearly, getting an accurate consumption profile for your customer is critical to finding the best solar design for their needs, and to accurately representing their potential savings from solar. Next time you’re putting together a design, consider taking advantage of these additional tools to enhance the accuracy of your load profile modeling.

Topics: energy load profile

Commercial Load Profiles: What the Solar Salesperson Needs to Know

Posted by Gwen Brown on May 31, 2017 12:00:00 AM

To effectively sell solar to potential customers, you need to accurately communicate the value that a solar installation will provide. An energy load profile is a key step in determining this.

A load profile shows how much energy a building uses at each time of the day for each day of the year. It is a critical first step to evaluating the financial return a solar installation will offer. A load profile is also helpful in determining what size installation will best meet a customer’s needs. This is the case whether the customer is a homeowner or the owner of a commercial or industrial building.

As a follow-up to our earlier article on residential load profiles, in today’s post we will take a closer look at commercial load profiles. As a solar installer, being able to show your customer the methodology behind your estimate of the value solar will offer them, and why you recommend a particular system size, is integral to building trust and ultimately increasing sales.

An example of an estimated load profile of a warehouse in San Jose, California during summer.

Why Do Commercial Solar Customers Need to Know their Load Profile?

One reason why load profiles, also known as consumption profiles, are so important is that they form the basis for assessing the finances of a potential solar installation. This is because, in the U.S., net metering is the prevailing approach for compensating solar system owners.

For customers with net metering, the electric utility adjusts their bill to pay them the retail rate for the excess solar energy they send to the grid. As a result, they pay only for their net energy consumption. Thus, to evaluate how much the customer will save on their bills as a result of adding solar, you must know how much energy they consume and how much solar energy their system will produce (which Aurora’s NREL-validated performance simulation engine can help you determine).

If that were the full story of utility billing, it would be enough to know the total amount of energy the customer used each month- but in many cases, utilities also charge different prices for electricity depending on when it is consumed. These Time-of-Use rates charge higher prices for energy at times when there is more demand. As such, you need to know not only how much energy the customer uses, but when they use it—and how that corresponds with the energy their solar installation is producing at different times.

Furthermore, a key difference in how commercial customers are billed compared to residential customers is that many commercial customers also have to pay demand charges. These charges, which penalize customers who use a lot of power at any given time, are determined by the maximum amount of power (kW) that a customer used in any (typically 15-minute) interval during the billing cycle. A detailed energy load profile, which shows energy consumption at the appropriate interval, allows one to see the points of high power usage that determine the customer’s demand charges.

Finally, a load profile also provides valuable information for determining the size of solar installation needed to meet a customer’s goals. For instance, if a customer wants to get their electricity bill as close to zero as possible, an energy load profile will allow you to assess how much energy their system would need to produce.

Ways to Determine Commercial Load Profiles

There are multiple ways to determine a customer’s energy load profile, but the two main options are to use actual energy usage data from a period in the past as a representative load profile, or to estimate the load profile based on the building’s characteristics.

Using Real Interval Data

Where it is available, using interval data of past energy usage is an ideal approach because you can be sure that the load profile exactly represents historical usage. (Of course, this doesn’t account for future changes in behavior or equipment, like installing more energy-efficient devices.) This is also the best approach if you want to account for demand charges because estimating a customer’s load profile won’t provide sufficiently granular detail to predict the customers highest demand over 15-minute intervals.

One way to get this information is Green Button Data, a standardized type of interval data that some utilities make available to their customers, which can be uploaded into Aurora to create a load profile.

Creating an Estimated Load Profile

If interval data for the building is not available, one can estimate the load profile based on electricity bills, characteristics of the building, the energy usage behavior of the occupants, and the geographic location of the building. Using a software program that can tailor a load profile based on these factors is an excellent way to easily develop an accurate estimate for your customer.

As you might expect, different types of commercial buildings have different energy consumption patterns. Think of a school, for instance. Its energy consumption will be lower in the evenings and weekends when it is unlikely to be occupied. In contrast, a grocery store’s energy profile will reflect that it is occupied for more hours of the day.

Example of a load profile for an elementary school in western North Carolina during winter, estimated with Aurora.

Example of a load profile for a grocery store in western North Carolina during winter, estimated with Aurora.

The Department of Energy (DOE) has developed profiles of 16 different “commercial reference buildings” that represent approximately 70% of the commercial buildings in the U.S. These commercial building archetypes each have their own patterns of energy usage as a result of typical occupant behavior, as well as the physical building characteristics that impact how they use energy (building size, types of appliances and machinery typically in use, etc.).

The DOE’s open source knowledge-sharing platform, Open Energy Information ( , includes sample interval data on these types of buildings. Aurora has leveraged these profiles in creating its commercial Consumption Profile tool, which provides a convenient and accurate way to estimate a customer’s load profile.

The DOE has developed profiles of 16 different commercial reference buildings that represent approximately 70% of the commercial buildings in the U.S.

Other factors that impact load profiles include the geographic location and local climate. For instance, as you would expect, buildings in hotter climates are likely to use more energy on air conditioning. Similarly, day length at different times of the year in different latitudes will impact the need for electric lighting. Aurora takes into account data from local weather stations and the sun’s path at the location throughout the year to adapt commercial load profiles accordingly.

When developing a commercial project in Aurora, users are prompted to specify the building type that most closely matches the site they are designing. Aurora uses DOE data on energy usage patterns for the building type to develop an energy load profile.

Aurora also takes into account weather data from a local weather station to account for how the local climate impacts the load profile of a site.

There are also methods to manually develop load profiles by measuring how much energy specific appliances use and the timing of their use; however, this is a complex and time-consuming process best left to experienced professionals.

While there are other stages that go into designing an ideal solar installation and evaluating its financial returns, developing an accurate load profile is one crucial step. As a solar installer, increasing sales comes down to adding value to the customer and gaining their trust. If you're able to show a commercial customer their load profile and the methodology used to ensure its accuracy, you’ll have greater credibility and increase the likelihood that the customer chooses your company. With Aurora’s Consumption Profile tool, you can easily develop an estimated load profile or upload Green Button Data for commercial clients, and know that the estimate reflects robust data on load profile trends.

Topics: Solar Sales, energy load profile

How to Estimate a Homeowner’s Energy Load Profile

Posted by Gwen Brown on Apr 10, 2017 12:00:00 AM

An energy load profile, or consumption profile, is essential to determining the value that a solar installation will provide—and thus to effectively selling solar to potential customers. We discuss what an energy load profile is, why it influences financial returns for solar, and how to model one.

When communicating the value of a solar installation to a potential customer, showing them accurate financial returns is extremely important. In order to accurately forecast the financial return of a solar system, you need to know exactly how much energy the customer uses.

In certain parts of the world, the process of determining a solar project’s financial return is simple and separate from the customer’s energy consumption. Many countries use Feed in Tariffs which pay the owners of solar systems a set amount for each unit of energy produced.

But in the US, the majority of residential solar installations are on a Net Energy Metering regime, which means that their utility bill is adjusted based on the energy the solar installation produces. Another way of looking at it is that their utility meter turns forward when energy is used, and backward when excess solar energy is sent to the grid.

This structure is further complicated by the fact that in many cases — especially for commercial customers—the price of energy differs based on when you use it (these are called Time of Use Rates). Utilities also charge customers different rates for electricity based on how much they use (Tiered Rates).

Diagram showing Time-of-Use rates Figure 1: An example of Time of Use rates, showing higher energy prices at times of higher energy demand.

Why Do You Need a Load Profile?

Because of these variations in the cost of energy at different times and different levels of consumption, just knowing a potential solar customer’s bill before they install solar is not enough to enable an accurate assessment of how much money they could save with solar. You also have to know when the customer was using electricity, and how much electricity they were using. You need to know this for every hour of the day, and every day of the year. This information makes up their energy load profile.

Example of an Energy Load Profile, showing how much hourly energy use results from different home characteristics Figure 2: An example of an estimated energy load profile in summer for a residential house in Stanford, California with air conditioning, electric heat, and LED lighting.

Once you have this data showing energy consumption for each time of the day, you will need to determine how much energy your PV system will produce for those same hours and days of the year (which Aurora’s industry-leading performance simulation engine can determine for you). By subtracting the amount of energy produced by the solar installation from the amount of energy consumed by the household, you can determine how much, and when, the customer will actually need to purchase from the utility.

This time-varying consumption profile will form the backbone of the financial analysis of the value your solar design will provide. Being able to show a customer the detail behind this analysis will help them understand—and be confident in—the financial savings solar can provide.

How Is an Energy Load Profile Determined?

Determining a customer’s energy use across each hour and day of the year and organizing it in an easily interpretable format is not easy. That is why Aurora developed its interactive Consumption Profile tool.

One of the best ways to determine a customer’s load profile is to upload their “Green Button data.” Green Button data is a way that utilities provide customers with detailed information documenting their energy consumption at set (typically 15-minute) intervals throughout the day. Green Button data provides the customer’s actual load profile for a period of time in the past (for however long you have data). If you have Green Button data, Aurora’s Consumption Profile tool imports and sorts it for you with the click of a button.

If you don’t have Green Button data, our tool can quickly and easily estimate a load profile with the entry of some additional details. While it is possible to manually estimate a load profile, it is a challenging and time consuming process—and without a deep knowledge of the process there is a lot of potential for mistakes. With Aurora’s Consumption Profile tool you can automate this process, increasing accuracy and saving a considerable amount of time.

To understand the variables that go into estimating an energy load profile, let’s review some of the different factors that influence a customer’s energy consumption at different times.

What Variables Affect a Load Profile?

There are a wide number of factors that affect how much energy a home uses and when that energy is consumed. Without Green Button data, a load profile must be estimated based on the building’s characteristics. In order to create an energy load profile that is accurate—and thus provide accurate financial analysis to your customers—it is essential that all of these factors be taken into account in a systematic way.

A utility bill from the client is an important starting point in developing an energy load profile, because it can provide the first data points for how much energy they are using, and what rate they are billed at by their utility. In Aurora, you can enter data from one month’s bill (bill amount or total amount of energy used), or as many months as you have from the customer, and Aurora will use that to extrapolate estimated energy use for other months.

screenshot of Aurora's Consumption Profile tool illustrating how you can enter utility bill data Figure 3: Aurora’s Consumption Profile tool uses bill amount or total energy consumption for one month, or as many months as you have data for, to estimate energy consumption throughout the year. This is supplemented by additional information about the building for increased accuracy (as we will discuss below).

The location of the building is one important factor because the local climate will influence the demand for heat or air conditioning at the site, and the amount of daylight at different times of the year will impact demand for electric lighting. Whether the building has air conditioning, and what type of heat it has (electric or other) will influence how much much energy the customer uses at different times of the year.

Take for example the case depicted in Figure 2 below, which shows the different estimated consumption profiles for the same house in Stanford, California with gas or other non-electric heat (top) versus if it has electric heat (bottom). The orange section in the image on the right shows the proportion of electricity consumption that heating comprises. As you would expect, electric heat contributes significantly to electricity consumption.

estimated annual load profiles for the same house, with and without electric heat Figure 4: Estimated annual load profile for the same house in Stanford, California with gas or other non-electric heat (left), or with electric heat (right).

Other factors that impact an energy load profile include the type of lighting (incandescent, fluorescent, or LED) and type of hot water heating. Additionally, two less common factors that have a very big impact on energy consumption are whether the customer has a pool (pools use a surprising amount of energy, partially because of the energy needed to pump and filter the water) and whether they have an electric vehicle.

Figures 5 – 7 illustrate the impacts of some of these factors on load profile. Figure 5 compares the load profiles of incandescent lighting versus more efficient LED lighting (top and bottom respectively), and Figures 6 and 7 show the impacts of an electric vehicle and pool respectively on load profile if the house has LED lighting.

estimated annual load profiles for the same house, with incandescent vs. LED lighting Figure 5: Estimated annual load profile for the same house in Stanford, California with incandescent lighting (top), or with more efficient LED lighting (bottom).

estimated annual load profile with an electric vehicle Figure 6: The load profile of the same house with an electric vehicle with no air conditioning, non-electric heat, and LED lighting.

estimated annual load profile with a pool Figure 7: The load profile of the same house with a pool, with no air conditioning, non-electric heat, and LED lighting.

As you can see, a home’s load profile can vary significantly depending on the characteristics of the home. As a result, when estimating a load profile it is important to enter as much information as possible to maximize accuracy, or use Green Button data. It should be noted that an estimated load profile cannot account for future changes in the homeowner’s behavior—like upgrading to more energy-efficient appliances or setting the air conditioning to a lower temperature—that may affect how much energy they use. However, it can provide a strong, data-backed estimate based on their current behaviors and home energy demands.

Aurora has made it easier to ensure that your estimated energy load profile reflects actual consumption patterns, by incorporating robust data about how different home characteristics (air conditioning, lighting, electric vehicles, etc.) typically affect energy consumption at different times of the day. This typical load profile is then tailored to account for average local weather patterns and the home’s total monthly energy consumption (based on their utility bill).

With an accurate energy load profile, you can precisely assess the financial benefits that adopting solar will provide to a homeowner.

Key takeaways

  • An energy load profile shows how much energy a building uses at each time of day across each day of the year.
  • Financial savings are a major motivator for many people who consider going solar. With an accurate energy load profile, you will be able to quantify the real savings that your solar design will provide to a customer.
  • A customer’s consumption profile can be obtained using their Green Button data (a log of their energy consumption over specific, typically 15-minute, intervals).
  • If you do not have Green Button data, you can create an estimated load profile with electricity bills and information about the characteristics of the site (whether they have air conditioning, what type of heat and lighting they have, etc.).
  • Aurora’s load profile tool automates this process, making the development of a load profile faster and more accurate.

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Topics: Solar Utility Bill, green button, energy load profile

The Value of Green Button Data for Solar Customers

Posted by Gwen Brown on Apr 4, 2017 12:00:00 AM

Green Button data — if you’re not familiar with it, it might sound like something that a Marvel comic book villain would enjoy reviewing. But, in fact, Green Button data is actually a very valuable tool for understanding a home or business owner’s energy usage. In this post, we’ll explore what Green Button data is and what benefits it provides for solar designers and customers.

Green Button data gives utility customers — both residential and commercial — timely access to energy use data in a standardized, computer-friendly format.

What is Green Button Data?

Green Button data refers to an option provided by some utilities that enables customers to download detailed data on their electricity usage with just the click of a (green) button from the utility website. Specifically, Green Button data gives utility customers — both residential and commercial — timely access to energy use data in a standardized, computer-friendly format. The Green Button Initiative emerged as a voluntary, industry-led response to a 2011 call-to-action from the White House to make energy data more accessible to consumers.

Beyond showing how much energy a consumer uses, one of the greatest benefits of Green Button data is that it also provides insight into when energy is being used. Historically utility bills have only shown how much energy was used over a monthly period. However with the increased deployment of “smart meters,” which track energy usage at intervals of one hour or less, much more granular energy use data is becoming available. If a customer has a smart meter, Green Button data will allow a customer to see exactly how much energy they use at specific intervals.

The measurement interval available to customers depends on what their utility offers, but many utilities — especially in California and Texas, where utilities are required to provide customers with their energy usage data — provide this information in 15-minute increments. Currently, more than half of American households have smart meters and they are increasingly being deployed by utilities around the country as part of utility efforts to modernize the electric grid. Smart meters and Green Button data go hand in hand as methods to give customers’ greater insight into and control over their energy use. The Green Button program is helping to make the improved data from smart meters more easily accessible.

Beyond showing how much energy a consumer uses, one of the greatest benefits of Green Button data is that it also provides insight into when energy is being used.

Why Is Green Button Data Important?

Green Button data offers numerous benefits to energy consumers and for solar professionals looking to design and sell high quality solar installations. Green Button data helps consumers better understand when they are consuming energy, and save on their utility bills. For instance, for residential customers in areas where Time of Use (TOU) rates are standard (like California), Green Button interval data can show how changing the timing of certain energy-intensive activities can result in reduced energy bills.

Green Button data is particularly useful for customers who are considering solar, because it makes evaluating projects and savings faster and more accurate.

Green Button data offers additional value for commercial customers. Beyond the insights it provides with regard to Time of Use rates (which are more common for commercial customers), Green Button data can also help commercial customers better understand demand charges, which are fees a utility charges based on the maximum amount of power a commercial customer consumes over a given time period.

Example of a load profile based on uploaded green button data An example of a customer's hourly energy usage based on Green Button Data uploaded in Aurora.

Green Button Data and Solar: A Perfect Combination

Green Button data is particularly useful for customers who are considering solar, because it makes evaluating projects and savings faster and more accurate. Having a clear picture of a household’s energy consumption is critical to determining the appropriate size of a solar array. Furthermore, precise data on energy consumption at different times throughout the day is important in enabling accurate evaluation of the financial returns of the solar design.

For instance, if the customer is billed under Time of Use rates, in order to understand how much a solar installation will reduce their utility bill, it is essential to understand how much energy they consume during peak demand times when energy is more expensive, and how those usage patterns intersect with the amount of energy their solar array is likely to be producing at different times. A customer’s savings will be greater if the energy produced by their solar installation coincides with and can offset much of their electricity consumption during hours when electricity is most expensive (typically in the afternoon). Furthermore, this consideration might influence the ideal location or orientation of a solar design (such as siting the design where it will get more afternoon light, and thus offset energy when electricity prices are higher, rather than where it would produce the most energy overall).

For commercial customers, whose utility bills include demand charges, the benefits of using Green Button data in the solar design process are a little more nuanced, so we will cover them in a later post.

With a customer’s Green Button data, you can save time by automatically importing the exact details of the customer’s energy consumption and Aurora will use that to model the customer’s electricity usage throughout the day and throughout the year (their load profile). Combined with Aurora’s simulations of the solar design’s energy production (the industry’s most accurate), you and your solar customer can be confident in the expected financial return on the installation.

Key Takeaways:

  • The Green Button Initiative is a program through which participating utilities provide customers with detailed data on their energy usage, in a standardized, machine-readable format.
  • Green Button data gives utility customers greater insight into the amount and timing of their energy consumption, helping them to understand how they can save energy and reduce their utility bills.
  • Green Button data is particularly useful in helping potential solar customers accurately evaluate the financial return on a solar installation.
  • Aurora’s software can automatically import and interpret Green Button data enabling faster and more accurate development of detailed solar sales proposals.

Are you using Green Button data? How has it impacted your solar business? Join the conversation on Twitter , Facebook , and LinkedIn with the hashtag #GreenButtonData.

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Topics: solar design, Solar Primer, electricity bill, Financial Analysis, Solar Finance, energy load profile

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