Solar panels capture energy from light and convert it to electricity. This is the most visible form of energy harvesting, but it is hardly the only one. Energy harvesting captures energy lost as heat, light, sound, vibration, or movement. Devices that harvest or scavenge energy can capture, accumulate, store, condition, and manage this energy into electricity for consumption. That’s important, because our existing electricity infrastructure is extremely wasteful in its use of energy. For instance, today’s technologies used in electricity generation are not energy efficient. Traditional gas or steam-powered turbines convert heat to mechanical energy, which is then converted to electricity. Up to two thirds of that energy input is lost as heat. Those old incandescent bulbs (technology invented by Thomas Edison in 1879) were real energy losers too. Ninety percent of the electricity flowing into incandescent bulbs ends up as waste heat. That’s lost energy, which is why smart federal legislation banned incandescents in favor of more energy efficient sources of lighting starting in 2012.
Any aggregated reductions in electricity ease the stresses on our aging electricity infrastructure and give us a little breathing room to evolve to a Smart Grid. The electric utility industry has put significant focus on reducing peak electricity needs through demand response or load management programs. These programs are beneficial, but they have temporary impacts on electricity use.
Every electricity-consuming device wastes energy – whether we’re talking about idling vampire loads or every day use of them. That heat you feel from your smart phone, laptop, or PC is wasted energy. That vibration you feel or motor hum in a refrigerator or dryer is wasted energy. If we can identify the right materials to harvest the energy lost to heat, vibration, sound, movement, and light into electricity, we can really embed energy efficiency where it counts – in the basic building blocks of microelectronics found in equipment and devices across the entire Smart Grid value chain of generation, transmission, distribution and consumption.
When it comes to electronics, better energy efficiency through harvesting technologies can also reduce the need for batteries. Perhaps future smart phones will be powered by light and movement and won’t need batteries at all. Energy harvesting also has profound implications for M2M applications – particularly those that are not economically feasible now due to remoteness, inaccessibility, or hazardous conditions for periodic replacement of batteries that power sensors. A sensor that can power itself will have a far better operating lifetime and interesting impacts cost/benefit considerations.
The market projections for energy harvesting are currently assessed at $3B, but this number seems too conservative. Given the range of applications – essentially embedded technology in every device used in the Smart Grid value chain as well as enabling many new M2M applications – it seems that this number could easily double. There’s a growing number of companies, mostly small players, that are developing and delivering solutions for civilian and military applications. However big Smart Grid players like ABB and General Electric are putting more investment into energy harvesting technologies.
So how do we accelerate the pace of innovation and deployment in this promising field? It takes R&D investment in physics to expand knowledge and experience about piezoelectric, thermoelectric, and pyroelectric materials. Nanotechnologies can also play important roles in innovations in materials and manufacturing processes. Advanced crystalline and ceramic materials are already capturing and converting wasted energy. Thermoelectric R&D and product releases are on the uptick, particularly in technologies to increase energy efficiency in industrial processes and automotive applications.
In the not too distant future, kinetic energy – such as people walking on a floor – could be converted to electricity by piezoelectric technologies. Just think how schools could harness the pitterpatter of little feet to power some of their building needs. But it’s going to take investment in basic R&D to realize the full potentials of energy harvesting. That means government intervention, because venture capital and corporate funds typically shy away from investments in basic R&D. The Advanced Research Projects Agency for Energy (ARPA-E) within the Department of Energy programs funded BEEST (Batteries for Electrical Energy Storage in Transportation) to develop innovative rechargeable battery technologies. A similar program called BEETIT (Building Energy Efficiency Through Innovative Thermodevices) is focused on developing energy efficient cooling technologies and air conditioners (AC) for buildings – and particularly for retrofitting existing technologies. This model should be applied to energy harvesting innovations, just like European consortiums have already focused in this area.
The bottom line is that in an “all of the above” energy strategy as defined by the Obama administration, we need to look at new energy sources, optimize existing infrastructure and operations, and deploy innovative technologies that support intelligent production and consumption of electricity. Energy harvesting technologies can produce electricity, and reduce loads across the grid. Those are two great reasons that energy harvesting technologies could and should be applied across the entire Smart Grid value chain.