Solar energy harvesting estimates continue to show growth over the next few years, with energy harvested for portable consumer products becoming more of a contributor in total overall harvested energy. The blue portion of the graph indicates the energy generated, in gigawatts, by portable consumer products that use solar power as their energy source. If an assumption is made that an average portable consumer product is equal to 1 W, then the total overall quantity of devices which generate the needed 1 W of power will equal nearly 1 billion devices by the year 2019.