One of the things that pleases me is the rate that 'off grid' electricty is rapidly improving. I was not alive in the 1970's but I imagine that a 5 watt solar panel could be purchased for about $50-$100. I can say that about in the year 2013'ish I bought 45 watt pannels for about $150. By about 2017 a person could purchase 100 watt panels for $150. However battery technology is limiting what can be powered with electricty, because batteries tend to weigh alot.