Solar energy become extremely inexpensive over the last decade. According to Understand Solar, the cost of solar energy has plunged from $4/Watt in 2008 to $0.65/Watt today. Because of declining solar energy costs, solar Operations and Maintenance (O&M) is changing rapidly as well. These changes are driven by new technologies like the Internet of Things (IoT), but, unlike modules, O&M can’t be commoditized. Each power plant requires unique O&M programs. Below you will find an approach to identify effective O&M strategies.
While all solar plants will bear O&M costs throughout their lifecycle, the objective of a purposeful O&M strategy should be to maximize energy output with minimal cost for ongoing operation. Though there are necessary costs you should always plan for including staffing for site access and plant controls, equipment inspection and service, module cleaning and emergency response to unplanned failures or events.
Capacity, location, value of energy
In addition to keeping costs to a minimum, the capacity of a plant, location and value of energy are other factors of an O&M program that help you decide what strategy is most effective. A 10kW solar plant may only require a few hours of O&M work per year, while plants on the scale of 100MW often need staff full time operators. Keep in mind that there are clear differences in planning for very large plants and very small plants, but there are two core O&M philosophies that scale does not affect - do nothing until it breaks or do everything possible to prevent it from breaking. The first approach in which plant managers don’t plan for change until something breaks can be dangerous as it exposes the plant to long unplanned outages. On the other hand, the preventive path can introduce unnecessary expenses in the name of caution. The optimal O&M program thoroughly balances both extremes.
When considering which O&M activities are effective for a given plant, there is a common metric to measure its return: Levelized Cost of Energy (LCOE). LCOE is used by solar developers to establish a normalized cost of producing energy. The concept of LCOE divides all the costs to build and operate the plant by the total energy output of the plant.
LCOE = Lifetime costs/Lifetime energy
O&M strategies can be evaluated using LCOE by comparing the cost of the specific strategy to the expected effect on plant energy output. After establishing the unit cost for the O&M strategy, comparison to the revenue for a unit of energy shows if the strategy is profitable for the plant.
LCOE for O&M = Cost of O&M Strategy/Expected
Change to Energy Output
Let’s take inverter monitoring as an example. Some solar owners may find that even monitoring at inverter granularity isn’t always worth it. How much does it cost to implement and monitor over time, compared to the reduced losses and increased energy yield from optimal performance? This simple approach can be used to evaluate various O&M strategies including annual maintenance plans, software & monitoring services and stocking replacement parts or equipment.
Changing the solar landscape
As mentioned earlier, emerging technologies such as the IoT promise to change the solar O&M landscape. IoT starts with the premise that all devices should be securely connected to the internet, then leverages that connectivity to deliver ongoing value through interconnecting various data systems, devices and platforms. Previous industrial networks and controls solutions have existed since before the internet, however, those solutions are no longer cost-effective and tend to lack the needed level of compatibly and flexibility needed. Some IoT solutions enable interoperability across manufacturers so that as your portfolio grows and new technologies from different vendors are introduced, you’ll be able to integrate all data producing devices rather than managing many data silos. IoT solutions are particularly exciting right now because of their low cost and lightweight architectures that can enable O&M where it was previously not cost-effective.
There is no one-sized approach to O&M, but planning should be adapted for plant size, location, value of energy, cost of labor and other relevant factors, and ultimately use the concept of LCOE for evaluation. When selecting O&M technologies and strategy, understand the options, be strategic and proactive about research, and make an educated decision that meets your objectives.
Written by Dan Bigelow, Senior Director of Customer Success at infiswift