Uninterruptible Solar Power Supply using LM3S811
The gradual warming of our planet due to man-made pollution is a topical issue. There are record high levels of greenhouse gas emissions, and 20% of these gas emissions can be attributed to residential energy use. One component of residential energy is the power used by standby loads, such as answering machines and cordless phones. The plug pack used to power such devices runs 24 hours a day, 7 days a week, consuming a small but constant amount of energy. Over a year, this figure can add up to a surprisingly significant amount of energy, for example 27kWh for the typical answering machine. This equates to roughly 27 metric kilograms (43 lbs) of CO2 gas generated from a coal-fired power station.
The uninterruptible solar power supply is intended to take these small standby loads off the grid, and power them directly from solar panels. The supply acts as an uninterruptible power supply (UPS), switching seamlessly back to the grid if the solar power is unavailable during the night or cloudy weather.
One advantage of using a solar-powered UPS is that it bypasses the usual regulatory requirements imposed by utilities on grid-interactive solar power systems, as the solar panels are never directly connected to the grid. Another advantage of focusing on powering only standby loads is the system cost is kept low, requiring in most cases only a single solar panel. The device is shown working below supplying a 40W globe.
This won a circuit cellar design award back in 2006, can't seem to find the link any more.