written by Kennedy Davies, Solar Consultant
When considering solar power for your home or farm, you may have come across solar installation companies that promise over 100% offset in energy production. While it might be tempting to think bigger is better, that number can sometimes be deceiving. Often times, if you’re being promised over 100% in Calgary by your solar design (and that design has been approved by your wire provider) the end result is far less than that originally promised number.
At Solar YYC we never over promise when it comes to your solar system’s capacity. Sometimes this authenticity can lead to us losing a sale since our designs may not always have the highest offset percentages displayed. Even so, we prefer to operate being able to guarantee that our designs are 99.75% accurate (a stat we have worked hard to maintain since 2016).
But why can’t my Calgary home produce over 100% offset?
The short of it is that the Alberta Utilities Commission (AUC) has set guidelines against it. This leads to another question… why would the AUC not want homes to generate more electricity than they require? The answer to this question is two fold:
- If one home were to install an oversized solar system, it could inhibit neighboring homes from connecting their own systems to the grid or transformer. By capping system sizes based on historical consumption, the AUC ensures a fair distribution of grid capacity across all users.
- To ensure the infrastructre of our grid is not overloaded to avoid mechanical failure and power outages (similar to the last point).
At Solar YYC we have successfully navigated over 1,000 project approvals in Calgary alone, and work closely with Enmax to ensure that the designs we submit adhere to the Regulatory Approval processes they are governed by so that they never (or rarely) get denied. Overpromising could lead to project declines, unnecessary delays, and ultimately, customer dissatisfaction—something we’re committed to avoiding. A surefire way to get a permit denied is to promise well over your home’s consumption on a design (ie. over 100% offset).
Ok, sure that’s great, but my system design is well over 100% and still got approved by our Calgary wire provider… how do you explain that?
In some cases, you may find that a system designed for 100%+ of your energy needs gets approved. How is this possible? It comes down to the system’s capacity to produce energy, which is ultimately limited by the AC inverters. To break it down, as an example, even if your solar panels are generating 500 watts of power, your inverters may only be able to convert 350 watts into AC current, depending on their capacity.
This concept, known as “clipping,” is an industry best practice within 10-20%*,1 and your wire providers can see that in your system’s design. Some systems may have a much higer clipping percentage than is necessary, and therefore makes your system appear to be more capable than it is. You see 107% production on the top line, but (if your system has been approved) we can almost guarantee that the reality of your system and your inverters will result in an offset much closer to 100% than it appears.
Another reason why your 100%+ system may have been approved is because you’re looking to add a new appliance to your home. To get approval for a larger system, you’ll need to provide proof of purchase (POP) for these appliances. For an EV, you’ll also need to provide registration and insurance documentation. This way, the additional energy consumption is factored into your system design, ensuring it meets AUC guidelines.
Great, so… now what?
If you’ve received a quote from another vendor that seems too good to be true, it probably is. At Solar YYC, we’re always here to help you read through your quotes—even if they’re from another company. We believe in transparency and want to ensure you’re making an informed decision that meets your long-term energy needs, and, ultimately, we want you to get the best system possible for your home. Need some help looking through your designs? Shoot us a line and we will be more than happy to take you through any questions you may have.
Ready to explore your solar options? Contact us today for a free consultation, and let’s build a system that works for you.
- Clipping helps reduce energy loss during periods of low sunlight, like early morning or late afternoon, when the solar panels might not be producing at full capacity. So, while your panels might be capable of producing more energy, your system is designed to ensure it never exceeds what your inverters can handle. ↩︎