SBIR-STTR Award

This Small Business Innovation Research (SBIR) Phase I project will research and develop an efficient, integrated single-chip solar powered charge control circuit charging lithium ion (Li-Ion) and nickel metal hydride (NiMH) batteries from micro-solar panels for remote sensor and portable electronic applications. To achieve this goal, our investigation will focus on the following areas: 1) Research and development of an efficient power control algorithm and boost circuit optimized for applications using micro-solar cells, 2) Research and development of programmable embedded control circuits required to automatically control proper charging of Li-Ion and NiMH batteries. The intellectual merit of the proposed activity is to provide efficient, low cost solar energy harvesting solutions for autonomous sensor and mobile consumer electronic products. At the end of this project, an integrated, single chip maximum power point tracking (MPPT) circuit with integrated voltage boost and programmable battery charger circuitry will be demonstrated. The novel automatic MPPT algorithm enables a single solution for 1 to 8 cell panels without a change in circuit board parameters and eliminates the need for external microcontrollers. The integrated boost/MPPT features do not exist on the market today. The broader impact/commercial potential of this project is very large because of the scalable nature of this technology. Scalable energy harvesting system blocks have application to solar charging for portable products, autonomous wireless sensors for real time system control, and larger rooftop solar harvesting for residential and industrial applications. This wide application space represents a significant opportunity to enable harvested renewable energy and reduce dependency on non-renewable energy sources. From a commercial perspective, all of these applications are anticipated growth markets over the next decade. Growth in cell phone use in developing regions like Africa, India, and China offers a large opportunity for solar charging. In addition, the recent earthquake in Japan has highlighted the need for solar charging for cell phones and flashlights when the power grid is vulnerable to natural disasters. Efficiency improvements in new wireless sensors systems and residential/industrial solar power systems will drive new demand and provide reduced costs of adoption for consumers. The results of this research project will increase solar energy harvesting effectiveness for small and large systems thereby providing consumers with new choices for energy savings and new freedoms for grid-independent power.

This Small Business Innovation Research (SBIR) Phase II project will address the efficiency issues with existing solar harvesting technology and the excessive power consumed by the power management circuitry. The proposed technology addresses the solar performance issues by including a low-power Maximum Power Point Tracking (MPPT) algorithm to maximize solar collection efficiency under variable lighting conditions. The patented technology reduces the power consumed in the charging electronics by 60x over existing products. The solar power solutions developed will minimize the charging time while meeting portable form-factor requirements in both indoor and outdoor lighting conditions. The first development phase will define specifications and develop system level implementations for portable charging and standalone off-grid applications. In the second phase, technologies used in the prototype systems will be integrated into a single device to further reduce overall size and system costs. The final product of this Phase II effort will be single-chip integrated power management devices for portable charging applications and standalone autonomous off-grid systems. These devices will deliver class-leading solar conversion efficiency both indoors and outdoors, and have revolutionary power dissipation levels that will enable new applications and markets that were not possible with products on the market today. The broader impact/commercial potential of this project is to improve the environment, enable new markets, and provide opportunities, jobs, and tax revenue. In the past, solar energy harvesting was not taken seriously due to lack of flexibility and portability. Early solar panels and harvesting electronics were too inefficient and expensive to be useable, and remained a niche product. With advances in harvesting and charging technologies, solar power can be used effectively in many consumer standalone and portable applications. The proliferation of these efficient, cost-effective solar and low-power solutions can reduce a system?s carbon footprint. Utilizing this proposal?s technology and working closely with solar panel manufacturers, solar charging and energy harvesting becomes a viable alternative to replaceable batteries and grid-power. North American consumers use approximately 200,000 tons of cell batteries each year, 95% of which end up as waste. High-efficiency solar rechargeable systems can reduce the amount of toxic battery waste that ends up in neighborhood landfills. In addition to the positive environmental impact, the technology enables new markets and growth in existing markets which allows firms to grow and provide opportunities, jobs and more than an estimated $1.5 million in federal income tax revenue over the next 5 years