Watching a debate last night between renewable fundamentalists and nuclear proponents after the CNN showing of Pandora’s Promise, helped bring together my thoughts on large scale renewables and natural gas and fracking. This article will not be my usual foray into numbers, but is based on impressions on what I have heard and read over the last few years.
It starts with the part time and fluctuating nature of solar-photovoltaic power and wind power, and the inability of coal and nuclear to rapidly adapt to fluctuations. Yet power in a grid must be supplied constantly. Batteries can only hold a small portion of energy to smooth it out, and are very expensive, and still somewhat hazardous.
Natural gas plants are now being built that can more rapidly vary their output to keep a renewable network stable. One talk I heard showed that to convert to 50% solar in California, we would still need 60% natural gas as a backup. Current California goals were for utilities to achieve 20% renewables in 2010. In the case of SC Edison, this was mainly through steady output nearby geothermal plants. The next goal is for 33% renewables by 2030.
There are steady output solar thermal plants where mirrors heat a fluid or salt, and that can store the heat and boil water to drive a steam generator for on the order of 6 more hours, through the 6 pm peak hour power demand. However, with the extra structure and generators, these are more expensive and few have been built. Also solar photo-voltaic (PV) arrays are getting cheaper. While the PV have an efficiency of around 15%, the standard steam generation of solar thermal itself has a low efficiency of about 33%.
The next question is where does fracking comes in? A few years ago, US natural gas was declining, a fraction was being imported by Liquid Natural Gas (LNG) container ships and East Coast and Gulf ports. More LNG was being forecast for the future. The Los Angeles – Long Beach Harbor LNG proposal was turned down due to catastrophic scenarios that were being considered for the highly populated area. It would only take one accident to sour the whole country on LNG. Now with natural gas being produced by fracking, it is cheaper, and we are even exporting it. The cheaper cost of it and its ready availability actually helps the case for more renewables, since renewables need it to smooth out the fluctuations and the variability with day-night and seasonal changes.
Natural gas, of course, only generates half the CO2 that coal does, for the same power. It also does not produce smog or particulates, leave ash mountains, or require continual rail transport.
The question of whether natural gas was exceeding 4% emission to counter balance its advantage over coal really never arose until the anti-fracking movement. We presume with sufficient scientific study and regulations, most losses can be prevented. A government study indicates that losses can be kept to less than 1%.
Finally, the fracking water disposal situation has to be considered. Very few cases have actually been cited among the tens of thousands of wells that had already fracked. With new attention to the issue, new regulations, and the greater centralization of drilling to top oil and gas companies, the containment and treatment of excess water should be able to be handled. Don’t forget that we already have sewer systems, farming and industrial pollution of water that is successfully confined and treated, and even ground restored and distributed in gray water systems. Fracking fluid is just another case of that.
