Green energy suppliers and home solar/battery setups

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Zasso Nouka
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Green energy suppliers and home solar/battery setups

Post by Zasso Nouka »

OnionChutney wrote:
Wed Dec 07, 2022 8:58 am
Does anyone run their house entirely on solar?
Does the battery store enough to give you the power needed for the winter months?

We're looking at installing 20 panels on our house in Fukuoka. With little to no snow each year, and fairly sunny winter days, I'm wondering whether we need to be hooked up to the grid at all.
Not yet. We're still looking to install a V2H pack so we can use our car as a home battery but the main problem is the Nichicon systems currently available aren't that "smart". Panasonic's Eneplat system, which will be released next year looks far more promising.

At the moment most domestic suppliers of home battery systems seem to want truly eye watering prices for their systems that are basically dumb batteries. My brother, back in the UK recently installed a home battery that checks the weather predictions for the next few days and decides whether to solely charge from his solar panels or if the predictions are for cloudy weather then to top it up from cheap rate night time electricity and all for a fraction of the price domestic manufacturers here are charging and it learns his daily usage patterns to predict how much power it needs to store. The glaring exception on price point seems to be Tesla.

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Green energy suppliers and home solar/battery setups

Post by OnionChutney »

In January we're having a new roof put on the house, so at the same time we want to install solar panels.
We're thinking of a 7000円 per month solar panel rental scheme (for 10 years), with an average sell-back of around 4000円 a month, still giving us around 4000KWH.
So that's only 3000円 a month... But, we will have to pay an additional 3000円 a month for the luxury of being connected to Kyushu Denki also.
Not so bad, only 6000円 a month in total.

But then, if we don't get a battery storage system, we'll have to pay Kyushu Denki for any and all electric used after sunset. So that takes the monthly cost to roughly 7~10,000円 each month, which is what we would pay without having any solar installed, so having solar would make no difference to our bills.

If we get the battery system, we can save on Kyushu Denki costs, but obviously would have to pay for either battery rental or the upfront costs of the battery. Renting a battery costs an additional 10,000円 a month! So that's not something I want to do.
Buying a battery, then using completely solar electricity is what I want to do, but I'm trying to get my head around the whole thing.

I'm leaning towards buying a battery outright (if the price is right...!), but I'm frustrated that I have to pay Kyushu Denki 3000円 a month regardless of if I use them or not.

Any advice or experience from fellow solar enthusiasts?
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Post by Zasso Nouka »

The monthly standing fee for all electricity companies seems somewhat unfair but I guess if they were forced to scrap this then they'd just add it on to the kilowatt price so there probably isn't a way to avoid it and even if you got a home battery installed you might still want to remain connected to them in case you had a couple of cloudy days and couldn't top up your battery. In that case where you are say 99% of the time using your own electricity then the monthly standing charge would seem even more exorbitant and unfair.
OnionChutney wrote:
Fri Dec 30, 2022 10:02 am
But then, if we don't get a battery storage system, we'll have to pay Kyushu Denki for any and all electric used after sunset. So that takes the monthly cost to roughly 7~10,000円 each month, which is what we would pay without having any solar installed, so having solar would make no difference to our bills.
Certainly for the time you are repaying the loan you won't see much financial benefit. However once you've paid off the loan then you'll begin to reap the rewards of your set up.
OnionChutney wrote:
Fri Dec 30, 2022 10:02 am
If we get the battery system, we can save on Kyushu Denki costs, but obviously would have to pay for either battery rental or the upfront costs of the battery. Renting a battery costs an additional 10,000円 a month! So that's not something I want to do.
Buying a battery, then using completely solar electricity is what I want to do, but I'm trying to get my head around the whole thing.

I'm leaning towards buying a battery outright (if the price is right...!), but I'm frustrated that I have to pay Kyushu Denki 3000円 a month regardless of if I use them or not.

Any advice or experience from fellow solar enthusiasts?
While you have a Feed In Tariff or FIT you can use the grid as your battery selling power during the day at a higher rate than you buy it at night. Once your FIT and loan expires you could then take on the cost of leasing or outright purchasing a home battery and hopefully in 10 years the price of home batteries has dropped to similar levels as elsewhere. With the exception of Tesla home batteries are ridiculously overpriced in Japan.

If you are thinking of changing cars to a Nissan Leaf or Ariya and your car is parked outside your house for most of the day and night then that could be a viable option instead of buying a home battery and fitting a V2H system instead.

Kyushu Denki does seem to charge rather a lot for their monthly fee compared to some other companies, are there any alternate suppliers in your area or would you still have to pay Kyushu Denki to use their infrastructure ?

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Green energy suppliers and home solar/battery setups

Post by Chuck2 »

OnionChutney wrote:
Fri Dec 30, 2022 10:02 am

I'm leaning towards buying a battery outright (if the price is right...!), but I'm frustrated that I have to pay Kyushu Denki 3000円 a month regardless of if I use them or not.

Any advice or experience from fellow solar enthusiasts?
What have you decided about buying a battery? About how much do they cost?

I noticed on another thread you shared your solar panel rental fee, thanks for sharing.

I am curious about 3000yen you say you have to pay to Kyushu denki a month regardless of if used or not. Here, we use Chugokoku denki and if no power is used we pay just under 500yen but we don't have solar and so don't sell back to the grid. I'm curious about your 3000yen fee has some kind of surcharge included because you are selling power back to the grid. If this isn't the case, I wonder why this fee is so much. How did you come up with this 3000yen?

What happens at the end of the 10yr lease? Do the panels become yours or do you have to sign another 10yr lease?
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Post by OnionChutney »

We've decided against buying the battery, the cost was astronomical (over £10,000)!

Kyushi Denki just had a flat monthly rate for the privilege of being connected. It doesn't matter if we are using solar or not, selling back to grid or not, that's just how they operate. I have found a cheaper base charge from them (1650yen per month for a 10kW supply), then 13.31yen per nighttime 1kWh, and 26.84yen per daytime 1kWh.

As for the lease, after 10 years the panels become ours. So no more monthly fees, but the caveat is that our sell-back rate drops a bit.
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Post by Zasso Nouka »

Batteries are ridiculously overpriced right now, perhaps they will come down in the future or maybe Octopus can replicate what they've done in the UK. Possibly in 10 years time when you've finished the lease batteries will be a lot more affordable.

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Post by czaujapman »

OnionChutney wrote:
Thu Jan 19, 2023 10:24 am
As for the lease, after 10 years the panels become ours. So no more monthly fees, but the caveat is that our sell-back rate drops a bit.
WOW so do you actually get 10yr price guarantee for the FIT here in Japan? That's pretty good!
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Post by Zasso Nouka »

czaujapman wrote:
Tue Jan 24, 2023 2:50 pm
WOW so do you actually get 10yr price guarantee for the FIT here in Japan? That's pretty good!
Absolutely yes. Our FIT rate was fixed at 43円 per kilowatt for the first 10 years, sadly now it's down to 8円 so it doesn't really make sense to sell the electricity so we try to use as much as possible during the day or use it to charge the car.

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Post by czaujapman »

My relative living in Hawaii uses this setup - they're not connected to the grid and it seems to do the trick for them.
Not sure if 120V would work in here.
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Post by Zasso Nouka »

Looks like a nice setup, what's the score with importing lithium batteries these days ?

It must be possible as they ship the things all over the world for commercial purposes but there were restrictions for individual customers a few years ago.