After building a DIY solar hot water panel in 2010, I wanted hard data to see how well it performed. So commenced a long, epic journey of Arduinos, Raspberry Pi's, sensors, servers and low power radios.

Later adding ‘real’ PV solar panels (needing electricity monitoring), export diversion (using surplus electricity to heat water), appliance monitoring (more monitoring), an electric car and charger (yet more monitoring), a house battery (urgh! complicated), weird 'Time Of Use' electricity tariffs (truly mind bending) and an in-depth look (with thermal imaging) of my gas central heating system, I can tell you what has worked for me, what failed and where i’m going next, plus how you can save energy, save money & save the planet!