68
4.1.4 Which Storage Battery Will Be Playing the Leading Role
in 2050?
Lithium-ion batteries are used in personal computers and smartphones, and they can
be regarded as one of the most familiar storage batteries in our everyday life. The
basic structure of a lithium ion battery is a positive electrode composed mainly of
lithium metal oxide and a negative electrode typically composed of graphite, which
are immersed in an electrolytic solution together with a separator dividing both
electrodes. When electricity flows, lithium ions from the positive electrode dissolve
into the electrolytic solution, then run through the separator and move to the negative electrode side and remain between the graphite layers. This is a state of electrical charge. When discharging, lithium ions dissolve out from the graphite layer and
move to the positive electrode side.
High stability and an economy that can withstand mass introduction are required
for the combination of fixed storage batteries with solar power generation. Lithium
ion batteries have higher energy density, longer life, and charge–discharge efficiency as high as 90% compared with conventional storage batteries such as lead
storage batteries and nickel hydride batteries. It can be said that this is an easy-tointroduce storage battery, as material development and manufacturing technology
have improved and prices have also declined in current expanding period.
The prices of current household storage batteries are shown in Table 4.3. The
selling price of a Japanese company is about 10 times the manufacturing cost of
¥13.9/Wh shown in Table 4.4, while the selling price of Tesla in the U.S. is about
three times this value. Severe price competition will start as the market develops,
due to such factors as expansion of production scale, improvement of product yield,
and development of new products.
In contrast to lithium ion batteries that have already become widespread, NAS
batteries are expected to become popular in the future. This battery was named
“NAS” because sodium (Na) is used for the negative electrode and sulfur (S) is used
for the positive electrode. A fine ceramic solid electrolyte membrane is used between
Table 4.3 Manufacturer and price of household energy storage systems(Li ion battery) (as of May
2015)
Manufacturer
Product type
number
Capacity[kWh]
Price
[10,000
Yen]
Unit price
[Yen/Wh]
Real price (subsidies
included) [Yen/Wh]
Sharp
JH-WBP07A
4.4
107
240
150
Panasonic
PLJ-25522K
5.6
119
210
135
Eliiy Power EPS-1 1
6.2
131
210
130
NEC
ESS-H002006B2A
5.53
123
220
140
Tesla
Powerwall
10
41
41
–
LCS cost calculation value of Tesla products: ¥15/Wh (Battery: ¥13, BOS: ¥2)
Source: Created based on materials from the Center for Low-Carbon Society Strategy, Japan
Science and Technology Agency
4 Technology to Support Low-Carbon Society (Utilizing Energy)
4.1.4 Which Storage Battery Will Be Playing the Leading Role
in 2050?
Lithium-ion batteries are used in personal computers and smartphones, and they can
be regarded as one of the most familiar storage batteries in our everyday life. The
basic structure of a lithium ion battery is a positive electrode composed mainly of
lithium metal oxide and a negative electrode typically composed of graphite, which
are immersed in an electrolytic solution together with a separator dividing both
electrodes. When electricity flows, lithium ions from the positive electrode dissolve
into the electrolytic solution, then run through the separator and move to the negative electrode side and remain between the graphite layers. This is a state of electrical charge. When discharging, lithium ions dissolve out from the graphite layer and
move to the positive electrode side.
High stability and an economy that can withstand mass introduction are required
for the combination of fixed storage batteries with solar power generation. Lithium
ion batteries have higher energy density, longer life, and charge–discharge efficiency as high as 90% compared with conventional storage batteries such as lead
storage batteries and nickel hydride batteries. It can be said that this is an easy-tointroduce storage battery, as material development and manufacturing technology
have improved and prices have also declined in current expanding period.
The prices of current household storage batteries are shown in Table 4.3. The
selling price of a Japanese company is about 10 times the manufacturing cost of
¥13.9/Wh shown in Table 4.4, while the selling price of Tesla in the U.S. is about
three times this value. Severe price competition will start as the market develops,
due to such factors as expansion of production scale, improvement of product yield,
and development of new products.
In contrast to lithium ion batteries that have already become widespread, NAS
batteries are expected to become popular in the future. This battery was named
“NAS” because sodium (Na) is used for the negative electrode and sulfur (S) is used
for the positive electrode. A fine ceramic solid electrolyte membrane is used between
Table 4.3 Manufacturer and price of household energy storage systems(Li ion battery) (as of May
2015)
Manufacturer
Product type
number
Capacity[kWh]
Price
[10,000
Yen]
Unit price
[Yen/Wh]
Real price (subsidies
included) [Yen/Wh]
Sharp
JH-WBP07A
4.4
107
240
150
Panasonic
PLJ-25522K
5.6
119
210
135
Eliiy Power EPS-1 1
6.2
131
210
130
NEC
ESS-H002006B2A
5.53
123
220
140
Tesla
Powerwall
10
41
41
–
LCS cost calculation value of Tesla products: ¥15/Wh (Battery: ¥13, BOS: ¥2)
Source: Created based on materials from the Center for Low-Carbon Society Strategy, Japan
Science and Technology Agency
4 Technology to Support Low-Carbon Society (Utilizing Energy)