Kenya’s coastal City of Mombasa receives on average 8 hours of sunshine every day. It is no wonder then that the Mombasa based Moi International Airport will try to harness energy from this sunlight and while at it try to cut back on the airport’s electricity Bill. We spoke to Eng. Owen Waithaka, the airport manager who volunteered details of the Airport’s Solar project. This discussion is part of our extensive coverage of the Airport rehabilitation project.
On the Airport’s Power needs…
The reason why solar was installed was for the gate equipment and that is why we call it solar at the gate. We have two gate equipment which are the air conditioning for the aircraft and the power supply for the aircraft when it is docked at the gate. That was the main reason to help us reduce on carbon dioxide emission.
We have this switchgear we call substation B where all the power comes before it is distributed. Power comes here from KPLC (two lines), two generators and the solar panels. We have a monitoring and control system for the solar power. We also have metering equipment from all the supplies just to show us what we are consuming from where.
It is called a gate because for international passengers this is like the gate to the country. Once the aircraft is parked here there are two things it requires as the people disembark or board. It requires air conditioning and external power supply so the pilot is able to switch off the engine. Boarding and disembarking can sometimes take long so the plane would need external air-conditioning and external power in order to save on fuel and consequently if we are not burning fuel then we are cutting down on emission. So the external air conditioner and power supply is what we refer to as gate equipment and we are now powering these by the solar project.
The project uses a total of 1,560 solar panels each of 315 watts giving us a total of 491,400 watts. The decision to put this panels at their current location (land side) was reached at after weighing various options. We considered putting them at the airside for security reasons, or build structures at the car park or just put them on top of roofs of our buildings but all those options were discarded because of glare. We didn’t want to disturb the pilots.
Because of the distance of the panels from to the substation, the power from the panels is transformed from 415V to 11KV for the purpose of transmission.
This project was necessitated by studies which are being done all over the world to mitigate carbon dioxide emission especially for international flights. So this particular project is a pilot project in Africa and its main purpose is to reduce emission at the gate. It is fully financed by ICAO together with the European Union but with the Kenyan government also putting in contributions like payment of taxes and provision of the land.
The project was started late 2018 and commissioned at the end of June 2019. We have already had good experience with this project and have been thinking about expanding it because its current capacity can only serve one gate at a time. We have six gates and would like to cover all of them. We have also realized a drop in our power bills and by expanding we will see the bills drop even further.
For the airport at the moment we have not experienced any challenges. The major challenge normally for a project like this would be the land or space but for us at the airport we have land and space available. The system is also still very new so we haven’t experienced any maintenance challenges. We have engaged someone to do a service contract for five years so we do not expect any issues. An issue that would arise is if we decided to shut down the mains power to use this at night because then we get a challenge of batteries which are very expensive and have a short lifespan.