Solar energy generation from buildings has been around for a long time. And although it has gained an increase in popularity, it seems there is still much scope for improvement. However, it seems that some consumers are still hesitant due to the assumed cost and then there is always the occasional horror story — especially regarding roof leaks due to improper installation.
Why consider a solar roof?
We live in a world which is more and more reliant on electronic equipment and appliances, so it would make sense that when planning new buildings that we think of the many benefits of a solar roof.
Here are some of the main reasons to consider a solar roof for your next project:
• The constant disruption to energy supply is one of the most compelling reasons to seek alternative energy solutions.
• An increasing amount of electricity consumption in many buildings mean considering on-site renewable energy sources that will reduce energy bills as well as reduce reliance on fossil fuels.
• Take advantage of battery storage improvements, which can also be linked to electric car charging.
• Increase the ability to meet the standards for lawfully specific requirements of energy efficiency associated with the Green Building Council of South Africa.
• The increasing trend in “green” projects initiative from lenders providing a margin discount to borrowers which seek Green Star classification.
• “Green estates” offer higher cost savings due to various green initiatives such as solar roofs.
Unfortunately, there also seem to be several challenges when it comes to solar roofs, with both the project and consumer challenges being cited as below:
A closer look at the solar photovoltaic (PV) options
Despite these challenges, with the advances in technologies and aesthetics as well as the effects of climate change, it is apparent that solar roofs deserve another look.
What is solar PV?
Solar PV technologies absorb sunlight through the PV array (a set of solar panels arranged next to each other) and then convert it into electricity using the silicon-based technology within. An inverter converts the electricity from a DC to an AC current, so it can be used in the building (either immediately or later if stored in a battery bank) or exported to the electricity grid, where it typically receives a feed-in tariff.
A complete solar PV solution is made up of:
1. A PV array — the part that sits on the roof, which turns sunlight into a DC current, and requires designing for maximum efficiency.
2. An inverter — converts the DC current into a usable AC current.
3. A charge controller — protects the battery from overcharging.
4. A battery bank — stores the energy produced by the PV array.
5. A connection to the electricity grid.
PV technologies are newer and should not be confused with solar thermal technologies, where the panels on the rooftop collect sunlight, which heats the liquid within the tubes and is then used for water heating.
Angle and orientation
To be efficient, PV systems need to face the sun, which requires a pitched installation. The optimum angle for solar panels typically nets out at between 35 and 40 degrees. The best orientation for your solar PV solution, so the panels receive the maximum amount of direct light throughout the day, is due south if you are in the Northern Hemisphere and the opposite if your project is in the Southern Hemisphere.
• Approach sustainability by using the roof as a source of clean and renewable energy, contributing towards specific sustainability criteria and environmental building certification.
• Own energy generation can reduce operating costs by lowering energy bills over the long term.
• Most suppliers can offer a complete solar PV and roof solution for a flat or a pitched roof, including advice on key components such as the design, inverter and battery recommendations.
• The continuous progress regarding improved solar efficiencies will also make the return-on-investment time much shorter.
But if aesthetics is not a consideration at all, it would be much more cost-effective to currently stay with traditional silicon panels. Traditional silicon panels have become quite cheap, and the price is continuously dropping.
The solar industry keeps moving forward at an amazing pace. In future it will probably be rare for roofs not to gather energy. And it will be very affordable, aesthetic and cost less than a normal roof.
Our sincere thanks and appreciation to BMI for some of the information contained in this article.
If you enjoyed this article, sign up for our newsletter: https://www.buildinganddecor.co.za/
Subscribe to our free magazine on https://www.freemagazines.co.za/ or join other discussions like these on http://www.facebook.com/buildinganddecor, http://www.twitter.com/buildingdecor and https://www.linkedin.com/showcase/10172797/