Optimizing Power-to-Heat Sector Coupling

Challenges faced in power-to-heat sector : In many scenarios within centralized power sectors, such as the waste of excess energy from data centers’ processor heat, high-temperature steam from thermal power plants, the waste stream of biofuels, heating of batteries, and other high energy density materials occurs.

Sector coupling is a holistic approach towards a carbon-neutral economy that helps one sector to benefit from another by sharing wasted or excess energy. It can also be called a sector integration or a multi-carrier energy system (MCES). The concept was first applied in Germany to explore the possibilities of using excess energy from renewable sources like solar and wind for other industries such as automobiles, manufacturing, and infrastructure projects. 

Sector coupling has evolved to encompass the increased flexibility that an energy system would need to manage the new grid stability concerns brought on by integrating significant shares of renewable energy. Sector coupling technologies, such as electric vehicles (EVs) with smart charging, electric boilers, heat pumps, and electrolyzers for hydrogen production, enable the demand to be more responsive to electricity prices or other signals in a physically interconnected network with the help of digitalized and smart systems.

Challenges in Sector coupling – Power-to-Heat

Governments and private agencies find sector coupling as a viable method to fulfill the Paris Agreement in which the participating countries have agreed to take ambitious steps to guarantee a low carbon future. Sector coupling can limit the worldwide temperature increase to less than 1.5 degrees Celsius (°C) compared to pre-industrial levels. However, sector coupling has to resolve the primary challenges to achieve such a mammoth goal.

Renewable energy sources like wind and solar are irregular and not always available. Any sector producing energy through these sources suffers from variability throughout the year due to daily and seasonal availability.Excess electricity is produced during peak summer when demand is low, and less electricity is produced during winter when demand is significantly high, especially for colder regions or European countries. However, energy storage is not the best economical alternative to utilize excess energy. It could be effective to convert this energy to make it available for various other industries through proper technological means.

Optimizing Renewable Energy Integration and Sector Coupling

Technologies such as district heating networks (DHN) integrate the excess renewable energy into thermal grids by using heat pumps (HPs), thermal energy storage (TES), combined heat and power (CHP) plants, electric boilers, and other systems. Each technology has its own merits and demerits.

Optimization of the challenges

Innovative energy systems can provide flexibility and security of supply by utilizing the produced energy in the best possible way. An intelligent system should contain the components of energy storage and power-to-heat by employing smart management algorithms. Several studies have shown that hybrid systems, such as heat pumps and CHPs in renewable production, are significantly better than individual technologies. Hybrid systems with smart management algorithms address issues such as excessive loads, sector-specific energy distribution, and fluctuating supply and demand.

Several scientists and engineers have developed smart management algorithms through mathematical and computational modeling and simulations. Most models use linear programming (LP) or mixed-integer linear programming (MILP). Researchers and developers use optimization tools to analyze power system flexibility, hybrid network interaction, economic performance, and more. Researchers have developed a few dynamic simulations to identify suitable operating conditions for economic power-to-heat conversion in a hybrid network. Some simulation results also suggest that thermal energy storage is more energy efficient than electrical storage when combined with heat pumps or CHPs. 

Reduced carbon footprint and improved safety

According to various optimization models, sector coupling could reduce greenhouse gas release by 60 % by 2050 in different sectors like automobiles, construction, etc., if implemented immediately. Instead of using fossil fuels, HPs or CHPs can utilize renewable energies. Since hydrogen is a clean fuel, coupling P2G industries with P2H industries can play a significant role in the future of sector coupling. With the flexibility of sector coupling, various low-carbon materials can be utilized as fuel. Better models for optimized performances can eventually help reach the net zero target and draw government subsidies in implementing such technologies.

Future of sector coupling

The global combined heat-to-power market may grow at a CAGR of 6.4 % from 2022 to 2029 to reach USD 23.83 billion. Early investments are already receiving an economic benefit over their contenders. The future of sector-coupling is highly dependent on renewable energy sources; however, thermal energy storage can also play a significant role. Studies and technological advancements can predict and realize the interaction between P2H, P2G, and P2X coupling. Moreover, modern artificial intelligence and machine learning developments can help improve economic growth optimization techniques. Systematic investment is required to build adequate infrastructures such as renewable energy production, transmission and distribution network, thermal energy storage, and other parts of the chain. Technological advances and computational prowess may soon make this sector a dominant player in the energy market.