Researchers have actually proposed a brand-new system that utilizes surplus PV energy in the spring and the fall to charge up underground thermal energy storage for later usage in the summertime and winter season. They have simulated it on a school center in Seoul, with a couple of optional setups for thermal storage. Power cost savings depended on 39%.
September 13, 2024 Lior Kahana
A global research study group has actually established an unique PV-powered heatpump system that utilizes surplus electrical power generation to charge up an underground thermal energy storage (UTES) center, which in turn improves the heatpump’s activity.
Based upon the simulation of 3 case research studies, the system had the ability to conserve as much as 14% of energy in power-to-heat (P2H) operations and as much as 39% for power-to-cool (P2C) operations.
“Solar photovoltaic setups have actually increased enormously, generating a massive surplus of electrical power generation, which has actually ended up being a problem needing alternative methods to be attended to,” stated the academics. “A balance in between generation and intake can be offered by leveraging P2H and P2C techniques to use surplus PV electrical power efficiently. One of the main concerns in its application consists of the absence of an advanced system setup with a functional technique paired with easy or complicated control approaches to achieve this balancing.”
The unique system was simulated in the TRNSYS 18 software application. Its primary functional technique is making use of surplus PV energy in the spring and fall, as heating & cooling are less required throughout those months. In the spring, the heatpump cools the UTES, later on supporting cooling the following summer season. In the fall, on the other hand, the heatpump charges the UTES with heating, later on supporting comfy temperature levels in the winter season.
The suggested system simulation was used to a public school structure in Seoul, South Korea. Its 2,500 m2 roofing system was covered with PV panels with 21% effectiveness to power an air-source water-load (ASWL) heatpump. It is presumed to have 160 kW heating and cooling capabilities with 40 kW and 50 kW power intake for cooling and heating, respectively. To transform the heat of the water to air that can be utilized in the heatpump, they likewise presumed a 4 kW heat exchanger with air and water circulation rates of 10,000 l/s and 300,000 kg/hr, respectively.
The base situation that was checked just utilized the PV-powered heatpump, while case 1 utilized a shallow UTES and case 2 released a deep UTES. The shallow setup consisted of 964 boreholes with a customized volume of 800 m3 and a depth of 1.5 m, and the deep UTES consists of 10 boreholes with a depth of 150 m and the very same volume of 800 m3.
“The school structure design was chosen for simpleness, and it includes 4 floorings, each with an overall external area of 1,312 m2 through which the thermal losses occur,” included the scientists. “The zone conditioning signal keeps the space temperature level in between 18 C and 22 C throughout the heating duration and in between 24 C and 28 C throughout the cooling duration.