JSFiddle - React, Tailwind, and code Playground

JavaScript

function createObj(proto){
    if(Object.create){
        return Object.create(proto);
    }

    function F() {}
    F.prototype = proto;
    var obj = new F;
    return obj;
}

function Network() {
    this._elements = [];
}

Network.DAY = "day";
Network.NIGHT = "night";

Network.prototype.addElements = function() {
    for (var i = 0; i < arguments.length; i++) {
        if (arguments[i] instanceof NetworkElement) {
            this._elements.push(arguments[i]);
        }
        else{
            throw new Error("Аргумент "+ arguments[i]+" не является элементом сети");
        }
    }
};


Network.prototype.getPowerProduction = function(timeOfTheDay) {
    var powerProduction = 0;
    for (var i = 0; i < this._elements.length; i++) {
        if (this._elements[i].getPowerProduction) {
            powerProduction += this._elements[i].getPowerProduction(timeOfTheDay);
        }
    }
    return powerProduction;
};
Network.prototype.getPowerConsumption = function(timeOfTheDay) {
    var powerConsumption = 0;
    for (var i = 0; i < this._elements.length; i++) {
        if (this._elements[i].getPowerConsumption) {
            powerConsumption += this._elements[i].getPowerConsumption(timeOfTheDay);
        }
    }
    return powerConsumption;
};

Network.prototype.getPowerExcess = function(timeOfTheDay) {
    return this.getPowerProduction(timeOfTheDay) - this.getPowerConsumption(timeOfTheDay);
};

Network.prototype.getProfit = function(timeOfTheDay) {
    var powerExcess = this.getPowerExcess(timeOfTheDay);
    var profit = 0;
    var result = 1;
    var lines = [];
    if (powerExcess < 0) {
        result = -1;
        powerExcess = Math.abs(powerExcess);
    }



    for (var i = 0; i < this._elements.length; i++) {
        if (this._elements[i] instanceof PowerLine) {
            lines.push(this._elements[i]);
        }
    }
    if (result > 0) {
        lines.sort(function(prevElem, currentElem) {
            return currentElem.getPowerCost() -...