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MYTH #103: Renewable energy isn't reliable

DENIERS SAY:

The wind stops blowing, the sun is covered by clouds, and the only backup for that unreliability is good old oil and coal.

SCIENCE SAYS:

All day and all night, rain or shine, renewable energy is a reliable way to keep the lights on in the 21st century.

Clean, renewable energy is turning out to be just as reliable as dirty fossil fuels — with the added benefit that it doesn't pollute the air or warm our climate. The right combination of a more flexible power grid and appropriate sources of clean energy can provide around-the-clock power — even when the sun isn’t shining or the wind isn’t blowing. In fact, by adding more clean energy, we’re making the entire grid more dependable. Which is a good thing, because every power plant is vulnerable to disruption. Take the coal-fired power plants in Nebraska, for instance, that were temporarily shut down in 2011 by flooding. One way engineers and scientists are working to improve the reliability of clean energy is through battery storage, which saves electricity when demand is low (or production is high) and releases it when demand is high (or production is low).

Clean energy technology will also get better as consumer demand increases. That trend is already underway: Clean energy is one of the fastest-growing industries in the world, accounting for more than half of all new electric power added in 2009 and 2010.

Additional info from The Climate Reality Project 


When people say renewable energy isn’t reliable, they usually mean it can’t generate continuous, round-the-clock electricity, or “baseload power." And for some sources of clean energy, that's true, as far as it goes. Wind turbines only spin when the wind is blowing, and solar panels generate electricity when the sun is shining. But does that mean wind and solar aren't clean, dependable and efficient ways to supply our energy needs? Not so fast. 

It’s important to remember that electricity systems operate as grids — networks of transmission lines that draw power from several sources across a region and then redistribute that power. In other words, there’s no telling whether the electricity powering your house at any given moment is coming from a coal plant in Missouri or a wind farm in Minnesota. 

Electricity grids are designed to handle variability in both demand and supply (PDF) because there is no such thing as a “perfectly reliable” form of energy. Even coal plants are susceptible to interruption; so when one power plant slows production or shuts down, another power plant picks up the slack. This means the lights don’t go out if a wind turbine stops spinning or a solar panel goes dark. And around the world, clean sources of energy like solar and wind are already being integrated into existing power grids. Take the American Midwest, for example, where 12 states rely on a system that has seen a 10-fold increase in wind energy between 2007 and 2011

The idea of relying on large, centralized grids is also considered a little outdated. In parts of the world where grids have yet to be built or where they would be too expensive to construct, the concept of decentralized power systems is becoming increasingly popular. This means that if a certain region has lots of sunlight, it can generate solar energy to meet its local energy demand through a mini-grid. Similarly, areas with high wind power potential can harness the wind for their own local or regional requirements and not depend on expensive energy sent from far away. In some places, programs that support decentralized energy generation also help local producers make money by selling surplus power back to local or regional grids (PDF). 

In addition to these trends, innovation in smart grids and storage technology is helping make renewable energy more reliable all the time. Smart grids can forecast the availability of renewable energy and adapt to changing power production levels, as demonstrated successfully (PDF) by the Electric Reliability Council of Texas, the biggest grid operator in the state. And energy storage projects — which can be used to store electricity for use when a power plant is offline — are starting to change the way we think of the availability of wind and solar power. Examples include the Advanced Research Projects Agency – Energy (ARPA-E) Grid-scale Rampable Intermittent Dispatchable Storage (GRIDS) project and projects capable of storing enough power to light 120,000 homes in China

In summary, adding more diversity to the electric grid by adding more renewable sources actually helps strengthen the ability of the grid to supply power at all times. As more renewable energy is added to the energy mix, it gives us more flexibility and helps bring power to areas that traditional grids may not reach.