Jump up ^ Faunce, T. A.; Lubitz, W.; Rutherford, A. W. (Bill); MacFarlane, D.; Moore, G. F.; Yang, P.; Nocera, D. G; Moore, Tom A; Gregory, Duncan H; Fukuzumi, Shunichi; Yoon, Kyung B.; Armstrong, F. A.; Wasielewski, M. R.; Styring, S. (2013), "Energy and environment policy case for a global project on artificial photosynthesis", Energy & Environmental Science, 6 (3): 695–698, doi:10.1039/C3EE00063J, archived from the original on 16 August 2013
Previously, the largest U.S. city fully powered by renewables was Burlington, Vermont (pop. 42,000), home to Senator Bernie Sanders, the jam band Phish and the original Ben & Jerry’s. Georgetown’s feat is all the more dramatic because it demolishes the notion that sustainability is synonymous with socialism and GMO-free ice cream. “You think of climate change and renewable energy, from a political standpoint, on the left-hand side of the spectrum, and what I’ve done is toss all those partisan political thoughts aside,” Ross says. “We’re doing this because it’s good for our citizens. Cheaper electricity is better. Clean energy is better than fossil fuels.”
Moving towards energy sustainability will require changes not only in the way energy is supplied, but in the way it is used, and reducing the amount of energy required to deliver various goods or services is essential. Opportunities for improvement on the demand side of the energy equation are as rich and diverse as those on the supply side, and often offer significant economic benefits.
In an electricity system without grid energy storage, generation from stored fuels (coal, biomass, natural gas, nuclear) must be go up and down in reaction to the rise and fall of solar electricity (see load following power plant). While hydroelectric and natural gas plants can quickly follow solar being intermittent due to the weather, coal, biomass and nuclear plants usually take considerable time to respond to load and can only be scheduled to follow the predictable variation. Depending on local circumstances, beyond about 20–40% of total generation, grid-connected intermittent sources like solar tend to require investment in some combination of grid interconnections, energy storage or demand side management. Integrating large amounts of solar power with existing generation equipment has caused issues in some cases. For example, in Germany, California and Hawaii, electricity prices have been known to go negative when solar is generating a lot of power, displacing existing baseload generation contracts.
Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A 2011 IEA report said: "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing investment opportunities without the need for specific economic support," and added that "cost reductions in critical technologies, such as wind and solar, are set to continue."
Solar power - The most prevalent type of renewable energy, solar power is typically produced using photovoltaic cells, which capture sunlight and turn it into electricity. Solar energy is also used to heat buildings and water, provide natural lighting and cook food. Solar technologies have become inexpensive enough to power everything from small hand-held gadgets to entire neighborhoods.
Renewable energy variability is a problem for corporate buyers. But what is undesirable to buyers is attractive for insurance companies, whose core business revolves around managing weather-related risks. VFAs sit on top of a new or existing PPA and are effectively designed to pay the corporate buyer when they’re getting less renewable power than they contracted for, and give money to the insurer when there’s more.
The locations with highest annual solar irradiance lie in the arid tropics and subtropics. Deserts lying in low latitudes usually have few clouds, and can receive sunshine for more than ten hours a day. These hot deserts form the Global Sun Belt circling the world. This belt consists of extensive swathes of land in Northern Africa, Southern Africa, Southwest Asia, Middle East, and Australia, as well as the much smaller deserts of North and South America. Africa's eastern Sahara Desert, also known as the Libyan Desert, has been observed to be the sunniest place on Earth according to NASA.
The International Energy Agency projected in 2014 that under its "high renewables" scenario, by 2050, solar photovoltaics and concentrated solar power would contribute about 16 and 11 percent, respectively, of the worldwide electricity consumption, and solar would be the world's largest source of electricity. Most solar installations would be in China and India. In 2017, solar power provided 1.7% of total worldwide electricity production, growing at 35% per annum.