SOLAR PANELS ON RV’s
This technical article is designed to give value to the reader knowledge on the Efficiency of Triple Insulated Flexible Solar Panels.
Solar Panel Efficiency is strictly speaking the measure of converting the sun’s irradiance into electrical energy. However, RV’s have limited roof space. So we will add into this equation the electrical energy available per square metter of RV roof space at typical mid-day temperatures in Australia.
Solar Efficiency is impacted by:
- Efficiency of the Silicon Cells;
- Design of the Silicon Cells transmitting the collected energy;
- Temperature of the Silicon Cells;
- Dust and debris on Silicon cells.
The Solar controller is excluded from this assessment. It is a topic by itself.
The orientation of the solar panels to the incidence angle of the sun is also excluded. This is a factor regardless of solar panel efficiency on electrical output.
Silicon Cell Design and Efficiency: the top 5 Manufacturers in 2019
Here are the top five best solar panel manufacturers in 2019 ranked based on the highest efficiency solar panel they have to offer:
1. SunPower (22.2%)
2. LG (21.1%)
3. Solartech Universal (20.2%)
4. Silfab (20.0%)
5. Solaria (19.4%)
The most efficient solar panels on the market today have efficiency ratings as high as 22.2%, whereas the majority of panels range from 15% to 17% efficiency rating. SunPower panels are known for being the most efficient solar panel brand available on the market. Though they will come with a higher price tag, SunPower will often be the consumer favourite for anyone concerned with efficiency as a primal metric of interest.
Safiery uses only SUNPOWER Silicon Cells. We use their Ultra High Performance Maxeon Gen III
Temperature Effect and Efficiency: the bigest killer to performance:
Glass Solar Panels have a typical 35C temperature rise above ambient in full sun.
EFFICIENCY IMPACT OF TEMPERATURE
Each manufacturer solar panel has a rated temperature impact in efficiency.
Glass panels are typically quoted at 0.3% to 0.4%.
Glass panels rise typically approx 35 deg C above ambient.
Glass panel drop in efficiency because of temperature is:
(35C +Ambient (28C say)-25C (std)) x 0.35% = 13.3% reduction.
Safiery Triple Insulated Panels are:
Safiery Triple Insulated Panels have a temperature co-efficient of 0.3%
Safiery Triple Insulated Panels rise by only 25 deg C above ambient.
Safiery Triple Insulated Panels drop in efficiency because of temperature is:
(25C +Ambient (28C say)-25C (std)) x 0.3% = 8.4% reduction.
This is nearly a 5% improvement in efficiency over Glass panels.
Here are photographs of real live test results:
1. HOW TRIPLE INSULATION IS ACHIEVED ON CARAVAN ROOF
There are three layers of cells that comprise the UV rated Polycarbonate material. The triple insulation promotes air-flow between the layers cooling the solar panel AND the caravan roof. The inside temperature of the caravan will reduce as the Polycarbonate has an “R” factor of 3. This means it transmits one third of the heat energy through to the caravans inside space.
The “Black” polycarbonate pulls heat from the back of the solar panel and dissipates it to the open air.
The polycarbonate is attached to the solar panel with two simple runs of Sika 252 and additional placement to secure the end caps. The solar panel can expand and flex comfortably.