Incatema is installing a photovoltaic solar pumping system in L’Azile (Haiti)

22 June, 2021

Incatema Consulting & Engineering is installing an autonomous direct solar pumping system within the project to expand and rehabilitate the potable water system of the city of L’Azile (Haiti). The system comprises 32 high-performance photovoltaic panels connected in two series of 16 panels each. These are polycrystalline solar panels of the type ATERSA 335 W 24 V, with 72 cells per panel. This type of panel offers a high performance with low light radiation, making it appropriate for the requirements of Haiti’s National Directorate for Potable Water and Sanitation (DINEPA) and guarantees sustainable energy for the installation.

Photovoltaic water pumping systems transform solar radiation into electricity through the photovoltaic panels. This electricity is then used to supply the electric pumps through the inverter. “In our case, as it is a direct system, without accumulators, power is not stored in the batteries, but rather pumping occurs in the hours when there is solar radiation, in other words, during the 8 hours when the greatest solar radiation is expected and always from a minimum of energy to be able to start functioning” points out Fernando Díaz, the company’s Director of Infrastructures.

As there are not accumulators, the system is autonomous and direct. The inverter itself has a direct power output to the pump set. To this effect, the equipment is fitted with a specific inverter for solar pumping of the type ATERSA-FUJI, Easy Sun Pump model ESP 5.5 kW / 400V, IP 54 F050, 60 Hz.

The system automatically adapts to the weather, increasing its efficiency and sustainability.

The Solar Pumping Control programme is included in the variable speed drive. It has functions specific to solar pumping, which reduces the number of necessary components and favours energy-saving.

The main functions incorporated are as follows:

1. Tracking of the Point of Maximum Power (PMP) for the PV solar generator. This exploits the maximum power available at the solar generator at all times.

2. "Passing Cloud" management. The system responds to sudden changes in radiation, avoiding shut-downs and start-ups of the pump that would not be acceptable in high power systems.

3. Pressure Control. This can limit the pressure of the pumping system to a maximum value by means of an external sensor. 4. Auxiliary AC input. The board assembly allows for an auxiliary AC input from a generator set or the grid to function in parallel with the solar panels without the need for any additional switches.

5. "Borehole dry" detection function. This function prevents the pump from running on empty without the need for senses. 6. Level detection. Equipped with inputs for configurable level sensors to shut down operation once the established level is reached. 7. Configurable for asynchronous and synchronous permanent magnet motors. Given their greater efficiency, permanent magnet motors are an efficient option for solar pumping.

8. "Wake" and "Sleep" function. This includes the programming required to operate only with the solar generator, avoiding unnecessary start-ups and shut-downs when the sun rises sets.

The systems include default factory settings that simplify and reduce the time required for set-up during commissioning; no two systems are the same.

The pumping equipment allows for a maximum operating pressure of 1600 KPa (Kilopascals) and a maximum supply pressure of 10 bar. It can operate at a maximum temperature of 50 ºC. The design flow rate is 39.40 m3/h (cubic metres per hour) and the height of the water column is 16.70 metres.

L’Azile is a commune in Haiti situated within the district of Anse-à-Veau,in the department of Nippes. “We are dealing with the dual challenge of bringing drinking water to the country where it is most difficult to obtain it in the world, and of doing so using sustainable systems that guarantee the efficiency of the installation with the resources available in the zone, which in this case centre on solar energy, a free resource available in a zone punished by the earthquake in 2010 and the scarcity of infrastructures.”

The project to expand and rehabilitate the potable water system of the city of L’Azile (Haiti) will optimise the current system by recovering existing infrastructure. At the same time, it will improve the access to drinking water for the city’s 30,240 inhabitants. It also includes construction of 10 km of pipes, a 130 m3-capacity tank, a chlorination system, and the rehabilitation and protection of the basin of the affluent of the Grande Rivière de Nippes river.

The budget for the project is 1.4 million euros financed by the World Bank.