Wifi control of 230VAC powerswitches

Hi' I am helping a hospital in the northern of Tanzania to control their limited resources of power from their hydro power plant. Actually I am renovating the entire hydro power plant control, which is why I need some software development assistance. From my Hydro controller, I send information to a Power Management Unit, which in turn can control up to 15 power outputs for electric water heaters mainly. Nomally I would then just place the heaters on a separate phase and add relays to turn on/off that phase to a particular house, but since they have only drawn 1-phase power line to most of the houses, this is not an option. Therefore I will have to place remote Wifi controlled relays on each house to switch on/off the heater only, and not all the other power to the house. I plan to use either: [login to view URL] or [login to view URL] at each house receiving a wifi signal from a central omni directional antenna. From the hydro power controller I get an RS232 serial single byte sent every 50 times a second, this is also transferred over a Wifi link from the hydro power plant, and received at the hospital. The single byte contains a value from 0 to 15 to indicate how many loads are allowed to be on. = = all off. 5= 1 to 5 on. 15= all on. The development task is to transform this received byte into a signal that the Wifi switches can understand. These switches are nomally controlled from an App on a smartphone, but in our application we should preferably disable this option, or only allow this from an app with a master password, so that individuals cannot override the control from the hydro power plant controller. I believe these Wifi Power relays utilise the ESP8266 microchips, and that a lot of support is available on the internet for programming these, so I hope the task of implementing this is fairly easy to overcome. Timeframe: approx. 1 month, which should be more than sufficient.