With the spectre of climate change looming ever larger, individuals and companies have a growing responsibility to reimagine a brighter future which they can help create. This starts with acknowledging the role which green energy plays in curbing the effects of global warming, and then harnessing its power to reduce greenhouse gas emissions and their devastating effects on the environment in the near and long term future.
Solar power as a leading source of green energy
Green energy is any energy type which is generated from natural resources, such as sunlight, wind or water. The common aspect of these energy resources is that they don’t harm the environment through factors such as releasing greenhouse gases into the atmosphere.
Green energy often comes from renewable energy technologies such as solar energy, wind power, geothermal energy, biomass and hydroelectric power. Each of these technologies works in different ways, whether that is by taking power from the sun, as with solar panels, or using wind turbines or the flow of water to generate energy.
Solar energy represents a clean, green source of energy, and is a great way to reduce your carbon footprint. There’s nothing about solar power which pollutes mother nature. Solar power doesn’t release any greenhouse gasses, and except for needing a source of clean water to wash dust and dirt off the photovoltaic (PV) panels, it uses absolutely no other resources. Hence, it’s safe and environmentally-friendly.
Solar power is self-sufficient and installing solar panels is a safe and easy path to contribute to a sustainable future and show you care about the environment.
Southern Africa has a high irradiation rate (i.e. the measure of solar potential) which ranges between 1 500 and 2 000 kilowatt hours (kWh) per year. This indicates that the weather conditions in our region are better suited for solar than the world’s current top solar producers which include countries such as Germany.
Solar roofs are cool roofs
A cool roof is one which has been designed to reflect more sunlight and absorb less heat than a standard roof. Cool roofs can be made of a highly reflective type of paint, tiles or shingles, or a sheet covering. This decreases roof temperature, which generally extends roof service life.
Beyond the building itself, cool roofs benefit the environment, particularly when many buildings in a community have them. Cool roofs can reduce power plant emissions, including carbon dioxide, sulfur dioxide, nitrous oxides, and mercury by reducing cooling energy requirements and use in buildings.
Cool roofs can also help mitigate the “urban heat island effect” which occurs when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces which absorb and retain heat. This effect increases energy costs (e.g. for air conditioning), air pollution levels, and heat-related illness and mortality.
Solar panels can contribute to a cool roof by absorbing the brunt of the sun rays and protecting the actual roof surface. Shaded areas between the panels and roof are cooler than a direct sunlit roof surface. This significantly reduces the overall heat transferred from rooftop to interior.
PV panels and Zincal® roofs – a perfect pairing
Safal Steel’s Zincal® coated steel roofs and solar PV panels are the perfect partnership of function, service life, and return on investment. The technique of coating steel with Aluminium and Zinc (55% Aluminium, 43.5% Zinc and 1.5% Silicon) has been extensively researched and surpasses the performance of traditional galvanised steel. The Aluminium coating component provides a tough physical barrier while the Zinc in the coating provides sacrificial protection and also protects the steel at the cut edges. This superior corrosive property increases the life of the steel core up to four times longer than that of galvanised steel. In Zincal®, the durability and service life of modern coated steel is extended even further.
Zincal® roofs are cool roofs, with a thermal mass significantly lower than traditional galvanised steel and clay tile roofs due to the addition of Aluminium. This increases the reflection of the sun’s rays, creating a cooler building in summer and a warmer building in winter. At a solar radiation level of 850W/m² equivalent to 30°C ambient temperature, a Zincal® roof transmits 65 watts/m² of heat compared with 120 watts/m² for a galvanised roof and 150 watts/m² for a clay tile roof.
In terms of lifespan, research shows that Aluminium-Zinc coated roof systems can last 60 years and more while the industry standard for solar PV panels is about 25 to 30 years. This means you shouldn’t experience the hassle of having to remove and reinstall a PV system when you replace your roof.
Because PV installations typically don’t take up the entire surface of the roof, and sometimes require highly reflective roofing to ensure sufficient system efficiency, cool roofs and PV panels are complementary technologies.
Sustainability is more than just a word – it’s a way of life which will have untold benefits for future generations. Cool roofs and PV panels are both excellent options for improving the environmental performance of a building, and each of these technologies has huge potential in terms of reducing the environmental impact of our cities.