"Would you like to buy a battery?"
If you don't have time to read this, the quick answer is "no".
A new contract with a different energy company brings an opportunity for salesmen to visit. They had sent an engineer a couple of weeks earlier who checked my solar system, took some measurements and switched the power conditioners off and on a couple of times.
The conversation with the salesman went something like this:
"We tested your solar panels, the connection box and the power conditioners," he started, then went through each of the items in the checklist he showed me, all of which were good. "...and it's time for you to replace your power conditioners."
Me thinking: "hmm... what? If there are no problems with my system, doesn't that mean I can keep using it?"
"So when you do replace it, here are some things to think about," he went on. "Here, look at this folded A3 photocopy that has been carefully designed with boxes for me to write fancy-looking numbers in."
The first part was under the heading How much are storage batteries spreading?
"We've had storage batteries for FIVE years," he said, writing "5" in the first box, "and the country is spending THIRTEEN BILLION YEN per year on subsidies." Writing "130" next to the Japanese character 億 oku, which is one with 8 zeros. There's a divide sign next.
"And there's HALF A MILLION yen available per house," writing "50" and the character 万 man meaning one with 4 zeros. "Which means there are TWENTY SIX THOUSAND houses with batteries," writing 26,000 in the last box.
Me thinking: "couldn't you just have told me how many houses there were first? And how much I can get? Are you trying to turn this into an elementary school arithmetic lesson?"
He went on: "Now, how much have they been paying you for your electricity?"
"Forty eight yen per kilowatt hour," I told him. He wrote "48" under the next section Why should you get a storage battery?
"And you're probably only going to get between ZERO and SEVEN yen for selling your electricity." The Zero was already there on the paper with a squiggle next to it. He wrote "7" in the next box on the other side of the squiggle. There was a graph with the price falling from 48 yen in 2009 to about 28 yen in 2019 then straight to zero.
"That's pathetic!" he said. Well, he didn't say that, but he obviously wanted me to think it.
That section on the crib sheet was about the fall in price of electricity sold. The next section was about the increase in the cost of electricity bought.
"So because of the nuclear problem the public has had to cover costs since 2020," he went on. writing "2020" in the box. "And because of natural disasters the price of electricity went up 31.1% in your area between 2011 and 2015," circling relevant parts of the table with various electric companies from around the country.
As he was saying this, already I was thinking: "Isn't increased renewable energy going to push prices down? You can't tell me with one breath that my solar electricity is worth nothing and then that prices are going to go up, can you?"
"And number 3, you're going to need a new power conditioner." Number 1 was the feed-in tarrif going down to zero and number 2 was the price of electricity going up. "You may not realise this, but the power conditioner is a very important part of your solar system."
I did realise.
"It does lots of things, and it's very important. And you probably need a new one around now."
Me: "..."
"And number 4, you're probably going to need a new IH cooker and to replace your Ecocute."
The Ecocute is the domestic hot water system, heated by an atmospheric heat pump. I'm wondering what that's got to do with anything, but he tells me.
"They both last around ten years. So while you're changing those things, you might as well just put in a storage battery, because that means you can store electricity when it's cheap and then use the electricity when it's expensive to buy."
"And by the way," he went on, "we have a special deal for-this-month-only where you can buy a new IH and an Ecocute and a new power conditioner along with a battery, and we'll give you a 300,000 yen discount."
So there's another piece of paper from a large domestic manufacturer with pictures of leaking spaghetti pipes from the boiler that wants to say "watch out for leaks", and a cooker with a cracked top that could say "watch out for leeks".
Another sheet of paper explains the post-FIT strategies, which seem to be categorised as CARRY ON AS BEFORE or GET A BATTERY, YOU IDIOT.
Back to the photocopy, the storage batteries range from 3 kWh, with a price of 1 to 1.5 million yen, up to 16 kWh with a price of 3 to 3.5 million.
"So," he goes on, "I can come back later and talk to you and your wife about getting a battery. When is a good time to have an appointment?" He then got out a calendar with names of people written into many of the days. I couldn't help thinking that the names and times were all made up.
Until now, this "conversation" has mostly been paraphrasing what he said, and telling you what I was thinking. Now it was my turn to talk.
"I've got an electric car. I wonder if you have some technology that could use that for storing energy from the house?"
"Oh, you could probably get one of those but it would cost, like, a million yen."
"Well," I replied, "When I looked into it, there was one for 380,000 yen."
"Oh."
"As you can see from the results on my system I have a pretty big solar array, and this house is very well insulated and airtight, so in fact I generate about twice the electricity I use. Rather than a battery, what I really want is some smart tech in the house, so for example the boiler will make more hot water while the sun shines. Do you have something like that?"
Him thinking: "I've no idea. They just pay me to wear a clean shirt and fill in boxes on bits of paper."
I went on: "And if I did get a battery, it would have to be a lot bigger than 3kWh for me to be able to go off grid and cover my electricity if there's a power outage. Which, to be honest, has maybe only happened once in the last ten years, and only for a short time." It was fun, we got to use our camping lights in the house. No time to break out the camping stove because the electricity for the cooker was back on in time for tea.
"So I'm not really worried about protection against disaster. And I don't really want to go off grid, because as I said I'm generating more electricity than I use, so I'd like to send it back into the grid so somebody else can use it."
I didn't have time to do a financial check on the price of the battery, but looking now, I've spent around a million yen buying electricity in the ten years since I moved into the house. During this time I've been trying to use as little of my solar power as possible since I was getting a good rate selling it. Going forward I should be using more of my own power, so my electricity bill should be less. Spending a million yen on a 3kWh battery may reduce my electricity a little, but it would not go to zero since there are days with no sunshine when we will use more than 3kWh. I don't even need an envelope to write on the back of to work out that the payback is over 10 years, and probably well over 10 years, if you ignore any kickbacks. They would have to be serious kickbacks to make me think about it on purely financial terms. More precise calculations on the financial value of storage batteries will need to wait for another post.
Also, it's important to say that storing electricity does seem like a good idea in general, but I'm not convinced I should be doing it now, in my house.
"Thank you for coming."
