Ключевые слова: alternative, background, battery, bio, business, clean, concept, conservation, design, eco, ecology, electric, electricity, element, energy, environment, environmental, flat, generator, graphic, green, icon, illustration, industrial, industry, isolated, line, logo, modern, natural, nature, oil, pictogram, plant, power, recycle, recycling, renewable, save, set, sign, simple, solar, sun, symbol, technology, turbine, web, wind,