Australia is home to some of the highest electricity prices in the world. Due to a lack of historical transmission and distribution infrastructure maintenance, today’s Australian consumers pay high prices each month to ensure that the country’s electrical grid is both reliable and efficient.
However, despite these increasing costs to maintain the electrical grid, many residents have experienced power blackouts. Expensive electricity and poor reliability are causing many residential energy users to adopt more reliable distributed power sources like solar energy.
Answering Consumer Demand with Solar
As a result of this growing consumer demand, Australia is taking broad steps to incorporate renewable energy technologies into its energy mix. Policymakers, such as the Australian Renewable Energy Agency (ARENA), have made a concerted effort to create a more resilient grid by funding clean energy innovation, projects and technology rollouts.
Solar plays a significant role in Australia’s distributed clean energy transition. A recent RenewEconomy report estimates that the country’s solar capacity is on track for 12 GW of installed capacity by 2020, double the current total. According to the Clean Energy Council, renewable energy amounted to approximately 17% of the energy generated in the country in 2016. While residential solar sites make up a large portion of the country’s current capacity, utilities and independent power producers are starting to develop large-scale installations at a rapid rate. These projects, spanning many square miles each, utilize thousands of solar PV modules. Once installed, energy is collected and transmitted to local grid-connected businesses and homes, providing them with clean, reliable solar power.
The Benefits of Solar Tracking
While adopting solar energy is an increasingly easy decision, selecting the right technologies to maximize a project’s energy output requires a little more analysis. Module type and brand, inverters, and other system components can have significant impacts on the performance of a solar project. However, and perhaps the most overlooked and important choice is that of selecting the proper racking equipment. It is important to point out that the racking or tracking equipment is the foundation on which the solar modules are mounted and therefore a very critical component. Making certain that the racking system will endure what mother nature dishes out over the next 25-30 years without compromising the solar modules or the structural integrity of the system is paramount. In the case of tracking systems, understanding the structural catastrophic risks and the operation and maintenance costs required to keep the system running at peak is equally important.
For the majority of solar sites, installing solar trackers instead of fixed-tilt solutions makes the greatest economic sense. Solar trackers allow the PV modules to follow the sun’s daily path, keeping them perpendicular to the power source, resulting in increased energy production and profitability of the power plant.
Deploying trackers can improve energy output by an average of 20 percent over similar fixed-tilt arrays. The power gain from tracking and additional expense befits a cost benefit analysis. The additional CAPEX cost to install a tracker plus the O&M costs over the system life must be less than the value of the extra power it produces to be economic. Implementing and operating trackers for a utility-scale power plant typically adds about 10% or less to the project cost. In most of Australia, trackers deliver about 20% more power. Spending 10% to get 20% makes a trackers’ economic advantage obvious, but increased power production is not the only benefit of tracking systems.
Fixed-tilt systems capture the maximum energy once a day when the sun moves perpendicular to solar panels, known as solar noon. Trackers however, rotate the panels to provide optimized power delivery on a continuous basis resulting in a broader, flatter, more useable, grid friendly power production profile. Increased energy production from tracking occurs in the mornings and evenings when the sun is lower in the sky. The gain from tracking is also higher in summer months when the sun follows a longer path in the sky. Not only do trackers provide increased energy output overall, but they enable a more efficient use of all system components such as modules, inverters and transmission lines. Trackers typically prove to be more economically viable and optimize the performance of a solar project by providing a lower Levelized Cost of Electricity (LCOE). LCOE is the measure of the cost of energy levelized over the lifetime of the power plant.
Solar tracking ultimately provides a significant increase in power production that also coincides with the peak power needs of the grid. Operationally, a tracker system’s cost of ownership should be relatively low with high reliability to ensure high uptime and great performance. Operational costs and performance vary by tracker architecture and vendor, so it is important to consider all factors when selecting tracker equipment for a project.
Selecting the Right Tracker
The installation of solar trackers is becoming ubiquitous on solar power plants in Australia. However, the advantages of trackers can be reduced or eclipsed if the equipment risk, and O&M costs are not fully understood and monetized over the 25-30 year lifespan of a typical solar project. Because solar trackers are expected to survive a plethora of meteorological conditions, issues of maintenance and long-term reliability need to be top of mind for solar project developers and owners, especially those building in wind-prone regions. Issues such as “galloping” (a resonance phenomenon that can occur with some tracker architectures) can even be experienced in low wind regions and can have a catastrophic effect.
When selecting a solar tracker, it is important to consider total lifetime costs and ensure that the selected technology is trusted to be safe, efficient and reliable in the project environment. While all trackers are manufactured to accomplish the same goal – track the sun from east to west to maximize productivity and power generation from PV panels – the design, mechanical components, and wind load relief approaches can vary greatly. On the O&M front, one of the biggest cost drivers between tracker architectures on the market is the quantity and nature of the electrical and electromechanical components required to operate the system.
A recent report authored by testing and certification company, TÜV Rheinland, examined the impact of these differences on operation and maintenance (O&M) costs, and overall project economics of two tracker architectures. The first architecture studied was a system driven by a single motor, linked by a rotating driveline to multiple tracker rows – Array Technologies’ DuraTrack® HZ v3. The second architecture was a system where each row operates as a self-contained unit with a dedicated photovoltaic (PV) panel, battery, motor, and other tracker system components. The report found that Array’s architecture can provide project owners with 4.6% higher pre-tax Net Present Value (NPV) and 6.7% lower Levelized Cost of Energy (LCOE). This is driven by 31% lower total O&M costs compared to the competing architecture.
Tracking Australia’s Solar Energy Future
Growth in the market for solar trackers is projected to accelerate in 2018. With buy-in from policymakers and utilities, Australia stands poised to increase its leadership in the global solar market with more installations and improving project economics through tracker technology. Our company looks forward to helping Australian solar businesses realize that opportunity.