os.loadAPI("ocs/apis/sensor")
sensor = peripheral.wrap("back") --#Power Sensor card in sensor on left
function mfsuPower()
    local power = 0
    for i, j in pairs(sensor.getTargets())
            if j.name == "MFE" then power = power + j.power end --#I don't know what the name or power is stored as, do a textutils.serialize() to find out, will also tell you what the MFSU name is which I am also guessing at
    end
    return power
end
print(mfsuPower())