The renewable energy industry is growing thanks to technology developments and economies of scale. According to U.S. Secretary of State John Kerry, the global renewables market expanded more than six times in the past decade. Global investment was $350 billion last year, more than was invested in new fossil fuel plants.
Such growth is supported by a wide range of initiatives, from the Paris Climate accords to local innovation events like the Boston Cleanweb Hackathon. The Hackathon brings together students, programmers, software developers, entrepreneurs, and energy experts to develop user-friendly, web-based applications to help consumers and businesses use energy and natural resources more efficiently. The cost for renewables to produce electricity is now at competitive levels with traditional fuel. A recent Forbes article discusses how far renewable energy has come. Long-term sales contracts between utilities and power producers (PPAs) are in the range of 3-4 cents per kilowatt hour for wind and solar energy; that compares favorably to 5.2 cents for natural gas and 6.5 cents for coal. The cost of LED lights has fallen from $35 four years ago to about 80 cents for a 9 watt LED.
Companies are increasingly committing to power their operations using renewable energy. Google, for instance, said that its global network of 13 large-scale data centers will be powered entirely by renewable energy by the end of 2017. Microsoft says it has been 100 percent carbon neutral since 2014; they hope to have half their electric power supplied from wind, solar, and hydroelectric sources by 2018.
Countries are stepping up their efforts to reduce reliance on fossil fuels. Costa Rica produced almost all of its electricity from renewable sources in 2015.
Clean Energy Technology Developments
Technology innovations are the surest way to continue to make progress on clean energy from high efficiency renewable energy sources to cheaper storage to smarter grids. Solar photovoltaics (PV) lead the rest of the renewable energy pack, with growth in global capacity averaging 42% annually over the past five years. Concentrated solar power (CSP) continues to show strong growth as well, with an average annual growth rate of 35% over the past five years.
MIT researchers have developed a solar thermophotovoltaic device that could push past the theoretical efficiency limits of conventional solar panel photovoltaics. The addition of carbon nanotubes and nanophotonics crystals collect energy from the sun and concentrate it into a narrow band of light. This approach could break the theoretical cap of about 30 percent efficiency on conventional solar cells.
Researchers at Stanford, Los Alamos National Laboratory, and the Swiss Federal Institute of Technology are making progress on boosting the efficiency and improving the stability of perovskite solar cells. They are cheap, easy to produce, and efficient at absorbing light, but quickly degrade.
Capturing carbon emissions is also an important part of any clean energy program. Recent advances include carbonate fuel cells to capture carbon in power plants and a process for injecting carbon dioxide and water deep underground which mineralizes when it reacts with the volcanic basalt rocks. Another approach is to recycle captured carbon dioxide back into usable fuels. Oak Ridge National Laboratory has developed a catalyst that converts a solution of carbon dioxide into ethanol at a high level of efficiency.
Power Conversion Technology
The high power levels of clean energy technologies require semiconductor power electronics, such as insulated gate bipolar transistors (IGBTs), to convert the power being generated — either as a variable frequency AC in windmills, or as DC in solar cells — to a well-regulated 50/60 Hz AC power than can delivered and distributed in the energy grid. This also allows devices to be smaller, faster, more reliable, and more efficient.
Switching losses that occur in inverters are an important issue to be considered to improve the efficiency of the inverter. Within the semiconductor devices, power substrates provide interconnections and cool the components. curamik® ceramic substrates are designed to carry higher currents, provide higher voltage isolation, and operate over a wide temperature range. Rogers’ ROLINX® busbars serve as power distribution “highways.” These laminated busbars provide a customized liaison between the power source and capacitors, resistors, integrated circuits (ICs), integrated gate bipolar transistors (IGBTs), or complete modules.