The hypothetical Green Island has an independent grid operator, competitive power producers and a smart grid. Cheap solar daytime energy and renewable nighttime energy (for example biomass or pumped storage) provide the basic energy. Additionally, operational reserve is available to regulate passing clouds and higher than anticipated loads.
In February we fed 602 kWh into the grid. This is roughly 3x the amount we consumed from the grid, and we had a small bill, not a credit at the end. This is because Schedule Q allows KIUC pay us 1/3 of what the charge per kWh.
A large-enough grid-tied PV system provides the energy to charge our Nissan Leaf. When our PV system is producing power during the day, the EV charger or any appliances that are running are directly fed by solar power.
For maximum efficiency we combined a solar-powered mini-split air conditioner with batteries – if the AC is not used the energy is stored for use in a energy-saving lighting system.