In the previous post we talked about our decision to go all-electric from the perspective of not wanting to deal with gas any more. However, this reasoning should not be taken as an unconditional endorsement of all-electric houses. Electricity is what it is—electrons moving in a certain way to transfer energy—and is separate in meaning from how it is produced. Natural gas is a substance whose mining and combustion have negative effects on the biosphere. Electricity is not a substance, so the issue surrounding electric power is how it is derived, and since we weren’t going to install solar panels—a choice that, at the time, was based on our financial outlook, and one we now regret—we assumed that we would have to buy all our electricity from the monopoly that supplied it in our area, Tepco, because at the time the energy market had not yet been liberalized. So it was a devil’s bargain, since at the time (2014) Tepco generated electricity chiefly from burning fossil fuels, though it was no secret to anyone that the company’s main wish was to bring back all the nuclear reactors it shut down in the wake of the Fukushima meltdown. We weren’t comfortable with either of these energy sources, and therefore had to live with the fact that we would (by buying thermally derived power) or could (by buying nuclear power) be paying into a system that was in some way unsustainable. 

In terms of climate control, summertime wasn’t a problem since we haven’t used air conditioners for years, mainly as a matter of preference. In fact, one of the criteria for choosing a place to build a house was relatively cooler temperatures during the summer. Given that we still opted to live in the Kanto region, that wasn’t very easy, but we managed to find a plot of land within a wooded area that was two to three degrees cooler on average than surrounding areas. So the main problem was heating the house in the winter with electricity, which can be expensive. We opted for storage heaters, which tend to be more popular in northern Japan and along the Japan Sea. The units are large boxes filled with ceramic bricks that heat up at night using electricity and then radiate this stored energy during the day. This method takes advantage of two phenomena—the human sleep cycle, and Japanese power companies’ practice of charging less for electricity at night than they do in the daytime. This latter point is based on the idea that large power generators are always online, but that the electricity they produce at night mostly goes unused, so businesses and homes that can use that surplus power pay less for it. Of course, our storage heating solution did nothing to help the environment, but at least it used power that would otherwise have gone to waste. Our water heating system, called Eco-Cute (a play on the Japanese word kyuto, or “hot water supply”), used the same cycle—heat the water at night for use in the daytime. We’ve been happy with the storage heating system. There is one unit on the first floor and another on the second floor, and by adjusting the amount of energy absorbed depending on projected temperatures, we’ve enjoyed a uniformly warm house throughout all the rooms during the winters we’ve lived here, something we, as a couple, have never really enjoyed in Japan, as anyone who has lived here for any length of time knows well. Moreover, we calculate that we don’t pay anymore to heat our home exclusively with electricity than we did to heat our home with gas, kerosene, and/or electricity in the past. 

But that may not last much longer. We recently received a notice from Tepco outlining payment changes for the future. The notice is supposed to be good news, since it essentially says that unit fees for electricity will be going down. However, the nighttime discount that we take advantage of for our heating uses will be discontinued. We were a bit taken back by this development, since the whole point of the storage heating system is to tap that surplus energy, but then we realized what it was all about. Some years ago, when we started writing about energy issues in Japan, especially with regard to nuclear energy following the 2011 meltdown, we learned that the nighttime discount was originally implemented because of nuclear energy. Reactors cannot easily be shut or powered down, and thus, unless they have to be serviced for whatever reason, they always run at full capacity. Thermal power stations that use fossil fuels—furnaces, to be exact—can be shut off or powered down more readily. So the nighttime discount became a normalized business practice in Japan because nuclear power by definition always produces a large capacity surplus at night. After the Fukushima meltdown, Japan shut off its nuclear reactors, and only 10 have come back online since, so the reasons for nighttime discounts are no longer as compelling, even though thermal power also produces a nighttime surplus. More importantly, as renewable energy becomes widespread, nighttime discounts become meaningless, especially with regard to solar power—the sun doesn’t shine at night, so there’s no excess power being generated. None of these functional aspects make our storage heating system any less effective in the task it was developed to perform, which is heat our house, but it does change the whole economic rationale for the system.