Using TEGs to Maximize Site Investments

In the Canadian and American oil and gas markets, thermoelectric generators (TEGs) are a familiar sight. These workhorses are considered the most dependable source of unattended off-grid power available. What makes TEGs so reliable? Simplicity! With no moving parts, they require minimal maintenance. Even in the harshest environments, TEGs just work. But they offer more than just power, TEGs can be used for a surprising range of underappreciated applications that enhance their overall utility.

Solar-Hybrid Systems

The oil and gas industry is increasingly focused on reducing emissions. Solar-hybrid systems are a powerful solution that combines TEGs with solar and batteries. Adding a TEG to an existing solar system enhances reliability while adding a solar system to a TEG improves its sustainability. This win-win approach can be applied to both greenfield and retrofit projects. In the case of an incorrectly sized solar system, adding a TEG can improve efficiency and minimize unplanned site downtime, all while still utilizing the 'green' benefits of solar.

Heat Recovery Systems

Another option is to integrate a Heat Recovery System (HRS) with a TEG. By capturing the waste heat from the TEG, users can provide heat to their site/buildings making for a more efficient system and investment. These can even be utilized alongside a solar-hybrid system to create a comprehensive solution that tackles various challenges such as battery performance in cold weather, emissions from catalytic heaters, and providing heat and power to remote off-grid locations.

Backup Power Source

TEGs excel as a reliable backup power source. Unlike traditional generators that require frequent servicing, TEGs boast a simple design with no moving parts. This translates to significantly longer maintenance intervals, minimizing downtime and ensuring they're always ready to spring into action. It can also lead to lower cost of ownership over their lifespan when compared to traditional generators. Due to their ability to generate power continuously, TEGs are particularly well-suited for situations requiring extended backup periods, ensuring critical systems and equipment remain operational.

TEGs in Action: Examples of Applications

Solar-Hybrid

Solar and battery systems offer a compelling clean energy solution. However, similar to electric vehicles (EVs) that see reduced battery range in cold weather, solar system performance can also suffer in frigid temperatures. This can lead to decreased reliability during cold snaps and a shortened battery lifespan due to accelerated degradation.

In cold climates, solar power installations often require oversized battery banks to ensure sufficient power year-round. However, this comes with drawbacks. A larger battery bank translates to a higher upfront investment, and the excess capacity might go underutilized during warmer months, leading to inefficiency.

The addition of TEGs to solar systems offers a targeted and cost-effective solution for maintaining optimal overall system performance year-round. Through the most challenging weather periods of the year, TEGs can assist a solar and battery system to meet the application’s power requirements. This can extend the lifespan of solar batteries by preventing over-discharge.

Secondly, the heat generated by an added TEG can be directed to heat battery boxes to maintain optimal temperatures. TEGs generate enough power to keep the batteries within a desired temperature range, even in places with harsh winters like Canada or the northern US. Here cold temperatures can cause batteries to degrade within 2-3 years, but the addition of a TEG allows batteries to reach their full lifespan of 7-10 years, reducing costs and waste. The TEG can also be strategically activated (powered-on remotely or locally) only during the coldest months when reliability issues are more frequent.

For solar panels, winter weather isn’t the only challenge. They are also negatively impacted by forest fire smoke during the summer. Smoke can drastically reduce a panel's output, potentially dropping a 100-watt panel to 30 or 40 watts. Adding a TEG keeps the system operational even during poor solar insolation periods.

Heat Recovery Systems

Combining a TEG with a Heat Recovery System (HRS) adds even greater versatility and efficiency. Adding an HRS allows the waste heat produced by TEGs to be captured and repurposed, which unlocks a whole new range of applications.

This pairing shines in remote locations. Take analyzer shelters, for example. These require both heating and an ultra-reliable, off-grid power source, a challenge that the TEG-HRS combination solves seamlessly. It also offers a flexible design that can be customized for specific needs. 

Integrating TEGs with HRS also offers environmental and economic benefits. By capturing waste heat and repurposing it for heating, it significantly reduces reliance on traditional methods like catalytic heaters, that generate harmful emissions. This aligns with the growing push for sustainable solutions. Leveraging waste heat as a free resource also translates to potential cost savings through lower overall energy consumption and operational costs.

Backup Power

49 CFR Part 192 - Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards requires a “back-up power source to maintain SCADA systems or other remote communications for remote-control valve (RCV) or automatic shut-off valve (ASV) operational status, or be monitored and controlled by on-site personnel”. The simplicity and reliability of TEGs make them a perfect solution for backup power needs. 

Additionally, a growing concern of solar sites is panel and battery theft, a problem that can leave an entire system inoperable. By implementing TEGs as a backup power source, the system functions at a reduced capacity, providing some level of power until replacements are secured.

Other Options to Boost the Reliability of Solar Power

While TEGs offer a compelling backup solution, there are also other strategies that can be used to improve solar power reliability. The most common approach is to oversize the system, installing additional solar panels and a higher capacity battery than required based on average power needs. The idea is to create a buffer for bad weather events when power generation might be lower. However, this comes at an added cost and physical size. Oversizing requires a larger initial investment and can add complexity, but more practically, in some instances, there is insufficient space for the increased solar/batteries. TEGs can reduce footprint by as much as 75%. 

Besides TEGs, there are alternative backup generator options available. These can kick in when solar power dips, ensuring continued operations. However, these generators often have shorter maintenance intervals and product life, leading to an overall higher cost of ownership than TEGs. 

TEGs: The Value-Adding Workhorse

TEGs can help bring out the value of a site's assets and investments in a big way. Their reliable, low-maintenance design ensures continuous power for critical applications. When integrated with solar-hybrid systems, TEGs extend battery life and maximize energy production. Additionally, TEGs combined with HRS promote sustainability by capturing waste heat. This not only benefits the environment but also reduces energy costs. TEGs can also provide consistent backup power in the event of theft or damage to a system. By enhancing reliability, efficiency, and sustainability, TEGs establish themselves as a value-adding workhorse in the oil and gas industry.

To learn more about the Global Power Technologies' TEGs, click HERE.