The three C’s when you get in trouble flying an airplane are: Control, communicate, and confess. Many an incident could have been avoided using this mnemonic.
When it comes to energy, the three C’s are Conserve, Combine, and Create. In that order. We don’t need to put enough solar panels on a leaky building to increase the rate of climate change, we need to tighten up the building envelope so that we can put a minimum number of collectors on to provide heat. Similarly, we don’t want to put enough building photovoltaic (PV) panels to power incandescent lights and a resistance water heater; we want to put the minimum number of panels on after we have converted to Light Emitting Diode (LED) lights, and a heat pump water heater. When it comes to the second C, the heat pump water heater is a good example: use it to both heat water and dehumidify the basement!