Long Range Power Transmission

by Matt Johnson

One of the problems that has grappled electrical engineers over the last few decades is the long-distance transmission of power. As the shift towards renewable energy continues, we are finding more and more electricity being generated farther and farther away from consumers. With an unavoidable power loss directly related to transmission distances, engineers have found themselves in a tough situation. The Economist (2017) dives into one technology, ultra-high-voltage direct-current connectors, as a particularly promising solution. Electric power grids were standardized on alternating current (AC) in the late 1880s and 1890s, and have stayed that way ever since. Alternating current travels like a wave: the energy shimmies back and forth through a conducting medium. As the distances of transmission increase, it takes more and more energy to push this wave through. Inherently, the more energy you put in, the more that is lost. Direct current on the other hand is a steady flow of energy, there is no oscillation. Therefore, over transcontinental distances, direct current power lines are much more efficient. The power lines are cheaper to build, because a smaller wire can carry more power: reducing weight and cost. Whereas the transformers for AC are relatively cheap, the comparable thyristors for voltage conversion in DC are pricy; but these prices are justified by increased transmission efficiency, especially over long distances. Continue reading

Berkeley National Laboratory Scientists Inventing Paint-on Retrofit for Energy Efficient Windows

by Erin Larsen

The US Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) researchers are in the process of developing a paint-on coating for windows to increase energy efficiency. It is estimated that 10 percent of aggregate energy consumption in buildings in the US is due to window performance. Warm and southern climates are particularly impacted because a significant fraction of energy usage goes to air conditioning. This inefficiency costs building owners about $50 billion annually. While window replacement or other commercially available retrofits would resolve this problem, the high cost of these options is prohibiting. Berkeley Lab’s polymer heat-reflective coating that can be painted on would be $1.50 per square foot, one-tenth the current market for commercially installed energy efficient retrofit window coatings. Continue reading

The Immense Risk Climate Change Poses to Electricity Supply

by Caroline Chmiel

US and European electricity supply is increasingly defenseless to climate changes. 91% and 78% of the total electricity in the US and Europe, respectively, is produced by thermoelectric power plants, which are nuclear and fossil-fueled. These plants and the processes to get electricity rely on the availability and temperature of water resources for cooling. The changing climate directly affects temperature and water resources, so the heavy reliance on these factors in electricity is at high risk. Freshwater withdrawals for cooling coal, gas and nuclear-fuelled power plants are highest in North America. Next highest worldwide is Europe. Continue reading

Incentivizing Renewable Energy Projects from Landfills

by Shannon O’Neill

Every year, a total of 164 million tons of waste is disposed of in landfills. This has created a concern for waste management, particularly due to the fact that landfills are the third largest source of methane, a greenhouse gas that negatively effects the environment. However, methane has been developed as an energy source, in which it is recaptured and used to power homes and businesses. Today, there are more than 630 landfill gas energy projects that together, produce 16.5 billion kilowatt hours of electricity a year. This is enough energy to provide for 1.5 million homes. The picture above suggests an additional approach of adding photovoltaics, but this post is just about biogas Continue reading

How to Reduce California’s Greenhouse Gases by 80%

by Emil Morhardt

According to the latest runs of a complex computer energy model (CA-TIMES) coming out of the University of California at Davis (Yang et al. 2015), the energy scene across California may be quite different by 2050. The model is not designed to predict what will happen, but instead to examine the economic and policy implications of just about every possible major perturbation of energy generation and use in the state to get us to the current policy goal of an 80% reduction in greenhouse gas emissions from 1990 levels. What results is a series of least-cost scenarios to get to various policy-driven energy endpoints. The bottom line is that greenhouse gas emissions can be reduced enough to meet the 80% goal at low to moderate costs, but not without major investments in wind and solar power generation, production of synthetic fuels directly from biomass using the Fischer–Tropsch synfuel pyrolysis process (more about that in upcoming posts), and hydrogen production and distribution infrastructure to power fuel cells. Continue reading