The Txchnologist, the GE-sponsored weekly technology magazine, continues its series on natural gas this week, including a feature on how gas could spell the demise of coal as a major energy source while speeding up the widespread adoption of renewables. Here are Txch’s 8 reasons gas can be green:
1. Natural gas enables renewable energy. Natural gas power plants fire up quickly and adjust their power output rapidly. That makes them the ideal dance partner for wind and solar, which are variable energy sources.
2. Renewable portfolio standards (RPS) mandate renewables. A growing number of states and countries are requiring a certain percentage of wind, solar and other non-fossil fuel on the grid. As long as legislators hold the line on those mandates, natural gas can’t crowd out renewables.
3. Integrated Solar Combined Cycle is crazy efficient. Modern gas plants working in combined cycle – using waste heat to drive a steam turbine – have efficiency ratings in the upper 50 to 60 percent range. Add concentrated solar power (CSP) and that figure can rise to 70 percent. See here for how. GE has teamed up with CSP pioneer eSolar to introduce this technology.
An eSolar field of computer-controlled heliostats, mirrors that reflect a concentrated sunbeam at a tower where steam is generated to power a turbine.
4. Carbon Capture and Storage (CCS) is advancing. CCS is often discussed in conjunction with coal but the technology, which involves storing CO2 from power plants underground, has perhaps even more potential for gas.
This technology actually works – it’s been tested and proven at multiple sites – but is still too expensive to deploy at scale.
5. Methane emissions from natural gas can be curbed. Recent criticism of gas have focused on leaks of methane, the principal component of gas and a potent greenhouse gas, during its lifecycle – the drilling, transportation and end use. But it’s possible to recapture the leaking methane and there is an incentive for industry to do it, since it can be sold.
6. Gas plants can, and likely will, knock out old coal plants. Tightening emissions regulations will make coal plants expensive to retrofit and natural gas plants, which emit about half the carbon dioxide, will likely pick up the slack. The emissions savings in the United States could be 150 million tons of carbon per year, according to one estimate.
7. There is a lot of idle natural gas capacity on the grid. Those combined cycle power plants are of a relatively recent vintage so they’re relatively efficient. M.I.T. researchers believe total carbon emissions in the U.S. could decrease by 8 percent if natural gas plants are utilized at a higher level.
8. China has a lot of natural gas, which is a good thing. Right now coal is the superpower’s fuel of the future, but gas is expected to represent 63 percent of primary energy consumption by 2015. Continued dependence on coal will have disastrous environmental consequences. Tapping China’s vast gas resources could help make its cities cleaner and electricity generation less carbon intensive.
