Introduction

The history of solar technology stands as a testament to humanity’s enduring efforts to harness the sun’s energy. This journey traces back to ancient civilizations, such as the Greeks, who ingeniously employed solar energy for heating and illuminating their structures. As far back as the 5th century BCE, the ancient Greeks designed buildings with large south-facing windows to maximize sunlight and warmth especially during the winter months.

The evolution of solar technology has accelerated over the past two centuries since the discovery of the photovoltaic effect and the development of the first true solar cell during the 19^th century. These breakthroughs paved the way for the modern era of solar energy, which has recently experienced exponential growth. For instance, global solar photovoltaic (PV) capacity surged over 25-fold from 40 gigawatts (GW) in 2010 to 1 terawatt (TW) by April 2022.

In recent decades, solar technology has emerged as a powerful force in the global shift towards renewable energy sources. Its impact spans diverse sectors, from the vast expanses of solar energy farms to the harnessing of solar power for IoT devices. The potential of solar energy to drive a sustainable and cleaner future remains a guiding force in the evolving energy landscape.

Solar Technology Overview

Evolution

In 1839, a solar technology breakthrough occurred when French physicist Alexandre Edmond Becquerel uncovered the photovoltaic effect. His experiment involved placing silver chloride in an acidic solution, which, when connected to platinum electrodes, generated an electric current. Later, in 1883, Charles Fritts constructed the first true solar cell by coating selenium (a semiconductor) with an extremely thin layer of gold.

However, it wasn’t until more than six decades later, in 1946, that Russel Ohl at Bell Labs made the next pivotal advancement by inventing and submitting a patent for the silicon solar cell. Subsequently, in April 1954, researchers at Bell Laboratories built upon Ohl’s work to unveil the first practical silicon solar cell. This silicon-based innovation marked the dawn of modern solar technology, setting the stage for further advancements in solar energy utilization and efficiency.

Solar Cell Efficiency

Solar cell efficiency is the sunlight that is converted via photovoltaics into electricity by the solar cell. According to the National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy, most solar panels used today for commercial and residential installations have efficiency ratings between 19% and 21%. Two companies, SunPower and Canadian Solar, have solar panels with maximum efficiency ratings of 22.8%.

In 2006, Spectrolab, a Boeing subsidiary, developed a multijunction¹ concentrator solar cell that reached a record efficiency of 40.7%. Spectrolab’s solar panels are currently generating power in a 33 kW full-scale concentrator system located in the Australian desert. In 2019, a multijunction concentrator cell developed by NREL achieved 47.1% efficiency in a lab environment.

¹ Multijunction solar cells are made of several layers of different semiconductor materials which allow the cells to absorb more light per unit area and generate more electricity.

Solar-Powered GPS Trackers Overview

Use of Solar Technology in the IoT Market

Solar-powered GPS trackers made their debut in the mid-2010s with a primary focus on unpowered assets that required extended monitoring periods with minimal service and maintenance support. Over the last decade, the variety of assets tracked using solar technology has expanded significantly. This expansion has been driven by solar efficiency gains and the use of long-lasting backup batteries, enabling these devices to continuously operate even during extended periods of limited sunlight.

Solar asset trackers are now deployed on a diverse array of applications, including but not limited to trailers, containers, construction equipment, rental equipment, portable light towers, and  generators.

The capabilities of solar asset trackers have been further enhanced through the integration of built-in connectors with cable accessories and the utilization of Bluetooth technology. These enhancements enable the monitoring of various parameters such as temperature, door status (opening and closing), and the detection of tractor power.

Key Benefits and Trade-Offs

Using solar power for asset tracking offers companies a cost-effective, sustainable, and versatile option, eliminating the need for frequent battery replacements and reducing environmental impact. Solar asset trackers ensure reliable and uninterrupted tracking, making them ideal for a diverse set of use cases.

Key Benefits

Trade-Offs

While solar technology offers numerous benefits for asset tracking, it’s important to consider the following trade-offs when choosing this option:

Initial Cost: The cost of solar asset trackers can be higher than traditional battery-operated alternatives due to the additional cost of the solar cells, charging circuitry, and other components.

Sunlight Dependency: Solar trackers rely on sunlight for power generation, so their efficiency can be reduced during extended periods of cloud cover, darkness, or when deployed on assets stored in covered areas while not in use.

Maintenance: Solar panels require periodic cleaning to ensure optimal energy generation. Dust, dirt, and debris on the solar panels will affect their efficiency, increasing the importance of installing devices on assets to maximize their accessibility to the sun, while protecting them from debris accumulation.

Installation Locations and Size: Installation of solar trackers must maximize their sunlight exposure which limits the ability to install the devices in hidden or more protective areas on the asset. The size of the device, due to its typically large solar panel, may also limit the installation location options on the asset.

Primary Decision Factors

When evaluating solar-powered versus battery-powered devices to monitor assets, it is crucial to consider the following factors:

Location and Environment: Assess the geographic location(s) where the solar trackers will be deployed. Ensure there is sufficient sunlight available throughout the year to charge the solar panel effectively. It’s important to also consider the amount of time the assets will spend in garages, storage areas, warehouses, and other covered locations which restrict the devices access to direct sunlight.

Battery Capacity and Operating Duration: Determine the battery capacity to ensure the solar tracker battery life aligns with the desired application. Also, identify the backup battery’s operating duration during periods of low sunlight. The backup battery lifespan, for specific reporting cycles, should be specified by the solar tracker provider (e.g., the backup battery will last 4 months at 12 reporting cycles per day).

Solar Cell Efficiency: Assess the efficiency of the solar cells in converting sunlight into electricity, as higher efficiency panels will recharge the solar tracker faster.

Deployment Duration: Consider the intended deployment duration. Solar trackers are ideal for longer term deployments with most devices offering between 5-to-10-year lifespans depending on tracking and reporting frequencies.

Cost and Budget: Evaluate the overall cost, including the initial purchase, installation, and ongoing operational costs. Determine the return on investment (ROI) based on a comparison of device, installation, and on-going maintenance costs.

Device Quality and Support: Research the solar asset tracker provider’s reputation for device quality, its customer & technical support capabilities, and its warranty period. A reliable support system is crucial for delivering a successful solar tracking experience.

Conclusion

Solar technology has undergone a remarkable evolution since the 19^th century, progressing from producing the first true solar cell in the last 1880s to deploying massive solar farms and solar cells with over 40% efficiency. In the IoT market, solar-powered solutions have experienced increasing adoption due to their reliability, versatility, sustainability, and cost-effectiveness.

It’s important, however, to understand the trade-offs associated with solar technology and to conduct a careful consideration of the key decisions factors when evaluating solar tracking for asset monitoring.

Positioning Universal: Solar Asset Trackers

Positioning Universal launched its solar asset trackers, the TT600 and TT603², in 2019. Key competitive differentiators for the TT600/603 are:

• Frequent Tracking & Reporting Intervals: 1-minute GPS fix intervals with every 10-minute reporting.
• Solar Cells Size & Efficiencies: one of the largest and most efficient (22%) solar panels in the market.
• Long-lasting Backup Battery: up to 4 months at 12 reports/day.
• Pre-Charged Battery: immediately monitor assets without concerns tracking will be inconsistent or stop due to depleted batteries.
• 6-axis Accelerometer: increases the data set available to evaluate accidents and roll-overs compared to the 3-axis accelerometers available on most solar trackers.

Positioning Universal continuously monitors relevant technological advancements, including emerging developments in solar technologies, in our constant quest to improve the quality of the telematics solutions we provide to our resellers and customers.