The intermittent nature of solar photovoltaic (PV) electricity generation creates a considerable barrier to relying on it as a source of consistent energy. Solar intermittency and power fluctuations vary greatly over the course of a day, in time intervals ranging from seconds to minutes.

To address this problem, NanoTune is working to modify solar panels to store small amounts of energy and be able to provide consistent levels of electrical power regardless of any variations in solar intensity. This will also relieve the need for other forms of costly backup generators that usually burn fossil fuels and have slow startup response times, ranging from seconds to minutes.

NanoTune’s modification consists of adhering a small box onto the back of conventional solar PV panels and wired in parallel with their output. Each box is a supercapacitor-based backup device or “booster”. These boosters are sized to provide at least 10 minutes of power continuation on standard 300 Watt solar panels to mitigate solar intermittency and at the same time condition power by smoothing the normal voltage fluctuations in PV outputs. The boosters will provide 95V at full charge and deliver 50Wh before their voltage falls below the typical 50V operating voltage of 300W solar panels. The boosters will be deployable already packaged with the solar panels themselves, adding less than 10% to panel weight and 15% to their installed cost, with projections to reduce cost to as low as 3%.

These devices are made possible by NanoTune’s breakthrough supercapacitor technology that enables a much higher energy density than currently exists, while still maintaining the intrinsic supercapacitor features of quick response and long cycle life. Currently, NanoTune has developed functioning cells that combine high usable surface area monolithic carbon electrodes with high voltage ionic liquid electrolyte to surpass the energy storage levels of all market leading supercapacitors. Our technology is currently measured at 34Wh/kg and projects to reach over 200Wh/kg. In addition, our supercapacitors use a pantented technology that allows us to package our cells in prismatic form, similar to some batteries, but using only carbon and other inexpensive and abundant materials. This feature also differentiates us from current market leaders and allows us to make cells of any shape and size, optimizing for each application. Currently, we are working to increase our manufacturing rate.

The market for smoothing of solar output extends to all industries that have begun to incorporate renewable energy. In addition to being a rapidly growing market, our smoothing technology can easily be applied to any form of inconsistent clean energy generation. In 2010, approximately $5B of energy was generated by solar panels, and this number continues to rise. Reducing one of the major frictions to solar adoption, while adding only marginal capital expense, can help this market grow even faster, for applications that range from small off-grid mobile generation systems to huge utility scale generators.