Energy-saving effects demonstrated in field test at the ENEOS Sakai Refinery | SPACECOOL Inc.
Press releases

Energy-saving effects demonstrated in field test at the ENEOS Sakai Refinery

Press releases

Energy-saving effects demonstrated in field test at the ENEOS Sakai Refinery

SPACECOOL Inc. (President: Takayuki Hoshuyama, referred to as SPACECOOL) is pleased to announce that it has conducted a joint project utilizing SPACECOOL® (referred to as “this material”), a radiative cooling material developed by Osaka Gas with proprietary technology, with ENEOS Holdings, Inc. (President: Takeshi Saito, referred to as ENEOS Holdings) and ENEOS Corporation (President: Takeshi Saito, referred to as ENEOS) to conserve energy at the (air-conditioned) high-voltage power substation operating at the ENEOS Sakai Refinery, and has successfully demonstrated the energy-saving effects of this material in an operational environment.


A new demonstration aimed at carbon neutrality was conducted at the ENEOS Sakai Refinery using SPACECOOL’s technology. In light of the results of this demonstration, we anticipate that promoting the wide-range use of this material at ENEOS Group companies in Japan and overseas will contribute to reducing CO2 emissions in the petroleum industry and solving social issues such as heat waves, global warming, and energy depletion. SPACECOOL will accelerate further product development and application development to provide tangible solutions contributing to CO2 emission reduction and global warming mitigation.

Demonstration overview

After considering candidates in the Kanto and Kansai regions, we found that the Sakai Refinery’s facilities were suitable for measuring the material’s effectiveness. Additionally, to quantitatively determine the reduction in energy consumption for air-conditioning, we selected a facility installed outdoors, exposed to direct sunlight, and contained air-conditioning units inside as our demonstration subject.

Figure 1. High-voltage substation for demonstration


(Ref.) Internal equipment

– Vacuum circuit breakers 3.6kV 600A x 6 units

– Mold transformers 3Φ3.3kV/210V 100kVA x 1 unit

– Mold transformers 1Φ3.3kV/ 210-105V 100kVA x 1 unit

– DC power supply 2.6kVA x 1 unit, Storage battery MSE 50Ah@10 hour rate 54 cells (MSE-50-12 x 9 cells, DC108V/set)

– Air conditioner capacity 1Φ100V 615W×3

Installation details

SPACECOOL® was installed on five surfaces: the roof, the east, west, south, and north walls.

Figure 2. Appearance after film installation


Effectiveness of reducing power consumption was measured over the periods of July 22nd to August 31st before the installation and September 1st and thereafter after the installation. Results of monitoring air conditioning energy consumption with and without this material showed a reduction of approximately 21% on sunny days and approximately 20% during the entire period, including rainy and cloudy days. This announcement was made by ENEOS Holdings, Inc. at the Nagano Conference of the Japan Petroleum Institute (October 27th-28th, 2022).

Figure 3. Change in power consumption before and after film installation

About SPACECOOL, our radiative cooling material

SPACECOOL® can reduce temperature without using energy through radiative cooling technology, allowing heat to escape into space. Heat generated on Earth by sunlight is constantly being emitted into space, but some of it is absorbed by atmospheric carbon dioxide and water vapor and stays in our atmosphere, contributing to global warming. This material radiates infrared wavelengths that are not easily absorbed by carbon dioxide or water vapor, allowing the heat to escape into space without being trapped in the atmosphere.

Figure 4. Conceptual view of SPACECOOL®
Figure 5. Film (white, silver)
Figure 6. Membrane material (white, silver)

Company Overview

Company name SPACECOOL Inc.
Establishment April 1st, 2021
Address Toranomon, 1 Chome−17−1, Toranomon Hills Business Tower, 4F, 1 Chome Toranomon, Minato City, Tokyo JP
Representative Takayuki Hoshuyama
Business activities Manufacture and SPACECOOL, a radiative cooling material
Sales and consulting for energy-saving products and products for environmental improvement
Shareholders Osaka Gas Co., Ltd. (49%), WiL Ventures III, L.P. (29%), WiL Fund II, L.P. (22%)



Our new material creates comfortable cooling while avoiding over reliance on using energy like electricity.
Protect important things from heat and allow everyone spend their days comfortable and safe.