But, is solar worth it?

Yes. Since installing solar I've saved ¥106,929 in electricity costs.

Here's a breakdown for each billing period since my installation.

Sep 15 ~ Oct 14

I consumed 255.04kWh and generated 164.74kWh.

This would have cost me ¥8,691 without solar.

My actual cost was ¥3,212.

I saved ¥5,479 with generation and earned ¥382 for a total savings of ¥5,861
Date Generation Consumption Bought Sold
2023/09/15 8.70 17.60 9.60 0.70
2023/09/16 11.64 18.64 7.80 0.80
2023/09/17 13.35 31.45 20.20 2.10
2023/09/18 16.01 22.81 8.70 1.90
2023/09/19 16.06 26.76 11.70 1.00
2023/09/20 9.69 14.29 7.60 0.40
2023/09/21 3.04 14.44 11.40 0.00
2023/09/22 5.81 11.41 6.10 0.50
2023/09/23 2.09 9.09 7.10 0.10
2023/09/24 11.75 11.35 3.40 3.80
2023/09/25 12.97 11.57 1.60 3.00
2023/09/26 13.58 12.58 1.80 2.80
2023/09/27 10.71 13.01 3.30 1.00
2023/09/28 14.47 15.47 4.10 3.10
2023/09/29 8.94 12.94 4.90 0.90
2023/09/30 5.92 11.22 6.60 0.40
2023/10/01 0.00 0.40 0.40 0.00
2023/10/02 0.00 0.00 0.00 0.00
2023/10/03 0.00 0.00 0.00 0.00
2023/10/04 0.00 0.00 0.00 0.00
2023/10/05 0.00 0.00 0.00 0.00
2023/10/06 0.00 0.00 0.00 0.00
2023/10/07 0.00 0.00 0.00 0.00
2023/10/08 0.00 0.00 0.00 0.00
2023/10/09 0.00 0.00 0.00 0.00
2023/10/10 0.00 0.00 0.00 0.00
2023/10/11 0.00 0.00 0.00 0.00
2023/10/12 0.00 0.00 0.00 0.00
2023/10/13 0.00 0.00 0.00 0.00
2023/10/14 0.00 0.00 0.00 0.00

Aug 15 ~ Sep 14

I consumed 572.21kWh and generated 372.81kWh.

This would have cost me ¥18,377 without solar.

My actual cost was ¥8,523.

I saved ¥9,854 with generation and earned ¥586 for a total savings of ¥10,441
Date Generation Consumption Bought Sold
2023/08/15 9.50 22.70 13.40 0.20
2023/08/16 9.12 16.72 8.30 0.70
2023/08/17 16.23 21.13 7.50 2.60
2023/08/18 15.90 16.70 3.80 3.00
2023/08/19 13.15 17.95 5.70 0.90
2023/08/20 12.11 20.81 9.20 0.50
2023/08/21 12.72 22.22 10.10 0.60
2023/08/22 9.81 21.81 12.30 0.30
2023/08/23 13.56 21.86 9.00 0.70
2023/08/24 13.44 20.24 7.50 0.70
2023/08/25 15.60 16.60 4.00 3.00
2023/08/26 8.76 18.26 10.00 0.50
2023/08/27 9.94 15.94 6.70 0.70
2023/08/28 12.07 19.07 7.60 0.60
2023/08/29 16.38 20.68 5.20 0.90
2023/08/30 14.69 22.99 8.90 0.60
2023/08/31 15.61 19.51 4.80 0.90
2023/09/01 16.68 15.58 3.60 4.70
2023/09/02 14.68 23.28 9.60 1.00
2023/09/03 13.01 17.41 5.30 0.90
2023/09/04 6.16 14.96 9.20 0.40
2023/09/05 16.51 20.11 5.20 1.60
2023/09/06 8.59 21.79 14.10 0.90
2023/09/07 5.34 14.54 9.70 0.50
2023/09/08 2.05 12.25 10.60 0.40
2023/09/09 5.55 7.85 2.90 0.60
2023/09/10 14.07 20.77 7.70 1.00
2023/09/11 9.98 15.78 6.40 0.60
2023/09/12 10.04 17.94 8.40 0.50
2023/09/13 15.57 16.17 3.60 3.00
2023/09/14 16.02 18.62 3.60 1.00

Jul 15 ~ Aug 14

I consumed 564.65kWh and generated 427.55kWh.

This would have cost me ¥18,106 without solar.

My actual cost was ¥8,142.

I saved ¥9,963 with generation and earned ¥829 for a total savings of ¥10,793
Date Generation Consumption Bought Sold
2023/07/15 9.90 14.00 5.20 1.10
2023/07/16 16.11 21.61 6.50 1.00
2023/07/17 15.80 18.30 5.30 2.80
2023/07/18 14.57 22.27 8.60 0.90
2023/07/19 14.56 16.86 4.00 1.70
2023/07/20 11.05 19.25 8.80 0.60
2023/07/21 10.13 11.93 2.90 1.10
2023/07/22 11.87 16.57 5.50 0.80
2023/07/23 16.16 14.36 2.30 4.10
2023/07/24 16.73 17.43 3.00 2.30
2023/07/25 16.28 20.38 5.20 1.10
2023/07/26 15.77 22.07 7.20 0.90
2023/07/27 15.99 19.89 4.90 1.00
2023/07/28 16.04 16.14 3.40 3.30
2023/07/29 16.68 18.88 4.70 2.50
2023/07/30 16.68 18.08 3.30 1.90
2023/07/31 15.61 20.51 5.80 0.90
2023/08/01 7.35 16.55 9.70 0.50
2023/08/02 16.72 19.12 4.50 2.10
2023/08/03 16.77 18.17 4.90 3.50
2023/08/04 16.16 15.46 3.70 4.40
2023/08/05 16.66 19.46 4.60 1.80
2023/08/06 11.11 14.71 4.40 0.80
2023/08/07 15.17 14.97 3.40 3.60
2023/08/08 12.57 18.77 7.10 0.90
2023/08/09 8.61 21.81 13.50 0.30
2023/08/10 13.69 20.79 7.80 0.70
2023/08/11 9.98 16.18 6.80 0.60
2023/08/12 13.96 19.96 6.80 0.80
2023/08/13 7.06 17.66 10.90 0.30
2023/08/14 11.80 22.50 11.20 0.50

Jun 15 ~ Jul 14

I consumed 428.28kWh and generated 339.18kWh.

This would have cost me ¥13,426 without solar.

My actual cost was ¥7,739.

I saved ¥5,687 with generation and earned ¥782 for a total savings of ¥6,469
Date Generation Consumption Bought Sold
2023/06/15 4.98 10.68 6.30 0.60
2023/06/16 14.04 13.14 2.00 2.90
2023/06/17 17.02 13.02 0.90 4.90
2023/06/18 12.12 11.72 1.10 1.50
2023/06/19 10.51 11.21 1.90 1.20
2023/06/20 9.81 10.71 2.10 1.20
2023/06/21 10.94 11.14 1.80 1.60
2023/06/22 5.13 9.33 5.00 0.80
2023/06/23 8.44 10.44 3.20 1.20
2023/06/24 9.74 11.04 2.50 1.20
2023/06/25 12.71 13.41 2.40 1.70
2023/06/26 12.18 13.98 3.00 1.20
2023/06/27 9.33 14.53 6.00 0.80
2023/06/28 14.46 17.96 4.60 1.10
2023/06/29 15.58 16.98 4.40 3.00
2023/06/30 7.59 15.99 8.90 0.50
2023/07/01 4.96 12.26 7.70 0.40
2023/07/02 16.45 13.55 2.50 5.40
2023/07/03 13.71 15.91 3.40 1.20
2023/07/04 12.42 13.32 2.60 1.70
2023/07/05 8.87 13.87 5.80 0.80
2023/07/06 15.07 13.17 2.60 4.50
2023/07/07 14.50 17.80 4.30 1.00
2023/07/08 7.70 12.60 5.80 0.90
2023/07/09 8.20 16.00 8.50 0.70
2023/07/10 16.33 19.83 4.60 1.10
2023/07/11 16.06 22.36 7.30 1.00
2023/07/12 16.30 22.60 7.20 0.90
2023/07/13 4.42 15.52 11.30 0.20
2023/07/14 9.63 14.23 5.40 0.80

May 15 ~ Jun 14

I consumed 287.29kWh and generated 314.30kWh.

This would have cost me ¥9,141 without solar.

My actual cost was ¥2,308.

I saved ¥6,831 with generation and earned ¥1,846 for a total savings of ¥8,677
Date Generation Consumption Bought Sold
2023/05/15 6.84 8.84 3.00 1.00
2023/05/16 17.63 12.13 2.90 8.40
2023/05/17 17.21 9.21 0.80 8.80
2023/05/18 16.96 9.46 0.70 8.20
2023/05/19 6.04 6.94 1.60 0.70
2023/05/20 6.54 7.04 1.70 1.20
2023/05/21 13.39 10.29 1.80 4.90
2023/05/22 13.63 11.23 1.10 3.50
2023/05/23 2.47 5.97 3.60 0.10
2023/05/24 17.64 12.04 1.90 7.50
2023/05/25 12.29 9.29 0.80 3.80
2023/05/26 12.83 8.43 0.60 5.00
2023/05/27 16.98 8.78 0.70 8.90
2023/05/28 14.28 8.18 0.80 6.90
2023/05/29 2.08 8.78 6.70 0.00
2023/05/30 8.37 9.87 2.40 0.90
2023/05/31 4.36 7.36 3.70 0.70
2023/06/01 13.27 10.97 1.60 3.90
2023/06/02 1.94 11.64 9.70 0.00
2023/06/03 10.42 5.42 2.20 7.20
2023/06/04 15.18 8.48 0.60 7.30
2023/06/05 13.63 10.63 0.80 3.80
2023/06/06 6.43 7.63 2.30 1.10
2023/06/07 14.91 10.91 1.70 5.70
2023/06/08 11.93 9.53 0.90 3.30
2023/06/09 2.92 6.32 4.00 0.60
2023/06/10 6.98 9.58 3.80 1.20
2023/06/11 4.59 8.19 4.50 0.90
2023/06/12 3.07 8.87 6.20 0.40
2023/06/13 12.09 12.89 2.90 2.10
2023/06/14 7.40 12.40 5.60 0.60

Apr 15 ~ May 14

I consumed 277.87kWh and generated 362.67kWh.

This would have cost me ¥10,184 without solar.

My actual cost was ¥1,969.

I saved ¥8,214 with generation and earned ¥2,476 for a total savings of ¥10,691
Date Generation Consumption Bought Sold
2023/04/15 1.88 3.18 1.50 0.20
2023/04/16 15.48 12.78 3.00 5.70
2023/04/17 12.45 10.75 1.10 2.80
2023/04/18 13.83 10.53 1.40 4.70
2023/04/19 13.21 10.31 1.70 4.60
2023/04/20 16.96 10.26 0.60 7.30
2023/04/21 15.47 8.77 0.50 7.20
2023/04/22 3.17 5.57 2.70 0.30
2023/04/23 10.87 10.37 2.20 2.70
2023/04/24 8.61 8.81 1.50 1.30
2023/04/25 8.76 9.86 2.10 1.00
2023/04/26 3.40 10.80 7.70 0.30
2023/04/27 18.43 12.43 2.70 8.70
2023/04/28 17.68 8.58 0.40 9.50
2023/04/29 16.18 9.28 0.90 7.80
2023/04/30 3.51 8.51 5.20 0.20
2023/05/01 13.24 11.44 2.70 4.50
2023/05/02 18.13 9.43 0.90 9.60
2023/05/03 17.71 9.61 0.80 8.90
2023/05/04 17.89 9.89 0.50 8.50
2023/05/05 18.06 9.76 0.90 9.20
2023/05/06 15.35 9.25 0.60 6.70
2023/05/07 2.19 6.09 4.20 0.30
2023/05/08 6.23 10.83 7.80 3.20
2023/05/09 18.45 11.75 1.40 8.10
2023/05/10 17.74 9.74 1.00 9.00
2023/05/11 13.35 10.65 1.70 4.40
2023/05/12 15.34 8.84 0.60 7.10
2023/05/13 3.66 3.66 0.80 0.80
2023/05/14 5.44 6.14 1.80 1.10

Mar 15 ~ Apr 14

I consumed 332.55kWh and generated 359.25kWh.

This would have cost me ¥12,042 without solar.

My actual cost was ¥3,194.

I saved ¥8,847 with generation and earned ¥2,081 for a total savings of ¥10,928
Date Generation Consumption Bought Sold
2023/03/15 16.12 10.22 1.70 7.60
2023/03/16 16.91 11.61 2.30 7.60
2023/03/17 6.29 10.39 4.80 0.70
2023/03/18 1.95 13.25 11.30 0.00
2023/03/19 17.67 14.07 4.60 8.20
2023/03/20 17.98 12.68 2.50 7.80
2023/03/21 6.49 9.89 4.20 0.80
2023/03/22 15.37 12.47 2.30 5.20
2023/03/23 2.49 7.09 4.80 0.20
2023/03/24 8.82 10.32 2.40 0.90
2023/03/25 2.30 6.70 4.70 0.30
2023/03/26 1.71 9.71 8.00 0.00
2023/03/27 8.64 11.24 3.70 1.10
2023/03/28 7.24 10.94 4.50 0.80
2023/03/29 12.80 12.40 2.90 3.30
2023/03/30 13.03 12.53 3.70 4.20
2023/03/31 8.11 7.71 1.00 1.40
2023/04/01 17.02 10.42 1.60 8.20
2023/04/02 7.95 8.75 2.00 1.20
2023/04/03 15.65 13.05 3.10 5.70
2023/04/04 17.23 13.23 2.10 6.10
2023/04/05 13.88 10.18 1.90 5.60
2023/04/06 12.83 9.43 0.90 4.30
2023/04/07 4.37 7.67 3.80 0.50
2023/04/08 9.08 10.78 2.80 1.10
2023/04/09 18.40 12.30 1.50 7.60
2023/04/10 18.65 11.65 1.60 8.60
2023/04/11 17.47 10.67 1.30 8.10
2023/04/12 13.67 9.97 1.30 5.00
2023/04/13 16.53 12.53 1.60 5.60
2023/04/14 12.63 8.73 0.80 4.70

Feb 15 ~ Mar 14

I consumed 322.37kWh and generated 354.87kWh.

This would have cost me ¥12,102 without solar.

My actual cost was ¥3,499.

I saved ¥8,603 with generation and earned ¥2,261 for a total savings of ¥10,864
Date Generation Consumption Bought Sold
2023/02/15 6.97 7.97 2.30 1.30
2023/02/16 16.61 8.31 0.80 9.10
2023/02/17 15.63 6.23 0.70 10.10
2023/02/18 15.30 6.40 0.70 9.60
2023/02/19 4.39 12.79 8.70 0.30
2023/02/20 15.31 13.31 3.80 5.80
2023/02/21 16.97 14.27 4.40 7.10
2023/02/22 16.54 16.44 6.50 6.60
2023/02/23 8.55 14.45 6.90 1.00
2023/02/24 3.62 12.32 9.10 0.40
2023/02/25 11.54 12.64 3.70 2.60
2023/02/26 17.09 14.79 5.20 7.50
2023/02/27 16.74 13.54 4.50 7.70
2023/02/28 17.10 15.70 3.90 5.30
2023/03/01 9.28 11.68 3.40 1.00
2023/03/02 11.01 10.21 3.10 3.90
2023/03/03 13.01 14.01 3.80 2.80
2023/03/04 15.55 11.25 1.40 5.70
2023/03/05 5.72 8.12 3.10 0.70
2023/03/06 11.68 12.58 3.80 2.90
2023/03/07 16.24 13.34 3.50 6.40
2023/03/08 16.39 12.39 2.50 6.50
2023/03/09 14.30 10.50 1.50 5.30
2023/03/10 15.72 10.22 2.30 7.80
2023/03/11 16.13 9.63 0.80 7.30
2023/03/12 10.07 7.77 0.80 3.10
2023/03/13 3.99 8.69 5.20 0.50
2023/03/14 13.45 12.85 4.10 4.70

Jan 15 ~ Feb 14

I consumed 389.96kWh and generated 266.96kWh.

This would have cost me ¥15,424 without solar.

My actual cost was ¥9,967.

I saved ¥5,456 with generation and earned ¥1,312 for a total savings of ¥6,769
Date Generation Consumption Bought Sold
2023/01/15 0.81 11.21 10.40 0.00
2023/01/16 0.60 14.20 13.60 0.00
2023/01/17 5.03 17.23 12.80 0.60
2023/01/18 6.27 16.27 10.50 0.50
2023/01/19 4.83 14.43 10.30 0.70
2023/01/20 14.02 14.02 2.70 2.70
2023/01/21 7.22 14.02 7.70 0.90
2023/01/22 11.09 16.49 6.60 1.20
2023/01/23 3.39 15.59 12.60 0.40
2023/01/24 7.83 16.33 9.40 0.90
2023/01/25 15.05 25.15 12.10 2.00
2023/01/26 14.74 21.54 10.60 3.80
2023/01/27 4.61 18.91 14.70 0.40
2023/01/28 12.73 14.93 4.90 2.70
2023/01/29 13.13 16.93 4.80 1.00
2023/01/30 15.06 19.86 8.70 3.90
2023/01/31 10.18 16.38 7.60 1.40
2023/02/01 12.38 18.58 8.70 2.50
2023/02/02 5.10 15.60 11.00 0.50
2023/02/03 3.58 10.48 7.50 0.60
2023/02/04 12.85 9.65 2.00 5.20
2023/02/05 14.11 5.91 0.80 9.00
2023/02/06 13.64 6.14 0.80 8.30
2023/02/07 8.13 5.33 0.80 3.60
2023/02/08 4.56 4.56 0.90 0.90
2023/02/09 14.49 6.49 0.70 8.70
2023/02/10 0.90 2.40 1.50 0.00
2023/02/11 15.76 9.66 1.90 8.00
2023/02/12 10.86 5.56 0.80 6.10
2023/02/13 1.03 2.03 1.10 0.10
2023/02/14 3.00 4.10 1.70 0.60

Dec 15 ~ Jan 14

I consumed 476.55kWh and generated 347.75kWh.

This would have cost me ¥19,129 without solar.

My actual cost was ¥10,114.

I saved ¥9,016 with generation and earned ¥1,458 for a total savings of ¥10,474
Date Generation Consumption Bought Sold
2022/12/15 11.99 14.99 6.20 3.40
2022/12/16 12.98 14.08 5.90 4.90
2022/12/17 3.16 15.16 12.10 0.20
2022/12/18 12.28 15.18 5.70 3.10
2022/12/19 14.05 18.95 8.60 4.00
2022/12/20 13.12 18.12 8.50 3.60
2022/12/21 5.64 15.24 9.80 0.50
2022/12/22 2.99 12.69 7.20 0.40
2022/12/23 14.40 14.00 4.20 5.20
2022/12/24 13.60 16.30 4.90 2.20
2022/12/25 12.67 14.47 4.40 2.60
2022/12/26 13.34 15.84 6.80 4.30
2022/12/27 13.68 17.18 6.50 3.00
2022/12/28 11.98 14.48 5.30 2.80
2022/12/29 13.08 8.58 1.10 5.60
2022/12/30 10.35 14.45 5.30 1.20
2022/12/31 4.23 13.73 10.30 0.80
2023/01/01 13.69 16.19 7.60 5.10
2023/01/02 10.96 16.96 7.10 1.10
2023/01/03 13.24 16.34 6.20 3.10
2023/01/04 12.98 16.98 7.40 3.40
2023/01/05 13.30 18.60 8.40 3.10
2023/01/06 10.75 15.15 6.50 2.10
2023/01/07 12.78 15.58 5.60 2.80
2023/01/08 13.02 16.12 6.00 2.90
2023/01/09 13.22 14.72 5.30 3.80
2023/01/10 14.02 15.52 5.70 4.20
2023/01/11 12.42 18.52 8.00 1.90
2023/01/12 12.61 18.51 8.10 2.20
2023/01/13 10.26 12.26 4.30 2.30
2023/01/14 0.99 11.69 10.70 0.00

Nov 15 ~ Dec 14

I consumed 378.59kWh and generated 249.79kWh.

This would have cost me ¥14,522 without solar.

My actual cost was ¥9,446.

I saved ¥5,076 with generation and earned ¥986 for a total savings of ¥6,061
Date Generation Consumption Bought Sold
2022/11/15 3.96 10.76 7.00 0.70
2022/11/16 13.95 13.16 3.30 4.40
2022/11/17 10.96 12.56 3.10 1.50
2022/11/18 12.87 14.77 3.10 1.70
2022/11/19 13.49 13.59 3.40 3.30
2022/11/20 2.33 10.83 8.40 0.30
2022/11/21 6.98 11.48 4.60 1.00
2022/11/22 12.36 11.96 3.60 4.00
2022/11/23 0.61 11.71 10.90 0.00
2022/11/24 12.35 11.85 3.20 3.70
2022/11/25 13.33 10.43 2.20 5.10
2022/11/26 5.01 10.21 5.80 0.90
2022/11/27 13.46 11.56 2.70 4.80
2022/11/28 3.12 10.72 7.70 0.40
2022/11/29 3.25 10.35 7.60 0.60
2022/11/30 3.63 10.23 7.00 0.60
2022/12/01 1.23 10.93 9.50 0.00
2022/12/02 5.16 12.46 8.00 1.00
2022/12/03 7.84 12.24 5.30 1.00
2022/12/04 7.92 13.52 6.40 0.90
2022/12/05 1.66 13.66 11.70 0.00
2022/12/06 4.28 14.28 10.40 0.60
2022/12/07 12.48 16.58 6.40 2.40
2022/12/08 12.94 14.84 5.40 3.50
2022/12/09 10.09 12.89 5.20 2.60
2022/12/10 13.00 13.90 4.80 3.90
2022/12/11 8.62 12.82 5.10 1.00
2022/12/12 13.30 15.70 5.60 3.30
2022/12/13 6.47 14.37 8.50 0.90
2022/12/14 13.15 14.25 5.00 3.90

Oct 15 ~ Nov 14

I consumed 291.30kWh and generated 282.76kWh.

This would have cost me ¥10,503 without solar.

My actual cost was ¥3,074.

I saved ¥7,428 with generation and earned ¥1,473 for a total savings of ¥8,901
Date Generation Consumption Bought Sold
2022/10/15 0.00 0.00 0.00 0.00
2022/10/16 0.00 0.00 0.00 0.00
2022/10/17 0.00 0.00 0.00 0.00
2022/10/18 2.25 6.20 4.40 0.45
2022/10/19 6.16 8.96 3.60 0.80
2022/10/20 15.93 11.63 2.20 6.50
2022/10/21 14.66 10.86 1.30 5.10
2022/10/22 4.25 7.45 3.80 0.60
2022/10/23 14.57 9.77 1.70 6.50
2022/10/24 4.61 8.51 4.60 0.70
2022/10/25 2.38 10.68 8.50 0.20
2022/10/26 15.72 12.72 3.80 6.80
2022/10/27 11.00 12.10 2.60 1.50
2022/10/28 4.59 7.59 3.90 0.90
2022/10/29 14.46 11.56 2.70 5.60
2022/10/30 13.00 11.70 2.30 3.70
2022/10/31 15.13 10.63 2.10 6.60
2022/11/01 3.37 9.17 6.20 0.50
2022/11/02 14.38 12.28 2.50 4.60
2022/11/03 14.71 10.21 1.50 6.10
2022/11/04 13.12 11.82 2.50 3.80
2022/11/05 7.06 9.46 2.90 0.90
2022/11/06 13.79 10.39 2.50 6.00
2022/11/07 6.72 11.22 5.10 0.90
2022/11/08 14.07 12.47 2.80 4.50
2022/11/09 10.96 10.46 2.20 2.70
2022/11/10 9.54 9.94 2.20 1.80
2022/11/11 13.29 11.59 1.80 3.50
2022/11/12 12.71 10.31 2.00 4.40
2022/11/13 6.61 10.71 4.60 0.60
2022/11/14 3.75 10.95 7.30 0.40

Made by James Van Dyne.