But advances in the industry and over-production have reduced their price by as much as 75%. The cheapest system, generating two watts of power, can cost as little as $10-20 and be expanded to almost any level, depending on the size and number of photovoltaic (PV) modules and the size of the battery storage unit.
这是一次全新的机会。直到三、四年前，光伏发电还极其昂贵。但行业进步和产能过剩使价格出现了高达75%的降幅。能发两瓦电的最便宜的系统成本仅10-20美元，而且只要光伏（PV）模块的数量和电池存储单元的容量允许，可以拓展到几乎任何水平。