Column: Ken Fujimoto's Solar Report The secret of the "housing creation-storage cooperation system" that stores electricity generated by sunlight in lithium-ion-home appliances WatchWatch

However, until now, it has been difficult to come up with products that successfully combine sunlight and storage batteries. Against this backdrop, Panasonic has announced a groundbreaking system called the "Residential Creation and Storage Linked System" that organically combines solar power generation and lithium-ion storage batteries.

　What is that system actually like? I interviewed Panasonic Eco Solutions Company.

　Mr. Masaharu Kawakatsu and Mr. Masato Inoue of the Energy System Business Group New Business Promotion Group Energy Management Business Promotion Group Product Planning Counselor, and Mr. Yuichiro Naoi and Mr. Seiji Ando of the Group's product technology There are a total of 4 people (honorific titles omitted below).

■ No need to change outlets in the event of a power outage, automatically switch power with a dedicated distribution board

Kawakatsu: Since the Great East Japan Earthquake, many customers have asked for a safe system to prepare for power outages. I can now take it. However, solar power generation systems alone cannot be used at night, and even during the daytime, power cannot be supplied if the weather is bad. On the other hand, in the case of a single power storage system, the system ends when the stored electricity is used up. Then, if we were to buy both and connect them together, there would be various problems, such as not being able to generate electricity well.

Therefore, this residential creation-storage linkage system consists of three main components: solar cells, a 4.65 kWh lithium-ion storage battery unit, and a power station that can intelligently control the solar cells and storage batteries. I'm here.

　This allows us to use the power generated by the sun during the day, and the surplus power can be used to repeatedly charge the storage battery. And the power stored in the storage battery stabilizes the power supply during the daytime, and at the same time, it can also be used at night.

--In the past, I've also tried using self-sustaining mode of solar power to see how useful it would be in the event of a power outage [past article here]. Of course, it was certainly more useful than not having it at all, but it was more inconvenient than I expected. First of all, power can only be supplied from an emergency outlet, so you have to reconnect the things you want to use.

Kawakatsu: Well, it's very difficult to use. Also, since it is only supplied from an emergency outlet, it is not possible to turn on the lighting equipment installed on the ceiling.

　On the other hand, in this residential creation-saving cooperation system, we have changed the way of thinking significantly. The "backup distribution board", which is also shown in the system overview diagram earlier, is a big key. Think of this as an isolated circuit in a typical residential distribution board. Normally, one circuit of a distribution board is 20A, but one of them can be used as an emergency outlet as a whole.

――So, in case of emergency, do you mean to prepare all the lighting and electrical equipment separately for backup?

Kawakatsu: Instead, it means that you can switch the place you normally use for backup.

In other words, during normal times, use it as one circuit of a normal distribution board. However, in the event of a power outage, it will switch to supply power only to the backup switchboard. For example, if the children's room on the second floor, where the TV and mini-refrigerator are installed, is connected to the backup switchboard, that room can be used normally even in the event of a power outage.

What's more, the biggest point of this system is that it can be used even at night because it can supply power not only from solar cells but also from storage batteries.

　Actually, the other day, I spent a night in a model house that incorporated a creation-saving collaboration system, and it was very comfortable. world. Only that room can use electricity as usual even in the event of a power outage, so you can live brightly at night, watch TV, and charge your mobile phone. I didn't feel any inconvenience.

-I see, that's amazing

■ Stable output of 2 kW even in the event of a power outage by linking with a lithium-ion battery

--Another problem I had when experimenting with an emergency outlet for solar power generation at home , The system is unstable, such as when the power used exceeds the power supplied, the entire system will shut down and require a restart. It was very difficult to use, especially when the weather was sunny or cloudy.

Panasonic Eco Solutions Company Energy System Business Group New Business Promotion Group Energy Management Business Promotion Group Mr. Seiji Ando

　Of course, we also want more people to use it, so we have been considering various things. However, the main reason why it is difficult to introduce it to existing houses is that construction work such as installing a 20A backup distribution board and tampering with the in-house wiring will occur.

　Since there are some houses where it is difficult to change the wiring, there was a discussion about whether it was okay to simply say "Yes, it is possible". Therefore, it is bad for customers to misunderstand, so basically we are limited to new users.

　In addition, if you are already using solar power, I think you have a contract with a unit price of 48 yen or 42 yen. However, if we were to introduce this creation-storage linkage system, even if we could keep the solar panels, we would have to replace everything, including the power conditioner, and rebuild the system. Since the contract with the electric power company will be concluded in the near future, it is likely that there will be various disadvantages in terms of the amount of electricity sold.

　Considering this aspect, I don't think it would be very realistic to install it for existing users.

――In that case, in the future, you're going to team up with housing makers and work on popularization.

Inoue: I definitely want to do that. Although it is a sales effort in the future, I hope that by appealing the creation-storage cooperation system, we will be able to adopt our products.

Kawakatsu: Actually, it would be nice if solar panels could be combined with other manufacturers' products, but there are problems such as a 10-year warranty, so it may not be possible soon.

――Looking at the scale, I think it is still at the level of being used in the event of a disaster or power outage in an emergency, but if the capacity of power stations and storage batteries increases a little in the future, it will be extremely difficult. Speaking of which, will we be able to achieve complete energy self-sufficiency without having to sign a contract with a power company?

Kawakatsu: It depends on how frugal you live, but it's actually difficult. In order to live a normal life to some extent, the capacity of the storage battery alone will be enough for several electric cars. Furthermore, considering that the rainy season will continue to be cloudy, the storage battery capacity will be 100 kWh or more.

　In the future, self-sufficiency would be ideal, but I think the first step is to realize a lifestyle that does not rely too much on the electric power company. It's not that I don't rely on them at all, but I do what I can by myself as much as possible. I hope that the creation-storage collaboration system will help with that.

――Thank you for today.