Carbon Crusaders

A solution to the intermittency problem by axelman
October 25, 2008, 12:41 am
Filed under: Uncategorized

One of the biggest challenges to increasing the level of renewable energy use in the United States is the fact that the most promising, nationally scalable energy technologies-solar and wind-are inherently unreliable. Solar panels obviously need sunlight to work, rendering them useless at night. Similarly, wind turbines are useless when the wind stops blowing. This poses a significant problem for the prospects of green energy, because an unreliable energy source  cannot be used for baseload or peak power without somehow storing the energy.

Normal energy utilities use power plants for two purposes: As baseload and peak sources of energy. The cheapest, most fuel efficient plants run constantly, providing the minimal demand within an energy grid. At times of peak demand (such as weekday evenings), utilities turn on additional, backup plants (which are usually the older generation, as they cost more to run) in order to meet demand. Currently, renewable energy does not fill either of these roles. Instead, it is used primarily as a supplement, feeding energy into the grid when it’s producing it. However, this minor role for renewables means that it will remain largely a niche market, with reliable coal, natural gas, and nuclear power plants continuing to dominate the energy market. If renewable energy is ever going to become the dominant power source in the United States, it will have to be able to replace either baseload or peak power (or, preferably, both). In other words, renewables must be capable of producing a steady, reliable flow of electricity in order to actually replace fossil fuel and nuclear energy generation.

One potential solution to this problem has been the creation of large batteries, which would store energy when it is being generated and release it onto the grid when it is needed. While theoretically possible, batteries of this scale don’t exist, and adding batteries to the grid would likely tack on significant costs to renewable energy. While the government could potentially step in and subsidize these costs, developing and  implementing a battery system would likely take years.

This problem, however, has another possible solution. The New Republic’s Bradford Plumer, citing a Stanford study, argues that

between one-third and one-half of yearly averaged wind power from a network of interconnected farms can actually be used as reliable, baseload electric power, the way coal is used now. For any given turbine, the wind’s not always blowing, but given a sufficiently high number of turbines, the wind’s always blowing somewhere. (Also, if you connect a bunch of distributed wind farms to a single point and then connect that point to, say, a faraway city, you can keep transmission losses to a minimum.)

If you build enough wind turbines and connect them all together in a national smart grid, which would move the energy to wherever it was needed, wind power could actually replace the baseload dirty energy generators. The electricity grid would have to be modernized, of course, but it’s already pretty clear what needs to be done for that to happen. Solar power could supplement the grid during the day, and the sunnier west could potentially provide peak power to the east coast during the evening (due to time zone differences).  While this solution isn’t perfect, and some sort of battery system might have to be implemented in order to reliably generate green peaking power, it’s becoming easier to picture what a green energy system would look like in the United States.


New member of the MMS team by axelman
October 15, 2008, 11:05 pm
Filed under: Uncategorized

Hey everyone,

My name’s Ben Axelman, and I’m the newest member of MakeMeSustainable. I just graduated from Tufts and I’m interning at MMS as a research assistant, further investigating green/clean energy sector issues. I’ll be updating the blog pretty regularly now, and I hope you’ll find my posts interesting. Feel free to leave comments, and I’ll be sure to respond to them. Thanks for reading!