SBIR-STTR Award

SmartSpark Energy Systems proposes a battery-free power supply for unattended field use that combines advanced power electronics with state-of-the-art photovoltaics and high-density double-layer capacitors. The technical challenges are to develop and apply sophisticated power electronics for optimal energy management of a photovoltaic source, to store the energy efficiently in a reversible process over thousands of cycles, to provide tightly regulated dc power supply outputs, and to package the system to be waterproof and reliable under harsh weather conditions. The expected outcome is a modular system that can produce power unattended for at least four years while delivering energy of 5 W-hr/day, scalable to 10 W-hr/day and 25 W-hr/day. SmartSpark plans to combine its patented solar power processing and energy storage management inventions with innovations in power electronics control to achieve the technical objectives. The objectives include efficient energy conversion from photovoltaics even at low and variable light levels, energy storage input-output efficiency exceeding 80%, outputs that support standard 12 V, 5 V, and 3.3 V loads, and a package that allows the system to reach 100,000 hr computed mean-time-between-failure in wet environments. A system is planned that achieves this with a 2.5 kg (5.5 lb) mass and volume under four liters.

Keywords:
Alternative Power Sources, Power Electronics, Remote Power, Unattended Operation, Photovoltaic Energy Processing, Dc Power Supply, Persistent Unattended Surveillance, Remote C

This project will develop fully functional prototypes of a battery-free portable power source that can be deployed in remote, unattended locations. The power source will provide up to five watt-hours per day under extreme weather conditions for a minimum of four years without maintenance. The design relies on solar energy, and uses ultracapacitors for energy storage. A modular interconnection permits scale-up to 10 W-hr/day, 25 W-hr/day, or more by direct interconnection of multiple units. The design applies power electronic circuits and nonlinear controls to draw maximum solar power, interact with energy storage, regulate the output voltage, and manage fault conditions. Ultracapacitors will be tested to ensure that lifetime improvements from voltage derating will offset lifetime reductions from extreme temperatures. The project plan involves construction and test of initial prototypes to complete and validate the design. Following this, and the completion of package designs, a second prototype version will be constructed for initial in situ field tests. Initial field test results will be used to adjust designs for complete, field-ready prototypes. An approximate size of 12" x 12" x 3" is anticipated for final units, based on silicon solar cells. Smaller sizes are supported by advanced triple-junction compound solar cells.

Keywords:
Power Electronics, Ultracapacitors, Remote Power, Photovoltaic Energy Processing, Remote Communications, Unattended Operation, Persistent Unattended