Tanzania is challenged by poor energy access in rural parts of the country. Access to energy in these rural communities will require off-grid and mini-grid projects. The Tanzanian government has set a goal of establishing 1.3 million electrical connections by 2022, especially in rural areas. This would raise their connected population to about 35% from 20% in urban areas and 7% in rural ones. Tanzania’s energy goals come around the same time as the African Union (AU) and United Nations (UN) are setting goals for the continent and the world. The UN stated their goal of Sustainable Energy for All by 2030 and the AU began the Africa Renewable Energy Initiative in 2015. The African Development Bank (AfDB) has been supportive in achieving these goals. In January they approved a grant of $870,000 to support off-grid energy systems in Tanzania. Continue reading →
Widespread use of traditional wood and coal-burning cookstoves has resulted in a significant source of anthropogenic emissions. Reductions in these emissions could be deeply beneficial to impact climate change and public health. It is estimated that cleaner technology to replace traditional wood and coal-burning stoves could decrease the global temperature by nearly a tenth of a degree and save more than 10 million lives by 2050 (Pidcock, 2017). Exposure to household air pollution is responsible for an overwhelming number of preventable illnesses and deaths. It is estimated that exposure to cooking smoke in poorly ventilated homes is the cause of 370,000 to 500,000 premature adult deaths per year. Cooking smoke is a source of risk for burns, eye and respiratory diseases. Traditional cooking methods use solid fuels such as wood, animal dung, coal and biomass as fuel for an open fire. Methods like these release methane and carbon dioxide. Emissions from wood-fuels alone are approximated at 2% of global emissions (Robert Bailis, 2014).When wood and coal are burnt, aerosols are released along with greenhouse gases—the climate effect of these aerosols being strongly regional. Cooking fires are a primary source of black carbon soot. This black soot can be carried as far as the Arctic atmosphere, bringing about ice and permafrost melt (What is Black Carbon?, 2010). Continue reading →
My family has worked for Saudi Aramco, a national petroleum and natural gas company based in Dhahran, Saudi Arabia for the past 16 years. In my time living in Saudi, I have experienced first hand the way in which the Kingdom uses/wastes their resources, providing oil to their citizens at a cheaper price than water, and subsidizing electricity to their populations. However with the decline in the price of crude (lost 67% of value since September 2014), the growing domestic oil demand of 7% per year, and the state of the environment, Saudi Arabia is in an awkward geopolitical situation, and is in need of comprehensive economic reform. Continue reading →
Forecasts about the future of solar energy tend to be rosy and optimistic, but is the solar revolution really a nobody-loses scenario? A study lead by Aixue Hu (2017) titled “Impact of solar panels on global climate” addresses some infrequently mentioned concerns.
It turns out that solar energy systems have consideration-worthy regional consequences. But you may ask: why? Solar panels are not 100% efficient, they are actually fairly far from it. The most efficient solar panels on the market today run at around a 40% efficiency, with some new technologies promising around 60%, however most are much lower. A few issues arise in the conversion of solar energy into electricity. Firstly, a small percent of the solar radiation is reflected, as a result of solar panels’ glare. Then, another few percent are lost in the conversion of direct-current into alternating current and along the transmitting wires to centers of population. The authors estimate the mentioned causes to sum to about a 10% loss. Continue reading →
The U.S. Department of Energy’s 2017 U.S. Energy and Employment Report, reveals that the renewable energy industry employs more people than the entire fossil fuel industry (including petroleum oil, natural gas, and coal). The report goes on to compare employment opportunities between 2015 and 2016 for all types of energy within the Electric Power Generation sector, which includes: solar, wind, geothermal, bioenergy, hydropower, nuclear, fossil fuels, and other generation/fuels. It is evident with this report that solar and other renewable energies are a rapidly growing industry with increasing employment opportunities for Americans. Continue reading →
As one of the world’s foremost developing countries, India provides a unique case in which to examine energy security. India defines its sustainable energy security (SES) policy as “provisioning of uninterrupted energy services in an affordable, equitable, efficient, and environmentally friendly manner.” According to India’s energy security policy, the end goal of any developing country should be to achieve this level of energy security and resource independence. The World Energy Outlook forecasts that India’s energy demand will significantly change during the period of 2014-2040 (IEA 2015.), where it will experience a move to the center stage of the world energy system which will cause a shift in demand. Thus, India needs policies for rapid expansion of energy systems while also looking for a sustainable means to achieve these goals. Continue reading →
Mark Chung, an electrical engineer trained by Stanford University, began his venture butting heads with climate change seven years ago. It is widely thought that in order to combat the worst impacts of climate change, global carbon emissions must be cut by 40 to 70% by mid-century. Chung’s company, Verdigris, seeks to aid the process by providing a solution to inefficient energy monitoring and usage. Verdigris came about as a response to “smart meters,” which track where energy is being used in houses, buildings, hospitals, etc. The “smart meters,” unlike Verdigris’ software, are unable to create electrical maps on a large scale to monitor appliances, machinery, lights, and more, and are thus unable to pinpoint the exact sources of energy usage. Continue reading →
Silicon photovoltaics are a proven sustainable energy solution and take up 90% of the solar cell market. Silicon cells have many practical advantages associated with them, including high cell efficiency, stability and longevity. They are also extremely cost effective. The cost of mass produced silicon cells has dropped below $1/W, in some cases as low as $0.3/W. At the same time, efficiency continues to increase to 20%. The biggest hindrance to further increases in efficiency are high rates of recombination at the surface of the cells, which is what Shinde et. al (2016) have been working on.
In order to lower the rates of recombination, the technique of passivation has been employed. SiNx and SiO2 compounds have been used for passivation in the past. Although the desired surface passivation is accomplished, these compounds require high process temperatures (300° – 1000° C). At these temperatures, the properties of the silicon crystalline structure are affected. If these temperatures are reduced, efficiency and longevity are expected to increase.
To combat high process temperatures, new techniques have been presented. It has been shown that passivation can be achieved by using Si-O and Si-H and organic passivation. Shinde et. al (2016), look at passivation of n-type emitter by organic cover layer Oleylamine (OLA). This passivation technique will increase efficiency and has the ability to be processed at room temperature. Continue reading →
The lithium-ion battery is the power source for most modern electric vehicles. Each battery is made up of many smaller units, called cells. The electrical current reaches these cells via conductive surfaces, including aluminum and copper. There is a positive electrode, the cathode, and a negative electrode, the anode. The battery is filled with a transport medium, the electrolyte, so the lithium ions carrying the battery’s charge can flow freely from one electrode to the other. This electrolyte solution needs to be extremely pure in order to ensure efficient charging and discharging.
Virtually every lithium ion cell produced today uses ethylene carbonate (EC), and most battery scientists believe it is essential. Petibon et al. (2016) tested electrolyte systems other than this within Li-Ion battery cells. Surprisingly, totally removing all ethylene carbonate from typical organic carbonate-based electrolytes and adding small amounts of electrolyte additives creates cells that are better than those containing ethylene carbonate. Petibon et al. (2016) used different surface coatings, electrolyte additives, and new solvent systems, and the impact was substantial. Continue reading →
The Aliso Canyon gas leak of 2015 in Los Angeles’s San Fernando Valley caused not only an environmental crisis—fuel shortages affected the region’s supply and source of energy. The crisis was a turning point for Southern California’s energy industry, the start of an experiment in the use of batteries to meet energy demands. Tesla’s contribution to the effort, 396 batteries at Mira Loma in the city of Ontario, went online on the 30th of January and is capable of providing power to around 15,000 homes for four hours. The batteries themselves are built at Tesla’s Gigafactory in Nevada, and the company’s process of vertical integration now means each component of the battery is built in-house. They are designed to store energy during the day and release at night during times of highest demand in the evening. California’s increasing demand and funding for renewable energy projects allowed the Mira Loma project to come together in just a few months’ time, with the threat of climate change and the impending closure of the last of California’s nuclear plants pushing the industry towards alternative sources of renewable energy. Continue reading →