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  • Elise Brown is the associate director.

  • Peter Schiffman is a geology professor emeritus at the University of California, Davis.

  • William Glassley is the director of the California Geothermal Energy Collaborative at UC Davis.

Viewpoints: Drill for energy? Yes, for more geothermal

Published: Thursday, Aug. 1, 2013 - 12:00 am | Page 11A
Last Modified: Thursday, Aug. 1, 2013 - 9:23 am

The age of natural gas fracking is upon us, and the debate about how hydraulic fracturing will be done in California has begun. Even assuming conservative estimates of natural gas reserves in the lower 48 states, the United States could easily move from a coal-based electrical portfolio to one that is based on natural gas. So why invest in renewable energies when natural gas is so cheap and for the time being, plentiful? The answer is multifaceted, but we will focus on two reasons: cost and greenhouse gas emissions.

First, there is an indisputable need to reduce greenhouse gas emissions. That is why California is requiring 33 percent of electricity be generated by renewable energy by 2020. The Renewable Portfolio Standard also calls for an 80 percent reduction in greenhouse gases from 1990 levels by 2050. By becoming more reliant on natural gas for power generation, emissions may be saved, as natural gas burns cleaner. But natural gas is still a carbon-based and finite resource that will continue to contribute to the very issue these statutes are trying to address.

Further, the increased domestic production of natural gas will mainly go toward exports for international markets such as Europe and China, where consumers pay roughly three to five times what we do. The infrastructure for the export of liquefied natural gas, or LNG – the pipelines, treatment and conversion facilities, storage tanks, container ships – is already being put in place. Once LNG becomes a globally traded commodity, the price of domestic natural gas will inevitably rise. So we will have built the infrastructure that depends on it domestically and abroad, further increasing electricity and transportation costs.

Simply put, any finite resource that has price volatility and building infrastructure to support it leaves few options on the table when supplies run low or the price runs high, as we have seen in the transportation sector and the electrical sector with coal.

Here in California, our Renewable Portfolio Standard mandates that, by 2020, 33 percent of electrical generation from our public utilities must be from renewable energy sources, including solar, wind and geothermal – all of which have no fuel costs and all of which have close to zero carbon emissions.

Cheap natural gas is positioned in the market to fill much of the remaining 66 percent, especially as gas-fired power plants are flexible and can provide most of the electricity we need. Solar and wind could help with much of the remaining 66 percent, but we will need another source of power at a high level of penetration to offset their variability – when the sun isn't shining and the wind isn't blowing.

Enter geothermal energy, using the natural heat within the Earth's interior for generating electrical power. In places where the temperature exceeds 375 degrees at depths of a mile or so – and we already know where a lot of these are in California – we can drill for deep fluids that have already mined the heat from the rocks they flow through. When that pressurized hot water is tapped, it flashes to steam that can power a turbine for electrical generation. Newer technology allows us to run the steam through heat exchangers, so that virtually all the fluid can be condensed and pumped back into the geothermal reservoir.

California currently leads the world in power production from geothermal energy. For many years our state has produced more geothermal power than any country. From the coastal mountains of Northern California to the Imperial Valley, geothermal power plants supply more than 2,700 megawatts of electricity, enough to power the homes of about 2.5 million Californians.

So why aren't we developing more geothermal energy to fulfill the requirements of the Renewable Portfolio Standard? The upfront costs – especially for drilling wells – for developing power production from geothermal energy are generally greater than those for other renewables. But once in operation, geothermal power plants deliver energy at a competitive rate with coal, wind and solar. They are also capable of generating electrical power for decades: The Geysers in Sonoma County recently celebrated its 50th anniversary of power production.

Moreover, the latest technology developments in geothermal power production will give us greater flexibility with the ability to ramp up and down with demand. That will help meet the growing need for energy production in California.

So let's change the debate: It shouldn't be just about whether we should be drilling – and fracking – for more natural gas. Let's ask why we aren't doing more drilling for another of California's golden resources, geothermal energy – which doesn't require fracking and doesn't have the myriad environmental consequences that come with natural gas.

Peter Schiffman is a geology professor emeritus at the University of California, Davis. William Glassley is the director of the California Geothermal Energy Collaborative at UC Davis. Elise Brown is the associate director.

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