Optimizing Heating Systems: OR Questions for Renewable Energy Integration

Abigail Rose Lindner
Abigail Rose Lindner
Worcester Polytechnic Institute

It doesn’t take long for new acquaintances and friends to learn, among other facts, two points about me: First, I grew up in sunny Southern California; and, second, as a product, I suspect, of that upbringing, my tolerance for cold leaves something to be desired.

Now, having lived in Massachusetts for several years, I have developed a greater resistance to traditional winter conditions. Still, I continue to rely on the efficiency of the heating systems in my home and workplace to keep me unfrozen through the chillier months.

Why am I talking about heating systems in what is, at the time of this publication, summer? Why should we bother thinking about our furnaces, radiators, and wood-burning stoves when the temperature for many of us is climbing to the 90s and sweaters are being shoved to the backs of closets? For one, warmer weather months in spring and summer are, for obvious reasons, busier and more popular times for construction projects, and, eventually, the contractors of those projects will need to decide what heating system to put into the buildings.

Hence, questions of which are “best” are relevant even as the sun beats down on us. In addition, by the time winter rolls around again, this discussion may prove helpful to better understand the complex mechanisms involved in heating our spaces, if not change our residential or workplace heating conditions.

Types of Heating Systems

Before we dive into how to optimize the heating in the places where we live and work, we need to understand what heating options are available.

Every heating system has three basic parts: a heat source, a heat distribution system, and a control system (Department of Public Service, n.d.).

The differences between heating systems lie mainly in the first two components. For households, forced-air furnaces, boilers, and heat pumps are among the most common (Woods, 2024).

  • Forced-air furnaces burn a fuel source. This can be natural gas, propane, or oil to heat a metal exchanger. A fan then blows the heated air into the house via forced conduction through networks of ducts (Orentas and Allen, 2024).
  • Boilers use a fuel source — this can be natural gas, propane, oil, or electricity — to heat water or steam (“boil” it), which then travels through a network of laced piping to baseboards and/or radiators throughout the house.
  • Heat pumps take advantage of the thermodynamic property that heat moves from areas of high temperature to areas of low temperature. Using refrigerant and a small amount of energy, usually electricity, alongside heat exchangers, compressors, and fans, heat pumps reverse this process, using ambient air, heat from the ground, or a nearby water source to create heated air that can be transferred through the house (Woods, 2024).

Considerations in System Selection

Depending on where we are geographically and what we value in our heating, we may value one system over another based on their known mechanisms, advantages, and disadvantages. Among the most prominent considerations are cost, efficiency, and energy-consciousness.

Political, geographic, financial, and social considerations may come into play when choosing a heating system.

- Personal correspondence, Donald Seaborn, September 1, 2023

Costs, both upfront and long-term operational, and efficiency are obvious factors in the heating system and energy providers that a homeowner or landowner chooses. At the end of the day, bills need to be paid, and, in general, we would like the amount of money siphoned to our utilities to be low. Here, geography may come into play, with different fuel sources being more or less expensive relative to one another, depending on the history and location of one’s home.

Energy-consciousness is often seen as being at conflict with the cost and efficiency concerns of the energy consumer. Granted that the cost of renewable technologies has been falling for several years (International Renewable Energy Agency, 2021), and in some areas rivals the cost of fossil fuels like natural gas (Jansen, 2023), the energy density and convenience of fossil fuel makes it an enduring and dominant player in the worldwide energy game (Gross, 2020). Change is hard, and the feasibility of renewable energy goals is uncertain, being highly dependent on the economy, leadership, and the energy literacy of a populace (Garrett et al., 2024). Nevertheless, for the individual consumer, the environmental impact of heating and its energy sources could be an important factor in system selection.

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Electrical Transmission Tower

Potential for Improvement

Suppose I am a thrifty, energy-conscious consumer who would like to both save money on my heating system and reduce my carbon footprint. What role does operations research have in such a decision?

While many business applications of operations research directly apply the insights provided by its tools to, for instance, streamline a supply chain or modulate merchandise prices, the influence of operations research on our heating systems is more indirect.

We noted previously that the most common heating systems for residential buildings are forced-air furnaces, boilers, and heat pumps. These systems can be run using natural gas, propane, oil, or electricity; the fuel choice depends on availability and affordability. A prime advantage of fossil fuels is their easy access and low expense (Cefaratti-Bertin, 2024), and, while some consumers have the means and interest to supersede these economic concerns in favor of environmental ones, this is not the case in general.

With these limitations in mind, one area in which operations researchers could make a difference is in improving the access and affordability of renewable energy sources. This may help enable consumers to keep both utility costs and environmental impact low. Examples of applying operations research tools in this area include:

  • optimal allocation of wind turbines to minimize interference and position-related costs and to connect offshore turbines (Fischetti, 2021)
  • optimal management of renewable energy resources to provide continuity of energy delivery that rivals the current stability of fossil fuels (Thomaidis et al., 2016) and integration of renewable energy into existing energy grids (Dizikes, 2023)
  • implementation of a renewable energy system, with all necessary storage infrastructure, in remote areas, where the delivery of energy of any type has been challenging (Kuznia et al., 2013)
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Wind Turbine

Panning out from changes influencing individual consumer choices, much of the existing scholarship on selecting optimal heating system solutions focuses on district heating systems. These operate on a large region, such as a neighborhood or a city. While the majority across the world run using fossil fuels, they are thought to offer “great potential for efficient, cost-effective and flexible large-scale use of low-carbon energy for heating” using, for instance, solar thermal district heat, large-scale heat pumps, or geothermal district heat (Delmastro et al., 2023). In organizing these large-scale changes, operations research has also been active (Balić et al., 2017; Bordin et al., 2016; Friebe et al., 2023)

References

Balić, D., Maljković, D., Lončar, D., 2017. Multi-criteria analysis of district heating system operation strategy. Energy Conversion and Management 144, 414–428. URL: https://www.sciencedirect.com/science/article/pii/S0196890417303916, doi: https://doi.org/10.1016/j.enconman.2017.04.072.

Bordin, C., Gordini, A., Vigo, D., 2016. An optimization approach for district heating strategic network design. European Jour- nal of Operational Research 252, 296–307. URL: https://www.sciencedirect.com/science/article/pii/S0377221716000035, doi:https://doi.org/10.1016/j.ejor.2015.12.049.

Cefaratti-Bertin, S., 2024. Renewable energy goals are unattainable by 2050. URL: https://news.web.baylor.edu/news/story/ 2024/renewable-energy-goals-are-unattainable-2050.

Delmastro, C., Briens, F., Voswinkel, F., Monschauer, Y., Martinez-Gordon, R., Lynch, J., 2023. District heating. URL: https://www.forbes.com/home-improvement/hvac/home-heating-systems/.

Department of Public Service, n.d. Heating & cooling. URL: https://energysaver.vermont.gov/heating-cooling. Dizikes, P., 2023. Embracing the future we need. URL: https://news.mit.edu/2023/andy-sun-embracing-future-0811.

Fischetti, M., 2021. On the optimized design of next-generation wind farms. European Journal of Operational Research 291. URL: https://doi.org/10.1016/j.ejor.2020.10.048.

Friebe, M., Karasu, A., Kriegel, M., 2023. Methodology to compare and optimize district heating and decentralized heat supply for energy transformation on a municipality level. Energy 282, 128987. URL: https://www.sciencedirect.com/science/article/ pii/S0360544223023812,   doi:https://doi.org/10.1016/j.energy.2023.128987.

Garrett, K.P., McManamay, R.A., DeRolph, C.R., 2024. When energy doesn’t add up: use of an energyshed framework in assessing progress towards renewable energy transitions. Environmental Research: Infrastructure and Sustainability 4. URL: https://doi. org/10.1088/2634-4505/ad0fef.

Gross, S., 2020. Why are fossil fuels so hard to quit? URL: https://www.brookings.edu/articles/why-are-fossil-fuels-so-hard-to- quit/.

International Renewable Energy Agency, 2021. Renewable power generation costs in 2020. URL: https://www.irena.org/ publications/2021/Jun/Renewable-Power-Costs-in-2020.

Jansen, M., 2023. Renewables are cheaper than ever yet fossil fuel use is still growing – here’s why. URL: https://theconversation. com/renewables-are-cheaper-than-ever-yet-fossil-fuel-use-is-still-growing-heres-why-213428.

Kuznia, L., Zeng, B., Miao, Z., 2013. Stochastic optimization for power system configuration with renewable energy in remote areas. Annals of Operations Research 210, 411–432. URL: https://doi.org/10.1007/s10479-012-1110-9.

Orentas, G., Allen, S., 2024. 10 types of home heating systems to know. URL: https://www.forbes.com/home-improvement/ hvac/home-heating-systems/.

Thomaidis, N.S., Santos-Alamillos, F.J., Pozo-Vázquez, D., Usaolo-Garcí’a, J., 2016. Optimal management of wind and solar energy resources. Computers & Operations Research 66. URL: https://doi.org/10.1016/j.cor.2015.02.016.

Woods, B., 2024. Types of home heating systems (2024 guide). URL: https://www.thisoldhouse.com/heating-cooling/reviews/ types-of-heating-systems.

Acknowledgements: I would like to thank Donald Seaborn for providing expertise on different heating systems and Justin Dumouchelle for taking the time to review this article.

Photo credit: Header photo by Alex Perz at Unsplash. Electricity tower photo by Satya Nemala at Pexels. Wind turbine photo by Pixabay. Footer photo by Pixabay.