I’ve had the pleasure of working with some clients who didn’t realize how bad things had gotten with their solar projects until they got online monitoring. I say ‘had the pleasure’ because people don’t really realize how much they’re missing without monitoring and are usually truly excited to see the level of detail they can get once they’re online. I’ve prepared the following as a basic ‘101’ lesson about your options to monitor your solar PV system.
The inverter(s) that you are using may already have installed capability to monitor. The inverter is the heart of your solar PV system. They convert the DC electricity generated by the solar panels to the AC electricity that is used in the electricity grid to provide our homes and businesses with electrical power. Generally, inverters have the capability to communicate through a ‘gateway’ of some sort but are quite often not connected to the internet to utilize this capability. If the inverter already has a gateway, either built-in or an external box, you simply need to get an internet connection to them and get them talking to the free, internet based portal provided by most inverter manufacturers.
If a gateway is not installed, they can usually be purchased after the fact for between $300 and $1200. The internet can be brought to the gateway a number of ways. If there is internet already at the site, it can be easily routed to the gateway by cable or wifi or wifi extender. If there is no internet at the site, it can be installed using either ‘point-to-point’ from a nearby building with internet or using an inexpensive cellular based option (usually with Rogers or Bell).
Depending on whether you are generating on a FIT or MicroFIT contract (Ontario only) or net-metering, the value of adding monitoring can be assessed quickly by doing some basic math.
Customer ‘A’ has a $0.80/kWh MicroFIT contract. Their system is a 10kW roof mounted system that produces about $8500 per year. If this system as an issue that inhibits production to 75% (a string of solar panels not functioning properly for example), they continue to receive a monthly payment from their LDC but are losing roughly $2125 per year in lost production and may attribute lower bills to variations in weather or not even notice at all. Sometimes these issues can continue for years. Monitoring can likely be added for a fraction of the cost of the loss in this example and will allow Customer ‘A’ to ensure maximum production for the remaining years of their MicroFIT contract.
Customer ‘B’ has a FIT project generating $0.54/kWh. Their system is a 250kW system mounted on the flat roof of their manufacturing facility. It generates $150,000 per year. The day after their June payment is settled, a rodent chews through one of the main AC wires and the system stops operating. When the customer receives their July statement, there is $18 of production – roughly a $19,000 loss! The larger the system, the more critical monitoring can be.
Some key benefits of monitoring:
- The ability to monitor your system from anyplace you have internet connection on a computer, tablet or smartphone.
- Alarms to notify you of things like variations between inverters (when there are multiple inverters on site) or underproduction compared to expected values
- Alarms for all problem ‘state-codes’ (like the check-engine light in your car)
- Verification of utility payments
- Grid voltage issues that may affect other equipment on your home or business
- Verification of issues to provide proof for warranty claims for solar panels and inverters. Also expedites warranty process.
Below is an example of a system that I monitor that has 4 inverters. I received an email from the monitoring portal that one of the inverters was underproducing compared to the other 3. Upon further investigation, the panels connected to this inverter were being shaded. If you look at the graph, you’ll see that the one inverter’s production drops significantly from the other 3. The shading object can now be removed/addressed. This never would have been detected by looking at the monthly bill!
In my opinion, there are very few reasons not to have monitoring on your system. I welcome any feedback or questions!