While most raceways are large ponds, built outdoors, to maximize the use of natural sunlight, they can struggle to perform in those open environments. There are a number of challenges faced by the open and fully exposed algae raceway, such as:
- Accelerated evaporation due to the large surface area, shallow depth, and maximized exposure to direct sunlight
- Temperature fluctuations that slow down algae growth or kill it off entirely
- Contamination from water that runs over the surrounding surface and flows into the pond
- Access from interested animals and humans, which can lead to water quality issues or injuries
- Lack of infrastructure for supporting supplemental lighting during certain seasons
- Water quality changes due to a rapid influx of fresh water during every rainfall or flood
- The introduction of unwanted algae species that can quickly take over or contaminant the product without detection.
Covering open raceways with either floating ballasts or more complex greenhouse structures can solve all of these problems and more. However, it’s also somewhat daunting to arrange to cover large raceway ponds that can stretch over half an acre or more each. BTL Liner’s cover products are ideal for enclosing raceways and other algaculture structures and systems. In addition to RPE liners that can be used to safely line the raceways and ponds, we also fabricate clear greenhouse covers that work well for algae production. Our covers can be applied directly over the surface of the water with a retractable high-tension frame or used to enclose a greenhouse.
Greenhouse vs Flat Covering
Both types of coverings for raceways and other algaculture systems provide similar benefits. You’ll enjoy more stable temperatures, can heat the water as needed to accelerate growth without losing the warmth to wind chill, and will experience far less evaporation on a daily basis. Greenhouses are well worth the extra effort and cost for most algaculture projects if you plan to cover the ponds at all. The extra air space offered by a greenhouse structure makes the cover far more effective at modulating heat and evaporation alike. It’s also far easier to access the raceways for harvesting or cleaning while the cover is in place, reducing wear and tear dramatically over retracting and replacing the material on a regular basis. If the climate is warm, it may be necessary to remove or vent the cover daily. This is easier with a full-sized greenhouse than with a flat covering, even with automatic retraction equipment. The one downside to a full-sized greenhouse cover is the cost, which is obviously higher than for a simpler, flat cover.
No matter your choice, BTL Liners has a covering material to match your algaculture project. Check out our selection or discuss your needs with one of our expert team members today.
