Solar Panel System Performance
Why did I receive a high utility bill?
It is important to keep in mind that the energy being offset by solar production is heavily dependent on how much energy is being consumed in the home. All systems are designed based on historical energy usage that we obtain from your utility bill. The actual offset will vary as we move throughout the seasons or if your home's energy consumption fluctuates. This is partially because of the seasonality of solar power; your panels will produce more during the on-peak seasons of spring and summer.
If your home requires more electricity than it did in the past, your offset will be affected even if the solar panels are performing perfectly. It doesn’t necessarily mean that solar energy isn’t saving you on costs, but it can be more difficult to observe when you receive a high utility bill.
Will my production degrade over time?
The process of converting solar energy will cause the system to degrade in efficiency by approximately 0.5% each year. This is very normal for solar equipment and occurs with every system. This is also accounted for when we design your system.
Degradation rates are used in our assessments so we can closely estimate production over the system's lifetime. However, please rest assured that your panels are designed with improved technology and manufacturing techniques intended to improve their stamina.
How will my utility credit me for unused energy?
Your usage charges with your utility will be based on how much energy your home used from the utility grid (resulting in usage charges) and how much unused solar energy was absorbed by the grid (resulting in credits).
If your home doesn't need all the produced solar energy during the utility's billing cycle, then any unused energy will be credited on your utility bill. If your home uses all the produced solar energy, then the rest of your electricity has to be provided by your utility. Your home does not produce energy at nighttime, for example, and therefore any electricity used during these hours is being provided by the utility through the grid. If there is not enough unused solar energy in your credit balance with the utility to cover that usage, you will see it reflecting as a charge on their invoice.
Why does my utility bill show less solar production than my inverter?
Most utility companies can only track the unused solar energy absorbed by the grid, not the system's entire production. The usage you see on the utility bill is what is pulled from the grid after you have used your solar energy, or during the night when your system is in ‘night mode’. Additionally, the Net Energy Metering credits that reflect on the utility bill show only how much unused solar energy was absorbed by the grid.
Can you explain how my utility bills me with solar panels?
Any inquiries regarding your local utility processes would be best handled through their customer support team, as they can access and explain the most accurate information. Each utility handles the addition of solar energy in their own way, but they are ultimately the best source for their programs and requirements.
Why can’t my system offset 100% of my consumption?
Our systems are designed to produce a certain amount of energy. Based on your average historical energy usage, we determined how much of that usage could be covered by solar. In other words, an ‘offset’ percentage. This offset would theoretically be met when your home’s usage doesn’t drastically fluctuate and when the system is performing as it should.
Given these two factors, we are able to estimate an approximate offset, as reflected in your proposal. These estimates do not serve as a precise expectation, since they depend on outside factors like the home's usage and the system's performance. Because of these variables, we're not able to guarantee a definite savings expectation; we can only guarantee that the system meets production estimates, as that is the factor within our control.
How can I improve my overall savings?
To get the most out of your system, here are some tips:
- Your home only uses solar energy during the day, so anything that requires electricity during daylight hours will use solar energy first. Your home does not produce energy at nighttime, so any electricity used during these hours is being provided by your local utility through the grid. Since solar energy is sometimes provided at a cheaper rate than the local utility, it's a good idea to try and limit high-usage appliances (like your A/C) to being used during the daytime.
- We also encourage you to keep your A/C on ‘auto’ and set at your preferred temperature. When the A/C is turned on only when needed, it actually uses more energy by trying to cool down your home from a hot temperature. If it is set to ‘auto’, the preferred temperature will be maintained with shorter bursts of energy usage throughout the day. This will ultimately use less electricity than turning the A/C on and off.
Does Tesla provide compensation for any system downtime?
We absolutely understand that any system downtime is unfavorable; equipment does malfunction from time to time, therefore you're protected by several contractual guarantees (please review your Tesla agreement for specifics). This solidifies our obligation to repair or replace any defective part with accordance to the manufacturer's warranty.
We experienced a power outage, why did I lose power in my home if I have solar panels?
Rest assured our system is designed to withstand the typical power outage. Even though you have solar panels, if there is a power outage in your area then your home will lose power. This is because the solar equipment is still tied to the utility power grid. As it stands currently, we are required by law to be linked to the utility grid. Even in areas that will allow a solar energy offset of 100%, your home must still be linked to the grid and charged for monthly fees and taxes.
In the future, if you do have another outage, we recommend contacting your utility company for the most efficient and accurate assistance. The solar equipment will turn back on once power is restored to your area.
Can I add a couple more solar panels to my current system to increase production?
In terms of adding panels to your home, please note that we are unable to alter existing systems by adding to or removing from the currently installed equipment. If we add more panels, they must be part of a new system that has been properly permitted through the installation process. Adding equipment to the existing system without obtaining new permits/approvals would make both Tesla and yourself vulnerable to fines. This means that a new system will require a separate contract.