How Much Money Can You Save with S20-1000 Compared to S11 Transformers?

During power system retrofits or new project equipment selection, many customers face a difficult decision: higher-efficiency transformers come with a significantly higher price tag. Is the extra cost worth it?

 

Today, we take the 1000kVA capacity as an example to clearly calculate the cost difference between the S20 (new Grade 2 efficiency) and S11 (traditional efficiency) transformers, helping you make the most economical and rational choice.

 

 

Transformers are major energy consumers in power systems. Their own losses include no-load losses (core losses) and load losses (copper losses). Core losses depend mainly on core material and manufacturing process and are independent of load; copper losses vary with the square of the load current.

 

With the implementation of the national standard GB 20052-2020 "Energy Efficiency Limits and Energy Efficiency Grades of Power Transformers", high-efficiency transformers such as S20 and S22 are gradually replacing older S11 and S13 series. Although the initial purchase cost is higher, the electricity savings over the full lifecycle often far exceed the price difference.

 

 

Parameter	S20-1000 (New Grade 2 Efficiency)	S11-1000 (Traditional Efficiency)	Difference
No-load loss (core loss)	745 W	1150 W	-405 W
Load loss (copper loss at 75°C)	8240 W	10300 W	-2060 W
Efficiency grade	Grade 2	Grade 3 (or old standard)	-

 

 

Assumptions (typical industrial scenario):

• Annual operating hours: 8760 hours (continuous operation all year)
• Average load factor: 70% (adjustable based on actual conditions)
• Industrial electricity price: 0.7 RMB/kWh (mid-range; actual peak/valley average is about 0.7–0.8 RMB/kWh)

 

1. Annual energy savings from no-load loss

 

 

2. Annual energy savings from load loss

Load loss is proportional to the square of the load factor. In actual operation, S20 has 2060W less loss than S11 at rated load. At 70% load factor, the actual reduction in loss is:

Annual energy saving:

 

• 1.0094 kW×8760 h=8842.3 kWh

 

3. Total annual energy saving

 

• 3547.8+8842.3=12390.1 kWh

 

4. Annual electricity cost saving

 

• 12390 kWh×0.7 RMB/kWh=8673 RMB

 

If the electricity price is 0.8 RMB/kWh, the saving is about 9912 RMB.
A comprehensive range of 8,000–9,000 RMB/year is a safe and widely accepted conclusion.

 

 

Based on current market conditions (2025 reference):

Model	Price Range (RMB)	Average Price (RMB)
S20-1000	75,000 – 90,000	82,500
S11-1000	54,800 – 87,000	70,900

Note: S11-M-1000 prices vary significantly by manufacturer, material, and copper/aluminum construction; high-end copper-wound products may approach S20 prices. Here we take the average for common all-copper products.

 

Average price difference ≈ 82,500 – 70,900 = 11,600 RMB (about 12,000 RMB).

 

Payback period:

Based on different load factors, electricity prices, or considering cost of capital:
If annual saving is a conservative 8,000 RMB and the price difference is a higher 14,000 RMB, payback period = 14,000 / 8,000 = 1.75 years.
Even with a 15,000 RMB difference and 7,000 RMB annual saving, it takes only 2.1 years.
In fact, the efficiency improvement of S20 over S11 is so significant that payback is usually within 2 years. We recommend customers use the formulas above to calculate precisely based on their actual load factor and electricity price.

 

 

The design life of a transformer is typically 20–30 years. Even with a conservative payback period of 3 years, the remaining 17–27 years will save 8,000–9,000 RMB each year. Assuming 20 years of operation after payback, the additional electricity savings are:

• 8500×20=170,000 RMB

This does not even account for possible future electricity price increases. An initial extra investment of 12,000 RMB can yield a net return of over 150,000 RMB – no business should ignore such a return on investment.

 

 

Scenario	Recommended Model	Reason
Long annual operation (>6000h), high load factor (>50%), high electricity price (>0.7 RMB/kWh)	S20	Fast payback, significant long-term benefits
Seasonal operation, short annual operation (<2000h), light load	S11	Lower initial cost, limited electricity savings
Government energy-saving subsidies or green factory rating required	S20	Meets Grade 2 efficiency, eligible for subsidies
Strict requirements for noise and temperature rise	S20	Lower loss design typically results in lower temperature rise and noise

 

Based on the detailed calculations above, it can be concluded: For most industrial or commercial users with annual operating hours exceeding 4,000 hours and load factor greater than 50%, choosing the S20-1000 transformer instead of the S11 offers an initial purchase cost increase of about 12,000 RMB, but saves 8,000–9,000 RMB per year in electricity bills. The actual payback period is between 1.5 and 2.5 years. Thereafter, it provides pure profit for nearly 20 years, with total electricity savings exceeding 150,000 RMB.

 

Energy efficiency upgrades are a long-term investment with stable returns and extremely low risk.

 

Chinese Transformer Manufacturer – GNEE Customizes Energy-Saving Solutions for You

As a professional manufacturer with many years of experience in the transformer field, GNEE provides a full range of high-efficiency transformers including S20, S22, and S13. We not only calculate accurate energy-saving models for you, but also tailor winding design solutions one-to-one based on your load profile, power supply environment, and budget, ensuring the optimal balance between efficiency and cost.

👉 Need an energy-saving calculation sheet for your actual operating conditions?
👉 Want to inquire about real-time pricing and stock of S20-1000?

 

Contact the GNEE technical team today, and we will provide you for free with:

• Customized loss and payback calculation report
• Transformer selection comparison proposal
• On-site energy efficiency diagnosis service

Save on electricity bills – start by choosing the right transformer.

 

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