Agricultural demand response for decarbonizing the electricity grid

Abstract

1Historically, the focus of the agricultural industry has been increasing profit through maximizing crop yield. Costs for energy and water are small compared to equipment and personnel, and are thus often overlooked. However, energy costs for irrigation are increasing and could be exacerbated with declining water levels in many Western states. This trend has motivated many farmers to explore sustainable irrigation water and energy management practices. Much of this new focus has been directed towards the adoption of new agricultural technologies with a misplaced assumption that technology alone will inherently bring all the benefits. On one hand, farms are going through a paradigm shift, and are turning into net electricity generators, and on the other, higher penetration of intermittent renewable sources into the electricity grid, require dynamic loads to help the grid balance its intrahour variability and short duration ramps. The agricultural industry could be restructured to utilize larger amounts of renewable energy such as wind and solar and provide a great deal of flexibility to the grid. As emerging producers of clean energy, farmers are required to learn and speak the complex language of the electricity grid in order to monetize their energy generation while making the renewable electricity grid more resilient and reliable. In this paper, we develop a foundational approach for understanding and connecting three important concepts that can help the agricultural industry during this critical transition period. Those three concepts are: (a) current and future needs of the electricity grid, (b) available electricity market mechanisms through which farms can provide services to the grid, and (c) understanding electricity consuming/generating equipment on farms. Defining these concepts and condensing them into a standardized framework, can remove a significant barrier for enabling farms to provide services to the electricity grid while improving their bottom line.

Operational scheduling of responsive prosumer farms for day‐ahead peak shaving by agricultural demand response aggregators

“…18 In 2019, a prominent research study suggested the deregulation in the agricultural industry to facilitate the integration of renewable energies to electricity markets. 19 The study stated that farmers not only can provide a great deal of flexibility to the grid but also can monetize their energy generation. The study suggested the irrigation systems as potential demands to overcome the intermittency of renewable energies.…”

“…Inequality (17) limits the power generation of DGs to lower and upper thresholds. Finally, the constraints (18) and (19) show the ramp-up and ramp-down rates of the DG units, respectively.…”

Aggregate capacity for TCLs providing virtual energy storage with cycling constraints

“…However, this is not complete as some TCLs may be forced to switch due to the temperature constraint (1). The upper bound should then be increased by d on k −1 and decreased by d off k−1 .…”

“…The first is, s τ : which counts the total number of TCL switches normalized by the number of TCLs. The desired value of s τ is small, as a smaller number of total switches is preferred, but some amount of switching is required for providing VES and maintaining thermal comfort (1). The second metric is,…”

“…This is trivially satisfied for both constraints as γ off k + γ on k ≤ 1. To show that the constraint setΩ = N t −1 k Ω k is non-empty, we start with the baseline trajectory r k = 0, z k = 0 and show that this would allow for aψ k ∈ Ω k for all k. If r k is zero for all k then n on k = n on constant, which due to (45) implies that u on k−1 [1] = u off k−1 [1] for all k. Consequently, this implies that u on k −1 = u off k −1 =ū k−1 for all k and that γ on k = γ off k =γ k for all k. Since the inequality constraints are always feasible, then for all k and for alln on there exists an elementψ k = [0, 0,ū k ,ū k ,γ k ,γ k ] such thatψ k ∈ Ω k . Thus the set Ω is non empty.…”