By Sri Chandrasekaran
The availability of electric power and its ability to drive economic productivity has long been a key characteristic of developed nations. Despite long establishment, many underprivileged communities around the world do not have access to electric power. According to the International Energy Agency’s World Outlook 2016, 1.186 billion people around the world lack electricity and its benefits. About one-sixth of the world’s population, particularly in sub-Saharan Africa and developing countries in Asia, live without lights, communications, adequate education, healthcare and economic opportunities.
Funding and building electrical infrastructure in places that lack electricity, however, is an expensive and prolonged solution. Instead, small, independent systems based on Low-Voltage Direct Current (LVDC) power can provide the opportunity to bring the benefits of electricity fast and relatively inexpensive to one-sixth of the world’s population. LVDC systems are by definition efficient and sustainable since they are based on solar Photovoltaic (PV) panels. PV panels produce Direct Current (DC) power which is also the power type used by most household devices. Therefore, only a DC-to-DC conversion link is required to transmit the power. This DC-to-DC arrangement skips the common DC-to-AC conversions characterized by unnecessary power losses.
Availability of electric power can transform billions of lives, from bringing light to many houses to enabling communication systems that can advance economic growth, education and healthcare.
An Introduction to LVDC Technology
Low-Voltage Direct Current (LVDC) refers to the production and use of DC power at or below 1100 volts (V). Although DC traces its roots to the origins of commercial electricity (championed by Thomas Edison), Alternating Current (AC) (championed by Nicolas Tesla and George Westinghouse) became the established power for large-scale electricity distribution.
However, LVDC has several attractive applications arising from the fact that renewable energy sources generate DC power, batteries use DC power and homes and commercial buildings depend on – or can readily be adapted to depend on – DC-based lighting, electronics and appliances.
Today, LVDC is being harnessed to benefit humanity via two basic approaches. First, LVDC enables small-scale renewable energy penetration in rural or remote villages in developing countries that lack basic electric infrastructure. Second, LVDC can benefit energy efficiency (EE) efforts in developed countries to minimize carbon emissions by serving microgrids with similar functions for homes, commercial buildings, and even large-load data centers.
Utilization of LVDC infrastructure is specifically practical in rural areas since renewable energy generation units such as PV panels and wind turbines produce DC power. Supported by related IEEE standards, standalone systems – essentially, microgrids – can be built relatively fast and inexpensive. These systems are efficient because both the power produced and consumed is DC, whereas in developed countries, the DC power from solar PV is converted to AC, injected into the grid, then reconverted to DC to power most electronics and home appliances. Each conversion results in a loss of power and, therefore, reduced energy efficiency. Small, self-contained systems also leapfrog the need for constructing expensive infrastructure in areas without access to the grid.
In addition to rural areas, LVDC systems have potential applications in developed communities. Renewable energy sources that produce DC power can be utilized to power DC-based microgrids with DC loads. This enables greater use of sustainable, non-polluting renewable energy sources and, therefore, lower carbon emissions than fossil fuel-based power generation. The use of LVDC systems may also provide load-shedding opportunities for power grids and uninterrupted service for basic electricity needs when grid outages occur.
The role of the IEEE
The IEEE fosters the LVDC as a paradigm and application case through multiple channels. The Standards Association (SA) has promoted the development of three LVDC test-beds in India, while it has also initiated the development of a foundational standard, the IEEE 2030.10 for DC Microgrids for Rural and Remote Electricity Access Applications. On the same time the IEEE Foundation has supported the IEEE Smart Village, a program that boasts LVDC projects, which have served more than 50000 in 34 villages worldwide. The path forward for LVDC applications is bright and will benefit humanity at multiple scales, regardless of their prompt access to technology, thanks to the sustainable and decentralized philosophy of the paradigm.
Sri Chandrasekaran has been associated with the IEEE-Standards Association and the IEEE India office for the past five years with focus on standards engagements globally as they relate to emerging technology programs within the IEEE-SA. Prior to joining IEEE, Sri was associated with Freescale Semiconductor Inc. (formerly Motorola Inc.) for 18 years, managing a global R&D team focused on electronic design automation with a concentration on behavioral modeling, physical verification, and electro-magnetic compliance. Sri also receieved the Accellera Technical Excellence Award in 2009 for his leadership and contributions to Verilog-AMS standardisation activities. Sri holds a bachelor’s in physics from Madras University, India, and a post graduation degree in electrical communication from the Indian Institute of Science, Bangalore, India.