With the Clean Power Plan, Paris Climate Summit, passing of the Investment Tax Credit and other recent policy initiatives clean energy nuts like myself have been giddy about the amount of renewable energy that is getting added to our generation mix. As of the end of 2013 the The Renewable Energy Policy Network for the 21st Century (REN21) notes that the global Solar PV capacity has grown to 139 GW from 2.6 GW in 2004. Wind has grown at a similar pace exploding from 48 GW in 2004 to 318 GW of global capacity at the end of 2013. And the past couple of years have only seen even greater growth. According to Bloomberg New Energy Finance 2014 was a record year for clean energy investment, defying the crashing oil prices.
Michael Liebreich, chairman of the advisory board at Bloomberg New Energy Finance, said: “These figures are a stunning riposte to all those who expected clean energy investment to stall on falling oil and gas prices. They highlight the improving cost-competitiveness of solar and wind power, driven in part by the move by many countries to reverse-auction new capacity rather than providing advantageous tariffs, a shift that has put producers under continuing price pressure.”
But while all this is great news, it isn’t all sunshine and strong breezes. While clean and renewable, wind and solar are notoriously variable. The sun only shines during the day and wind does not always blow, contrasting very clearly with our demands for regular, stable, and dependable electricity. This puts enormous pressures on the grid. The variability of wind and solar demand an upgrade of the grid to be able to handle new pressures. For example, as the sun goes down and solar production goes down, the grid needs to be able to switch quickly and smoothly to other sources of generation to balance out the load. This requires increased transmission capabilities to balance geographical demand, advanced predictive technologies to be able to forecast demand and weather patterns, and advanced grid-scale storage to be able to offset demand.
Shayle Kann and Stephen Lacey of Greentech Media recently discussed the challenges of integrating variable power sources with Jamie Mandel of the Rocky Mountain Institute. They noted three ways to help fight these challenges. First was having a diverse portfolio of generation sources. The generation profiles of solar PV and wind often complement each other well enough to balance out many of the worries of intermittency. This reinforces the need for accurate weather and demand data to be able to craft whole systems that work in compliment. Second was demand flexibility. By allowing customers to voluntarily shift their demand in response to market changes, the grid creates another system to fluctuate load. Lastly they reiterated the need for modern grid-scale battery technology to be able to turn solar and wind energy into something that can be flipped on and off as needed.
For the grid to accommodate the increased penetration of solar and wind all of these methods and more need to become standard. The Brattle Group put together a report for the Advanced Energy Economy Institute highlighting the success of a couple grids in integrating variable resources. This and a report that shows how the Southwest Power Pool (SPP) could handle 60% wind penetration show that these modernization steps are possible and affordable. Not only that but New York’s Reforming the Energy Vision (REV) plan includes massive grid upgrades and the Energy Department just announced $220 million in funding for grid modernization projects. All good signs that we are moving towards a more sustainable, exciting future.