In less than a decade, solar power is likely to be the lowest-cost energy option almost everywhere on the planet, according to Bloomberg New Energy Finance analysts. It is already the least expensive energy source in a number of countries, where auctions bring in record-low costs that are half the average global cost of coal-fired power. That trend will become the norm by 2025, says Bloomberg. Since 2009, solar prices are down 62 percent, with technology advancements, improving economies of scale and manufacturing experience driving a supply-chain “Wal-Mart effect” of higher volumes and lower margins. BNEF analysts project the average 1 megawatt-plus, ground-mounted solar system will cost 73 cents a watt by 2025 compared with $1.14 now, a 36 percent drop that is similar to projections from others analysts.