[Survey of approximately 3,000 people] Solar power and storage battery estimates: 1 in 3 experience a price difference of 1 million yen or more
Goodfellows Inc., which operates the solar power and storage battery bulk estimate site 'Tainavi', announced the '2026 Survey on the Actual Situation of Residential Solar Power and Storage Battery Introduction Considerers'. The survey revealed that approximately 33.2% of users who obtained estimates from multiple companies experienced a price difference of 1 million yen or more. Additionally, 22.1% of users who requested estimates abandoned the introduction, with 'disagreement among family members' being a significant reason.
📋 Article Processing Timeline
- 📰 Published: April 15, 2026 at 19:00
- 🔍 Collected: April 15, 2026 at 10:31
- 🤖 AI Analyzed: April 16, 2026 at 01:33 (15h 1m after Collected)
Goodfellows Inc. (Headquarters: Shinagawa-ku, Tokyo), which operates "Tainavi," a bulk estimate site for residential solar power generation and storage batteries, analyzed an questionnaire survey (2,918 valid responses) conducted from January 2025 to December 2025 targeting users of "Tainavi" and "Tainavi Storage Battery," and announced the "2026 Survey on the Actual Situation of Residential Solar Power and Storage Battery Introduction Considerers."
In recent years, there has been a growing possibility of electricity price increases in Japan, against the backdrop of soaring fuel prices and a review of the government's electricity bill support system.
Due to these changes in the electricity cost environment, interest in solar power generation and storage batteries as a means of self-sufficiency in electricity at home is increasing.
This survey targeted users who considered introducing solar power generation and storage batteries, and analyzed the reasons for introduction, differences in estimated prices, and reasons for abandoning introduction.
The survey results revealed that approximately 33.2% (about 1 in 3) of users who obtained estimates from multiple companies (2 or more companies) experienced a "price difference of 1 million yen or more." In addition, 22.1% (about 1 in 5) of users who requested estimates abandoned the introduction, and "disagreement among family members" (22.1%) accounted for a large proportion of the reasons for abandonment.
Since solar power generation and storage batteries involve equipment investment on the scale of several million yen, the difficulty of decision-making within the family is considered to be one of the hurdles to introduction.
【Main Survey Results】
◆ Estimate difference of "1 million yen or more": Approximately 33.2%
◆ Users prompted by door-to-door sales: 42.8% experienced a price difference of 1 million yen or more
◆ No. 1 reason for considering introduction: Measures against soaring electricity prices (77.2%)
◆ Abandonment rate: 22.1% (about 1 in 5 people)
◆ No. 2 reason for abandonment: Disagreement among family members (22.0%)
◆ Comparison with other sites: Approximately 75.0% responded that "Tainavi is cheaper"
＜Survey Outline＞
Target: Residential solar power generation and storage battery introduction considerers (2025 Tainavi and Tainavi Storage Battery users)
Survey period: January 2025 - December 2025
Valid responses: 2,918
Survey method: Internet questionnaire
■Reasons for considering introduction ranking
The reasons for considering the introduction of solar power generation and storage batteries were surveyed, and the following results were obtained.
*Multiple answers allowed
1st place: Measures against soaring electricity prices (77.2%)
2nd place: Measures against disasters and power outages (43.2%)
3rd place: Received sales pitch from door-to-door sales (15.7%)
4th place: Part of SDGs initiatives (10.5%)
5th place: Income from selling electricity (8.2%)
It can be seen that against the backdrop of rising electricity prices, an increasing number of users are considering solar power generation and storage batteries as a measure against household electricity costs.
■Actual situation of estimated price differences
Among users who obtained estimates from multiple companies (n=2162), when the difference between the "highest price" and "lowest price" was surveyed, 33.2% (about 1 in 3) of users responded that there was a price difference of 1 million yen or more.
・Price difference of 700,000 yen or more: Approximately 47.0%
・Price difference of 400,000 yen or more: Approximately 71.5%
It became clear that there is a large price difference among retailers in the residential solar power and storage battery market.
Furthermore, when analyzing users who responded that they "received a sales pitch from door-to-door sales" and obtained estimates from two or more companies (n=397),
・Price difference of 1 million yen or more: Approximately 42.8%
・Price difference of 700,000 yen or more: Approximately 60.5%
・Price difference of 400,000 yen or more: Approximately 80.9%
The results showed a higher percentage than the overall average.
Users who started considering introduction due to door-to-door sales tended to recognize larger price differences by comparing multiple companies. It is thought that the increase in combined introduction of solar power generation and storage batteries has led to higher equipment prices, and differences in proposals and pricing among retailers are appearing as price differences.
■Approximately 75% say "Tainavi is cheaper" when comparing with other sites
When users who used other estimate sites (n=907) were surveyed for price comparison, approximately 75% responded that "Tainavi was cheaper."
Utilizing multiple estimate services suggests the possibility of comparing equipment prices and proposal contents to grasp a more appropriate price.
■Reasons for abandoning introduction ranking
It was found that 22.1% of users who requested estimates abandoned the introduction.
When the reasons of users who abandoned (n=644) were analyzed, the following results were obtained.
1st place: Cost feeling did not match (44.3%)
2nd place: Disagreement among family members (22.0%)
3rd place: Told by retailer that it was unnecessary or impossible to install (3.1%)
While "cost feeling did not match" accounted for approximately 40%, "disagreement among family members" also exceeded 20%.
Solar power generation and storage batteries are often residential equipment that requires the agreement of the entire family, and it can be seen that decision-making within the family affects the feasibility of introduction.
■Representative's Comment
Goodfellows Inc.
Vice President | Solar Power Expert
Junji Saeki
"Against the backdrop of rising electricity prices and increasing disaster awareness, the number of people considering the introduction of solar power generation and storage batteries is increasing year by year. On the other hand, because equipment prices are high, price differences among retailers are also large. The reality of price differences of 1 million yen or more revealed in this survey indicates the importance of price transparency through comparison of multiple companies. Because solar power generation and storage batteries are equipment used for a long time, we believe it is important to make a satisfactory choice while comparing multiple proposals."
◆ About "Tainavi," a bulk estimate site for residential solar power generation
"Tainavi" is a bulk estimate comparison site for those considering the introduction of residential solar power generation (+ storage batteries). You can obtain estimates from up to 5 retailers and consider them while comparing prices, proposal contents, and warranty conditions.
Tainavi: https://www.tainavi.com/
◆ About Goodfellows Inc.
Goodfellows Inc. aims to be "Japan's leading energy company" by developing energy media business, power generation development business, merchandise sales business, and more.
It specializes in solar power generation, storage batteries, and renewable energy fields, and widely develops businesses ranging from information provision to equipment introduction support, power plant buying and selling, and M&A support.
Company name: Goodfellows Inc.
Location: DK Gotanda Building 8F, 7-13-5 Nishi-Gotanda, Shinagawa-ku, Tokyo 141-0031
Representative: Representative Director Yasuhiro Nagao
Business activities: Energy media business, power generation development business, merchandise sales business, power generation business, M&A business, etc.
URL: https://www.goodfellows.co.jp/
◆ Main services of Goodfellows
・Residential solar power generation bulk estimate site "Tainavi": https://www.tainavi.com/
・Storage battery bulk estimate site "Tainavi Storage Battery": https://www.tainavi-battery.com/
・Industrial solar power generation bulk estimate site "Tainavi NEXT": https://www.tainavi-next.com/
・Investment property buying and selling site for solar power generation and grid-connected storage batteries "Tainavi Power Plant": https://www.tainavi-pp.com/
・Bulk estimate comparison site for corporate electricity rates "Switch Biz": https://www.tainavi-biz.com/
・M&A service for the energy industry "Tainavi M&A": https://www.tainavi-pp.com/ma/lp/lp01/
・Wholesale sales of creative energy (solar power, storage battery) equipment: https://tainavi-pp.com/procurement/
・Land buying and selling for solar power generation and sales/brokerage of new and used solar power plants
【Notes on reproduction and citation】
The copyright of this report is held by Goodfellows Inc. These survey results can be widely utilized.
When reproducing or citing, please clearly state "According to a survey by Goodfellows Inc." as the source.
*When citing these survey results on a web medium, please clearly state "According to a survey by Goodfellows Inc." as the source and include a link to "Tainavi (https://www.tainavi.com/)."
In recent years, there has been a growing possibility of electricity price increases in Japan, against the backdrop of soaring fuel prices and a review of the government's electricity bill support system.
Due to these changes in the electricity cost environment, interest in solar power generation and storage batteries as a means of self-sufficiency in electricity at home is increasing.
This survey targeted users who considered introducing solar power generation and storage batteries, and analyzed the reasons for introduction, differences in estimated prices, and reasons for abandoning introduction.
The survey results revealed that approximately 33.2% (about 1 in 3) of users who obtained estimates from multiple companies (2 or more companies) experienced a "price difference of 1 million yen or more." In addition, 22.1% (about 1 in 5) of users who requested estimates abandoned the introduction, and "disagreement among family members" (22.1%) accounted for a large proportion of the reasons for abandonment.
Since solar power generation and storage batteries involve equipment investment on the scale of several million yen, the difficulty of decision-making within the family is considered to be one of the hurdles to introduction.
【Main Survey Results】
◆ Estimate difference of "1 million yen or more": Approximately 33.2%
◆ Users prompted by door-to-door sales: 42.8% experienced a price difference of 1 million yen or more
◆ No. 1 reason for considering introduction: Measures against soaring electricity prices (77.2%)
◆ Abandonment rate: 22.1% (about 1 in 5 people)
◆ No. 2 reason for abandonment: Disagreement among family members (22.0%)
◆ Comparison with other sites: Approximately 75.0% responded that "Tainavi is cheaper"
＜Survey Outline＞
Target: Residential solar power generation and storage battery introduction considerers (2025 Tainavi and Tainavi Storage Battery users)
Survey period: January 2025 - December 2025
Valid responses: 2,918
Survey method: Internet questionnaire
■Reasons for considering introduction ranking
The reasons for considering the introduction of solar power generation and storage batteries were surveyed, and the following results were obtained.
*Multiple answers allowed
1st place: Measures against soaring electricity prices (77.2%)
2nd place: Measures against disasters and power outages (43.2%)
3rd place: Received sales pitch from door-to-door sales (15.7%)
4th place: Part of SDGs initiatives (10.5%)
5th place: Income from selling electricity (8.2%)
It can be seen that against the backdrop of rising electricity prices, an increasing number of users are considering solar power generation and storage batteries as a measure against household electricity costs.
■Actual situation of estimated price differences
Among users who obtained estimates from multiple companies (n=2162), when the difference between the "highest price" and "lowest price" was surveyed, 33.2% (about 1 in 3) of users responded that there was a price difference of 1 million yen or more.
・Price difference of 700,000 yen or more: Approximately 47.0%
・Price difference of 400,000 yen or more: Approximately 71.5%
It became clear that there is a large price difference among retailers in the residential solar power and storage battery market.
Furthermore, when analyzing users who responded that they "received a sales pitch from door-to-door sales" and obtained estimates from two or more companies (n=397),
・Price difference of 1 million yen or more: Approximately 42.8%
・Price difference of 700,000 yen or more: Approximately 60.5%
・Price difference of 400,000 yen or more: Approximately 80.9%
The results showed a higher percentage than the overall average.
Users who started considering introduction due to door-to-door sales tended to recognize larger price differences by comparing multiple companies. It is thought that the increase in combined introduction of solar power generation and storage batteries has led to higher equipment prices, and differences in proposals and pricing among retailers are appearing as price differences.
■Approximately 75% say "Tainavi is cheaper" when comparing with other sites
When users who used other estimate sites (n=907) were surveyed for price comparison, approximately 75% responded that "Tainavi was cheaper."
Utilizing multiple estimate services suggests the possibility of comparing equipment prices and proposal contents to grasp a more appropriate price.
■Reasons for abandoning introduction ranking
It was found that 22.1% of users who requested estimates abandoned the introduction.
When the reasons of users who abandoned (n=644) were analyzed, the following results were obtained.
1st place: Cost feeling did not match (44.3%)
2nd place: Disagreement among family members (22.0%)
3rd place: Told by retailer that it was unnecessary or impossible to install (3.1%)
While "cost feeling did not match" accounted for approximately 40%, "disagreement among family members" also exceeded 20%.
Solar power generation and storage batteries are often residential equipment that requires the agreement of the entire family, and it can be seen that decision-making within the family affects the feasibility of introduction.
■Representative's Comment
Goodfellows Inc.
Vice President | Solar Power Expert
Junji Saeki
"Against the backdrop of rising electricity prices and increasing disaster awareness, the number of people considering the introduction of solar power generation and storage batteries is increasing year by year. On the other hand, because equipment prices are high, price differences among retailers are also large. The reality of price differences of 1 million yen or more revealed in this survey indicates the importance of price transparency through comparison of multiple companies. Because solar power generation and storage batteries are equipment used for a long time, we believe it is important to make a satisfactory choice while comparing multiple proposals."
◆ About "Tainavi," a bulk estimate site for residential solar power generation
"Tainavi" is a bulk estimate comparison site for those considering the introduction of residential solar power generation (+ storage batteries). You can obtain estimates from up to 5 retailers and consider them while comparing prices, proposal contents, and warranty conditions.
Tainavi: https://www.tainavi.com/
◆ About Goodfellows Inc.
Goodfellows Inc. aims to be "Japan's leading energy company" by developing energy media business, power generation development business, merchandise sales business, and more.
It specializes in solar power generation, storage batteries, and renewable energy fields, and widely develops businesses ranging from information provision to equipment introduction support, power plant buying and selling, and M&A support.
Company name: Goodfellows Inc.
Location: DK Gotanda Building 8F, 7-13-5 Nishi-Gotanda, Shinagawa-ku, Tokyo 141-0031
Representative: Representative Director Yasuhiro Nagao
Business activities: Energy media business, power generation development business, merchandise sales business, power generation business, M&A business, etc.
URL: https://www.goodfellows.co.jp/
◆ Main services of Goodfellows
・Residential solar power generation bulk estimate site "Tainavi": https://www.tainavi.com/
・Storage battery bulk estimate site "Tainavi Storage Battery": https://www.tainavi-battery.com/
・Industrial solar power generation bulk estimate site "Tainavi NEXT": https://www.tainavi-next.com/
・Investment property buying and selling site for solar power generation and grid-connected storage batteries "Tainavi Power Plant": https://www.tainavi-pp.com/
・Bulk estimate comparison site for corporate electricity rates "Switch Biz": https://www.tainavi-biz.com/
・M&A service for the energy industry "Tainavi M&A": https://www.tainavi-pp.com/ma/lp/lp01/
・Wholesale sales of creative energy (solar power, storage battery) equipment: https://tainavi-pp.com/procurement/
・Land buying and selling for solar power generation and sales/brokerage of new and used solar power plants
【Notes on reproduction and citation】
The copyright of this report is held by Goodfellows Inc. These survey results can be widely utilized.
When reproducing or citing, please clearly state "According to a survey by Goodfellows Inc." as the source.
*When citing these survey results on a web medium, please clearly state "According to a survey by Goodfellows Inc." as the source and include a link to "Tainavi (https://www.tainavi.com/)."