Mr. Hoult signed up for Powershop last April 2009 – mainly to save money, but as soon as he discovered that Powershop offered an open API (Application Programming Interface) he started tinkering with it. Since nighttime power is 25% cheaper than daytime power he set out to shift some of his power usage from the day to evening. He works from his home office and he did what a good enterprising tinkerer does: he ran experiments with his own power usage putting together available technologies in new ways.