Drip irrigation is an ideal application for solar pumping. The inherently rural nature of agriculture leads to a high upfront cost of bringing grid power to the fields. The cost of diesel in rural and remote areas makes diesel generators or diesel driven pumps impractical.
Historically, drip irrigation has been deployed using one large, central pump coupled with an industrial variable frequency drive or a large shaft driven diesel pump. The central pump distributes water to numerous zones via a series of valves. This architecture has multiple inefficiencies and limitations. The centralized pump and motor drive represent single points of failure for the entire system. The centralization of a single pump also creates challenges in keeping numerous irrigation zones balanced and requires multiple zoning valves.
By moving to a distributed architecture where each zone is powered by its own autonomous solar powered pump with a VFD controller, all of these issues are eliminated. There is no longer any single point of failure. Each zone can now be individually controlled allowing for easier flexibility in managing a variety of crops. The operating expense of powering a large industrial pump off of either the power grid or diesel goes away. Since the smaller pumps are manufactured at such dramatically higher volumes than the larger devices, the overall capex investment also is reduced.
The PicoCell’s sensor management capabilities allow for the zone specific integration of soil moisture and other sensors. The integrated WiFi or cellular communications module allows for the remote management of the system at a very granular level.
SunTech offers turnkey kits that include the pump, the appropriately sized solar array complete with panels, racking, cabling, disconnect and the PicoCell to control it all. An optional float switch can be added to turn off the pump when the tank is full or when the well is low.
Due to the need to provide aeration after dark to maintain critical O2 levels once natural photosynthesis driven oxygenation has ceased, solar power alone is often not sufficient. SunTech’s Pico architecture addresses this with its combination of PicoCell solar controllers and Hybrid Controller modules. The combination of these devices allows for the seamless blending of power from solar and other sources such as the grid, diesel gensets, and batteries. The SunTech Drive powered system works equally well with pump, compressor or paddle wheel driven aeration.
As cloud cover comes over the panels or day turns to night, the system will automatically draw power from the grid or other sources as needed to maintain full power. In areas of high power cost where only periodic night time operation is required, the system can be run in a timer mode to further reduce operating costs.
Decorative or aerating fountains are a popular feature in ponds. In addition to fountains for agricultural and decorative ponds, many are being added to bodies of standing water as a means of mosquito control, particularly in areas impacted by the Zika virus. Since these fountains are often installed in bodies of standing water where grid power is not available and prohibitively expensive to extend, solar power is the answer.
Evaporation ponds are used in a variety of industries including oil & gas, mining and salt farming. Whether the objective is to evaporate waste water or harvest salt, the approach is the same. Applying energy to atomize water or otherwise accelerate the passive rate of evaporation needs to be done cost effectively. Many installations today rely on diesel powered pumps or generators which are only marginally profitable when compared to a Solar or Solar-Grid Hybrid System. Other locations currently rely on natural, passive evaporation rates because diesel systems do not provide a positive return on investment. Some locations also have to contend with the challenges associated with freezing temperatures during the winter months.
SunTech Drive has developed sophisticated evaporation pond solutions incorporating surface based elements such as misting nozzles and liner drip lines during warm temperatures and automatically switching to subsurface elements such as compressed air diffusers when temperatures drop. All of these mechanical elements are driven by common solar PV assets to optimize ROI. The system is comprised of multiple autonomous zones each driven by small pumps and compressors taking advantage of the variable drive and boost capability of the PicoCell. Integral communications and sensor inputs allow for the incorporation of sophisticated sensor networks measuring wind speed and direction, air and water temperature, humidity, etc. Enhanced evaporation rates up to 6x the passive rate can be achieved with little variable operating expense. ROIs can be less than 1 year.