Ключевые слова: bill, cash, cheap, cheapness, coins, cost of light, cost of living, costs, dark, decrease, ecology, economy, ecosustainability, ecosustainable, electricity, electricity costs, energy, energy classes, energy dependence, energy sources, energy tariffs, environment, eur, expenses, household budget, incandescent, increase, increase in costs, lamp, light, light bulb, lighting, money, ordinary costs, raw, raw materials, resources, saving, savings, sustainability, sustainable, tariff, value,