For those of us in Tokyo there are still huge government subsidies for Solar and Battery installations.
I won't break down the maths but you should be able to install over 5kw of Solar and a 10kwh Battery and be out of pocket for around 1mil yen.
Good information here:
https://standard-project.net/solar/
Batteries are still expensive but they provide a backup and will allow you to consume more of the electricity you produce.
Which is good as the FIT (Feed in Tariff) has been gradually reducing. Now 16 yen per kwh since 2023.
https://www.taiyoko-kakaku.jp/archives/3657.html
Your ROI (break even point) will vary based on usage patterns. And sunlight hours. Apparently a big thing with Solar..
I would not be considering this for purely financial reasons if there weren't subsidies.
The process I followed was.
1. Contact Solar Partners. Provide them information about roofing material and a plan of the house. (Which failed to upload but it said "this might not work" so i skipped and they later emailed me asking for it.)
Tell them how many firms you want estimates from. (You'll need to meet with each of these firms.)
1.5 There was one phone conversation with Solar Partners that took about 10 mins. Confirming most of the information I provided and confirming how many firms I want estimates from. Provide various schedules when you’d be available.
2. Appointments with the firms are scheduled who will arrive with quotations. These should be considered indicative quotes as a detailed inspection will be required if you choose to proceed with them.
Check they are quoting accurately. One firm had a quote assuming an incorrect roofing material.
3.Take time to research extensively online and have intelligent fact based discussions with your partner/friends... (Alternatively, peruse the glossy brochures wondering if all these blonde Caucasian babies realize they alone form the backbone of Japan's Solar marketing materials, ponder if you could live with yourself going with the cheaper firm knowing the sales person keeps dangerous dogs, sit on any decision for a month and then 偶然に cycle past the head office of one firm and take that as a sign from on high...)
4. The next step will be to ask any preferred company/companies to perform a proper inspection 現場調査 to confirm exactly how much can be installed and provide a revised quote.
I'm sure there is some room to haggle as I got an improved price after their proper inspection. And that included an external weather proof outlet I wanted.
5. Once you have a quote you are prepared to proceed with, you'll need to prepare a bunch of things for the contract signing. This may vary by company but in my case this was.
- 印鑑証明書 - Certified proof of registered hanko.
- 住民票 - Certified copy of resident registration.(Remember to exclude your mynumber folks!)
- 建物の登記簿謄本 全部事項証明書 - Certified copy of the building registration. (Get this at the living museum/land registry office for 200yen.)
- Your Bank account information for the Subsidy. (Realize the Mickey Mouse branded Bank book/ATM card your chose 25 years ago no longer accurately reflects your mood..)
- Details on your current Electricity supply contract.(The installer should sign you up for the Feed In Tariff. 売電.
I'm sure there are other aggregators, but Solar Partners seems a no pressure way to get multiple estimates. None of the firms I invited to provide estimates chased me later.
Oh, it's possible there are additional subsidies at a local municipal level. We'll delay the start until April to get in on that lottery. About 20万 in our case.
This is a fact based tool using post-code to estimate expected solar production. If you have multiple roof aspects (directions) eg 2kw south and 3kw west then make two estimates and combine them.
https://www.jyuri.co.jp/solarclinic/index.htm
I'm not expert in this, or anything, but I've found the process pretty painless.
Maybe check how they will anchor the external power convertor and battery outside. (i.e. pour some concrete rather than just drop on blocks).
If you aren't getting a loan then payment will vary by company but typically at least half prior to installation.
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