Money-saving tips to prepare for the gas price increase starting in October

We are pleased to announce that “enepi”, a propane gas company information and price comparison service operated by ZIGExN Co., Ltd. (Headquarters: Minato-ku, Tokyo, Representative Directors, Operating Officer, and CEO: Joe Hirao, Tokyo Stock Exchange Prime: 3679, hereinafter referred to as ZIGExN), has launched an information and price comparison service (https://enepi.jp/area_citygas)  of city gas companies starting in August.

Considering the recent trend of increasing utility costs, with the launch of the new service, we have conducted research on the gas bills associated with showers and baths. We are pleased to introduce a report that summarizes these findings along with energy-saving tips.

The summer of 2023 witnessed a record-breaking heatwave, putting a strain on utility costs. While temperatures have cooled down since October, there is still concern over gas prices. Due to soaring energy prices, the government has been implementing relief measures for businesses and households since January of this year. However, starting in October, these subsidies have been reduced by half, leading to an increase in gas costs.

With the launch of their city gas price comparison service, enepi conducted research to determine which option, having “shower only” or “bath only”, is more cost-effective in terms of gas bills. While most households have a combination of “bath and shower” rather than “bath only”, for the purpose of this study, Enepi deliberately separated these scenarios to better understand the associated costs and to offer effective cost-saving strategies. While the daily savings might seem small, the cumulative effect can significantly reduce the financial burden on households. We will be sharing a report that summarizes the survey results and provides tips for saving on gas bills.

■Up to a difference of approximately 2,000 yen per month! Comparing gas costs for showers and baths by gas type and household size.

Assuming a 10-minute shower, it’s generally estimated that around 10 liters of water are used per minute. We conducted research to determine the gas costs for a single shower with city gas and propane gas under the following conditions:

<City Gas = 37 yen per shower>
・Volume-based rate = 161 yen/m³ ^[1]
・Heat generation capacity = 10,750 kcal/m³ ^[2]
・Water volume 100L × (40°C – 20°C) ÷ (10,750 kcal × Thermal efficiency 80%) × Gas rate 161 yen ≒ 37 yen

<Propane Gas = 63 yen per shower>
・Volume-based rate = 600 yen/m³ ^[3]
・Heat generation capacity = 24,000 kcal/m³ ^[4]
・Water volume 100L × (40°C – 20°C) ÷　(24,000 kcal × Thermal efficiency 80%) × Gas rate 600 yen ≒ 63 yen

<Hot Water Supply = 63 yen per shower>

・Tap water = 20°C
・Hot water = 40°C
・Thermal efficiency = 80%
・Water volume 100L × (40°C – 20°C) ÷ (24,000 kcal × Thermal efficiency 80%) × Gas rate 600 yen ≒ 63 yen

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[1] Tokyo Gas: Tokyo Area, etc. / General Contract Fees / Meter Reading for September 2022
[2] Tokyo Gas: Gas Type, Heat Value, Pressure, Composition
[3] Data calculated independently by “enepi” based on the Japan Energy Economic Research Institute’s Oil Information Center (Tokyo)
[4] Ministry of Economy, Trade and Industry, Energy Agency: Standard Heat Value, Carbon Emission Coefficients (Comprehensive Energy Statistics)

Next will be the gas costs when taking a bath. We assume a bath filled with 200L of water, and the other conditions are the same as mentioned for the shower.

<City Gas = 75 yen per bath>

・Water volume 200L × (40°C – 20°C) ÷ (10,750 kcal × Thermal efficiency 80%) × Gas rate 161 yen ≒ 75 yen

<Propane Gas = 125 yen per bath>

・Water volume 200L × (40°C – 20°C) ÷ (24,000 kcal × Thermal efficiency 80%) × Gas rate 600 yen ≒ 125 yen

When comparing gas costs for showers and baths by gas type, the following results were obtained. Using a shower only is more cost-effective than heating water for a bath. In the case of city gas, this results in a monthly savings of 1,140 yen, while for propane gas, the savings amount to 1,860 yen.

However, there’s a catch when considering the “gas cost for a single use” aspect. Once you’ve heated the water for a bath, you won’t use any more gas. On the other hand, with showers, as the number of uses increases, so does the water consumption, leading to differences in gas costs and water bills depending on the number of people in the household. To address this, we calculated the utility costs for showers and baths, factoring in the water bills (0.16 yen per liter[5], assuming 100L for showers and 200L for baths) for households of varying sizes.

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[5] Bureau of Waterworks Tokyo Metropolitan Government

For individuals living alone, using a shower is more cost-effective, whereas, for a two-person household, there is little difference. However, in the case of a three-person household, heating water for a bath becomes more economical. Utility costs vary based on household size, and for households with three or more members, it becomes evident that showers can be more expensive than baths.

■Cost-saving tips for showers and baths! Switching to a different gas company will be more cost-effective

The key to saving on showers is to avoid leaving the water running and to stop it frequently. Assuming a 10-minute shower, with 10 minutes of hot water for “leaving it running” and 5 minutes for “stopping frequently”, you can save cost as below. For city gas, this results in a cost of approximately 26 yen per shower, which equates to about 780 yen in savings per month. or propane gas, the cost is around 39 yen per shower, resulting in approximately 1,170 yen in monthly savings.

To prevent “leaving the water running”, it’s recommended to use shower timers and water-saving showerheads. Shower timers help conserve water and energy by measuring the time spent in the shower. Water-saving showerheads reduce water usage while maintaining water pressure by adjusting the shower holes, mixing in air, or rotating internal blades. Even when using the shower as usual, these products can help you save on water and gas bills.

Next, we would like to introduce three tips for saving on your water heating bill when using the bath, especially for households with many members:

1. Limit Extra Heating: Avoid excessive reheating of your bathwater. For each 1°C increase in the bath’s temperature, it costs about 4 yen for city gas or 7 yen for propane gas. Over the course of a month, this can add up to an extra 100-200 yen in costs. Try to limit reheating as much as possible.
2. Use heat retention items: Hot water tends to lose heat over time. To combat this, use heat retention items for your bath, such as a bath cover or heat retention sheets that float on the water’s surface. These items help maintain the water’s temperature, and when you have a larger household, it’s essential to prevent heat loss to save on energy costs.
3. Lower Water Heating Temperature: Reducing your water heating temperature can have a significant impact on cost savings. As mentioned earlier, each 1°C increase in the bath temperature costs around 4 yen for city gas. Therefore, lowering the water heating temperature by 1°C can save you approximately 4 yen. Consider lowering the temperature by 2-3°C, especially on warmer days, to further reduce your energy costs.

Finally, regardless of whether it’s a shower or a bath, there is an option to change your gas company. Changing the gas company can significantly reduce household gas bills, not limited to bathing. Gas pricing plans vary from one gas company to another, and particularly for propane gas, there are often plans with significantly higher fees compared to the market average due to the lack of regulation on pricing.

“enepi” is a service that allows you to easily compare the pricing plans of gas companies in your residential area on the web. Starting this summer, we have expanded our services to include not only propane gas but also natural gas. We recommend comparing the market rates in your respective residential areas and considering a review of your gas bills.

For those using natural gas, please visit here: https://enepi.jp/area_citygas
For those using propane gas, please visit here: https://enepi.jp/area

We will continue to provide various energy-related information to assist in your daily life and aim for better matches between users and gas companies in the future.

■About enepi

“enepi” is a propane gas company information and price comparison service with its unique pricing comparison system. It allows users to easily search and compare gas prices, which can be challenging to understand due to market variations and differing rates based on location. In addtion, there are no costs involved, from requesting a quote to switching gas companies.     
Furthermore, the affiliated gas companies are carefully selected through a screening process, ensuring that only reputable gas companies are part of the network. When switching between old and new gas companies, “enepi” handles the coordination, providing users with peace of mind. In addition to its pricing simulation feature, “enepi” also serves as an information hub for all things related to propane gas, including fundamental knowledge and money-saving tips that can benefit your lifestyle. It’s a service that helps you find the most cost-effective gas company that suits your needs.

URL: https://enepi.jp/?pr=press