Sponsored by
Making Hydraulics Obsolete
Every excavator, forklift, and crane on the planet runs on hydraulic fluid. It leaks. It fails. It burns through 60% of the energy you put into it. That's been true for a hundred years.
RISE Robotics built Beltdraulics™ to fix all of that. Their patented actuator swaps out hydraulic cylinders for a fluid-free electric system that runs up to 3X faster and cuts operating costs by 50%. No oil. Full digital control. Built-in sensors that hydraulic systems can't touch.
The U.S. military is already a customer. MIT-founded. $9.3M in revenue. 20+ patents protecting the core technology. Dylan Jovine of ‘Behind the Markets’ said RISE “has all the little ingredients to be one of those really big winners.” His readers have been backing it ever since.
You can invest today through the community round on Wefunder.
AS 1170.1 AS 1170.2-2011 AS 1170.3-2003
Why Structural Engineering Comes First
The first question any competent solar designer must answer is not "how many panels can we fit?" — it is "can this roof safely carry those panels for 25 years?" The AS 1170 series of structural design action standards provides the engineering framework to answer that question definitively.
In Australia, structural compliance is not optional. Roof-mounted solar systems add both dead loads (permanent weight) and wind-induced loads (uplift, drag, and racking forces). A failure to account for either can result in panels detaching from roofs — a hazard to people on the ground and a source of major property damage.
AS 1170.1 — Permanent and Imposed Actions (Dead Loads)
AS 1170.1 covers the self-weight of structures and their permanent fixtures. For solar, the relevant loads include:
Component | Typical Weight | Load Type |
|---|---|---|
Standard 400W solar panel (glass-framed) | 18–22 kg | Dead load (G) |
Aluminium rail mounting system (per panel) | 3–5 kg | Dead load (G) |
Roof penetrations, brackets, fixings | 1–2 kg per point | Dead load (G) |
Ballasted flat roof system (per panel) | 40–80 kg | Dead load (G) |
Personnel during maintenance | 1.0 kN point load minimum | Imposed load (Q) |
For a standard 6.6 kW residential system with 15 panels at 22 kg each, plus mounting hardware, the total roof load is approximately 380–420 kg spread across the array footprint. The structural engineer must confirm that existing roof framing (rafters, purlins, ridge beam) can carry this load without exceeding allowable deflection or causing rafter roll.
AS 1170.2-2011/R2016 — Wind Actions
This is the most technically demanding standard for solar installers. Wind loading governs the fixing design — how many screws into rafters, what thread engagement depth, and what pull-out force each fixing must resist.
Wind Regions in Australia
Region | Location | Design Wind Speed (VR500) |
|---|---|---|
A (Non-cyclonic) | SE Australia, Vic, SA, Tas interior | 45–57 m/s |
B (Non-cyclonic, coastal) | NSW coast, SE Qld, SW WA | 57–66 m/s |
C (Cyclonic) | Tropical coast — N WA, NT, N Qld | 66–80 m/s |
D (Severe cyclonic) | Pilbara coast, NW WA | 80–100 m/s |
Critical for installers: A system designed for Region A fixings is not compliant in a Region C cyclonic area. Using undersized fixings in a cyclone zone can cause full array detachment. Always check the wind region map at the start of every project.
Key Wind Load Calculations for Solar Arrays
The design wind pressure on a solar array panel is calculated as:
p = qz × Cfig × Cdyn
Where: qz = free stream dynamic wind pressure at height z
Cfig = aerodynamic shape factor (for roof-mounted arrays)
Cdyn = dynamic response factor
For residential rooftop panels at typical tilt angles (10–25°), the critical load case is usually uplift (wind pulling panels off the roof), not downward pressure. Edge panels and corner panels experience significantly higher uplift coefficients than interior panels — this is why perimeter rows need more fixings per panel.
Terrain Categories and Topographic Multipliers
TC1 — Exposed open terrain (coast, open land): highest design wind speeds
TC2 — Open terrain with scattered obstructions: moderate
TC2.5 — Suburban terrain
TC3 — Urban terrain with closely spaced buildings: most shielding, lowest design speed
Additionally, local topographic effects (escarpments, hills) can increase wind speed by a topographic multiplier (Mt) of up to 1.45. A hillcrest installation may see wind forces 80% higher than a flat-terrain site in the same wind region.
AS 1170.3-2003 — Snow and Ice Actions
Required for installations in alpine zones (Snowy Mountains, Victorian Alps, ACT high country). The standard defines:
Ground snow load based on altitude and return period
Roof snow load conversion factor (accounting for roof pitch and thermal effects)
Snow drift loads — panels can cause snow to accumulate at their lower edge, creating concentrated loads on the roof below
Ice accretion — adds dead load to panels and affects aerodynamics
Practical Checklist — Structural Sign-Off Before Installation
Roof material, age, and framing type confirmed
Wind region and terrain category determined from AS 1170.2 maps
Panel dead loads calculated and confirmed within allowable rafter loads
Fixing type and quantity determined (engineer-specified or racking manufacturer's table)
For TC1/Region C/D: engineer's certificate of structural adequacy obtained
Roof condition inspected for rot, corrosion, or previous penetration damage
Snow loads considered if site elevation exceeds 1,200 m
Engr. Jason Morales — Founder, SolarEnergyPH