More and more roofs are used for placing installations that contribute to the functionality of a building. These roofs are filled with installations such as ventilation and air-conditioning systems and solar panels, leaving nearly no room for maintenance personnel to do their job when one of these installations fail and require maintenance and/or a repair.
Of course, the importance of roof safety and the protection of (maintenance) workers have been explained in our blogs and articles many times before, but for this blog we want to take an in-depth look on how to combine safety systems with a roof installation (in this case solar panels). How do these objects influence and complement each other? And more importantly: how does it benefit the people involved?
Maintenance and roof safety
To ensure maximum efficiency solar panels (also called PV systems) will require regular maintenance in the form of cleaning, inspection and/or repairs. The integration of a roof safety plan can play a major role in this. To ensure that workers have safe access to the PV panels all fall hazards have to be taken away by which can be done by means of an integrated fall protection system.
In a previous blog we already explained what the possibilities are for fall protection systems are in combination with solar panels. When choosing a solution you’ll always have to ask yourself if the chosen solution will affect the efficiency of the PV system.
Efficiency of PV panels
With ideal positioning and on a good sunny day, a standard series of PV (photovoltaic) panels with an average efficiency level of 15 to 20% could produce around 150 to 200 Watts per square meter/per hour. As you could imagine with a large sized roof of for example a distribution center or a production factory a large number of panels could be installed which could heavily impact the monthly costs in electricity.
There are a number of factors that can affect the efficiency of the solar panels on a roof. Some are controllable, such as the number of modules and the positioning of the panels. However, there are also a number of uncontrollable factors that can be taken into mind such as the hours of daylight that panels receive, the (seasonal) weather circumstances and potential shading – from trees or other objects near the building or on the roof.
How does shading influence a solar panel?
As mentioned above, shading can be a big factor in how efficient a solar system is. But how can a safety solution, such as a guardrail system, play a role in this?
In most cases where guardrail systems are used we speak of temporary guardrail systems, also called non-penetrating guardrails. This means that the system is not mounted (drilled) onto the roof and could be removed at any time. A temporary (free-standing) guardrail system consist out of a couple of components:
- A set of uprights (1),
- connected with a horizontal beam (2),
- and a counter weight (3).
All connected via two tubes which function as a hand- (4) and knee (5) rail.
On free end guardrail systems, as pictured below, the first/last horizontal beam has to be covered by a double counterweight block. Also, there can be chosen to add toe boards (6) to the guardrail in order to prevent items or objects, such as tooling, to be accidentally kicked of the surface and injure someone below.
As you could image this set up will also guarantee a small amount of shading on the roof surface and the solar panels. Let us explain how this can affect the efficiency of a PV system and how it can be resolved without bringing the roof safety into question.
Solar panel build-up
A solar panel system consists out of a series of PV modules. Each PV module is build out of a grid of individual solar/PV cells. Each cell is generating its own energy by absorbing the sunlight that is reflected on this cell. All PV cells that are on the same module are connected in series, which means that if one cell fails to generate energy the complete efficiency of that particular module is affected.
In case of shading, if one PV cell is covered by shade for an amount of time (variating per brand of panel) it stops working. Imagine of that approximately 20% of a solar panel is covered by shadow. This means that this panel will produce 20% less energy than when the whole panel is fully covered by sun.
Flexible guardrail systems
To ensure the maximum amount of required safety on a roof and the lowest amount of efficiency loss, the choice for a flexible (foldable) guardrail system can be made. This way you ensure workers that they have safe access to the PV modules at all times without the requirement of extra fall protection PPE (and training). When correctly positioned, guardrails can serve as a collective safety solution; protection for the entire roof surface with one solution.
When not in use, flexible guardrail systems can easily be folded down. This not only keeps them from creating shades on the solar systems, but also hides them out of sight for people who walk or drive past the building.
Advantages of flexible free-standing guardrails
- Collective solution providing full protection;
- Cost-effective solution (full protection with one solution);
- No requirement for additional scaffolding;
- Non-penetrating: no damage to roof surface;
- Flexible usage (fixed, removable and foldable in one);
- Additional toe boards if required;
- Low maintenance and inspections;
Download our fact sheet
Interested in how free-standing guardrails can serve your project or building? Download our XSFlex fact sheet and get to know our latest innovation when it comes to collective roof safety.