The power efficiency of electronic components and systems just keeps getting better and better. Advanced CMOS processes, clever power-supply designs, and sophisticated power-management schemes have combined to produce higher performance for less power. This reduction in wasted power permits denser packing of circuitry, which makes for smaller products. It also lowers power consumption, enabling battery-powered portable products to run longer.
Wouldn't it be great if higher power efficiency in our electronics reduced the amount of raw ac power we drew from the local electric utilities? Certainly, and maybe it will one day. But the data indicates that electric energy usage continues to grow year by year as the volume and variety of products plugged into the power grid rises. How we'll meet the increased demand for energy over time remains to be seen. But given concerns over the cost, availability, and environmental impact of existing sources, particularly fossil fuels, it seems clear that renewable energy sources will be playing a greater role in the future.
Solar energy has been much discussed over the years because of its great potential. We've also been tempted with its statistics. For example, the sunlight that shines on the U.S. in a single day contains more energy than we consume in two years. Photovoltaic (PV) systems seek to tap into this vast sea of energy by converting sunlight directly to electricity. Development of PV systems has been ongoing, but has real progress been made? And is the technology advancing quickly enough to make solar electricity a significant source of energy in the near future?
Evidence suggests that the answer to both questions is yes. After two decades of research, the cost of manufacturing a PV system has been reduced from $4.50/W to $2.20/W. According to a recently issued industry roadmap (available at www.nrel.gov), the cost of solar power could be lowered even more dramatically in the coming decades, if members of the U.S. PV industry, universities, and government coordinate their efforts to advance PV technology and build mass markets.
The product of a workshop conducted by the National Center for Photovoltaics, the roadmap establishes guidelines and goals that will enable the PV industry to overcome existing technological, marketing, and regulatory barriers to widespread adoption of solar-electric energy. It also seeks to defend the U.S.'s leadership role in PV technology in the face of growing competition from abroad.
Looking ahead to the year 2030 and beyond, the roadmap envisions "a thriving United States-based solar electric power industry" growing at a rate of 25% annually. Such growth would mean domestic shipments of 3.2 GW of capacity in 2020. That value, it's predicted, will account for 15% of our increased electrical capacity that year and contribute to a total installed capacity of 15 GW in the U.S. User cost then should be just $1.50/W.
Besides promoting the cause of PV research, the workshop identified other steps that must be taken to ensure commercial success. The industry must develop standards for PV products, improve reliability, and simplify system maintenance. It also must raise consumer awareness of the benefits of solar electricity and develop major distribution channels. For its part, the government must act to remove legislative and regulatory barriers to progress.
An industry roadmap can't anticipate a multitude of unforeseen developments in technology, energy markets, and politics. But it can signal a level of commitment that may drive research forward and create a major new industry. Such results may well fuel future demand for engineers while powering many of the products they build.