Controlling stored energy in a concentrating solar thermal power plant to maximise revenue

Abstract

New electricity generation technologies are often assessed using simple metrics such as average return, break-even energy prices or levelised cost of electricity. These simple metrics do not always capture the full economic value of a technology, particularly those that can react quickly and efficiently to changes in demand. In a wholesale spot market, opportunities exist to capture greater revenues, as currently achieved by peak power plants. This study demonstrates the use of two complementary methods to determine how storage should be operated to maximise revenue. First, the authors formulate and solve the problem as a linear program. The results indicate that there are distinct control modes. They then use Pontryagin's principle to confirm that the optimal operating strategy has three distinct control modes: (i) store all collected power, without generating, (ii) generate using collected power only and (iii) generate at maximum capacity using both collected and stored power. The mode that should be used at any instant depends only on the spot price of electricity relative to a pair of critical prices. These critical prices depend on the total energy that will be collected and the turnaround efficiency of the storage system.

Transient Analysis and Execution-Level Power Tracking Control of the Concentrating Solar Thermal Power Plant

“…To fill the generation gaps in intermittent solar energy, the CSP plant is generally integrated with thermal energy storage (TES), which enables the CSP plant to control its power output flexibly in the presence of solar uncertainty [3]. Actually, the TES enables the CSP plant to be partly independent from constantly changing solar radiation [4], reducing the short-term load variation and extending or shifting the power supply period [5]. Therefore, the CSP plant is potentially capable of supplying the power on demand, participating in electricity markets by scheduling the power production throughout each day [6], and providing ancillary services such as regulating the grid frequency [7].…”

AGC of dish‐Stirling solar thermal integrated thermal system with biogeography based optimised three degree of freedom PID controller

“…Wind energy conversion system in power system studies has been prevalent during last few decades [3, 7]. The modern solar energy technologies are available in recent literatures [9–15], but are restricted to stand‐alone system except few [16]. Das et al [9] applied dish‐Stirling solar thermal system (DSTS) for the analysis of AGC of stand‐alone hybrid system.…”

“…Gafurov et al [14] carried out power system reliability studies for concentrating solar power plants. Revenue collection maximisation by controlling the stored energy in a concentrating solar thermal power plant is explained in three different processes by Cirocco et al [15]. Sharma and Saikia in their paper [16] proposed AGC of interconnected system incorporating solar‐thermal system.…”

Optimal control of electrical and thermal energy storage to minimise time-of-use electricity costs

“…Previously we have considered the optimal control of a large concentrating solar thermal plant with storage, to maximise the income from exporting energy into the wholesale energy market with time-varying prices (Cirocco et al, 2015). In this paper we consider how a consumer can use both electrical energy storage systems and thermal energy storage systems to minimise the cost of energy from the grid when the price of electricity from the grid varies with time.…”