Ground mount commercial solar systems and Agrivoltaics
Veli
Ground mount commercial solar systems and Agrivoltaics
Ground mount systems are becoming more and more common in rural areas where roof real estate tends to be lacking.
Compared to roof based solar there are a lot of extra considerations to look at with ground mount which include:
Soil types you're dealing with
The proximity of the main switchboard to the array
The fact that a considerable amount of trenching is involved
Row spacing, not only from a shading perspective, but also vehicular access
In addition a ground mount solar system can include another concept called Agrivoltaics.
Ground mount versus roof
Basically a ground mount system involves the construction of a freestanding steel or aluminium structure which is firmly anchored to the ground and supports the photovoltaic array.
Commercial ground mount systems compared to a roof mount system add another layer of complexity on top of existing installation requirements and also there's a lot more documentation required such as:
Vegetation overlays
Aboriginal heritage overlays
Traffic management plans
Rare and endangered species survey results
The considerations
So with ground mount systems we are looking at a completely different canvas from roof mount.
Other considerations include is the area a flood plain?
You really don't want to be designing your ground mount system in an area that has a dry ephemeral nature.
In other words it can be flooded for three or four months of the year and then dry for the rest!
Also when it comes to ground conditions, reactive clays are probably one of the worst things that you can deal with because crack sizes can fluctuate depending on the level of moisture and this has resulted, historically, in a considerable number of the piles installed developing a bit of a lean and contractors have had to go to site and basically put a concrete collar around these posts to establish their original vertical position.
Roof mount
When it comes to configuration with a roof situation, commercial solar companies will design for the panels to be flat to the roof or on tilt and the decision is based on the physical nature of the roof and it's weighted based on cost benefit analysis around increased labour and material cost with tilted systems versus more output versus system price but with ground mount systems, in nearly all cases, panels are tilted at the optimum for the location in question or have a tracking type of arrangement.
Agrivoltaics
The concept of agri-voltaics came about in 1981 and effectively what it means is the combination of renewable energy, in most cases solar but also wind farms, with cropping and the use of livestock.
So how does it work?
The solar panels are put into a ground mount configuration with some slight variations on your standard ground mount.
In some cases they are positioned higher up so more available light can come in under the panel.
The row spacings can sometimes be wider to allow crops to flourish and animals to graze and the other option is when the panels are actually placed, instead of being butted up against each other with a 15 to 25-30 mm gap they tend to have a wider gap.
Agrivoltaics: a mixed land proposition
So what we're talking about is a mixed land proposition where the panels are producing an income in addition to livestock and/or cropping, also contributing.
Also there are advantages because of the potential micro climate created by the solar panels that may allow the farmer to grow other crops that previously he wasn't able to due to higher temperatures etc.
Arizona University has a site where the panels are three metres off the ground and the tomato production doubled and the water efficiency increased by 157%.
What it comes down to is this; when you place any structure anywhere it'll create an effect so if I place a shading structure out on a rural setting or anywhere, it will create its own microclimate not only under the panels but around the panels and those effects will be transferred to whatever else is living or growing under the panel.
Reduced bird strikes
In addition there's been numerous studies in regards to bird strikes so, in other words, sheep giving birth to lambs are very susceptible to eagles especially in Australia and the solar panels actually installed on grazing land act as a barrier or a deterrent against the eagles attacking the birthing mothers.
There will be areas of land that are totally suitable only for agriculture and you wouldn't want to install a commercial ground mount system at these locations and then, at the other extreme, there's areas of land that would only benefit from a commercial solar system but they're the extremes and most land tends to fall in the middle so it's finding that mix, that energy density of the solar panel array, what crops can be grown or stocking rates with sheep or cattle and in some cases there's been examples where there's been crops, livestock and renewable energy all grown together!
This is such an exciting area and really is a no brainer; water, food, energy.
Have any any you been involved in a Agrivoltaic project and if so please let us know here at Community!