Since the industrial revolution, accelerated emissions due to various human activities have been responsible for causing global warming, acid rain and various kinds of pollution – of air, water and soil – and have become environmental threats with critical impacts on the planet’s climate and its species. The scientific evidence that has established this truth is incontrovertible, though the truth may be inconvenient. 
Understanding these adverse impacts of conventional energy sources is critical for informing our choices around the future of energy production.
What is clean energy? In 1976 energy policy analyst Amory Lovins coined the term “soft energy path” to describe an alternative future where energy efficiency and appropriate renewable energy sources steadily replace a centralized energy system based on fossil and nuclear fuels, which is the hard path.
Soft energy paths involve efficient use of energy, diversity of energy production methods (matched in scale and quality to end uses), and special reliance on co-generation and “soft energy technologies” such as solar energy, wind energy, biofuels, geothermal energy, wave power, tidal power, etc. 
Soft energy technologies (appropriate renewables) have five defining characteristics. They (1) rely on renewable energy resources (2) are diverse and designed for maximum effectiveness in particular circumstances (3) are flexible and relatively simple to understand (4) are matched to end-use needs in terms of scale (5) are matched to end-use needs in terms of quality 
The term ‘clean energy’ therefore, refers not only to renewable energy (RE) but also to energy saved through energy efficiency (EE) measures. Energy efficiency (EE) manages and restrains the increase in energy consumption.
A system or process is more energy efficient if it delivers more services for the same energy input, or the same services for less energy input.
Is 100% renewable energy possible? One may ask, why do we need energy efficiency at all? Why can’t we aspire for 100% renewable energy – solar, wind, bio-energy, wave and tidal power replacing the conventional sources of energy? As a vision and ideal, we can aspire for such a future, as recent scientific research confirms such a possibility. According to Chris Field, founding director of Stanford’s Carnegie Department of Global Ecology, the landscape has really changed in terms of whether or not the world community understands the transition to 100 percent non-emitting energy as something we can accomplish. The answer only a few years ago was maybe, and now the answer is clearly yes.
Field further explains that a system of 100 percent renewables is technically possible, but it is too expensive and not currently affordable. With an ambitious commitment to building out the storage and load-balancing and demand-balancing components, it is technically feasible to build an energy system with a high amount of renewables. 
The supporting infrastructure required for transitioning to 100% renewable energy system There are challenges in renewable energy systems, such as variability in power (solar power dips after sunset and wind power dips when there are no winds), the problem of energy storage and high cost of installation. For an economy to transition into 100% renewable energy, the supporting infrastructure to evacuate power from new renewable energy installations must be in place. Power evacuation is a critical function that allows generated power to be immediately evacuated from the wind farm or solar farm to the grid for distribution. New substations need to be constructed for evacuating power to the grid, because the generated power cannot be stored (in the absence of energy storage technology); it must be transmitted from the place of generation to the place where demand for power rises. The grid infrastructure must ensure national connectivity, for transmission of renewable power between any part of the country.
The governmental/political aspect is also very important and there needs to be clarity in renewable energy policy and its implementation, so that investors are encouraged to invest in renewable energy and sell their power to the grid
A blended model – multiple approaches in parallel Shifting the total global primary energy supply to renewable sources requires a transition of the energy system. Energy transition is generally defined as a long-term structural change in energy systems. A total shift in regime is required – the underlying technological, political and economic structures of a nation will need to change radically – for energy transition to happen.
Solving the energy/global warming problem is regarded as the most important challenge facing humankind in the 21st century.  Piecemeal measures often have only limited potential, so a timely implementation for the energy transition requires multiple approaches in parallel. Energy conservation and improvements in energy efficiency thus play a major role. An example of an effective energy efficiency measure is improved insulation for buildings. Smart electric meters can schedule energy consumption for times when electricity is available inexpensively. 
A clean energy economy powered by both renewable energy (RE) and energy efficiency (EE) is the most sustainable energy planning scenario available. 
Opportunities in India
Ministry of New and Renewable Energy (MNRE) India was the first country in the world to set up a ministry of non-conventional energy resources, in the early 1980s. Renewable energy in India comes under the purview of the Ministry of New and Renewable Energy (MNRE). It is responsible for development and deployment of new and renewable energy for supplementing the energy requirements of the country. India’s overall installed capacity has reached 329 GW, with renewables accounting for 58.3 GW, as of 30th June 2017 . Therefore renewable energy contributes around 17.5% of total power capacity in India. The installed capacity of wind power is 32.5 GW and that of solar power is 13 GW. Small hydel power accounts for 4.3 GW and biomass power accounts for 8 GW.
India’s renewable energy sector is amongst the world’s most active players in renewable energy utilization, especially solar and wind electricity generation. India ranks 4th globally in wind power installation. Solar power in India is a fast growing industry. India quadrupled its solar-generation capacity from 2.6 GW in May 2014 to 13 GW in June 2017. The average current price of solar electricity has dropped to 18% below the average price of its coal-fired counterpart. 
India – a world leader in renewable energy The Government of India, under Prime Minister Narendra Modi, has set an ambitious target to install 175 GW of renewable power by the year 2022, which will include 100 GW of solar power, (with 40 GW from rooftop solar), 60 GW of wind power, 10 GW of biomass power and 5 GW of small hydro power.  Such an ambitious target would place India amongst the world leaders in renewable energy use and place India at the centre of its International Solar Alliance (ISA) project, promoting the growth and development of solar power internationally to over 120 countries.
International Solar Alliance Our Prime Minister, Narendra Modi ji, has given a significant boost to the development of renewable energy in India. The International Solar Alliance (ISA) is an alliance of more than 120 countries, most of them being “sunshine” countries, which are located completely or partly between the Tropic of Cancer and the Tropic of Capricorn. The alliance’s primary objective is to work for efficient exploitation of solar energy and thereby reduce the dependence on fossil fuels. This initiative was first proposed by Modi ji in a speech in November 2015 at Wembley Stadium, in which he referred to sunshine countries as suryaputra (“sons of the sun”). The alliance is a treaty-based intergovernmental organization. In January 2016, Narendra Modi ji and French President Francois Hollande laid the foundation stone for the headquarters of the International Solar Alliance (ISA) in Gwal Pahari, Gurugram. The ISA hopes that wider deployment will reduce production and development costs, thus facilitating the increased deployment of solar technologies to poor and remote regions.
An excerpt from Modi’s speech at the launch of the ISA (November 30, 2015) -
“Since ancient times, different civilizations have given a special place to Sun. In the Indian tradition, Sun is the source of all forms of energy. As Rig Veda says, Sun God is the Soul of all beings, moving and non-moving. Many in India begin their day with a prayer to the Sun. Today, when the energy sources and excesses of our industrial age have put our planet in peril, the world must turn to Sun to power our future. As the developing world lift billions of people into prosperity, our hope for a sustainable planet rests on a bold global initiative. It will mean advanced countries leaving enough carbon space for developing countries to grow. That is natural climate justice. It also means a growth path with lighter carbon footprint. So, convergence between economy, ecology and energy should define our future.
The vast majority of humanity is blessed with generous sunlight round the year. Yet, many are also without any source of power. This is why this alliance is so important. We want to bring solar energy into our lives and homes, by making it cheaper, more reliable and easier to connect to grid. We will collaborate on research and innovation. We will share knowledge and exchange best practices. We will cooperate on training and building institutions. We will discuss regulatory issues and promote common standards. We will attract investments in the solar sector, encourage joint ventures and develop innovative financing mechanisms. We will partner with other international initiatives on renewable energy. There is already a revolution in solar energy. Technology is evolving, costs are coming down and grid connectivity is improving. It is making the dream of universal access to clean energy become more real.” 
Solar cities Narendra Modi ji has called for establishment of model solar cities where the power needs are fulfilled solely by solar energy and he has given thrust to manufacturing of solar equipment, which will also help in generating employment and in deriving maximum benefit from the renewable energy drive. 
Job opportunities India’s ambitious aim to install 160 GW of renewable energy by 2022 will need more than 300,000 full-time workers in these 5 years and there is potential to create employment opportunities for around 1 million people. As much as 70 percent of the new workforce will be employed by the rooftop solar component, creating 7 times more jobs than large scale projects such as solar farms. 
India – the leader in climate action and in renewable market The recent months saw solar and wind tariffs falling to record low values in the country. The cost of wind power in Tamil Nadu has fallen to 3.42 per unit*, the lowest in the country.  Tariffs for solar power in Tamil Nadu touched as low as Rs 3.47 per unit in biddings for 1,500 MW solar plants. Solar power tariff dropped to a historic low of Rs 2.44 per unit at the auctions for solar plants at Rajasthan’s Bhadla.  This tariff is less than coal. The average NTPC** coal plant tariff is Rs 3.20 per unit.  Solar has a brighter future now, even literally speaking! The record low bids certainly signal a “green future” for India. India has overtaken the US to become the second-most attractive country after China for renewable energy investment.  The World Bank has noted that with her conscious choice to use significantly more clean energy to fuel her growth, India is emerging as a frontrunner in the global fight against climate change, with solar power is gradually displacing coal as the energy source. With a sweeping commitment to solar power, innovative solutions and energy efficiency initiatives to supply its people with 24x7 electricity by 2030, India is emerging as a frontrunner in the global fight against climate change. Some years ago, people were talking about “the future of India”. But now, the statement is “India is the future”!
*1 unit = 1 kiloWatt-hour of electrical energy = 1 kWh. 1 kWh refers to 1 kiloWatt or 1000 Watts of power consumed in 1 hour. For example, if a bulb is rated 100W (0.1 kW) and is switched on for 10 hours, it would consume 0.1 * 10 = 1 kWh of energy, which is referred to as 1 unit of electrical energy.
** National Thermal Power Corporation, limited, is an Indian Public Sector Undertaking, engaged in the business of electricity generation and allied activities.
 Sajed Kamal, author of “The Renewable Revolution : How we can fight climate change, prevent energy wars, revitalize the economy and transition to a sustainable future”
 Amory Lovins (1977). Soft Energy Paths, p. 54
 H. Nash (Ed.) (1979). The Energy Controversy: Soft Path Questions and Answers, Friends of the Earth, San Francisco, CA, pp. 100–101.
 Amory Lovins (1977). Soft Energy Paths, pp. 38–39
 Nicola Armaroli, Vincenzo Balzani, The Future of Energy Supply: Challenges and Opportunities. In: Angewandte Chemie 46, (2007), 52–66, p. 52, doi:10.1002/anie.200602373.
 Ben Sills (Aug 29, 2011). “Solar May Produce Most of World’s Power by 2060, IEA Says”. Bloomberg.
 North Carolina Sustainable Energy Association
 “Physical Progress (Achievements)” (web). report. Ministry of New and Renewable Energy, Govt. of India. Retrieved 29 July 2017. Web link : http://mnre.gov.in/mission-and-vision‑2/achievements/
 “India’s solar capacity to cross 20GW in next 15 months: Piyush Goyal”. Economic Times. Retrieved 2017-04-06 Web link : http://economictimes.indiatimes.com/industry/energy/power/indias-solar-energy-capacity-expanded-by-record-5525-mw/articleshow/58037873.cms
 Report by Council on Energy, Environment and Water (CEEW) and Natural Resources Defense Council (NRDC) — “Greening India’s Workforce : Gearing Up For Expansion of Solar and Wind Power in India”, published June 2017 https://www.nrdc.org/sites/default/files/greening-india-workforce.pdf