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Solar Option initially had a single product, the SUNGOLA® solar optimised pergola (re-designated passive sun control).

Shade may not be the first thing you think of when 'solar' is mentioned, though it does have significant benefit toward energy conservation. It has a higher effect on energy conservation than producing electricity via photovoltaic (PV) panels, for cooling and heating, as it impacts all the energy in direct sunlight that may (without control) easily enter your home.

Later joined by the Solar Access Composite Image (SACI) to present the solar access for the whole year, specific to your building/location, in a pictorial/graphic and data report format. Showing clearly to what extent a decision to install a PV system or a Solar Water Heater (SWH) will be of benefit, or to what extent it may be effected by shade at any time of year.

More recently, the intent to minimise building damage/loss due to leaf litter build-up on roofs, has led to the design of products to eliminate debris from roof valleys and gutters.

©2016 Solar Option

The worst time to consider shade is when you really need it. It is most likely you select the most available option at that time, rather than the most appropriate for your needs.

Obviously maximum shade can lower cooling load during Summer. Not so obvious, a reduction of shade can assist with heating and lighting, during Winter.

Sunlight/shade varies year 'round!

Maximum benefit occurs by matching that variation!

Sungola logo

Passive Sun Control.

• Prevent direct solar heating of adjacent rooms during summer.
• Enhance solar heating and lighting of adjacent rooms during winter.
• Provide an outdoor entertainment area, year around.
• Self regulating shade, from 20% in winter to 100% in summer (designed to alter with the Sun path).
• Reduced rain beneath shaded area.
• No moving parts to wear or fail.
• No operational requirement/cost.

The SUNGOLA was designed to control the year around effect of the sun on comfort inside the home, and also create an outdoor entertainment area. The main criteria being to provide maximum shade during the hotter months, whilst also permitting maximum sun (light/heat) penetration during the coldest months.

The worst time of year to make a decision about which type of shade to install is during summer when the need is greatest, as the overall impulse is to get the maximum shade installed as quickly as possible. Then when winter rolls around you wonder where all that natural sunlight/heat has gone, and why you now need to use artificial lighting in the house during the day (when you never had previously).

The more objective time to decide is during winter or spring when you have time to evaluate the options, and choose which will suit you best throughout the year, as its impact/effect on lifestyle will be felt throughout the home' lifetime.

Preventing direct summer sun from reaching the windows is far more cost effective than trying to remove the heat from inside the building, after it has entered (passed through the glass).

     Summer shade  Summer shade photo                 Winter sunlight  

At the opposite end of the year, allowing penetration of winter sun into the building is the most cost effective form of heating and lighting. For maximum benefit replace North facing eaves with a SUNGOLA. Tuscan style houses benefit most as they normally have no eaves. Can be equally effective on the East and West sides, though is more dependent on depth (and height) due to low sun angles early and late in the day.

Due to the low sun angle throughout winter (and low angle of the shade elements), direct and reflected light can penetrate far into rooms, to reduce the need for lighting (as well as heating). The health benefit of natural sunlight and heating during winter is greatly under appreciated.

No other (fixed element) shade product provides the same extremes of shade, optimised for both the Summer and Winter solstices. As timber is not structurally capable (possibility of warping) of the same extent of optimisation, the SUNGOLA is only available in colourbond steel, or powder-coated aluminium. Metal shaping for strength allows integrated gutters to reduce rain penetration (timber could not normally incorporate this).

Any fixed shade product will require the addition of clear plastic sheeting to provide total rain protection, requiring a heavier structure to cater for wind loading of the 'solid' surface. Solar Option does not recommend this addition. The SUNGOLA has optional removable clear inserts which can easily be added as/when needed (and removed for improved ventilation). They also act as a safety valve during high winds if left in place.

As with any solar product, orientation is critical to functionality. Within 10° of the four cardinal compass points is ideal for easy installation as shade elements run either parallel or perpendicular to eaves (see element orientation on right), beyond 15° from ideal requires diagonal installation, or it will not function correctly.

Primarily locations between 28° and 38° latitude offer maximum benefits from the SUNGOLA design, due to mostly defined Summer and Winter weather patterns through those areas.

Available; fully installed, as pre-assembled panels or a completely knocked down (CKD) kit* for DIY.
*mainly outside Perth metro.

Though corrugated steel and opaque plastic sheeted verandahs create good summer shade, that shade carries over to winter, when it keeps the house interior dark. Depriving it of valuable heat and may require that lights be turned ON, even in the middle of the day.

Clear plastic sheeting can work well during winter by permitting heat and light into the house, but can create an unpleasant heat trap during hotter months. Though the sheeting is lightweight, the support structure must be 'beefy' enough to handle wind loading imposed by the solid covering.

Shade sails may be very aesthetic, but the majority are not installed for efficient/permanent passive shade. This requires them to be removed and stored during winter for good solar input, and reinstall again for summer. As mentioned in the name, it is a sail, and as such requires strong attachment to handle high winds, which can happen at any time of the year.

A North facing SUNGOLA can also be used to cover skylights to control the amount of high level (direct) sunlight permitted into a building.

Over skylight Over skylight          View from inside Under skylight

SUNGOLA pricing approx. $550 /sqm installed (Perth metro).

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Sungola Brochure.pdf (1mb)
Sungola pics.pdf (2mb)

Shade element orientation:

North facing
(True) North facing install


East/West facing
(True) East or West facing install


Diagonal install
Diagonal install
(greater than 15° from either of the above)

In development is an adjustable version which will be less reliant on correct orientation, and therefore be more expensive. It will be electronically self adjusting (open/close), to match your need for shade or sun, and the weather conditions.

SACI logo

Solar Access Composite Image.

• Specific to your proposed installation location.
• Shows sun path over the location for the whole year.
• Shows hourly position of the sun for each month.
• Clearly indicates if shade will be a problem, and to what extent.
• Proof of overshadowing in neighborhood disputes.
• Plan your new garden for future solar products.
• Show tree lopper exactly what needs to be removed/trimmed.
• All solar products function best with good direct solar access.
• Could be the difference between an investment and a costly mistake.

Resulting from an extensive knowledge of the sun path throughout the year (acquired whilst designing the Sungola), and observations of some inadequate solar installations, this product was developed. The Solar Access Composite Image (SACI) is designed to provide a visual image of how much direct sunlight a location can expect to receive for the whole year (and cause of reduction). SACI currently only available in Perth metro, and surrounds.

It is near impossible (even for those well qualified) to accurately envisage solar access at a location for the whole year. And then accurately convey that information to the relevant person, without some form of device to assist. This is currently the only service designed specifically to present the end-user/purchaser with an assessment of solar access at their location, in a form they can easily interpret. It is better/cheaper to know of any solar access problem/costs before committing to an expensive purchase, than try to rectify it later.

Though photo-voltaic panels and water heating collectors both rely on direct sunlight (and should face due North) for maximum efficiency, each has its ideal tilt angle (see Other Info). Solar water heating collectors are less prone to the effect of shade as they just drop efficiency, whereas some photo-voltiac panels can completely drop output from the same shade. Knowing of the likelihood of shade (where and to what extent) is essential.

If shade from trees alone is a big problem at your location and you are not prepared to have trees trimmed to the correct height forget about solar, as it will never be able to function properly. Even deciduous trees whose leaves have fallen in late autumn can still create enough shade (thick branches) to drop PV efficiency considerably, and should be treated as if they had leaves year around.

SACI requires a full circle (360 degree) photograph be taken at the location, showing all features above the horizon. This shows any building/structure/tree that may cast a shadow over the location. A graphic representing the (monthly) sun path over the location throughout the year is overlaid on the photo. The composite image indicates clearly if surrounding/overhanging features interrupt/block direct solar access.

From the circular image (which includes timelines) it is easy to estimate the amount of direct input, or determine what action may be required to maximise efficiency. The circular image can also be converted to rectangular, which may give a more recognisable image, as it shows a panoramic horizon that you may more easily relate to (containing the same information as within the circular image). The following image* is a converted version of the 'Good Solar Access' image (upper right) .

West.                                               North.                                                East.

Good panorama

Sunset.                                               Solar Noon.                                              Sunrise.

The SACI (and table produced from the composite image) will show you if/what remedial action may be required. If it is cost effective (tree lopping), or not possible (buildings/structures), which could mean the difference between an investment and a costly mistake. Otherwise it may be years before it becomes obvious that/why the system is not performing the way that had been anticipated prior to purchase. A bit to late to reconsider, but maybe not to late to rectify (if trees are the only problem).

Though primarily aimed at determining solar access, to enable solar products to function at maximum efficiency, a SACI can be used for proof of overshadowing by proposed (tall) buildings, as most local councils have some form of regulation/guarantee of solar access at a site (request R-code from your local council).

Price approx. $140 (Perth metro).

*The converted image does not normally show a full 360° horizon, as only features that create shade between/within the winter and summer solstice arcs of the sun path (and more than 15° above the horizon) are of concern. The image may still appear slightly distorted as it represents a hemisphere, shade features close to the horizon should be recognisable to the client.

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Good access img

Good Solar Access

Bad access img

Bad Solar Access

SACI leaflet.pdf (0.4mb)

SACI Table .pdf example (0.3mb)


Sunpath overlay features:

Red arcs = sun paths for summer/winter solstice and equinoxes
Black arcs = sun paths for months between
Vertical purple line = solar noon
Black lines = hours before/after solar noon
Blue lines = due East and West
Yellow circle/line = 15° above horizon.

(below 15° sun intensity drops dramatically and may contribute very little useful input)

Debris Exclusion Guttering (valley).
  • Exclude leaves and twigs from roof valleys.
  • Centre of valley always clear for water flow.
  • Eliminates valley overflow.
  • In bushfire, removes fuel source from inside roof cavity.
  • Assists wind to dislodge/remove leaves.
The roofs of many houses have multiple roof intersections, more for aesthetic reason than functionality, resulting in multiple locations where debris can accumulate in roof valleys.

The most common method to direct rain water from the tile/metal roof cover to down pipes, is by installation of open gutters and valleys. Being open, debris can build up over time, and eventually corrode the metal. Three flooding events prompted me to devise a way to eliminate debris from these areas.

Roof valleys at the intersection of two roof axis are at a flatter angle than either roof pitch. This results in retention of leaf/twig and other debris, often assisted by wind. During heavy rain, damming by this debris can cause valleys to overflow into the roof cavity, on to ceilings and down walls. During dry spells collected debris will dry out to become a fuel source that can easily be ignited by embers during a bushfire. If the debris is in the valley (under the roof cover) resulting flame has access directly into the roof cavity.

Mesh can be used to cover the valley, but will still retain debris and allow it to corrode the valley, requiring replacement. If the mesh is plastic it can also add to the fuel load during bushfire by collapsing into the valley along with the flaming debris.

The valley solution is a simple metal insert that is a D.I.Y. retro-fit for any roof. No tools required (apart from a ladder). Being solid rather than mesh, it minimises both debris retention and wind blowing debris/flame under the roof material (into the roof cavity), while ensuring the middle of the valley is always clear for water to flow.

The edge/main gutter is not a simple D.I.Y. solution as it does entail total replacement of the gutter. Being still in development, it will likely be a two part plastic and metal (or all metal) gutter, designed primarily to fit the rebate style fascia common throughout W.A. An essential item if you intend to collect all the roof water for personal use (or fire suppression).
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Leaves and other debris when dry will become a fuel source during a bushfire, or during rain can create a dam and result in overflow/flooding.

Such debris can be both difficult to remove and a danger to the property. Flooding can be expensive to repair, and fire could result in a total loss of the building.

Debris settling in the gutter/valley will eventually degrade it to a point where it has to be replaced.

Eliminating the amount of settled material will vastly extent the life of the gutter/valley.

Ensuring loose debris remains above the roof material means it is impossible for it to cause a flood, and prevent flame gaining direct access into the roof cavity.

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