Once in a while we get asked about ground mounted solar pool heaters. We normally install solar panels on roofs, mounted flush to the roof. This is the easiest and most economical installation method. It makes sense for many reasons.
Some of the reasons people cite for requesting solar panels on a ground rack are:
- Avoid seeing the solar panels on the roof, or they want to see them (it happens).
- Not enough roof space to fit solar panels.
- Concerned about roof damage or their roof will need replacement soon.
- Think it will work better or will be more easily serviceable.
- They think it’s cheaper.
Arguments Against Ground Mounted Solar Pool Heaters
It’s completely reasonable to explore something other than a roof mounted solar panel system. However, there are some key reasons that ground mounts are not the way to go.
We can’t argue with aesthetic reasons for requesting solar panels on the ground. It’s a matter of personal preference. All we can say is that tens of thousands of homes in Southwest Florida have solar pool heating systems, and it’s the norm. People are accustomed to seeing them. Once installed, customers report that they rarely look up and notice them.
If you don’t have enough space, that is a legitimate problem. Solar pool heaters do take up a lot of space – roughly the same surface area of your pool. On hip roofs that are all cut up into small sections, it can be tough to get enough coverage for effective operation.
Roof damage is pretty rare, and extremely rare when installed by a well trained, competent staff. The first factor is knowing how to properly walk on roofs. Stepping carefully in the right places will help eliminate damage, especially to tile roofs. Second, the installer needs to be an expert at flashing and sealing all fasteners penetrations. This takes training and experience. Third, using the proper products and methods to protect each roof type is of paramount importance. Cutting corners is common in the industry. And finally, a company culture that encourages extreme care and respect for customers’ property yields excellent safeguarding of roofs.
If you are going to need a new roof soon, you should explore the removal and reinstallation costs for solar panels. This can often be done economically, and you can negotiate this in advance for future potential reinstallation.
There are some types of roof that are not suitable for solar pool heating panels, like metal simulated tile, true slate, and some glazed clay tile.
A ground mounted system will not work better. The lift required to get water to your roof is small for a well designed product and system, and the downward flowing water creates a siphon effect that makes flow restriction from heights negligible. Roofs also tend to radiate head onto the back of solar panels, adding to their performance. Roof mounted panels are often (but not always) less susceptible to shading.
Solar pool heating panels also need to drain properly when the pump shuts off (unless you install and use a manual drain). Sometimes panels placed at ground level are actually below the pool or pool equipment level, so they do not drain. This can cause freeze damage, heat damage (from stagnation), and other problems.
This is where we have to stop people thinking about ground mounted solar pool heaters. The costs associated with building a ground mount are very high if done correctly. We have seen our share of rickety racks for solar panels that fall apart, causing damage to the panels and plumbing. We have also seen competitors just lay solar panels on the ground. That is a terrible idea from both a performance and drainage standpoint.
To do a proper ground rack you need to install both an aluminum rail system and something to hold it down. That is usually a concrete footer or tubular footings. To meet the stringent Florida Building Code you would be surprised at how much wind uplift needs to be accounted for. That means ground racks sometimes require a huge amount of concrete in the ground.
The cost of the aluminum rack, labor, and the concrete footer can sometimes double the cost of the solar pool heater. The biggest problem is often engineering. A professional engineer needs to design and stamp drawings for the ground rack. Since this would be a case-by-case basis, the costs are high.
Consequently, roof mounted solar pool heaters are far more economical because the roof itself is the mounting rack. Specially designed hardware is available to cover virtually all roof types. Engineering is standardized to account for all likely scenarios.
Your Best Mounting System Is Your Roof
Your roof is designed with a structure below it that supports live and dead loads and also resists uplift from high winds. The truss systems on homes are engineered to support far more weight than solar pool heaters add. The roof membranes used today (shingle, metal, tile, etc) are very durable. Tailor made products exist for the mature solar pool heating industry for each roof type. Sealants have come a long way. Methods and materials that protect roofs are well established.
Since you already have a roof (we hope), it stands to reason that using will be the most economical route.
If you just can’t stand the look of solar panels, you are quickly falling into the minority. Solar panels have become the norm rather than the exception in many parts of the country. Solar pool heating is so popular in Southwest Florida that you would be hard pressed to find a neighborhood without several systems. We don’t want to be rude, but the best we can offer is “get over it!”
And if you roof does not have enough space for a solar pool heater, we may recommend an electric heat pump. Also, if significant shading eliminates some areas from consideration, we might recommend tree trimming. And if there is truly no opportunity for roof mounted solar we are willing to talk to you about a ground rack. Just be prepared to pay the price.