On October 2, 2015, at Times Square in New York City, USA, the renewable energy sector’s most efficient solar panel was announced by SolarCity. Clocked at 22.04 per cent efficiency by Renewable Energy Test Centre, these cells enable users to extract maximum power from the large fusion explosion in the sky that we endearingly call our Sun. What other technology advances drive the renewable sector?
Technology updates affecting renewables
Countries like Switzerland are already working on restructuring their entire energy supply systems. The new supply mix will be free from nuclear power, low in carbon intensity and resting upon much higher efficiencies based on the newest and the most energy-efficient technologies. The new systems will also rely on development of smartgrids, decentralised power suppliers, hydro power, wind power, photovoltaics, biomass, wood and rigorous use of burning waste to generate energy whenever materials cannot be recycled. Switzerland most likely has to find its own energy supply mix, with the biggest sustainability potential. How will they do it?
Bernard Bonin and colleagues from Atomic Energy Research Centre CEA Saclay, France, simulated the behaviour of the energy mix for a large number of such variables using so-called Monte-Carlo simulations. They found the energy cost of the mix presents a minimum as a function of the installed power. This means that if installed power is too large, fixed costs dominate the total and become overwhelming. In contrast, if it is too small, expensive energy sources need to be frequently solicited.
Ted Brekken, an associate professor and renewable energy expert at College of Engineering, Oregon State University, USA, has done an analysis that suggests that large-scale wave-energy systems developed in the Pacific-Northwest are comparatively steady, dependable and able to be integrated into the overall energy grid at lower costs than some other forms of alternative energy.
The single-most significant advancement in technology is real-time monitoring of all aspects of our energy-generation and delivery system. “We must eliminate the waste that exists in the open-loop systems deployed globally. This is the only way we will reduce the impact on the environment, improve efficiency of energy extraction and delivery, and provide our children with a clean and sustainable energy future using solutions that integrate all elements of real-time monitoring, including machine-to-machine (M2M) learning that builds intelligence into the monitoring system,” says Lyle Shuey, consulting vice president – Americas, Product Engineering Services, Embitel Technologies.
Solutions for the energy sector, including renewables, in general, will be most rapidly available as companies embrace the inter-market technology advancement that is occurring today. All companies seeking new technologies need to only look at parallel markets and adopt technologies for their specific needs. For example, sensing technology is now available for most constituents of energy exploration and extraction. It is now being ruggedised to enable application in the harsh environment of energy exploration. Companies are already working on this. For example, Embitel Technologies from India was selected as one among top ten companies to present Internet of Things (IoT) solutions at Oil and Gas CleanTech Challenge in Colorado, USA, under the digital oil field category.
Doctoral student Joseph Carr developed an electrical power-converter system that can simultaneously accept power from multiple energy sources and convert it for use in the electrical grid. “The researchers’ high-frequency matrix converter addresses these shortcomings. Its simplified control system uses power converters to allow connection of a variety of power sources to a small, high-frequency transformer. Then, using a high-frequency matrix converter, it produces stable electricity ready to be supplied to the electrical grid system,” explains a report in Science Daily.
“In data centre server racks, power requirement is based on the server situations. Enabling customers to have access to power demand per server rack allows them to better optimise the systems,” explains Simarpreet Singh, head strategy, Hartek Power Pvt Ltd.
National Renewable Energy Laboratory CSP group manager Mark Mehos, co-author with Jennie Jorgenson and Paul Denholm of the study, finds that concentrating solar power (CSP), with its ability to store energy for several hours or more, helps maintain firm capacity in those hours when the Sun is below the horizon.
While photovoltaics convert light into electricity, CSP technologies concentrate the Sun’s energy and capture it as heat, which then drives an engine or turbine to produce electrical power. However, NREL explains that thermal energy CSP generates can be held back for several hours via storage systems such as molten salts. These can later be used after the Sun sets.
While SolarCity has the highest efficiency in mass-produced solar cells, the world record is held by a 46-per-cent-efficient multi-junction solar cell developed by Soitec and CEA-Leti, France, together with Fraunhofer Institute for Solar Energy Systems ISE, Germany.
As wind turbines increase in number, atmospheric science professors from University of Kansas, USA, found in August 2015 that wind turbines in large wind farms trigger a slowdown effect. This causes a decrease in the power generated per wind turbine as each additional turbine is installed.
While controlling the number of turbines is one way to prevent this problem, one Spanish start-up may have found a solution. Called Vortex Bladeless, the company is working on building blade-less turbines. It converts oscillations caused by vortices, created by air movement around the structure, into power using an alternator at the base of the device. The blade-less design reduces manufacturing costs, allows to have a denser installation in a given area and is much more silent than existing wind turbines.
In addition to hardware, there are innovations in the form of control systems that improve renewable energy sources. For instance, researchers at Applied Electronics Research Team have developed an adaptive algorithm that orders the wind turbine to adapt to change in wind speed such that the efficiency is at the maximum.
Connecting renewable energy with communities
Something similar to connected small energy sources can be read about in the sequel to the Social Science fiction book Daemon, released in 2006, by author Daniel Suarez. The setting described in the book has self-sufficient communities using natural energy sources and connected technologies to avoid the centralised agency-controlled systems seen today.
What we are working on now is to make the system smart. Everybody has a combination of biomass, wind, solar and biogas. “With the new model, everyone could be a consumer and everyone could be a generator of energy. So any building with surface area available on top can be used to generate and supply extra power to the grids in the morning and then consume the power at night if it needs it,” says Prabaljeet Kalia, product manager – drives and motion, Fuji Electric.
Most energy systems (oil, wind and solar) from the last 30 years have been installed as open-loop systems, creating a challenging business case for sustained business feasibility. Technology is now enabling these energy verticals to be integrated into a holistic ecosystem, linking these together in a closed-loop structure. “As an example, multiple residual constituents (such as natural gas or carbon-dioxide) are by-products of energy extraction. Technology is enabling these constituents to be used as renewable sources of energy that can be used in a closed-loop environment,” explains Shuey.
Embitel, a product engineering services company based in Bengaluru, is connecting the elements of the energy ecosystem through technologies like sensors, communication gateways, cloud storage and retrieval, data analytics and finally the graphical user interfaces (GUIs) that enable operators to make real-time decisions to optimise the performance of the energy domain. These are all essential to enabling an energy system that meets the needs of the global community.
Alok Chandna, power and social infrastructure initiative, Fuji Electric, says, “We have partnered with a company named Lotus Wireless that provides management and control systems for developing building energy management systems (BEMSes). BEMS depends a lot on weather conditions. For instance, if you know that tomorrow will not be sunny, you know that your solar-energy-harvesting system will not work, so you will need to charge your batteries in advance so that you can use these or figure out an alternative source of energy like wind or hydro or a backup grid.”
BEMS is the basic building block of forming a community energy-management systems (CEMSes) in capital, which, in turn, leads to forming micro-grids. The benefit here is that even if a natural disaster were to hit and all sub-stations and power generation was lost, a micro-grid would be able to bring the city back to life. In a way, this can be seen as an aid to disaster management as well. Fuji Electric Japan has already partnered with a state government in India to implement micro-grids.
Today there are engineers who are considering using ultracapacitors instead of batteries. Why? The tipping point that caused people to move from batteries to ultracapacitors is driven by battery maintenance and replacement cost. Lifetime cost is also lower since you have to change batteries frequently; ultracapacitors last much longer.
Grids
The problem is that, we also see almost 40 per cent transmission and distribution losses in our grids. “This means you need to make it efficient first and then make it smart. Micro-grids are something that I am very bullish on. A concept like this where the community can drive their own self-sustaining power is absolutely fantastic,” says Sanjay Kumar, CEO and MD of Altran India.
Shuey says that firms like Embitel Technologies are building connections and partnerships with leading clean-tech companies that are providing solutions to the energy sector. “We are working with companies delivering real-time monitoring solutions using the latest sensing technologies, companies that are delivering power-generation systems that run on alternative fuel and those that enable closed-loop systems that link traditional fossil fuel and renewable-energy solutions. It all starts with collaboration and partnership; demonstrating solutions where there is the largest return on investment. The days of junk science are over.”
The idea is to start from the consumer side by implementing smartmeters that have two-way communication, as well as the ability for the utility company to connect or disconnect the power supply itself. “It also tracks usage data and status to provide the utility company with data to help make its system more efficient. Outage management systems are also implemented these days in tandem with Fuji Electric’s SCADA system to provide information to call centres and consumers to get information on status of grids, reasons for failure and estimated time for it to be back in action,” says Chandna. Fuji Electric intends to provide a Haryana State Electricity Distribution company an end-to-end solution including smart metering, meter data management and outage management.
What is driving this sector? Decentralised solar power plants, new energy-storage solutions, higher-efficiency inverters, which can deliver efficiency to the tune of 98.3 per cent and better cooling systems have come up. “The rooftop market is what excited me the most. We have done a series of installations in Manesar, which alone has about 5000 roofs. Using this, Gurgaon by itself can bring in about 40MW of solar power in a span of two months. Godrej itself is setting up the systems to generate 5MW of power on our own rooftops,” says Nitesh Madan, manager – north PIRE, Godrej Electricals & Electronics.
Transformers play a big role in transmission losses. “What is happening today is that, low-quality equipment are used because there is no prior inspection being done by the client. The second is the project-management-execution capability and quality that plays an important role. Even if good equipment is used but cable execution was not properly done, it will cause an increase in losses,” according to Simarpreet Singh, head strategy, Hartek Power Pvt Ltd. Quality should be maintained by having inhouse testing facilities that are accredited by a third party like National Accreditation Board for Testing and Calibration Laboratories (NABL).
Solar modules have become a commodity these days because there are many players in this space and there is very little invention happening. However, inverters are one area where there is change happening, especially on inverter-optimisation technology to help with domestic installations.
Anurag Garg, vice president, Solar Business, India, Schneider Electric, thinks that a big focus would be on storage. “This is because in renewables, usually a large part of the power requirement is consumed over a short period of the day and then you need to figure out how to source power when it is not there. So stabilising the grid is the challenge, and storage will be one of the biggest solutions here,” he adds.
Schnieder is also working on a pilot project with this aim. Rooftop-level storage solutions are okay, but storing it in power plants where storage has to scale to megawatts is the challenge.
Singh says, “At Hartek Power, our focus is on connecting renewable power to the grid and making the entire grid smart by implementing various automation techniques so that the entire power-system value chain can be controlled. We have connected close to 150MW of solar power to the grid and another 100MW is in pipeline, which should be achieved by March 2016 through our power systems and sub-station expertise. Our fundamental concern is that, with so much attention given to generation, the transmission and distribution space should not get ignored, since the grid has to be made fully equipped.”
Equipment
Over a period of five years, test and measurement equipment in this category have been gaining momentum. “Early testers were more or less general-purpose testing units that were employed in the renewable energy sector. Now, more refined specific test systems for photovoltaic, wind and geothermal power generation are in force. Capabilities such as onsite and online data logging for wind and solar energy sectors are in vogue now,” explains Muthu Kumar, director, Tangent Test Technologies.
While building photovoltaic cells, panels and solar arrays, engineers test the micro-inverter by simulating cell behaviour for sunny, cloudy, rainy or dark days and other similar weather changes using a normal power supply, which is very hard to do. The transition from sunny to rainy needs a power supply with substantial power and high wattages, while being capable of modulation from low to mid to high.
To make things easier for these engineers, Keysight’s N89xxAPV photovoltaic array simulator is one recent launch that drops down voltage and power levels based on sunny days going to cloudy and then to rain without the engineer having to code. “Moreover, the new GUI allows you to drag and drop a cloud or rainy environment, or change the time of rain and more. When manufacturers make solar products, they create these based on the region they want to serve. So a US-focused product might be tuned to work without a lot of sun but an Indian version might get a lot of sun. The new simulator allows them to test micro-inverters based on region by easily changing weather conditions,” opines Mukul Pareek, marketing programme manager – Wireless & Digital at Keysight Technologies.
High-accuracy power meter Hioki PW6001 is an industry-leading 0.02-per-cent-accuracy power analyser that can measure new-generation devices like insulated-gate bipolar transistors (IGBTs) that have very high efficiencies. “There is going to be a lot of difference when a power meter qualifies an inverter as 98 per cent efficient or 98.3 per cent efficient. This minor difference will help engineers conserve a lot of energy when there are solar and wind power plants that generate GW of power,” adds Muthu Kumar.
What is next
Singh says, “An ideal smartcity or ideal sustainable solution is when I have an independent power plant at my home and it lets me sell or buy power whenever I want. This is something that will be sustainable. Dependency on fossil fuels has to finish, it cannot go on forever.”
What we foresee is that there need to be pre-fabricated structures for different roofs that let you easily affix modules and install like a consumer product. Currently, a non-technical person has to consult an engineer or a technician for installation. In the end, the whole system will have to be so easy to install and prices will have to drop so much that one could order online and install without outside help. “Solar energy as a service will be the next big thing,” adds Singh.
As you can see, a lot depends on the Sun. What would we do if something happens to it? Well SolarCity founder Elon Musk announced his desire to trigger nuclear bombs above Mars every few seconds to warm up the planet! Hopefully, someone will find a more subtle idea for Earth.
Dilin Anand is a senior assistant editor at EFY. He is B.Tech from University of Calicut, and is currently pursuing MBA from Christ University, Bengaluru
Sneha Ambastha is a technical journalist at EFY
