This chart shows the total coal used for heating shower water for all of the USA in one year. Water heating accounts for 9% of a household's electricity usage, in addition I have added 1 percent for the embodied energy used in water treatment, so this cube represents 10% of the total electricity consumption of American households which was 1,286 billion kWH in 2009 (EIA). It does not take gas hot water heating into consideration, so it is only relevant for households with electric hot water systems. Solar hot water systems are an easy and viable alternative to using so much coal for heating showers. Solar hot water is the 'low hanging fruit' of sustainability. Systems cost approximately $3,000 and pay themselves off in 3 to 5 years and most have financing plans available for those who are not able to pay the upfront cost. Most of America's coal is generated through the environmentally catastrophic method of mountain top removal, so all means of reducing load on the electricity grid, not only reduces carbon dioxide emissions, but also reduce the viability of new mountain top mines being opened. Morning showers create the largest peak demand on the electricity grid - these peaks in demand are the greatest driver of new coal power stations.