Solar Heat Dissipation Coat
Measures to prevent deterioration of power generation efficiency due to overheating of PV panels

◆Problem of output reduction due to overheating
The Solar panels have a characteristic as follow.
① It will increase output when the surface temperature of panel will come to be lower.
② It will decrease output when it will come to high temperature.
That is, even if it is received in the panel of the same area of the same light intensity,
Output changes depending on the temperature of the panel. By international standards,Catalog performance of solar panels, are supposed to be measured at 25 degrees.
Power generation capacity from 0.4 to 0.5 % per degree will change as performance standardof the 25 degrees.
That is the case of 35 degrees, a temperature difference of 25 degrees is 10 degrees.
It will be the amount of power generation 4-5% is down compared with 25 degrees.
In addition, the aged deterioration of the panel itself due to thermal expansion and contraction
has become a problem in areas where the temperature exceeds 40 ℃.
Relationship of power generation efficiency andthe temperature of the solar cell module

Efficiency(%)

the temperature of the solar cell module◆Heat radiation technology
In order to suppress temperature rise, technology to release heat (heat dissipation technology) isnecessary.
Heat is transferred in the form of conduction, transmission, and radiation.
At our company, by mixing SWCNT (single-walled carbon nanotube) with the best thermal
conductivity and emissivity with room temperature inorganic binder = SGB binder,
We have succeeded in developing a heat-dissipating coating that can be applied to varioussubstrates.
As the most important point for improving the performance of heat dissipation coating*There is an air problem in the thermal conductivity in Table 1.
Air (voids) remaining in the paint film or on the adhesive surface is a factor that prevents heatdissipation due to its heat insulating effect. The organic dispersant that uses SWCNT
Thermal Conductivity
as a solvent also causes thermal resistance and voids after deterioration over time.
Material（W/ｍ・K)
Sketch uses CNTs with as few pores as possible, high thermal conductivity,
CNT
3000～5500
Diamond1000～2000
and no organic dispersants in the particles that fill the gaps between SWCNTs.
Ag428
For this reason, we have formed a coating film with few pores
Cu403
and improved heat dissipation properties.
Au
319

Carbon nanotubes are more than 15 times more thermally.
conductive than aluminum.
Excellent heat dissipation effect.
Easy to heat up, easy to cool down.

Al236
Fe168
Stainless16.7～20.9
SiO2（Crystal）
8glass1PC
0.24
Acrylic
0.21
Air
0.0241

Table 1.

◆The feature of Solar heat dissipation coat
Solar heat dissipation coat is a coating agent that can be applied at room temperature withheat dissipation, antistatic, abrasion resistance, and chemical resistance characteristics byusing SWCNT. By applying it to the back surface of the solar panel (back sheet), it
suppresses the increase in panel temperature = the decrease in power generation efficiency.
Power generation efficiency drops by 0.5% for each 1℃ above 25℃, the efficiency drops by 10% at 45℃.
Heat radiation effect of each substrate
55
50

4540

ガラス
Glass

35

CopperGlass coating
ガラス塗布

30

Copper coating

250123458分1 2 3 4 5 6 7 8

7分

6分

5分

4分

3分

2分

0

1分

0秒

20(min)

(min)

(min)

0 1 2 3 4 5 6 7 8 9 10 11 12

Aluminum

PCAluminum
CoatingPC coating00

12345(min)Solar heat dissipation coat for Back Sheet
12℃ difference

Product with improved coating solution
for Solar Self-Maintenance Coated CNT
1. Application using dedicated rollers
20 g of water retention of the roller
2. It can be applied 50㎡ with 1L
3. Apply 20g per square meter4, Coating application after cleaning back sheet withalcohol
5, A worker can apply to coat 100㎡ with 8 hours
6, It dries in 15 minutes after applicationcoateduncoated10Ω3~4 on the surface resistivity meter.

New product announcement
Japanese Patent No.7146223“Antistatic coatings, antistatic glass substrates, andsolar panels”

Solar Self MaintenanceCoat CNT&Back Sheet Heat
Dissipation Coat

10Ω4~5 on the surface resistivity meter.

10Ω3~4 on the surface resistivity meter.