Cogeneration helps mitigate natural gas and grid power supply chain disruption risks

The uncertainties of 2022-2023, in terms of natural gas and electricity prices and volumes, top the agenda of boards of directors of the paper and tissue-making industry across Europe and around the world. Given potential natural scarcity, now is an excellent time to look at the role of cogeneration in the energy landscape. Combined heat and power (CHP) is a key ingredient in our energy future for two primary reasons:

1. Cogeneration offers a primary energy savings of more than 10 percent. It saves more than 10 percent of fuel compared to the separate production of heat and electricity.
2. Cogeneration in general and tissue-integrated cogeneration assets in particular can produce low CO₂ power and heat when variable renewable power generation sets cannot (i.e. when the wind isn’t blowing or the sun isn’t shining) enabling a larger amount of variable renewable penetration in the power grid.

Alternative fuel sources to consider

There are several ways to mitigate the risks of natural gas rationing, including the use of liquefied natural gas (LNG) or liquid fuel (like diesel #2) in cogeneration equipment – both consolidated solutions in the power generation industry. Doing so may require a modification of the turbogenerator package to accept the second fuel and additional balancing of the plant equipment to allow its storage and conditioning. Feel free to contact your local Solar Turbines customer service representative to evaluate the solution.

It’s also important to take into account CO₂ reduction targets when considering the implementation of an alternative fuel source. Diesel #2 may appear to be the easiest option to locate, supply and store. Its CO₂-equivalent intensity coefficient, however, is 38 percent greater than natural gas. NOx emissions during diesel #2 operation are slightly higher than with natural gas as well, requiring a verification of the plant’s emissions permit. LNG, on the other hand, has a composition very close to pipeline natural gas and presents the same basic characteristics in terms of NOx and CO₂ emissions. The LNG supply chain is well-developed and packaged cryogenic modules have been created for industrial applications, making LNG a possible alternative fuel for GT-based cogeneration.

Powering the future through sustainable, innovative energy solutions

Biogenic alternatives also exist and continue to grow, primarily in the form of compressed biomethane, bio-LNG, green hydrogen and renewable diesel like hydrotreated vegetable oil (HVO). These solutions are compatible with Solar Turbines’ SoLoNOx™ gas and dual-fuel combustors. Though biomethane and renewable diesel NOx emissions are comparable to their fossil fuel counterparts, CO₂ emission reductions can be as high as 80 percent.

This makes using fuels of biogenic origin a possible strategy to mitigate natural gas supply risk while maintaining CO₂ objectives.

In addition, with green hydrogen supply chain development, hydrogen may also displace natural gas supply with the above-mentioned biogenic secondary fuels.

Flexibility has its advantages

Looking at the current market situation in Europe, with an eye toward the medium-term future, CHP flexibility continues to be a key driver to maintain production continuity, reduce production CO₂ intensity and optimize operating costs. That includes:

• Fuel flexibility for onsite heat and power generation capability, given natural gas and power availability concerns.
• Operational flexibility, specifically the ability to manage gas turbine or plant production load with a short response time to address specific electrical market demand (taking advantage of low day-ahead pricing, high balancing or high intraday pricing).

Smart digital solutions for CO₂ and cost optimization

The ideal solution is to maximize the use of an onsite gas turbine during high grid power price days (typically also when the grid is most GHG-intensive). Minimize gas turbine operations when variable renewable power is in excess and when price and CO₂ emissions are at their lowest. That enables the operation to benefit from the lowest CO₂ power in both situations. Smart digital solutions can help you achieve this goal – optimizing production, CHP operation and CO₂ emissions while considering variables like natural gas costs, green fuel input, power prices, onsite renewable power generation, stored energy and more. Solar Turbines’ products, capabilities and digital offerings allow you to capture the full spectrum of the cogeneration flexibility that will result in lower GHG intensity, reduced operating costs and greater production resiliency. Visit www.solarturbines.com for more information.