Solution: Combined heat & power

In 2018, 33.1 gigatons of energy-related carbon dioxide (CO₂) were emitted globally, underscoring the need for immediate action to reduce this staggering number. Put another way, that’s 33.1 billion metric tons, a collective mass equal to 66 times that of all humans on earth.

As greenhouse gas emissions have continued to increase, energy utilities have sought to reduce the amount of CO₂ that is released into the atmosphere, as a result of burning traditional fossil fuels.

To combat the rising CO₂ levels, many utilities have committed to reach net-zero carbon emissions by either 2030 or 2050. For some, switching to fuel alternatives with lower emissions, such as natural gas, is an interim step to get there, while others look to renewable energy sources, such as wind and solar. While there are many possible paths to reach net zero, one thing is clear: time is of the essence.

But what exactly does net zero carbon emissions mean, and which method of energy production will yield the greatest environmental benefits? Let’s take a closer look.

What is net zero?

The term “net” zero does not mean there are no carbon emissions emitted. At the moment, all fuel-burning energy generation methods emit some carbon. However, after these emissions have been reduced as much as possible, companies can offset the remaining emissions by investing in assets that absorb carbon, such as forests, carbon capture, or other emerging technologies. Those assets effectively cancel out the carbon emissions being produced, resulting in net zero carbon.

Harnessing the power of renewables

Recognizing this need for change, energy utilities have sought alternatives to traditional generation sources to enable continued provision of their essential services. Unlike fossil fuels, such as coal and oil, renewable energy resources are neither extractive, nor reliant on a single resource that depletes over time. Wind, solar, and biofuels are all renewable resources that utilities are investing in to reduce their carbon footprint.

One method for reducing CO₂ emissions that can already be utilized is combined heat and power (CHP). Unlike traditional power plants that take excess heat produced during power generation and discard it, CHP efficiently harnesses that excess heat as thermal energy that can be used to keep buildings warm or cool, humidify the air or sterilize equipment. By taking advantage of this resource, utilities can conserve fuel, rather than burn more to produce heat, effectively cutting CO₂ production dramatically.

Perhaps what is most exciting about this energy source is that CHP generators can also burn biofuels, such as waste vegetable oil from restaurants or organic matter. By fueling CHP with biofuels, the total amount of carbon emissions produced during energy generation can be additionally decreased.

No matter the method, utilities that choose to utilize the energy potential of renewable resources will see a reduction in carbon emissions. When renewables are combined with generation methods such as CHP systems integrated with biofuels, even greater benefits can be achieved.

The road to net zero

A broad swath of energy generators are shifting to renewables to replace natural gas, especially utilities. Challenges remain, however, especially when it comes to transforming the entire grid to be more environmentally beneficial.

While wind and solar are good renewable resources, they are reliant on ideal weather conditions to produce at maximum efficiency. When there is no wind or sunlight, utilities must turn to other energy sources, such as natural gas, to continue supplying power to the facilities they serve. Although a cleaner resource than burning coal, natural gas does emit CO₂ and still contributes to greenhouse gas buildup. Regardless of weather conditions, customers must continue to receive services, and falling back on traditional fuel sources that will produce emissions while providing necessary services is a challenge to decarbonization efforts.

Another obstacle that utilities face is upgrading existing infrastructure. For many utilities, their incumbent grid technology is outdated and ill equipped to accommodate alternative fuel sources that previously were not used or available during the original infrastructure’s development. Because of this, utilities are tasked with not only transitioning to renewables, but also updating systems that have known no other fuel source and were designed for a one-way distribution path. Utilities also have to take into consideration that the majority of U.S. communities leverage onsite boilers for residences and buildings, which means every end user will need to have their infrastructure updated to convert to greener fuels and generation methods as well. The hurdle is a high one – accompanied by a price tag that utilities will have to take into account.

Other facilities have turned to natural gas as a bridge fuel as they shift away from fossil fuels to greener solutions. Though as previously mentioned, natural gas is not carbon-free, although it has a lower carbon footprint than coal or fuel oil. Additionally, those who employ natural gas as a main energy resource may consider transitioning completely away from it to be a daunting challenge. Similar to electric utilities, these organizations will need to seek alternative fuel sources, while also upgrading existing infrastructure, in order to reach net zero. 

In contrast, district energy companies can more quickly transition to renewable fuels and technologies through upgrades at their central plants. Unlike other conventional utilities, upgrades to the distribution system are not required. The improvements made at these central plants, whether this is integrating renewable fuels or converting boilers to renewable electricity, will then benefit all the buildings connected to the district system, dramatically reducing carbon emissions. By nature, district energy is typically found in urban environments, which eliminates the need to transport energy over long distances to customers. It is highly reliable, cost-effective and cuts the amount of fuel that is required by individual buildings using onsite generation. Utilizing renewable resources, energy efficient equipment and green technology at the central plant means that all connected buildings connected to the district become greener. In effect, a district energy system can dramatically reduce the carbon footprints of entire cities relatively quickly and easily.

A greener path

Time is often an overlooked resource, as it is easily spent, but it can never be recouped. As we look to the mid-century, it is crucial that energy utilities explore and implement renewable strategies to reach net zero carbon goals. It is already estimated that global carbon emissions are expected to increase by 0.6% per year until 2050, underscoring the battle against time itself. That equates to more than half a billion additional metric tons per year above 2018 levels.

By harnessing the power of renewable resources, energy providers can dramatically cut carbon emissions and diminish the climate impact of their operations, ushering in a healthier, greener world for generations to come.